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W-ALTER A. LUCE Duriron Co., lnc., Dayton 1 . Ohio
through the use of the extra-lowcarbon grades are considered in the literature and practical examples of its feasibility are given (39). Briefly the data indicate that weldments of the ELC stainless steels are the equivalent of the stabilized grades as far as resistance t o intergranular corrosion is concerned, provided a service temperature of 800' F. maximum is used. Additional detailed information on methods for providing resistance t o intergranular corrosion is provided under separate topics. Metal conservation measures are alfio considered more fully in several other p a r k of the tcut.
Methods for conseriing critical elements in stainless steel continued to be highlighted. When practicable, the substitution of essentially nickel-free alloys (A.I.S.I. 400 series) for conventional 18-8 types was suggested. Much basic information was reported on such important topics as corrosion, heat resistance, physical and mechanical properties, welding, and other fabrication m e a n s and typical applications.
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HE previous literature l e n e \ \ on this topic (1621 emphasized the serious shortage of many basic elements needed in stainless steel production and outlined methods being employed for maintaining a n adequate supply of these alloys to meet the needs of the chemical industry. The use of oxygen during melting to salvage stainless scrap of inferior quality and the substitution of titanium for niobium (columbium) as a satisfactory stabilizing element were two of the more important considerations previously covered. No appreciable change has occurred during the past year i n the availability of nickel, molybdenum, and niobium, and NPA approval is still necessary before alloys containing the elements can be produced. The inteuded application or end use of the particular alloy desired must warrant the use of critical elements and if a material containing a lower percentage of these elements will suffice, the necessary downgrading must result. The ultimate user of these alloys is encouraged t o specify critical materials only when a definite economic advantage is obtained. T o facilitate this trend by the consumer, data have been published on many less critical materials which exhibit desirable properties. For instance, three articles (191, 240, 260) have been published since June 1951 on the nickel-free stainless steels (A.I.S.I. 400 series), encouraging their possible substitution for other, more critical stainless alloys. The producers of these materials also provided published information (10, 210) comparing these alloys t o the conventional 18-8 types. The references incIuded detailed data on compositions, mechanical properties, and typical uses of these alloys. Such other important aspects as welding characteristics, polishing, drawing, and forming were also considered. It was emphasized that except for A.I.S.I. Types 414 and 431 they are no longer controlled by XPA and this makes them very attractive for many applications. In this same vein of alloy conservation, Schoefer (226) discussed various cast stainless alloys with emphasis on the high-nickel-containing analyses generally used on high temperature applications. The American Society for Testing Materials recognized that a distinct problem has arisen because of these shortages and has issued a series of Emergency Alternate Standards dealing with the stainless dloys. The announcements (12, I S ) of these changes pointed out that they were partially due t o the substitution of the niobium-tantalum combination for niobium in A.I.S.I. Type 347 and CF-8C (Alloy Casting Institute cast equivalent t o Type 347) stainless steel and partially due to higher phosphorus contents no-r being encountered in t h e wrought materials. These higher phosphorus contents result from t h e reduction of chromium in furnace slag with silicon and must be tolerated if all chromium is t o be utilized. The substitution of the 40% niobium-20yu tantalum ferroalloy for the standard type of ferroniobium previously used is practicable and data substantiating this change were presented by Grove (96). Other means for conserving niobium
CORROSIOR
The literature coiitained numerous articles dealing with the various factors controlling the corrosion resistance of the stainless steels. The susceptibility of these alloys t o intergranular corrosion is always of paramount importance from both the theoretical and practical standpoints and this one factor was again considered in great detail. Information on such other specialized subjects as passivation, inhibition, and galvanic corrosion was also available. However, by far the greatest amount of information concerned the resistance of these alloys t o specific corroqives such as sulfuric acid, phosphoric acid, etc., and descrihed the application of the alloys in the chemical industry. Colombier and Hochmann ( 4 7 ) discuss the serisitization of austenitic stainless steels during welding operations, and although a rhromium-impoverished area adjacent t o the grain boundaries causes the eventual failure, they state that the inhomogeneity in the steel caused by prior treatment is an important factor in the failure. I n other TF-ords, they do not believe that the short time exposure during R elding is sufficiently drastic t o cause concentration of carbides t o such an extent that a continuous network is obtained. From photomicrographs they reason that carbon was already concentrated a t the boundarie8 owing t o prior thermal treatment. A series of tests on various high purity 18 Cr-8 Ni stainlets steels was described by Rosenberg and Irish ($19). The carbon content in these alloys was varied from 0.007 to 0.30% t o determine the solubility of this element in an alloy of this type. Metallographic examinations were made on this series after various thermal and mechanical treatments to detect the presence or absence of carbides. I n another study t o obtain basic information on the theory of intergranular corrosion, Standifer et a2. ( 2 S 7 ) attempted t o find a relationship between the potentials a t the grain boundaries and in the grains themselves through micropotential and gross potential readings, Unfortunately, the micropotential technique proved unsuccessful and no accurate readings were possible between grains and grain boundaries on solutionquenched or sensitized specimens. Other information was available on the testing of stainless steels for susceptibility t o intergranular corrosion. Ferri (77) made a comparison between the Strauss (acidified copper sulfate) and Huey (boiling nitric acid) tests on three austenitic stainless steels (straight 18-8, 18-8-ibI0, and 18-%Ti). It was concluded that the Strauss test is the more sensitive and the
2346
October 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
scatter of test data was discussed in relation to factors influencing intercrystalline corrosion : grain size, amount of carbide precipitation, surface condition of steel, etc. Bleton et al. (86)compiled data on 91 different heats of the general 18-8 type in the Strause solution and concluded that the behavior of these materials under this test is closely dependent on the carbon and chromium contents, nickel having little influence. Shirley (888) studied the mechanism of attack by concentrated nitric acid on titanium-stabilized stainless steel and stated that it appeared to be an extension of intercrystalline corrosion from boundary chromium impoverishment. A more complete discussion on the value of titanium-stabilized steels was presented in the 1951 review (162) where it was pointed out that close metallurgical control is necessary for 18-8-Ti (A.I.S.I. Type 321) heats topass the Huey test. Other factors, notably sigma, play an important part in the resistance of these steels to nitric acid. Ebling and Scheil(6W) presented very comprehensive corrosion data on welded low-carbon stainless steel (Type 304L) and made an accurate comparison t o the stabilized grades. It was found that this low-carbon variety is superior in nitric acid under all conditions of heat treatment except for long-time sensitization a t 900" to 1000' F. Welding this material with electrodes of Types 308 or 347 does not sensitize any portion of the heataffected zone. Urban (2666)discussed the practicability of partial stabilization of a stainless alloy with titanium or niobium and concluded that the entire carbon content must be united with a stabilizing element in order to obtain freedom from intergranular attack. I n these cases, a 0,0770 carbon heat with no stabilizer was compared with a similar heat containing approximately 0.16% carbon. One part of this high carbon heat was poured as such and the second was treated with o.3YOtitanium which should effectively tie up about 0.09% carbon. It was found that the high-carbon modification containing some titanium behaved the same as the high-carbon, titanium-free part and both were markedly inferior t o the lower carbon, titanium-free material. It was pointed out that in these high-carbon alloys the titanium appears to form complex carbides much different from the normal titanium carbide and thus the titanium does not act as an effective stabilizer. I t was also anticipated that niobium would behave similarly under identical conditions. In a discussion on the prevention of intergranular corrosion in welded stainless steels, Orr (191) expounded the merits of the three principal methods utilized and stated that proper heat treatment is often better than the use of stabilized material or the extra-low-carbon varieties. Prior t o this discussion on methods for preventing corrosion of this type, he discussed in detail the role of the various elements common to the 18-8 varieties, and described sensitization and the sources of carbide precipitation. This should serve as a good basic discussion on this important subject. Another very practical discussion was given by Lee ( I @ ) , who explained the problem of intergranular corrosion and the role played by various elements. The use of 0.03% carbon maximum stainless steel is considered by him to be the best means for overcoming intergranular difficulties. Holtzworth et al. (111) provided a comprehensive discussion on the mechanism of knifeline attack in welded Type 347 stainless steel. They briefly aummarized the accepted theories on intergranular corrosion in these steels and illustrated how this condition is normally prevented by the addition of the stabilizing elements niobium and titanium. An explanation of this peculiar type of attack was then advanced based on this previous knowledge. The mechanism is based on the solid solubility on niobium in 18-8stainless at very high temperatures, thus rendering it ineffective during subsequent sensitization. It was emphasized that knife-line corrosion may not occur under all conditions, but its possibility should not be overlooked in the fabrication of stainless steel equipment. I n a discussion on methods for preventing intergranular corrosion of sensitized stainless steel, Gillmore (88) mentioned that heating for long periods in the temperature range 750' t o 1500' F. will cause chromium
2347
diffusion into the impoverished areas and thus overcome the tendency for intergranular corrosion. Maze1 ( 1 7 6 ) described the influence of temperature and duration of heating for various types of welding on the corrosion resistance of 18-8. A discussion on the passivating characteristics of various stainless steels by Renshaw and Ferree (209) provided data from experiments relating t o air passivation and passivation in such solutions as nitric acid, phosphoric acid, and sodium hydroxide. Although results show that 30% nitric acid solution when used as a cleaning agent will accelerate rate of passivation, there is no essential difference between air and acid passivation in its effect on corrosion resistance. They pointed out that for general corrosion resistance, there is no better passivating agent than air, although the surface must be clean and free from scale for best results. Ground or sand-blasted surfaces were found t o passivate as readily as other finishes. Knox (135) presented brief data on the apparent passivating tendency of sodium chloride in sulfuric acid solutions. Two typical Type 304 heats (both solution-quenched and sensitized) showed a passivating tendency in a dilute sulfuric acid solution as long as sodium chloride was present; this same degree of resistance waa not obtained when a pure sulfuric acid solution was used. By way of explanation, it was pointed out that the presence of molybdenum might cause the noted difference in corrosion resistance. Brief information was also available on the inhibiting effect of various chemicals on stainless steels immersed in common corrosives. Matthews and Uhlig (174) discussed the inhibiting effect of sodium hydroxide in a sodium chloride environment. They pointed out that as a group the stainless steels are very susceptible t o pitting in aerated solutions containing chloride ions and that this susceptibility can be greatly decreased by the alkali. Potential measurements show that the sodium hydroxide depresses the noble potential of the passive 18-8 stainless steel and thus minimizes the potential difference between the large passive areas and the small points of localized breakdown. Cavallaro and Indelli (98) discussed the effect of various chromates on the corrosion resistance of the ferritic and austenitic stainless steels when tested in sulfuric acid and sodium sulfate. They pointed out that the chromate ion always acts as an anodic inhibitor for stainless steels, regardless of the degree of acidity. Another report by Endo and Ishihara (67) discusses the effect of potassium dichromate in hydrochloric acid solutions with respect t o the various high-chromium stainless steels, It was mentioned that two contrary actions actually take place, the first anodic inhibition and the second cathodic acceleration. Molybdenum added t o the high chromium steels was found t o be effective in preventing pit or cavity-type corrosion and also lowered the percentage of dichromate needed t o provide inhibition. Information on crevice corrosion was provided by Ellis and LaQue (639, who exposed numerous test panels to running fresh sea water for almost 3 months. The test panels were prepared t o provide an experimental approximation of a crevice, with the crevice area being small compared to the outside area. The data obtained confirmed their expectations that the extent of attack within a crevice was proportional t o the area of freely exposed metal outside. They pointed out that these results indicate that the greatest danger exists when a crevice is associated with a large area of freely exposed metal and that when the area of metal outside a crevice approaches zero, the extent of corrosion within a crevice will also approach zero. The access of the corrosive medium and oxygen t o surfaces within a crevice is also very important. Endo (66) reported the results of experiments on cavity corrosion of the various commercial stainless steels. This type of attack on 22% chromium steel in a 10% ferric chloride solution was ascribed t o the formation of a capillary spacing between two materials (sample in contact with nonconductive substance). Since diffusion of the solution is stopped, its oxidizing capacity is lost and localized breakdown of steel sample results. Addition of 3 t o 7% of molybdenum greatly overcomes this condition. In-
2348
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
formation on galvanic couples as applied t o corrosion and cathodic protection was presented by Holler (108). Numerous articles were presented during the past year on the resistance of the various stainless alloys t o specific corrosive media. Shepard (227) provided a general review on the use of various materials of construction, including stainless steels in sulfuric acid handling. A chart illustrated the expected resistance from the various stainless steels including the Type 300 series, the Type 400 series, and the miscellaneous high-alloy stainless steels. Particular emphasis was given t o Types 316 and 317 and the miscellaneous high alloys. Fontana ( 7 9 , 8 1 )presented very comprehensive discussions on the sulfuric acid resistance of Type 316 stainless steel as well as t h e high alloy stainless steel Durimet 20. Illustrative charts were included in his discussions. These charts provide a very ready reference for determining the degree of resistance exhibited by these alloys for given acid conditions. A German article (271) also presented basic data on the behavior of the chrome-nickel stainless steels in sulfuric acid. A. very comprehensive discussion on the testing of various materials of construction for resistance to phosphoric acid was presented by Ebling and Scheil ( 6 1 ) ,who described a test method which can be used for evaluating the resistance of the various materials t o this acid. Data were also presented from tests conducted in their own laboratory by the described method and comments were presented on the results obtained. The numerous variables which are capable of providing inaccurate results were also pointed out. T h e presence of copper ions in solution was found to have an inhibiting effect on the stainless steels and a definite minimum quantity of copper was necessary t o achieve this effect. The resistance of the various stainless steels t o high strength hydrogen peroxide was also considered by Davis and Keefe ( 5 3 ) . T h e information indicates that the various stainless steels are applicable for certain types of equipment, in contact R ith this highly reactive chemical. Such items as pumps, valves, and piping, where short-time contact is obtained, can be made from the conventional stainless steels, A more general review on the resistance of stainless alloys t o all concentrations of hydrogen peroxide was given by Reichert and Pete (do”), Luce (159), and Pratt (203)for the conventional stainless steels, Durimet 20 and Worthite, respectively. A report issued by Tice (256) on the resistance of various materials for pickling operations prior t o electroplating indicates that stainless steels are satisEactorily resistant t o sulfuric acid-chromic acid solutions. The resistance of the various stainless steels to miscellaneous corrosives was also considered in some detail. Teeple (247) included the stainless steels in his discussion of the resistance of various materials of construction to organic acids, particularly those of the lower aliphatic series. Data included results from both laboratory and large-scale tests. Related compounds such as aldehydes, ketones, esters, and anhydrides were also included in this coverage. I n another paper, Teeple (248) discussed the use of stainless steels in the various phases of the pulp and paper industry, including mechanical, sulfite, and sulfate pulping operations. Wilcox and Gow (275) also provided information on the use of various stainless steels in both acid and alkaline pulping processes. The results of an interesting experiment were given by Johnson and Gibson (125) on the use of welded stainless steel strips on the inside of a pulp mill digester. A report issued by Yates (281) describes the results of a very comprehensive test program conducted t o determine the resistance of various alloys, including stainless steels, to common corrosives encountered in fertilizer production. The report was necessarily verr extrnsive because of the large number of corrosives encountered. Corrosion forums on phenol, sulfur, and alcohol were published during the past year and included information on the various conventional and high-alloy stainless steels. I n this regard, Snair ( W 4 ) , West (274), and Renshaw (208) considered the conventional stainless steels, Luce (155, 156, 161) outlined the resistance of Durimet 20, and Pratt (202, 202, 204)considered Worth-
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ite. A comprehensive discussion by Poe and Malcom (198) was presented on the action of dilute inorganic acids on 18-8 stainless steel. The acids considered included boric, hydrobromic, hydrochloric, nitric, phosphoric, sulfuric, sulfurous, and several others. The acid concentrations varied from 0.01 t o 1.0 N and the test durations varied from 1 day t o 10 weeke. Complete tabular results were included with the discussion. Several articles were available on t h e resistance of stainless steels t o various corrosives encountered in the petroleum industry. Holmberg (109) considered several high-alloy stainless steels in his discussion on materials resistant t o sulfuric acid sludge services encountered in the refining of petroleum. Corrosion test data on five different sludge conditions were reported in this paper, with comparisons between Aloyco 20 (Durimet 20) and the other alloys. Larrabee and Rogers (143) in their work on materials of construction for tanks containing sour crude oil pointed out that all of the austenitic stainless steels tested show relatively good service life as tank bottoms, while t h e ferritic steels (A.I.S.I. Types 410 and 430) were severely attacked. The sulfide-bearing salt water which separates from the crude oil on standing caused some pitting on the Type 347 but the presence of molybdenum largely overcame the situation. The use of stainless clad steel in several large oil refineries in the United Kingdom was reported by Erskine ( 6 9 ) . These clad steels are being used in distillation units for handling sour crudes. The particular stainless materials used in these clads include 18-8-Ti, 18-8-Sb, 18-10-Nb, and 14% chrome steel. Notes are given on the proper handling of these various grades. A survey was made by Tibbetts et al. (255) on the effect of various fuel oils on several materials of construction including the conventional stainless steels. The effect of vanadium containing fuel oils was particularly noteworthy. The satisfactory resistance of the stainless steels to other miscellaneous conditions was also considered. In the production of hydrogen-gas mixtures where corrosion by hydrogen and sulfur will be encountered, Nelson (186) pointed out t h a t 12% chromesteel or 18-8 stainless steel is required in preference to standard low-alloy steels. The stainless steels have also been found satisfactory where nitrogen is encountered with the hydrogen, since these materials tend t o resist nitriding. A study of materials satisfactory for handling various corrosives in a plant producing methallylamine was reported by Treseder and Miller (259). Their study included the conventional austenitic stainless steels plus other highly alloyed materials of the Durimet or Worthite types. Their results indicate that this latter type of high-alloy stainless steel is needed for satisfactory resistance for the reactor, x-hile the conventional alloys are suitable in several other points of process, The corrosion resistance of various stainless steels was considered by Riesenfeld and Blohm ( $ I d ) for amine gas treating systems. They stated that in most aqueous amine installations, Type 304 stainless steel was satisfactory, although certain particularly corrosive conditions required the selection of Type 316 stainless steel or Carpenter 20. Bryan and Selby (32) provided results of experiments showing that the molybdenum-containing Etainless steels are satisfactorily resistant t o various citric acid conditions encountered in the production of fruit juice concentrates. Stainless steels of the high-chromium variety are suitable for handling various liquid bismuth alloys used in heat transfer applications. Everhart and Van Nuis ( 7 4 ) described this resistance and particularly pointed out t h a t these high-chromium alloys are often superior t o the austenitic stainless steels. MECHANICAL PROPERTIES A S D STRUCTURE
The information on mechanical properties as reported in the literature was relatively limited during the past year. General information on the average physical and mechanical properties of the conventional A.I.S.I. Type 300 stainless steels was given in a general report (170). Other data on the high temperature properties on these same materials w-ere given in a second report (172)
. October 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
2349
embrittlement of stainless steel with particular emphasis on comwhich included nielting points, thermal conductivity data, etc. pressor blades. H e pointed out t h a t prior painting of these blades A comprehensive article by Kohn (136) compared the properties greatly decreases this susceptibility t o cracking. Zinc is also of stainless and alloy steels as influenced by such elements as tiknown t o embrittle nickel-chrome stainless steels as described in tanium, niobium, and tantalum. This review illustrated the efa n article (1)on drop-hammer operations. It was faund in this fects of these elements and was supplemented by information on work t h a t zinc contamination was being obtained on t h e stainlest various complex phases which result. An investigation on imsteel surface prior t o a high temperature normalizing treatment pact was made by Satz (%%$),who studied the path of fracture on and its impregnation on the surface during normalizing was the numerous samples tested. He concluded t h a t the path of this cause of resultant cracking of production parts. A pickling fracture was apparently influenced by the presence of tougher materials or phases in the immediate vicinity of the break. Zapffe and Worden (284) also discussed fracture phenomena in ferritic stainless steels as influenced by temperature and stress rate. Grover ( 0 7 ) provided data on the fatigue notch-sensitivity of 18-8 stainless steel. Although many data were tabulated and charted, they fail t o provide rules for accurate design of certain aircraft structures. Bardgett and Gartside ( 1 7 )reported data on the effect of shot peening on the fatigue properties of 18-8 stainless steel. A translated article (178) on t h e room temperature creep and relaxation of various materials including stainless steels also appeared. T h e effect of the rare earth elements cerium and lanthanum on high temperature ductility of various alloys, including the high-alloy stainless steels .. . . - - .. - .. and the conventional stainless steels, was disF i g u r e 1. Forged Cones of Stainless Valve Steel S h o w i n g Effect of cussed by Post et ul. (199, $00). Although they R a r e E a r t h Additions had n o suitable explanation for the greatly inSpecimen at right with no misch metal. Improved forgeability is evident from creased ductility, it was believed that increased sample at left deoxidation and increased fluidity of the molten metal provide some of this benefit. This increased operation prior t o the forming step removed all traces of zinc and ductility was noticeable during forgeability tests conducted on eliminated the cracking tendency. Thielsch (249) considered the these stainless steels. Figure 1 illustrates this effect. high temperature embrittling tendency iq 12 t o 16% chrome-iron Considerable information was available on the low temperature alloys and related t h e tendency t o the solution of carbides a t eleproperties of the various stainless steels. Krivobok and Talbot vated temperatures. It was stated that grain growth is not re(159) provided the results of investigations showing that the sponsible for the embrittlement, and t h a t means should be taken mechanical properties and other characteristics of the commercial t o keep the carbides in a precipitated form. Thermal treatments austenitic stainless steels are enhanced a t subzero temperatures. for accomplishing this end result were discussed. An adequate The commercial rolling of these steels a t low temperatures would composition balance and the presence of carbide stabilizers also be improved, as the ductility of these alloys is increased by a detend to decrease t h e carbide solubility at elevated temperatures. crease in temperatures. Armstrong and Miller ( 1 1 ) provided inIn the 1951 review on stainless steels (169) considerable attenformation on t h e subzero impact properties of Types 310 and 316 tion was given to the nature, occurrence, and effects of the sigma stainless steels. Specimens were prepared from both annealed phase on various stainless steels. I t was mentioned that informamaterial and butt-welded material and then subjected to liquid tion on this relatively unknown phase was extremely important in nitrogen for long periods under stress. Test results show t h a t the order t o expand the knowledge of stainless steel metallurgy. Most vtlues for any one series appear t o be unaffected by the duration -of the information provided in this previous review resulted from of exposure under stress. Good results were obtained for all maa symposium on the sigma phase held a t the 1950 aanual meeting terials tested. Spretnak et ul. ($36)presented data on the effect of of the American Society for Testing Materials. A compilation of notches on the tensile and fatigue properties of Type 304 stainless articles presented at this symposium is available from t h a t society steel a t room temperature and at - 196" C. They concluded t h a t the unnotched properties tend to increase with a decrease in tem(7). perature while the notched specimens have a n increase in certain Additional information on this subject was published in several properties and a decrease in others. technical articles during the past year. Cooke ( 4 8 ) described exInformation on the thermal conductivity of Type 321 stainless perimental work carried out in Australia on t h e occurrence of steel a t low temperatures was presented by Berman (21). Hogan sigma phase in an 18-8 stainless alloy containing 3% molybdenum and Sawyer (107) charted thermal conductivity data on various and 1%titanium. T h e effects of this phase on the structure and stainless steels a t high temperatures. A third paper (171) also mechanical properties of this alloy were described. H e pointed presented chart data on the thermal conductivity on such stainout that this type of alloy exhibits a duplex austenite-ferrite structure in the softened condition and is therefore prone t o sigma less alloys as A.I.S.I. Types 302, 321, 347, and 430. formation. The presence of sigma after various thermal treatThe question of embrittlement of stainless steels was discussed ments was studied by changes in magnetic properties, mechanical in some detail during the past year. Zapffe and Landgraf (185) considered the embrittling effect of steam on stainless steels at properties, microstructure, and corrosion resistance. As noted by others, t h e presence of sigma resulted in a deterioration of the elevated temperatures. Types 410 and 403 stainless steels are known t o provide a full bend after quenching from a dry atmosvarious properties of the alloy. Vollers (164) also described sigma phase in iron-chrome alloys. This description included data on phere. However, they have a greatly reduced angle of bend when the effect of sigma on the properties of the material and inoluded steam is present in the furnace. The authors described the causes of this hydrogen embrittlement and methods available for overthe various type alloys in which it is expected to be present. The author stated t h a t formation of sigma phase appears to be procoming the tendency. Durkin (60) also described the hydrogen .
hen studying any one of many stainless steel compositions t o detect sigma formation. Strong potassium hydroxide solutions tend t o color sigma much more rapidly than carbides, while dilute solutions have the reverse effect. Explanations are advanced for various phenomena noted with sigma phase. A patent was issued to Clarke (49)on a stainless composition which is essentially free from sigma phase formation even under continuous exposure t o high temperatures. T h e subject of other phase transformations in stainless steels was also considered in some detail. Dulis and Smith (58) studied the formation of ferrite in two austenitic 18-8 stainless steels dur-
Vol. 44, No. 10
ing heating in the "sensitization iaiige" arid itsnoriated it
H ith carbide precipitation. On heating, they found that ferrite s t a r b to transform t o austenite a t about 900' F., whereav the reverse transformation during cooling does not occur until t h e metal ie below 500" F. Therefore, their observations tended t o support the theory that ferrite is associated with carbides and does no1 form in the carbide precipitation range, but actually during cooling below that range. The) utilized microscopic, x-ray diffraction, and magnetic meam for detecting the ferrite phase. Ai! :trticle by Zwart (287) described u method for ascertaining t h r magnetic properties of austenitic stainless steels. The amount of ferrite in these steels is a function of the ferrite content anti serves as a ready method for evaluating per cent ferrite in thew steels. A study of martensite formation in an iron-chromenickle alloy in subzero temperatures was made by Kulin and Speich (240),who determined that this phase forms isothermall\ and follows a C-curve behavior with decreasing temperatures. A similar study was made by Das Gupta and Lement (6%')on high chrome-steels. The austenite-martensite transformation had been previously observed in a, 15% chromium-0.7~ocarbon steel and partial but not complete supprcbsion of the martensite ~ V N < obtained by quenching in liquid nitrogen. Isothermal tian&formation occurred a t all subzero temperatures below -65" E In a study of Lashko and Nesterova (146)on steel samples containing various percentages of chromium u p t o 21 % and moIy11denum up t o 4%) it was found that with chromium contents kwlow 1.5% only (Fe,Cr)rC was formed, m-hile a t higher chromium contents (Fe,Cr),Ca and ( Fe,Cr)zaCs were formed. They provide a phase diagram relating per cent chromium t o annealing time and discusped the various phases formed in this system. A study ot &he transformations occurring in lon carbon (0.06, 0.10, and 0.12%) chromium stainless steels was made by Nehrenberg (184,. who determined that austenite increases a t temperatures between 1480' and 1700' F., becomes constant a t its maximum value from 1700" t o 2000° F., and then is eliminated entirely between 2475" and 2525' F. A study on the effect of carbon on the type carbidec which precipitate was also included in this work. Rickett el ai (211)studied isothermal transformation, hardening. and tempeiing of A.I.S.I. Types 403,410, and 416 stainless steels. Austenitt. formation in these steels and the transformation characteristic6 of this austenite were investigated. A series of charts was also printed (179) showing S-curves for seven different stainless steelb of the 400 series. A brief investigation by Esling ( 7 9 ) on the magnetic properties of Type 416 stainless steel indicated that thi. alloy retains its magnetic properties a t 450' F. Two separate reports mere published during the past year outlining techniques utilized t o determine the segregation of small percentages of lead in stainless steels. Lead is known t o havr R deleterious effect on the properties of many alloys including t h c stainless steels. I n their work on cast stainless alloys, Standifel and Fontana (238) describe their findings when 0.04% radioactivp lead (Pb210 or radium D) mas added t o cast Durimet 20. Thk percentage of lead was well above the solid-solubility limit and was selected to provide a representative picture of lead distribution a t a low concentration. Although it was assumed that in tlui. wholly austenitic alloy the lead would be located a t the giaiii buundaries, the radio-autographs indicated t h a t it was actualh trapped between small dendrites present within gross grains. N o abnormally high lead concentrations were found at the gi ail! boundaries. Erivall et al. ( 7 1 )made a similar study using O.OOlY, lead (radioactive lead isotope) in an 18-8 stainless steel and the3 , too, found that a lead distribution was located between the dcndrites or the last part of the specimen t o solidify. However, thc lead segregation was not uniformly distributed but tended t c ~ occur in isolated aggregates.
HIGH TEMPERATURE
Considerable information was available during the past y e w on the various aspects of high temperature stainless allow and in-
October 1952
INDUSTRIAL AND E N G INEERING CHEMISTRY
cluded such topics as alloy research, mechanical and physical properties, corrosion resistance, and welding problems. Several new alloys were described which are claimed t o offer desirable properties for specific services. A patent was issued to Foley (7'8) on a nickel-chrome-cobalt base alloy which was stated to be adaptable as gas turbine blades produced by forging or working. Another alloy of this type, patented by Hagglund and Rehnqvist (99), contained 10 to 40% chromium, 0.2 to 2.5% silicon, 0.1 t o 9.0% aluminum, and the remainder iron. A method for improving the high temperature strength of austenitic chromium steels was described by Binder (23). Small additions (0.005 to O.lyo) of boron were stated t o produce this desirable effect. Other general information on the high temperature alloys included discussions an gas turbine steels by Oliver and Harris (189) and Morlet (181). A very comprehensive article on creep and stress-to-rupture characteristics of many stainless steels of the A.I.S.I. 300 series was presented by Wylie and-Thielsch (880). General information on definitions of propertiw and methods of testing were first given. Factors affecting creep strength were then considered. These factors included chemical composition, structure and grain &e, and structural stability. Data were presented on the properties of the various alloys. Several other articles were published on new techniques for utilizing stainless steels a t high temperatures where they might normally not be completely satisfactory. These techniques involve coating with ceramic-type materials. The use of a vitreous ceramic coating was described by Close (44), who utilized these combinations for various jet engine parts. His discussion dealt primarily with the method of application to stainless steels; a similar article by Hubbell (114) provided a more general discussion on the effect of these high temperatures on the 3tainless steel interior. T h h latter paper pointed out that a definite saving in critical stainlms steel could be extended by use as aircraft engine parts operating up t o 1800' F. Comparative tests were conducted on coated and uncoated samples and ii was determined that the ceramic material greatly increased the expected service life. Other stainless alloys such as Type 310 and 17-14 CuMo were included but were not investigated in such great detail. Service tests were made to determine the comparative thermal shock resistance of the various combinations. Pitts and Moore (196) also investigated the beneficial effect of ceramic coatings for stainless steels operating a t very high temperatures and particularly determined the effectiveness of the ceramic in preventing absorption under strongly carburizing conditions. They found that in most cases the ceramic prevented the adsorption of carbon by the stainless steel. Another similar article was presented by Harrison (100). Other general information on the high temperature serviceability of stainless alloys was given by Holmberg (110), who described considerable experience with austenitic stainless alloys in high temperature service in the petroleum industry, and Evans (73), who provided similar information on oil ash corrosion a t temperatures between 1000' and 1500' F. A comprehensive discussion on a stainless steel material called Discaloy was given by Losco (153). This austenitic material having a normal composition of 54% iron, 26% nickel, 13.5% chromium, 3.2% molybdenum, 1.6% titanium, and o.03y0 carbon can be hardened up t o 300 Brinell, depending on the titanium content. This increased hardness over the normal 170 Brinell hardness is accomplished by thermal treatment. It was stated that the alloy has especially high creep strength combined with good ductility and excellent oxidation resistance in the range of 1OQO' to 1350' F. Another comprehensive report was given by Clark et al. (41) on the high temperature properties of the common 16 Cr-25 Ni-6 Mo alloy. The report provides data on tests conducted up t o 12,000 hours a t temperatures of 1200', 1300', and 1400' F. on two heats of this material. Test bars were treated in the heat treated condition and after high temperature rolling followed by tempering. Room temperature data indicate that the worked sample was much harder and had increased strength without sacrificed ductility. It was found that in contrast t o the
2351
room temperature mechanical properties, the working treatment did not appreciably affect minimum creep rates a t the temperatures of test. The treatment did, however, reduce the total elongation during creep test and improved the rupture strength at 1200' F. Electron micrographs of this alloy show that a t the temperatures of test, its strength is due to precipitation effects. In an article by Kirkby and Sykes (131), data were given on the properties of a niobium stabilized 18 Cr-10 Ni steel a t high temperatures. The information provided includes creep properties, tensile properties, and fatigue results. A metallographic examination of this type alloy under the conditions of test was also considered. The various factors that may influence the shape of the creep curves were discussed. Another report by these same authors (138)provides a general review on the properties of creepresisting steels suitable for use in gas turbine and jet engines. The materials are broadly classified rn ferritic steels and austenitic steels. Comparisons can be readily made on the important properties of the various materials. Data are provided relating the results t o the size of the specimen used. A report on the possible substitution of the H F type alloy (21% chromium, 9% nickel) for the H H type (26% chromium, 12% nickel) was given by Avery ' e t al. (16). They suggested this change because of the greater ductility insensitivity to carbide embrittlement and excellent creep strength of the former. Data were reported on mechanical properties in the as-cast condition and after aging a t 1400' F. Creep and rupture properties were given a t temperatures from 1200' to 1600' F. as well as the magnetic permeability after various thermal treatments. The information also includes its resistance t o oxidation, hot hardness variation with temperature, influence of thermal history on the structure, and other important properties. Specific information on the creep and rupture properties of various alloys was also considered by several authors. Data on these two Properties were provided by Smith el a2. (229)on annealed 18 Cr-8 Ni-Mo steel a t l l O O o , 1300°, and 1500' F. Similar information was alsogiven for an annealed and half-hard 17 Cr-7 Ni steel a t 600' and 1100" F. Frey and Freeman (83)dealt with the effects of cold working on the creep resistance of an austenitic alloy (low carbon, N-155). By x-ray diffraction techniques, they found that t h e creep resistance was improved by the internal stresses in the lattice of the alloy which was induced by cold work. Larson and Miller (144) provided a comprehensive discussion on the time-temperature relationship for rupture and creep stresses in high temperature alloys and surveyed a large amount of test data in an attempt to determine a relationship between the results of short- and long-time tests. They agreed that the relationship shown by previous investigators was approximately correct and could be used with a reasonable degree of accuracy. An article written by Smith et al. (231) dealt with the effectof long exposure (about 10,000 hours) a t various high temperatures of 900°, 1050', and 1200' F. on the microstructure, room temperature hardness, and notch impact strength of various common ferritic and austenitic steels. The notch impact strength was impaired in approximately 67% of the tests conducted, while in the remaining tests the results were unaffected or an improvement was shown. A description of the microstructure of t h e various alloys was given and comments were made relating the impact data t o the microstructure. Erthal (70) provided data 0'11 the various properties of stainless W in the heat-treated condition (high tensile properties). Mechanical data, impact and hardness values, and fatigue characteristics after exposure to various high temperatures were given. The purpose of this work was t o investigate this and other alloys for possible adaptation in aircraft operating a t very high speeds. Exposure t o high temperatures (900' R. maximum) increased the tensile strength and yield strength of stainless W and also decreased the impact and ductility values. Ferguson (76) studied the effect of surface finieh on the fatigue properties of a low-carbon N-155 alloy. Theinformation indicates t h a t the smoothness of surface has an important
2352
INDUSTRIAL AND ENGINEERING CHEMISTRY
effect on the fatigue values of a given material of this type. Coniplete data were provided on surfaces with three varying degrees of roughness, and fatigue tests were conducted a t 80", 1O0Oo, 1350", and 150Oc F. Freeman et aZ. (82) also made a study on this low carbon, K-155 alloy containing niobium and tantalum in place of niobium alone. Particular emphasis was given t o rupturr properties. The data on this experimental alloy based on rupture tests a t 1200" and 1500" F. on forged and heat-treated bar stock indicated that the niobium-tantalum alloy would be a t least equivalent t o the standard composition and would actually constitute a saving in the critical element, niobium.
Vol. 44, No. 10
stainless-clad molybdenum in their discussion on materials for high temperature service. Creep data were provided. Although the general welding characteristics of stainless alloys are considered in the next section, analyses utilized in high temperature work are included a t this time. Lardge (142) provided a comprehensive discussion on methods and procedures for welding the various heat-resistant alloys used for gas turbines. Solomon (236) and Stevenson (841)also provided similar information on parts used for jet engines and rockets where high temperatures are encountered, The u elding of high-alloj- castings was covered by English (68) and included such alloys as the HH ( 2 5 Cr-12 Xi), HI< ( 2 5 Cr-20 Ni), and HT (15 Cr-35 Ni) types. Thomas (264) discussed a welding project on castings of the HT alloy sanctioned by the High-Blloy Steel Committee of the Welding Research Council in cooperation with the 911oy Casting Institute. Four foundries made typical welds under similar conditions and the welds were closely compared. Although continuous vel tical welding is not good practice, other cited procedures appeared to be acceptable. WELDIhG
COURTESY A
0 SMITH GORP
Figure 2. Dendritic Growth through Several Subsequent Deposited Layers in 14-Pass Stainless Steel WeIdment
Other miscellaneous high temperature data were reported in the literature. Apblett and Pellini (9) described thermal expansion experiments on a number of high temperature alloys including 19-9 DL, N-155, the 16-25-6 alloy, and others. This investigation utilized wire resistance strain gages and heating was accomplished by passing currents through them a t a known rate which controlled the temperature obtained. Thermal shock tests \yere also described by Bentele and Lo\\ thain (19) on rotor blades and nozzle segments made from various high temperature alloys. These thermal shock tests involved severe temperature fluctuations. Information on the "accelerated oxidation'' of materials a t high temperatures was presented by Brasunas and Grant (88). Certain metals containing elements which form oxides of low melting points or high vapor pressures have been observed t o be susceptible t o accelerated oxidation. It was found that the oxide formed on the 16 Cr-25 Xi-6 Mo alloy is a spinel having a 27% interconnected porosity. Oxygen thus has an easy access t o the oxide metal interface and oxidation can proceed a t a rapid rate. On studies of this type alloy, only those containing more than 30% nickel were found t o have satisfactory oxidation-resistant properties. I n an investigation on high temperature ovidation of stainless steels, Iitalia el aZ. (116) showed by electron-diffractionstudies that in the oxidation of iron-nickel-chrome, iron-chrome, and ironnickel-molybdenum a protective coating of mixed spinel and (Fe, Cr)*03is formed. Retardation of diffusion of iron, chromium, and nickel by these protective layers causes the slovi rate of oxidation of the iron-nickel-chrome alloys. Information on the measurement of total emissivity of metals in the range of 575" t o 1475" F. was given by Sully et al. (242). Smith et al. (232) also provided information on the effect of long-time exposure a t temperatures ranging from 900" t o 1200" F. on the microstructure, room teniperature hardness, and notch-impact strength of eighteen different ferritic and austenitic steels. The fracture characteristics of high temperature allow was related t o the direction of forging by Brown et al. (30). The 16-25-6 alloy was the only stainless alloy considered in detail. Bruckart and Jaffee (31) included
Numerous contributions made during the past year on factors encountered in the welding of stainless steels include discussions on the general art of melding these alloys, the use of specific methods of welding, the metallurgy of stainless steels as it pertains t o welding, and finally the application of these weldments in industry. The effect of welding on the corrosion resistance of certain of the austenitic stainless steels was considered in detail in the section on "Corrosion" and is only briefly mentioned here. Pocock (197) provided detailed information on equipment and techniques required for the successful processing of these nickelchrome stainless steels, including notes on various compositions, prevention of ~ e l ddecay, and general precautions necessary in handling these alloys. H e described the causes of unsatisfactory welds and provided information on investigations conducted t o develop optimum metallic-arc welding techniques. An article on the eld ding of coppel-bearing stainless steels was given by Thielsch (251),who divided the various alloys into ( a ) martensitic or ferritic alloys, ( 6 ) austenitic materials containing up t o 30% chrome and 3 t o 10% nickel, (c) austenitic materials containing 12 t o 30% chrome and 10 to 20% nickel, and ( d ) high-nicliel austenitic steels containing 15 t o 30% chrome and 20 t o 35% nickel. H e pointed out that these steels usually contain 0.07% carbon maximum and the welding precautions normally observed or other stainless steels must be used. The only noted undesirable effect of copper during welding is its tendency t o precipitate in the form of copper-rich alloy phases. S'uchnick (266) also discussed recommended procedures for the arc welding of stainless steel. Another discussion ($70) on the fabrication of chemical plant equipment concerns the welding and construction procedures used a t a British plant, and the numerous miscellaneous forming and welding operations on stainless steels. A German article was also published by Klosse ( I S $ ) , Tvho provided general rules on the weldability of various corrosion-resistant and heat-resistant ferritic and austenitic stainless steels. In a more specific article, Pruger (205) described the welding techniques utilized with 17%) chrome stainless steel (A.I.S.I. Type 430). H e stated that the main drawback for this material after welding was its low ductility and its possible added cost of fabrication. T h e paper described the results of experiments on the effects of various heat treatments on ductility and also outlined the corroaion resistance t o several solutions. Carpenter et al. ( 3 7 ) described in detail some of t h e considerations in joining dissimilar metals for high temperature, high pressure service. This work comprised an esamination of dissimilar metal welds a t the junction of austenitic t o ferritic tubing as used in the subheater section of boilers where metal temperatures approach 1900' t o 2500" F. The tests
October 1952
e
INDUSTRIAL AND ENGINEERING CHEMISTRY
were designed to investigate the effect of the welding itself and were much more severe than would normally be encountered in service. Although various tests were conducted t o check stresses, other metallurgical factors such as carbon depletion in the heataffected zone, oxide notches occurring in the ferritic metals, accelerated creep a t the line of fusion, etc., were considered. Practical directions were given for overcoming some of the troubles that might be encountered in actual service. Emerson and Hutchinson (64) also described the effects of time and temperature on the structure stability of weld joints between austenitic and ferritic steels using austenitic electrodes. Mechanical data and photomicrographs were included t o augment the comments given in the paper. With regard t o the arc welding of the various stainless steels, a comprehensive chart presented (122) information on various electrodes of comparable composition as supplied by the prominent electrode manufacturers I n the welding of the special stainless steels resistant t o the effects of intergranular corrosion, some data were published on the inore practical aspects of their handling. Hopper (112) described the effect of welding on the general corrosion resistance of the various stainless steels from the practical effect as concerned with everyday failures rather than the theoretical aspects. He attempted t o clear up many of the difficulties often encountered by plant men. Hopper emphasized that stabilized rod does not affect the heat-affected zone in stainless welding and suggested rapid welding with means provided for rapidly cooling subsequent t o the welding operation. He noted various case histories on plant failures and gave a detailed description of the practical means for eliminating the failures due to a misunderstanding of the problem. Goodford and Kaufmann ( 9 2 ) also provided information on the welding of stabilized stainless steels without carbide precipitation and pointed out that rapid cooling of the heat-affected zone is usually sufficient to reduce this tendency. In a discussion on the welding of extra-low-carbon stainless steels Linnert (160) described the properties of the welded joints, particularly with respect to their resistance to intergranular corrosion, and stated that these steels are particulady good because all welding methods can be utilized. Postweld annealing is not required and field repair can be conducted without fear of subsequent failure. The optimum composition of these extra-lowcarbon stainless steel weld rods was described in a patent t o Feild (76). I n a comparison of the effects of titanium versus niobium as a stabilizer in stainless steels, McDowell (164)summarized the evidence in favor of the use of titanium-stabilized material in preference to the scarce niobium-stabilized type. He concluded that titanium-stabilized sheet may be purchased and welded with superior welds at less expense than the cost of the niobiumstabilized sheet alone. Limited data were also available on the metallurgical aspects of welding the austenite stainless steels. Scheil (226) provided a brief discussion on the dendritic growth in Type 316 weld metal and illustrated it with two macrographs showing the dendritic pattern commonly encountered in the austenitic-type alloys. In one instance the dendritic pattern which originated in the initial pass of a fourteen-pass weldment extended through several subsequently deposited layers (Figure 2). The importance of metallurgical control in the fabrication of corrosion-resistant materials was reported by Lancaster ( 1 4 l ) ,who put major emphasis on the welding procedures associated with this type work. A patent ( 8 7 ) was issued to a French firm outlining a procedure for overcoming the hot cracking of welds made in the austenitic stainless steels containing niobium by adding 0.9 t o 8.0% niobium and 0.6 t o 3.001, manganese t o a steel of the same composition as the base metal. Electrodes were also developed by Kauhausen and (Vogels (128) for the welding of austenitic stainless steels in high pressure boilers. The eIectrode, free from ferrite, can be used t o weld very thick sheets of this steel without forming phases which decrease the strength of the weld material a.e compared to the base metal. I n his patent, Linnert (149) described methods for spot,
2353
seam, or butt welding of two or mor6 martensitic stainless steel parts (Types 410, 414,416,420,431, 440A, 440B, and 440C) and obtained a hard, nonbrittle, and ductile weld without annealing. A welding flux compound described by Linnert (148) provides welds free from hydrogen pickup. Information was available on special welding processes, Kelley (129) reviewed the development of pressure welding in part 1 of a two-part article, while specifically discussing the cold-pressure-welding process developed by the General Electric Co., Ltd., in the second part. He featured the method for preparing the surface t o be welded and gave details of the welding operation itself, and information on the type of joints tested. The work included the welding of 18-8 stainless steel to itself and such other alloys as nickel, iron, copper, and brass. A discussion on inert-arc welding of various alloys including stainless steel by Zeno and Leslie (286)primarily dealt with the factors influencing the welding of thin-walled Type 347 stainless steel tubing. Their investigation also included information on welding Type 347 to other alloys and welding different thicknesses of tubing t o each other. A complete discussion of the various factors and variables was given. Benz and Sohn (20) discussed the mechanical properties and resistance to corrosion of austenitic stainless steel welded metal and weld joints when made by the inert-gas shielded metal-arc process. This relatively new welding technique (sigma) was considered in great detail in the literature and its widespread coverage indicates that it is gaining popularity as a method for welding stainless steels. Herbst (104) and Pettit (194) provided information on the general details of sigma welding, while Rockefeller (216) compared the cost between sigma welding and heliarc welding for stainless steel. Urbain (261) discussed a measurement technique for determining tungsten consumption in inertgas arc welding. The very small loss of tungsten during welding made a radioactive tracer method necessary. Welds were made under constant conditions and the amount of tungsten lost was measured by the radioactive tracer (tungsten isotope). Negatives were exposed to determine the tungsten in the weld and that deposited on adjacent plate. Fumes were also collected by a n aspirator and analyzed. The use of the oxygen-argon mixture for improving sigma welding was described in three articles (4,36, 120). Lower current densities, more economical mds, and increased speed of welding were some of the advantages of using this combination. The sigma welding technique has been utilized for producing all-welded passenger coaches (869). Gross and Smith (95) described techniques developed for satisfactory machine welding using inert-gas shielded consumable electrodes, and the advantages provided by this process for increasing production of aircraft parts. Mays (176) described the improvement of inert-gas welding by using high purity helium. This alteration of technique provided superior welds particularly where a difficult part was to be welded. Welded structures have been generally applied in industry during the past year. Burt (84),West (272), and Toland (257) all described the welding of a stainless steel spherical vessel from plate 311/16 inches thick for handling liquefied nitrogen. The spherical container was made from Type 347 stainless steel and was welded by the heliarc method. Hill (106)described the welding procedures utilized in making stainless steel dishwashers for use by the armed services. Zimmerman (286) also described the arc welding fabrication of stainless steel towers for use in a Scottish oil refinery. A general discussion on the welding of gas turbines was provided by Robertson (Ha), who stated that the technique and problems involved vary with the type of turbine concerned. Large turbines must be fabricated like those involved in high-temperature steam plants, while the small turbines can be assembled as in aircraft units. The welding operations used in dairy equipment and in the manufacture of mixing bowls made from stainless grade material were discussed by Clason (63) and Davis (64), respectively.
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INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
Roberts ( 2 1 4 ) described clir spot welding of various alloys, including stainless steel, and particularly covered resistance variations encountered during this operation. Denne (66) discussed the application of stitching techniques for joining stainless steels to various alloys or nonmrtallic materials of construction. H e pointed out that for best results ideal techniques and procedures must be utilized. The brazing of stainless steels was also considered and Jacobsmeyer (164) particularly discussed this method of joining stainless steel to other alloys including brass, steel, and the silver alloys. Beall (18) described a novel method for overcoming the necessity of special fluxes during stainless steel brazing. He mentioned that if the parts to be brazed are first plated with iron, they can be readily joined without the need for flux. A very well illustrated article on silver brazing was published by Emmerich (66). Practical recommendations on materials and techniques were included and H detailed sequence of operation was featured in this paper, Rose (218) described the successful application of titanium metal as an aid in the brazing of Type 321 stainless steel during fabrication. Since the titanium cannot be successfully brazed, it serves as a dam for holding the silver solder in those places where it is utilized. Kinzel(130) also provided informationwn the powder cutting of stainless steels, By this technique, iron powder is introduced into the gas stream, thus permitting rapid oxidation of the stainless steel. This paper deecribed the equipment used in this technique, outlined practical recommendations on the best method for handling the various Jloys, and discussed the possibility of postheat treatment. Park (19s)also described the pondpr rutting of mch hard-to-cut ma. terials as stainless steel GENERAL
General information 011 the various stainless steels was published. A very comprehensive and interesting review on the use of stainless steels in industry as well as the properties of these materials was given by hlonypenny (180). His book contains practical data and recommendations on the fabrication of stainlese steels and their behavior under conditions of stress, corrosive attack, and temperature. .\ special chapter is concerned with the selection of stainless steels for specific industrial applications. I n a book on engineering materials. DuMond (69) devotes an entire chapter to stainless steels. This book is a compilation of articles and data sheets published in Materials and Methods. Thielsch provided comprehensive reports on copper in stainless steels (165)and the physical metallurgy of chromium stainless steel (160). These reviews give information on the various aspects associated with these important topics. Piatti's general review on the properties of stainless steel (196) included such topics as chemical resistance, metallurgical principles, types of alloys in commercial use, effect of alloying, etc. D a t a are also given on the proper use of stainless steels in industry. The stainless steels used in Russia were described by Kashchenko (127). Other papers on the properties of stainless steels included work by Boyer ( 2 6 ) , Mott (181,183), and others (6, 170). Ludwig (163) provided a selection chart for alloys suitable for investment casting, which included various stainless alloys. Manufacture. In the opening paragraph of this year's review, mention was made of the advances in melting practice in recent years for utilization of stainless steel scrap which had heretofore been considered too poor for reworking The use of t h e oxygen lance was particularly instrumental in reducing thc carbon content to levels which could be utilized in the corrosionresistant stainless steel alloys ( O.lOyocarbon or less). Bungardt el aE. (33) described experimental heats in a 300-kg. furnace as well as heats in LO-, 20-, and 30-ton furnaces where this oxygen treatment was used, Information on the efficiency and working pressure of oxygen, the stability of metal oxides, the temperature dependence of the chrome-carbon equilibrium, rste of carbon removal, the influence of original carbon content.
Vol. 44, No. 10
life of refractory linings, and ultimate effect of this trcatment on steel produced wras given in detail. Crafts and Rassbach (60) also discussed the melting of low-carbon stainless steels and the effect of oxygen introduction during melting on the metallurgical aspects of the alloy. Carbon was very difficult to maintain at an extremely low level, particularly with basic lined arc furnaces where carbon introduction is an easy matter. Brandt ( $ 7 ) discussed the decarburization of stainles steel heats with the oxygen lance. This information augmented the similar information provided in thc 1951 review. Ogan (188)deecribed thc recent trends in stainlesb steel melting practire as they influenced production and quality of modern stainless steels. '17'ilcox ($76) provided a similar discussion on the induction furnace melting of stainless steels and described the procedure for making a typical 18 Cr-8 Ni heat of corrosion-resistant material. A description of a small semiproduction vacuum furnare was given by Taub and Doll (244) for the production of special stainless steel heats of 5 to 50 pounds each. A description was given by Godecke (90) of the production of 18-8 stainless steel in a graphite-bar furnace in Germany. This furnace was lined with stabilized dolomite and was used for basic melting. Under these conditions of operation, relatively no chromium, nickel, or molybdenum was lost. McFarlane (166)provided information on the use of low-carbon ferrochromium-silicon in the production of stainless steel ingots. The use of this material resulted in a definite cost advantage. Several aspects in the production and handling of wrought stainless steels were covered in the literature during the past 12 months. Walker and Gerrard (167) described a gas-cutting machine which utilizes oxygen for cropping of stainless steel blooms. This machine was designed t o cut material up to 30 inches in thickness at oxygen pressures of 20 to 35 pounds per square inch. Hull and Scott (116) described the induction heating procedure for continuous heat treatment of sheet and strip and provided data on the results from a n investigation on 18-8 stainless steel and other alloys. In the production of seamless stainless steel tube, Kritscher (138) described a method for high temperature, high speed heating. Heating rate graphs for a stainless steel material were provided on the barrel-type furnaces used in this work. Previous mention was made of a paper by Post el al. (800) on the beneficial effect of the rare earth elements cerium and lanthanum on the hot forgeability of various stainless steels. The use of these elements has definitely changed rertain alloys from the difficultto-work category to relatively easily worked materials. New techniques were also described in a n article (239) on improved drop-hammer practice. It mas stated that drop hammers are about the only forming method which satisfactorily produces compound curves and sharp radii in heavy grades of corrosion-resistant stainless steel. An article (277) on the American Steel and Wire Co. stainless steel plant a t Waukegan outlines the important phases of stainless steel wire production. This provides an excellent discussion on the production of wire products, including the annealing, cleaning, finishing, and cold rolling of the wire. Hinman (106) described the recommended design of dies for the production of 18-8 stainless steel products, as well as procedures used in the manufacture of stainless steel pipe, where such operations as resin coating, shearing, sawing, roll forming, and welding are considered. In the production of stainless steel products where rolling operations are involved, the selection of proper lubricant and coolants is extremely important. Bible (11)discussed a suitable lubricant for this type handling of stainless steel products. I n the production of stainless steels by foundry procedures, Czyzewski et at. ( 6 1 ) described the utilization of ceramic molds and the methods used to produce molds suitable for making castings. The materials tested included fireclay grog, steatite, cordierite, high alumina, and zircon porcelain. Under the prescribed method the molds successfully withstood the thermal shock involved in pouring standard test,bar castings of 18-8 stainless steel. Good surface conditions were noted on the castings. Merhaniral
Oatober 1952
INDUSTRIAL AND ENGINEERING CHEMISTRY
properties of the resultant castings were described as suitable. Samuels and Schuh (122) provided a very interesting discussion on recent developments in the field of centrifugal castings with particular emphasis on a method employing metal molds. I n a description of foundry techniques for overcoming difficult t o produce castings, McLeer (168)described techniques used with problem castings. Important variables are distortion, shrinkage, and feeding, and five typical examples were cited t o illustrate the point in question. Several authors provided information on investment casting techniques. Wood and Von Ludwig (279) studied the physical properties of several alloys, including stainless steels as produced by investment foundry techniques. Variables investigated included pouring temperature and its effect on grain size and ductility, investment and flask-temperature effects on grain size, and mechanical properties. The effect of turbulence as controlled by gating techniques and the effect of standard heat treatment on the Droduction of desirable mechanical properties were also considered. A description (166) was also given of the Osborn-Shaw process of precision casting. This procedure was experimentally developed and tested over a 5-year period by a British firm and after having been used for several years on commercial production, it should interest American producers. Analytical techniques for identifying stainlevs steels by spot check methods or by the complete identification of certain elements were briefly discussed in the literature. Smolla (933) provided a method for identifying Types 316, 321, and 347 stainless steels. This method is adaptable to small pieces or trim scrap and thus does not require the expenditure and time of milling or drilling samples. The Type 316 stainless steel is identified by the presence of molybdenum, Type 321 by the presence of titanium, and Type 347 by the presence of niobium or niobium plus tantalum. Young (182)described an accurate analytical technique for determining tantalum and niobium in Type S47 stainless steel, which can be utilized by the average laboratory. For routine analyses of certain stainless steels where rapidity is mandatory, the use of a mass spectrometer was suggested by the National Bureau of Standards (946). Machining. Information on the machining of stainless steels was specific in most cases, although one article by DeFeher (66) included information on all machine shop techniques. This was actually a series of pamphlets available from the Department of Commerce, giving information on problems arising in the production of items in the defense program. The characteristics of ferritic and austenitic stainless steels are considered and recommended procedures for machining are concisely summarized under the following headings: machining characteristics, turning tools, drilling, reaming, tapping, threading, cutting fluids, drawing, spinning, polishing of various types, riveting, blanking, punching, and shearing. The information given is described as being relatively elementary but practically useful. Von Hambach (966)states t h a t with good tools, particularly if they are sharp, any stainless steel can be machined at high speeds. He specifically mentions that the installation must be rigid and husky in order to obtain good results. Machining problems associated with the heat- and creep-resistant alloys were described by Wolfe and Spear (278), including results of research work on turning, milling, drilling, broaching, and grinding of stainless steels. Some practical information was also given on the examination of cutting fluids t o make certain they are functioning properly. The presence of selenium and/or tellurium and/or sulfur was described in a patent (190) as inducing increased machinability. The alloys in question contained relatively high nickel and chromium contents and were generally classed as austenitic stainless steel. Another article by McWilliam (169) provided general information on the handling of stainless steel, particularly in the machine shop, including data on finishing operations, grinding, and polishing. From the standpoint of forming stainless steel (16) in the manufacture of aircraft parts, limitations associated
2355
with its use were described. Half-hard material must often be used for certain operations and suggestions for its handling were given. The automatic spinning of stainless steel in production was described in some detail by Court (49). Although these alloys are rather difficult to spin, this process shows definite advantages over press forming on parts made of light gage stock. Excellent illustrations were included. Linsley (161) provides general information on the operation of a drill press from the standpoint of handling the stainless steels, with data on the various feeds and speeds for different, rlasscs of materials, the ideal coolants to use, when and how to grind drills, how to hold the work, and how to perform operation8 other than straight drilling.
COURTESY MICHIOAN STEEL CASTINOS CO
Figure 3. Effect of Selenium Additions on Porosity in Stainless Steel Castings Casting at left with n o selenium; other from s a m e melt has been treated in recommended mnnner
Surface Treatment and Miscellaneous. A general review of the various ways in which a high degree of surface finish can he obtained on stainless steels was given by Lomas (169). The pickling of stainless steels wm one of the operations considered and this was compared with the type of surface obtained from polishing and buffing operations. A table showed t h e recognized scale of finishes on stainless steel. Notes were also provided on the finishing of welds in items fabricated from stainless steel. Recommended procedures for cleaning various stainless steels by both mechanical and chemical means were provided by RossiLandi (990) and an anonymous author (6). Klouman (134) provided data on the proper care of stainless steel equipment in the paper industry. He described the items of machinery used in the paper mill that may be made from stainless steel, the type of stainless steel available, and the methods recommended for keeping this stainless material in proper condition. Medoff (177) described the cleaning procedure used in Japanese shipcargo tanks for the transportation of vegetable oil where the use of stainless steel reduced the cost of between-trip cleanings up to 75%, and welding techniques utilized in this installation. The use of electropolishing techniques on the production of fine stainless steel wire was described by Colner et al. (45). By dthis proceure, wire is fed through a bath a t a steady rate under constant electriral
'2356
INDUSTRIAL AND ENGINEERING CHEMISTRY
conditions, with the result that all parts receive the same treatment and the wire emerges with a uniform cross section. This procedure is much simpler than the mechanical means previously used. Although a phosphoric-citric acid mixture was used in the experimental work, the authors conclude that any of the common electropolishing solutions for stainless steel would be suitable. I n the Electropol process for electric polishing of stainless steels ( 1 4 )the work is made an anode and when current is passed, metal is removed from the outer surface of the work, thus providing a smooth finish. Bronn (29) described a process for restoring the finish on small areas which have become marred during fabrication as a result of welding, tooling, etc. This method involves the grinding and polishing of stainless steels with coated abrasives. Brief information n-as also available on nitriding or case hardening the stainless steels to increase their wear resistance. Detailed information on Malcomizing vias given by Low (154). A cycle of 40 hours a t 1000" F. was used t o dissociate and ionize ammonia, and this provided a satisfactory nitrided surface on stainless steels of the A.I.S.I. 300, 400, and 500 series. Nascent hydrogen removes the chromium oxide layer on the surface of the alloy and allows the action to take place. This procedure is said to be adaptable to conventional furnace equipment. Some basic information was reported by Van Rossum (263) on the corrosion resistance of sprayed nickel-chrome stainless steel coatings. These coatings after application were compared in corrosion resistance with the original m-ire. A marked difference was observed between the attack of sprayed metal in nitric acid and copper sulfate solutions and that observed in 99% acetic acid. I n the first two solutions, the oxide layer was removed, exposing a large surface area of material t o the acid. I n acetic acid the oxide layers were gradually dissolved away and the speed of penetration of the acid into the metal was much more gradual. It was the consensus, however, that apart from the inherent porosity of sprayed metal, a good degree of corrosion resistance can be anticipated. Tour (958) also provided a discussion on modern developments in metal spraying and techniques for making the resultant product more resistant and impervious t o corrosion. General information on mechanical properties, corrosion protection, etc., was included. A general review on the manufacturing of stainless clad steel by Thielsch (96W)covered manufacturing methods, physical and mechanical properties, heat treatments, welding procedures, selection of proper welding electrodes, and flame cutting methods. Such metallurgical topics as the effect of carbon diffusion and dilution during fabrication were also considered. Numerous photomicrographs, diagrams, and charts were an integral part of this paper. A Japanese article by Abe et al. ( 1 ) discussed the manufacturing of stainless steel-clad material. Base material used was low-carbon steel while the cladding material was the conventional 18-8 stainless steel. Casting was the most suitable manufacturing method for maximum production. The tensile strength of the clad steel generally agreed with the value calculated from the thickness ratio of the two metals, but the endurance limit was much higher than the calculated limit. Other factors included welding, flame cutting, etc. I n a special article (668),mention was made of the occurrence of graphitization in carbon steel in stainless-clad vessels as used in petroleum refineries. It was stated t h a t stresses caused during the cladding operation were probably responsible for this situation and research is now being conducted in an attempt to overcome the trouble. Sangster (223) described a process used by a large steel company for cladding with stainless steel. The steel base was first electroplated with nickel and then clad with stainless steel or other alloys. Information was also available on the electroplating of stainless steel. Head (102) provided a general discussion on the desired method of scale removal, polishing, racking, cleaning, plating, and the best type of chromium baths for this operation. This article also included a recommended procedure for stripping chromium on rejected parts prior to reworking.
Vol. 44, No. 10
Haas (98) reviewed some major technical and patent literature in the plating of stainless steel, with a table illustrating recommended procedures. Operation details from the precleaning of the stainless steel through the various rinses, acid dips, and finally the various plating cycles of nickel, copper, brass, or chromium were given. Committee B-8 of the American Society for Testing Materials has issued a report on recommended standard practice for preparation and plating of stainless steels as reported by Sample (2s1). The production of Type 316 powder metal products was discussed by Grobe and Hoffman (94). This stainless material can be readily pressed and sintered a t pressures and temperatures which are commercially feasible. The mechanical properties of the finished parts and applications for these powder compacts were included in this discussion. Stainless steel compacts were also considered in the report on powder metallurgy by Kalischer (126). The available data on various compacts including stainless steels were given in this report. Applications. The various applications of stainless steels in the chemical and allied industries where corrosives are handled were considered in detail under Corrosion, Despite the restrictions on the use of these alloys for nonessential projects, information was still being published on their successful application for many such uses. A history of the use of stainless steel for roofs was given by Paret (192),who described the performance of such installations dating as far back as 1924. Excellent service has been obtained in all instances. Havighorst (101) described the use of welded pipelines in large dairies where contamination, product losses, plant maintenance, and clean-up costs have been greatly reduced. Oxyacetylene and arc welding procedures are used. Howard (11s)discussed the use of stainless steel to handle process by-products of the meat packing industry The uses of stainless steels in such other varied categories as office buildings (M), railway coaches (%06), and the lithographic industry (93) were also described. Much stainless steel was also found valuable for services pertinent t o the armed forces. Stainless steels were used for mobile army shower baths ( I T S ) , in parachutes (187), and for other aircraft and jet engine installations (46, 123, 137). HIGH-SILICON IRON§
Previous articles in this review series have provided information on properties and applications of high-silicon cast irons a i utilized in the chemical and allied industries. Although the conventional grades contain a nominal silicon value of 14.5%, for the purpose of general information, cast irons with silicon contents above 5% are considered in this review. Chipman et al. (40)studied the solubility of carbon in molten iron and in iron-silicon and iron-manganese alloys. Although the primary objective was a study of the iron-carbon system, the solubility of carbon as influenced by manganese and silicon was also determined. It was stated t h a t the solubility of the carbon a'as decreased by silicon. I n 21 to 23% silicon (depending upon temperature), a second solid phase appeared and above this silicon percentage the solubility of graphite could not be determined. Goertz ( 9 1 ) provided information on the heat treatment in a magnetic field of iron-silicon alloys containing betv,Teen 2 and 10% silicon, He reported that the maximum permeability waq obtained a t approximately 6.5y0silicon. I n a single crystal of this composition, magnetized parallel t o a (100) direction, the hysteresis loop was squared by this magnetic anneal and the maximum permeability was increased over 7 5 times. Riley (913) provided notes on the barley shell structure as obtained in ironsilicon alloys. He described how the structure may be produced and used in distinguishing between higher and lower silicon areas in a micro specimen. Corrosion information on the high-silicon iron alloys was rather extensive and several general reviews were presented. Fontana ( 8 0 ) provided an excellent discussion on the corrosion resistance
October 1952
INDUSTRIAL A N D ENGINEERING CHEMISTRY
of this alloy to various sulfuric acid concentrations at temperatures t o the normal boiling points. A descriptive chart was presented, subdivided into various categories depending on the degree of attack obtained for the various conditions. The properties of these alloys and the effect of passivation on corrosion resistance were also considered. Shepard (227) included information on the high-silicon iron alloys in his comprehensive discussion on materials of construction for handling sulfuric acid. Corrosion forums on such chemicals as hydrogen peroxide, phenol, sulfur, and alcohol were handled by Luce (166, 167, 158, 160). On the corrosion resistance of relatively low silicon-containing cast irons Iitaka and Sekiguchi (117') considered alloys in the 5.5% silicon range. Hydrochloric acid solutions were used on these specimens and variouv quantities of copper were intentionally added in an attempt to improve their resistance. IRON-NICKEL ALLOYS
Blanter ( 2 4 ) discussed the influence of nickel on the diffusion of carbon in austenite. The effect of 4 to 18% nickel was systematically studied and the relationship between the nickel content and diffusion coefficient of carbon in austenite was determined. On the various phase relationships in iron-nickel alloys, Machlin and Cohen (167) discussed martensite transformations in a 69% ir0n-317~nickel composition. Their particular interest was t o investigate the burst phenomenon associated with this transformation at subzero temperatures. Allen and Earley (3) and Takeuchi (243)also presented information on the transformations taking place on iron alloys containing from 9 to 27% nickel. The use of iron-nickel alloys for corrosive services was also considered in some detail. Friend (84-86) considered the resistance of Ni-Resist alloys t o alcohol, phenol, and hydrogen peroxide. West (274) described the resistance of these alloys t o sulfur. Teeple (246) provided data on the mechanical properties and corrosion resistance of the various austenitic cast irons to various caustic solutions, in an attempt to interest users of caustic handling equipment in utilizing this type of alloy in place of pure nickel whenever possible. Shepard (227) provided data on the Ni-Resist alloys in sulfuric acid solutions. H e stated t h a t these alloys could be used generally for reducing sulfuric acid services at low concentrations and a t moderate to low temperatures. Specific information was given on the use of Nicloy 9 (9% nickel steel) tubing in oil wells (118) and the use of Ni-Resist pumps in spraying equipment used for handling weed killers, bug killers, etc. (119). -4 comprehensive discussion of the welding of various nickel alloys including Ni-Qesist, by West (273), includes general details on welding technique and the effect of welding on the base metal. The various fusion-welding processes were handled separately and proper techniques for each type were cited. AUSTENITIC MANGANESE STEELS
Information was provided during the past year on the production of 12% manganese steel castings. Roll ( 2 i 7 ) described a n investigation on the effect of annealing-quenching treatments on the properties of this type alloy. This investigation included tensile strength and elongation, bending strength and deflection, toughness, and Brinell hardness. Doepken (67) reported data on the tensile properties of wrought austenitic manganese steel in the temperature range from 100' t o -196" F. These steels were tested in axial tension to determine flow and fracture stresses as well as other conventional properties. The ductility and related properties such as fracture stress decreased continuously with temperature. Peculiarities during straining indicated possible martensite formation or mechanical twinning. LITERATURE CITED (1) Abe, F., and Kimura, K., and Saito, T., J . Japan. Tech. Assoc. Pulp Paper Ind., 5 , 1 9 5 2 0 1 (1951). (2) Aircraft Production, 13, 327 (October 1951).
2357
(3) Allen, N. P., and Earley, C. C., J . Iron SteelInst. (-London),166, 281-8 (1950). (4) Am. Machinist, 95, 154-5 (Aug. 6, 1951). (5) Ibid., 95,163, 165, 167 (Oct. 15, 1951). (6) Ibid., 95,173 (Nov.12, 1951). (7) American Society for Testing Materials, Spec. Tech. Publ. 110 (1950). (8) Andrews, K. W., and Brookes, P. E., Metal Treatment, 18, 30111 (July 1951). (9) Apblett, W. R., and Pellini, W. S., American Society for Metals, Preprint 2W (January-February 1952). (10) Armco Steel Corp., Bull. 5-2071 1951). (11) Armstrong, T. N., and Miller, A. J., A S T M Bull., No. 177, 35-6 (October 1951). (12) ASTM Bull., 176,5 (September 1951). (13) Ibid., 178,15 (December 1951). (14) Automotive Engr., 42, 56 (February 1952). (15) AutomotiweInds., 105, 42-4, 130, 132 (July 15, 1951). (16) Avery, H. S., Wilks, C. R., and Fellows, J. A., Trans. Am. SOC. Metals, Preprint 15 (1951). (17) Bardgett, W. E., and Gartside, F., Iron and Steel (London),24, 195-7 (June 1951). (18) Beall, F. W., Steel, 130, 57 (Jan. 14, 1952). (19) Bentele, M., and Lowthain, C. S., Aircraft Eng., 24, 32-8 (February 1952). (20) Benz;, W. G., and Sohn, J. S., WeldingJ., 30, 911-26 (October 1951). (21) Berman, R., Phil. Mag., 42, 642-9 (June 1951). (22) Bible, M. L., Iron and Steel Engr., 28, 91-3 (June 1951). (23) Binder, W. 0. (to Union Carbide and Carbon Corp.), U. 8. Patent 2,562,854 (April 22,1949). (24) Blanter, M. E., Zhur. Tekh. Fiz., 20, 217-21 (1950). (25) Bleton, J., Blanot, J., and Bastien, P., Rev. mBt., 48, 325-36 (July 1951). (26) Boyer, H. E., Steel Processing, 37, 287-92 (June 1951), 345-9 (July 1951). (27) Brandt, D. J. O., J. Birmingham Met. SOC.,31, 44-60 (1951). (28) Brasunas, A. des., and Grant, N. J., American Society for Metals, Preprint 3W (1951). (29) Brown, A. E., Electroplating and Metal Finishing, 4, 123-6 (April 1951). (30) Brown, W. F., Schwarzbart, H., and Jones, M. H., Natl. Advisory Comm. Aeronaut., Reseaich Mem. R.M. E-50128 (Feb. 12,1951). (31) Bruckart, W. L., and Jaffee, R. I.,American Society for Metals, Preprint 18 (October 1951). (32) Bryan, J. M., and Selby, J. W., J. Sci. Food Agr., 2, 359-64 (August 1951). (33) Bungardt, K., Pakulla, E., and Tesche, K., Stahl und Eisen, 72,245-55 (Feb. 28,1952). (34) Burt,.F. M., Welding Engr., 36, 40-2 (August 1951). (35) Business Week, 7 2 4 , 77 (March 29, 1952). (36) Can. Metals, 15,54 (February 1952). (37) Carpenter, 0. R., Jessen, N. C., Oberg, J. L., and Wyllie, R. D., Proc. Am. SOC.Testing Materials, 50, 809-57 (1950). (38) Cavallaro, L., and Indelli, A., Rev. mSt., 49, 117-24 (February 1952). (39) Chem. Eng., 58,177 (November 1951). (40) Chipman, J., Alfred, R. M., Gott, L. W., Small, R. B., Wilson, D. M., Thomson, C. N., Guernsey, D. L., and Fulton, J. C., Trans. Am. SOC.Metals, Preprint 4W (1952). (41) Clark, C. L., Fleischmann, M., and Freeman, J. W., Am. SOC. Metals, Preprint 16 (October 1951). (42) Clarke, W. E. (to Armco Steel Corp.), U. S. Patent 2,540,509. (43) Clason, C. B., Welding Engr., 36, 25-8 (July 1951). (44) 'Close, G. C., Finish, 8 , 27-9, 90-1 (October 1951). (45) Close, G. C., Steel, 129, 64-5 (Oot. 29, 1951). (46) Colner, W. H., Feinleib, M., and Francis, H. T., Metal Progress, 59,795-7 (June 1951). (47) Colombier, L., and Hochmann, J., Compt. rend., 232, 176-8 (July 9, 1951). (48) Cooke, C. H., Australasian Engr., 80-90 (Aug. 7, 1950). (49) Court, L. W., Materials and Methods, 33, 86-7 (May 1951). (50) Crafts, W., and Rassbach, H. P., J . Metals, 4, 20-5 (1952). (51) Csyzewski, H., Cook, R. L., Frederick, P., and Jero, J. P., Am. Foundryman, 20, 38-9 (July 1951). (52) Das Gupta, S. C., and Lement, B. S., J . of Metals, 3, 727-31 (September 1951). (53) Davis, N. S., and Keefe, J. H., J . Am. Rocket Soc., 22, 63-9 (March-April 1952). (54) Davis, W. M., Welding J., 30, 829-31 (September 1951). (55) DeFeher, $., U. S. Dept. Commerce, Business Information Service, Defense Production Aids, No. 9 (March 1951). (56) Denne, A. G., Iron Age, 168, 78-82 (July 26, 1951). (57) Doepken, H. C.. J . Metuls, 4 , 166-70 (1952).
.
2358 158) Dulls, E. Y., a i d Siiiitti ( i Preprint 14 (1951).
I N D U S T R I A L A N D E N G I N E E R IN 0 C R E M I S T R Y
v., dmerioan
Hoc*iety for Metals,
Materials lLranua1 ” New York, ‘69) DuMond, T. C., “Eng~iieeii~ig Reinhold Publishing Coip., 1951. 160) Durkin. A. E.. Steel. 130. 76. 78 (March 24. 19521 /61j Ebling, H. F., and Scheil, M. A,, Trans. Am. SOC..kech. fi(ILg16., 73,975-87 (Octobel 1951). 82) Ebling, H. F., and Scheil, 11. h., W e l d m g J . 30, 513s 8s (October 1951). 163) Ellis, 0. B., a n d LaQue. P’. L.. C‘owosion. 7, 3@2 4 (November 1951). 64) Faerson. R. ’M .. and Hutchinson. TV. R.. W e l d m a .I . 31. 126s 31s (March 1952). ,135) Emmerich, J. P., Ibid., 31, 50-3 (Januaiy 1952) (66) Endo, H., Kinzoku (Metals), 20, No. 9, 18-22 (1950). (67) Endo, H., and Ishihala, S.,Sci. Repts. R e s e a ~ c hI n s t s . ’I’ohoku Uniu., Ser. A, 2,209-15 (April 1950). (68) English, R. H., Weldzng J., 30, 907-10 (Octobei 1951). (69) Erskine, J., Brzt. Petioleurn Equipment News, 2, 37-30 (19.50). ‘70) Erthal, J. F., I r m Age, 267, 91-5 (May 10, 151). ’71) Erwall, L. G., Franzen, A., and Rdlert, N,, Jei n k o n f o i e f s A w n . 135,219-28 (1951). (72) Esling, R. H., I r o n Age, 169, 106-8 (March 20, 1952). 173) Evans, C. T., Ameiiran Soo. Testing Materials, Symposium 011 Corrosion of Mate]i d s a t Elevated Temperatures, pp. 59 105 (1951). (74) Everhart, J. L , and Van Nuiu, E. L J4atemnl‘s and Methods 34,112-14 (October 1951). (759 Peild, A. L. (to Arrnco Steel Corp.), U. 8. Patent 2,564,474. (76) Perguson, R. R., Natl. Advisory Comm. Aeronaut.. Rept. RM. E51D17 (June 26,1951). (77) Perri, A., Met. ital., 43, 432-4 (October 1951). (78) Poley, F. B. (to Midwtle Co.). 1‘. A. Patent 2,543.841 (March ti 1951). Fontrtna, M. G., hi). ENO.C ~ H Q M . , 43, 107.4, 108A, 110.4 (Octaber 1951). Ibid., 44,85 A (February 1952). Ibid., 44,89 A, 90 A, 92 A (March 1952). Freeman, J. W., Reynolds, E . E., and White, A. E.$ Nati. Advisory Comm. Aerona,ut., Tech. N o t e 2469 (1951). Prey, D. N., and Freeman, J. W., J . Metals, 3, 755--60 (1951). Friend, W. Z., Chem. Eng., 58, 222 (August, 19.51). Ibid., 58,267 (October 1951). Ibid., 58,297---8(Novernhor 1951). Gebr. Bohler and Co., A.G., French Patent Y68,580. Gillmore, R. X., Iwlt d[7e, 168, No. 5, 81-5 (1951). Gilman, J. J., Trans. Lzh. S O C .Metals, Prepr?;nt 12 (10.51). Godecke, W ~ Giesselei, , 38, 169-74 (April 19, 1951). Goertz, : v , , .T. i l p p l i e d Phys., 22, 964-5 (1951). id Kaufniann, D. .W., M a t e ~ i a l sand Methveniber 1951). Mu, 23, 65, 68, 72, 74, 76. 78 (Xovember 1951). Grobe, A. H.. and LIoI‘t’niau. K.. P r o d u ~ 1Eng.. 22, 168.-72 (December 1951). Gross, B,, and Sniit,h, I < , .\.. M ~ c ! i l i i iJ~ ./ , 30, 81% I6 (Septeniher 1951). Grove, H. A., -4Sri1f Hzdl., 177, 17-19 (i)~.fatK1~ 1951). IS. P T O C . . 50. 717-29 Grover, H. J., Am. Soc. Testing Mat (1950) Haas, J., Metal b’inishing, 49, 50-4 (June lMI.,,. Hagglund, E. H. RI., and Rehriqvist (to AktieimlaKet Kanthal), U. S. Patent 2,580,171 (Dee. 25, 1953). Harrison, W. N.,Am. Soc. Testing Materials, Symposium on Corrosion of Materials a t Elevated Temperatures, Spec. Tech. Pub. 108 (I 950). Havighorst, C. R., Food E:)ig.,23, 74--9 (Septemher 1951). Head, H. H., MetaZ I n d . , 78, 287--90 (April 13, 1951). Heger, J. J., Metal Progress, 60, 55-61 (August 1951). Herbst, H. T., Welding J.,30, 618-31 (July 1951). Hill, A. R., I n d u . d w and Welding, 24, 4 0 4 1 , 4 3 4 , 73 (July 1951). Rinmah, c. w., Modern iMachinr Shop, 24, 154 156, 160, 162, 164 (August 1951). Hogan, C. I,., and Bawyri, K. E., J . Applied Phgs., 23, 177-80 I 1 952) Hiller, ir. D., Elec. Elag., 71, 367-73 (April 1952). Holmberg, E. G . , paper presented to Am. Petroleum Inst. Subcommittee o n Corrosion, Los Angeles, Calif., Nov. 11, 1980. Holmberg, M. E.. T?uns. Am. SOC.Mech. Eng., 73, 733-9 (August 1951). Holtzworth, M. L., Beck, F. H., and Fontana, M. G., Cowoaion, 7,441-9 (December 1951). Hopper, E. W., Welding J., 30, 503-7 (June 1951).
.
Kol. 44, No. 10
(113) Howard, R. W., Strelways, 7, 12-14 (.July 1951). (114: Hubbell, W G., M p t n l Progress, 60, 87-91, 166 (December 1951). (115; H u l l ~ @ . ~and C 9 Scott, H., Ibid., 62, 5 7 6 1 (February 1952). (1 16) Iitaka, I., Nakayama, T., and Sekiguchi, K., J . S c i . Rmearch Inst. (Tokyo),45,57-64 (1951). (1173 litaka, I., and Sekiguchi, X., “Reports of the Casting ReRearcb Laboratory,” Tokyo University, No. 2,ii--A(1951). (118) I m o Magazine, 26-7 (spring 1951). (119) Ibid., p. 17. (120) Iron Age, 167,85 (June 14, 1951). (121) Ibid., 168, 144 (Dee. 13, 1951). (122) Ibid., 168, 245-8 (Oct. 4,, 1951). (123) Ibid.; 169, 227 (March 6, 1952). (124; Jacobsmeyer, L., Metai Ind., 79, 215 .I9 (&!lit. 14, 1951); 244-5 (Sept. 21,1951). (125) Johnson, S. C., and Gibson, N . .J.. Puper. 7‘ro*lt: J . , 133, 20, 22-4,2G-7 (Sept. 14, 1951). (126) Kalischer, P. R., Pmi.rior: M e t a l M o l d i n g . 9 , 4.5--7. 80--3 (September 1951). (127) Kashchenka, G. A., ’*Fundamentalaof Metallurgy,’~Moscow, State Publishing House for Scientific and Technical literature on Ferrous arid Sonferrous Metallurgy, 1949. (128) Kauhauaen, E., and Vogels, H. A., Schweissen ltnd Schneiden, 4 , 35--40(February 1952). (129) Kelley, I?. C., W e l d i n g J., 30, 728-36 (Auguut 1951). (130) Kinzel, A. B., Steel, 129, 94-6 (Nov. 5, 1951). (131) Kirkby, K. W., mid Sykes, C., Iron and Steel Institute, Synlposiuni on High Temperatiire Steels and Alloys for Gas Turbines, pp. 8144,1951. (132) Ibid., pp. 95-106. Klosse, E., C h ~ n a . - l ? i y . ~ 7 ’ e c h24, , ~ . , 12--18 (January 1962). Klouman, G . H., Paper Mi22 iZ‘ews, 74, 60-2 (Aug. 18, 1951). Knox, R., Metal Progress, 60, 77-8 (Sept.ember 1951). Kohn, A., Reo. m&, 48, 687-711 (September 1951). Kostook, F. R., wester?^ Metals, 9, 32-4 (December lY51). Kritscher, A. F., Iron Steel Eng?., 29, 55-00 (March 1952), (139) Krivobok, V. N., and Talbot, -4.M., A m . SOC. Tcsting Materials, Proc., 5 8 , 895-928 (1950). (140) Kulin, S. A., arid Speich, G. R . . Traris. A n i . I n s f . Min,irig Met. Eng., 194,258--63 (1952). ( 1 4 1 j Lancaster, J. F., Welding nn,d Metal Pnbri (June 1951). (142) Lardge, H. E,, Aircraft Produetiote, 13, X4--7 (March 1951); 1.21-3 (April 3 951). (143) Larrabee, C . P., snd Rogers, \V. F.. G O ~ I Y J S ~ C7,I L 276-8 .
(133) (134) (135) (136) (137) (138)
(-4ugust 1951). Larson, F. R., and Miller, J., Am. Soc. Mechxnicd en,^ ~neers. Prenrint 51-A-36 iiYovember 1951). (1451 Lashkb, N. F., and Westerova, NI.‘DSpIzwal. Aknrl. S.S.S.R. Ser. F i z . 15, 67-71 (1951). (1461 Lee, R. K., Welding J., 30, 447-9 (May 1951). 1147) Link, H. S., and MarRhall, P IT., American Society for Met,als. Preprint 11 (1951). (148: Linnert, G. E. (to Arrnco Steel Corp.), U. S. Patent 2,544,334 (March 6,1951). (149) Ibid.,2,544,335 (March ti, 1951). (150) Lirinert, G. E., Welding Eng,., 37, 51-8 (Jaiiuary 1952). (151: Linsley, a.E., Am. Machinist,96, 147-62 (February 1952). (152) Lamas, S., Machinery Lloyd (OverseaB Edition), 23, 85-8 (May 26,1951). (153) Losco, E. P.,Materiais and Methods, 32, 65- 9 (October 1950), (154) Low, S., Steel, 129, 82, 84, 87 (Aug. 6, 1951). (155) Luce, W, A., Chem. Eng., 58, 224 (Aligliat 1951). (156) Ibid., 58,287--8 (September 1951). 1157) Ibid., pp. 288,290. (158) Ibid., 58,267-8 (Octo.kr 19511~ (159) Ibid.,p. 271. 1160) Ibid.. 58. 294 (November 1951). (161) Ibid., pp.‘294,296. (162) LuCe, w.A., I N D . ENC. C H G M . , 43, 2258-71 (1951). (163) Ludwig, D. TI., Product Eng., 22, 203, 205, 207 (November 1951). (164) McDowell, D. W., Metul Progress, 59, 650-2 (May 1951). (165) McFarlane, N. B., Iron Age, 169, 108-10 (Feb. 21, 1952). (166) “Machinery” (London), 80, 506-7 (March 20, 1952). (167) Machlin, E. S., and Cohen, M., J. Metals, 3 (September 1951). (168) McLeer, ToJ., Iron Age, 168, 86-9 (Nov. 22, 1951). (169) McWilliam, J. A.. Welding a n d Metal Fabrication, 19, 133-9 (April 1951). (176) Materials and Methods, 33, 9Yr 101 (May 1951). (171) Ibid.,33,107 (June 1951). (172) Ibid.,34,113 (September 1951). (173) Ibid.,34,190, 192,194 (October 1951). (174) Matthews, J. W.? and Uhlig, H. H., Corrosion, 7, 419-22 (December 1951). (144)
October 1952
i
INDUSTRIAL AND ENGINEERING CHEMISTRY
Mays, W. A+,Welding J., 30, 602s-6s (December 1951). Mazel, A. G., Avtogennoe Delo, 22, 7-9 (March 1951). Medoff, J., Welding Engr., 36, 30-2 (August 1951). Metal Progress, 59, 546, 648 (April 1951). Zbid., 61,96B (April 1952). Monypenny, J. H. G., “Stainless Iron and Steel. Vol. I. Stainless Steels in Industry,” 3rd ed., revised, London, Chapman and Hall, 1951. Morlet, E., Metallurgie, 83, 915, 917-19, 921, 923 (November 1951). Mott, N. S., Chem. Eng. Progress, 47, 542 (1951). Ibid., p. 654. Nehrenberg, A. E., Metal Progress, 60, 64-9 (1951). Nelson, G. A., Trans. Am. Soc. Mech. lhgrs., 73, 205-11 (February 1951). Nicholson, M. E., Samans, C. H., and Shortsleeve, F. J., American Society for Metals, Preprint 13 (1951). Nickel Topics, 4, NO. 8, 8 (1951). Onan. A. C.. Elec. Furnace Steel. 8. 120-2 (1951). Ozver, D. A., and Harris, G. T:, Iron and Steel Institute, Symposium on High Temperature Steels and Alloys for Gas Turbines, pp. 46-59,1951. (190) Oliver, D. A,, and Harris, G. T. (to W. Jessop and Sons, Ltd.), Brit. Patent 654,294. (191) Orr, S. C., Chemical Eng., 59,286,288,290,2924,296 (March 1952). (192) Paret, R. E., Sheet Metal Worker, 42, 35-6, 65 (August 1951). (193) Park, A. S., Compressed Air,56, 328-31 (December 1951). (194) Pettit, G., Can. Metals, 14, 52, 54, 56 (August 1951). (195) Piatti, L., Chimia, 5, 221-8 (Oct. 15, 1951). (196) Pitts, J. W., and Moore, D. G., Natl. Advisory Comm. Aeronaut., Tech. Note 2572 (December 1951). (197) Pocock, P. L., Sheet Melal Inds., 28, 933-42, 944 (October 1951). (198) Poe, C. F., and Malcom, R. M., IND. ENG.CHEM.,43, 2572-5 (1951). (199) Post, C. B., Schoffstall, D. G., and Beaver, H. O., Iron A g e , 168.162-3 (Dec. 6.1951). (200) Post, k.B., Sbhoffstall, D.‘ G., and Beaver, H. O., J . Metals, 3, 973-7B (November 1951). (201) Pratt, Mi.E., Chem. Eng., 58, 222 (August 1951). (202) Ibid., 58,284 (September 1951). (203) Ibid., 58,268-9 (October 1951). (204) Ibad., 58, 288, 290, 292 (November 1951). (205) Pruger, T. A., Steel Horizons, 13, No. 3, 10-12 (1951). (206) Railway Gazette, 95,596 (Nov. 30, 1951). (207) Reichert, J. S., and Pete, R. H., Chem. Ew., 58, 263 (October 1951). (208) Renshaw, W. G., Zbid., 58, 298, 300 (November 1951). (209) Renshaw, W. G., and Ferree, J. A., Corrosion, 7, 353-60 (October 1951). (210) Republic Steel Corp., Bull. 571-R (1951). (211) Rickett, R. L., White, W. F., Walton, C. S., and Butler, J. C., American Society for Metals, Preprint 17 (1951). (212) Ricsenfeld, F. C., and Blohm, C. L., Prtroleum Refiner, 30, 107-15 (October 1951). (213) Riley, R. V., J. Metals, 3 (May 1951). (214) Roberts, W. L., Welding J., 30, 1004-19 (November 1951). (215) Robertson, J. M., Trans. Inst. Welding, 14,68-73 (June 1951). (216) Rockefeller, H. E., Can. Metals, 14, 36-8 (October 1951). (217) Roll, F., Neue Giesserei Techl-wiss. Beihefte, Metallkunde u. Giessereiw., 4,147-60 (1950). (218) Rose, A. S., Iron A g e , 169, 96-7 (March 20, 1952). (219) Rosenberg, S. J., and Irish, C. R., J . Research Natl. B u r . Standards, 48,40-8 (1952). (220) Rossi-Landi, G., Metallurgae, 83, 763, 765 (October 1951). (221) Sample, C. H., American Society for Testing Materials, Preprint 13 (1951). (222) Samuels, M. L., and Schuh, A. E., Foundry, 79,78-9,218, 220, 222, 224, 226 (July 1951); 84-9 (August 1951). (223) Sangster, 5. E., Products Finishing, 12-16 (June 1951). (224) Satz, L. H., Metal Progress, 61, 79-80 (March 1952). (225) Scheil, M. A., I b d . , 61, 80-1 (February 1952). (226) Schoefer, E. A., I n d . Heating, 18, 1799-800, 1802, 1804, 1806 (October 1951). (227) Shepard, S. W., Corrosion, 7, 279-82 (August 1951). (228) Shirley, H. T., J . Iron SteelInd., 170, 111-18 (February 1952). (229) Smith, G. V., Dulis, E. J., and Houston, E. G., A S T M Bull., No. 174,15 (May 1951). (230) . . Smith. G. V.. Dulis. E. J., and Link, H. S., Weldino J.. 30, 385-96 (August 1951). (231) Smith, G. V., Seens, W. B., Link, H, S., and Malenock, P. R., h e r . SOC.Testing Materials, Preprint 28 (June 1951).
2359
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RECEIVED for review July 28, 1052.
ACCEPTED July 29, 1952.
