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INDUSTRIAL AND ENGINEERING CHEMISTRY
Shellac az a conipounding ingredient. (244) Trevaskis, H., Wright, J., and Dunlop Rubber Co., Ltd., Brit. Patent 550,101 (Jan. 6, 1943). Hard rubber wind vanes to spin wheels of large aircraft prior to landing. (245) Tupper, E. S., Ibid., 553,912 (June 23, 1943). Ebonite combs. (246) Turner, C., Ibid., 518,936 (Feb. 28, 1940). Roller coverings with a soft cushion layer. (247) United Aircraft Corp., Mech. World, 116, 364, 458 (1944). Porous ebonite cuffs for propeller blades. (245) U. S. Rubber Co., Brit. Patent 525,537 (Kov. 11, 1940). Flexible ebonite; porous hard rubber filters. (249) Ibid., 532,475 (Feb. 5 , 1941). Increasing pore size in microporous products through use of silica gel. (260) Ibid., 547,648 (Sept. 16, 1942). Static-free combs. (251) Ibid., 569,076 (May, 16, 1945) and 569,989 (June 27, 1945). Use of natural-synthetic blends in abrasive articles. (252) U. S. Rubber Co., Sci. American, 167, 28 (1942). Use of cellular hard rubber as insulation under decks of naval vessels and for supporting fuel tanks in aircraft. /253/ Ibid., 171, 227 (1944); Mech. T o d d , 116, 515 (1946). Advantages of hard rubber battery separators. (254! Van Antwerpen, F. J., IKD.ENG. CHEM.,32, 1580 (1940). Characteristics of uorous hard rubber comuared with those of other filtering media. (255) Vanderbilt Sews, 10, No. 1, 8 (1940). Fillers. (256) Ibid., 10, 90.6 , 12 (1940). Preparation of ebocite directly from latex. (257) Ibid., 11, No. 5, 4, 66 (1941). All reclaim ebonite. (258) Wakeman, R. L., Modern Plastics, 18, No. 11, 65 (1941). Dimensional effects of prolonged immersion in cold and boiling water. (243) Trans. I T L S Rubber ~. I n d . , 15, 225 (1939).
Vol. 39, No. 1C
(2.59) Walker, B. F. (to hl'etaylaat Corp.), Brit. Patent 524,819 (Aug. 28, 1940); India-Rubber J . , 100, 378 (1940); (tc Metaplast Corp.). U. S.Patent 2,303,571 (Dee. 1, 1942)
Metal-coated plastic material including hard rubber. Chromiurr boride cutting tools. \Tallace and Tiernan Products Inc., Brit. Patent 562,537 (July 19, 1944). Applications of expanded ebonite. Waring, J. R. S., Trans. Inst. Rubber Ind., 16, 23 (1940,. Method of following changed during vulcanization by measuring electrical conductivity. Washburn, L. 8. (to Norton Co.), C. 8. Patent 2,196,09(1 (Apr. 2, 1940). Rubber-bonded abrasive. Webster, D. E., Canadian Pat,ent 389,911 (July 9, 194Ui Cutting-off wheel. Wells, L. E. (to Willwd Storage Battery), T2.S. Patent 2,247,. 161 (June 24, 1941). Storage battery. Weathead, J., and United Ebonite & Lorival, Ltd., Brit Patent 564,773 (Oct. 25, 1914). Method of curing litrgc battery boxes. Winspear, G. G., Herrmann, D. B., Malm, F. S . , and Kemp 1.R., ISD. ESG. CHEM., 38, 687-94 (1946). Comparison of natural and synthetic hard rubbers. Winton, G. E., Rubber Age (N. Y . ) , 50, 363 (1942). Specia: abrasive cloth for wet use during finishing operations. Woods, S. H., and Ebonite Container Co., Ltd., Brit. Patent 523,690 (July 31, 1940). Special machinery for nianufarture of storage battery cases. Zhornitskii, I. G., Gosudarst. Inst. Prikladnoi Khim.,Sbornih Statei., 1919-39, 233-40 (1939) ; Khim. Referat. Zhur. 1940, No. 3, 97-8. Microporous ebonite from nat,iiral latex.
(260) Wall Colmonoy Corp., Plastics, 6, 191 (1942). (261) (262) (263j (264)
(266) (266) (267)
(268) (269) (270)
Stainless Steels and Other Ferrous Alloys E. 1. d u Pont de iliemours & Company, Znc., Wilmington,Del.
R
ESEARCH and development in the field of stainlebs ateels
and related alloys were greatly influenced during the war by urgent and specialized needs. Examples of such investigations aimed specifically at wartime objectives were: ( a ) the development of information t o permit the use of the high strength-toweight ratios of cold-rolled stainless steels in aircraft construction: ib) the application of austenitic stainlebs electrodes to the welding of ferritic materials, such as armor plate; (e) the wtension of basic knowledge t o allow the eld ding and application of the high chromiuni ferritic alloys in synthetic rubber process equipment; and ( d ) the development and production of alloys possessing high strength a t elevated temperatures and meeting other requirements for gas turbine service. Traluable results of the last-named investigation have been recently published but are not discussed here because most of the alloys involved are no6 within the scope of this article. There has also been considerable progrebs on some of the mole fundamental aspect5 of stainlesa steels, such as stresscorrosion cracking, the phenomenon of passivity, occurrence of sigma phase, and modifications in composition t o meet specific needs. This review deals principally with the advances made in austenitic stainle.ss steels diiring the period from the bt,ginninp of the war through 1946. YEW COMPOSITIONS
Several new eompositionP, some uf major importance, have heen developed during this period. Shortly before the war, the use of columbium-stabilized 18-8 in the chemical industry became widespread. The principal advantage to be gained through the
addition ~f this and other stabilizing elements to stainlesa -tee1 Ithe elimination of post-fabrication heat treatment without liability of service failure by intergranular attack. Columbium additions to molybdenum-bearing 18-8 seemingly should be simi. l a d y effective, but early attempts to add columbium to converrtional Type 316 and Type 317 alloys gave erratic and unsatisfar tory results. Franks, Binder, and Bishop (40) reported thai close control of composition to maintain an austenitic structurt was required in order to obtain effective stabilization, and that, ain Type 316 or Type 317, formation of sigma phase (a brittle constituent) occurred upon exposure to intermediate temperatures, ii appreciable amounts of ferrite were present. B molybdenum COIItent of approvimately 2y0 was recommended by these workers Developmmt of the alloy was retarded by the war, but limitec rommercial experience has supported the conclusion that a whollj austenitic ~ t r u c t u r eis highly desirable. The present preferred cornpodion range (in per cent by weight) is C 0.07 may., Cr 17.50-19.00, S i 13.0-14.5, MO 2.0-2.5, >In 1.50 min., Si 0.7.'~ max., Cb and 0.5CFO.90. Further extending the field of columbium-stabilized alloys, ti considerable tonnage of 25-12-CtJ (composition in per cent b~ weight C 0.07 max., Cr 22.0 min., S i 12.0 min., M n 1.25-2.5 Si 0.75 mas., Cb ten times c/c C min. to lYo max.) has been employed for severe service conditions, and limited quantities of 2520-Cb have been produced. Another possibility for achieving thc same objective -that is, avoiding the necessity of heat treatment for severely corrosive service-which is under investigation ann in limited commercial use, but not yet reported in the literature. is an extra-low carbon (0.03% max.) grade of 18-8 and 18-8-1Itr
October 1941
INDUSTRIAL AND ENGINEERING CHEMISTRY
jmith, Kyche, and Gorr (89) debcribed the development of an ige-hardening steel known as Stainless IT, This material is of -tit> lean 18-8 type (17cc Cr, 7 5 Si) to which has been added 11.7mr Ti and 0 . 2 5 AI. The precipitation-hardening reaction in -his case involves a phase change from austenite to ferrite on coolnq to room temperature fioni the solution temperature of 1200?OOO" F. Then on reheating to a temperature Jightly less than 'he ferrite-to-austenite transformation temperature, a constituent, -till unidentified, can be made to precipitate in the ferrite. i i s a w u l t the hardness is increased t o Rc 38-40, and the yield 9rrength and the ultimate strength to 180,000and 198,000 pounds r square inch, respectively, TTith 5-10yc elongation. The r,arerial is reported to be readily weldable. A method ha5 been 7 iirked out for retaining the titanium in the weld metal, and the r d d s may be heat-treated in the same manner as plste stock. Thc corrosion resistance of the alloy appears to be suitable for mild corrosive conditions. For more severe service, the corrosion wistance, particularly in the hardened condition, is likely to be nferior to that of the annealed 18-8 alloys. iddition of up to about 0.1 ciAg to 18-8 and 18-8-110 was proJosed by Kaye, Williams, and Kulff (51)for enhanced resistance ' 0 pitting. These alloys m r e not popular commercially, since -heir resistance to pitting was not improved sufficiently to be of practical importance. Machinability was somewhat improved "y the silver addition. The effect of addition of 0.1-0.5Vo Bi I O cast stainless steel was described by Prav, Peoples, and Fink 79js Machinability and reqiqtance to galling are stated to be aonsiderablv improved with some sacrifice in ductility and impact .trength. Some improvement in corrosion resistance, particuerly when bismuth is added l o free-machining compositions containing sulfur or selenium, is also reported. Franks (35) reported .hat the addition of 0.1-l.5qc 8 b to alloys of 12-307c Cr, 518% Xi (or M n or both) increases resistance t o corrosion under -educing conditions. Because of the shortage of nickel, extensive work was carried &.)utin Germany on the partial substitution of nitrogen for nickel in the austenitic stainless steels. Tofaute ( 9 1 ) and Tofaute and Schottsky ( 9 d ) described an alloy containing 23mc Cr, 4% Ni, i).25cc S , and 0.057, C as almost purely austenitic, and indicated ihat such alloys are distinguished by their remarkably high yield strength and woikability. Mechanical propcrtim in the as-welded condition nere stated to be satisfactory. These alloi :ensile strength than 18-8 and comparable elongation a t similar amounts of cold reduction. Although little is said regarding porrosion, it seemi: certain that resistance to many media n-ould be adversely affecttd. Rudorff (81) reports O.lYr S will replace 2-47 Si, and 0 . 2 5 k 1; will replace 2.5-6Tc Si. Scherer, Riedrich, and Xessner (87,88) discws partial substitution of *itrogen for nicbel in 18-8 and 23-20. Feild ( 2 9 ) describes the ievelopment in Germany of substitute lowr-alloy materials or ?eplacement of scarce molybdenum, nickel, and cnlumbiun: with manganese, titanium, and varisdium. Aluminum was eutensively used in the straight chromium tvpe of heat-resisting steels. \lack (60) reviews the properties of high-manganese itainless steels, and concludes that the corroqion and oxidation resistance i f such alloys are generally inferior to the standard compositions. Harder and Gow ( 4 5 ) give the resulta of extensive tests on cast wbstitute heat-resisting alloys of 10-13 Cr, 4-10 S i , 1-10 Mn, 2 Si, and 0.30-0.35 C, expresaed in weight per cent. Their prop4 e s are not good enough to rompete with 18-8 under normal 1-nnditions. jc
EFFECT OF NITROGEY 1h S T I I N L E S S S T E E L
\\-ith further reference to the effect of nitrogen in stainless jteels, Uhlig ( 9 6 ) found that nitrugen-free 18-8 quenched from 2100" F. is ferritic a t room temperature. Sufficient nitrogen is present in commercial stainless steels to inhibit the gammadpha transformation n-hic-h was found to ocrur a t about 210" F.
1249
in the cooling of nitrogen-free 18-8. The ferritic alloy was reported to be comparable t o normal austenitic material in corrosion resistance; higher in yield strength, hardness, and magnetic permpability; but lower in elongation. i t is possible to transform the ferritic alloy to the austenitic condition by annealing in purified nitrogen for 5 minutes a t 2100' F. The reverse transformation will occur in purified hydrogen in the same time. Uhlig ( 9 7 ) also compared the effect of carbon and nitrogen on the susceptibility of 18-8 to intergranular attack in Straws solution and in nitric acid-hydrofluoric acid solution. The influence of nitrogen, although less than half that of carbon, is definite, and intergranular attack occurred in the nitric-hydrofluoric acid solutions on sensitized 18-8 containing 0.aP0 S and 0.007% C. Slight but definite intergranular attack mas also noted in Straws solution on a specimen of 18 0 - 2 4 Ni alloy conLaining 0.003c0 C anti 0.00641, K after exposure for 169 hours a t 500" (3. Intergranulni attack in this alloy cannot be explained on the basis of the chromium depletion theory, and the author concludes that the mechanism of corrosion appears to involve grain boundary precipitwtion nf a metallic phase. PASSIVITY AND COHKOSXON RESISTANCE
A cuiisiderable nuinher of papers have been published uri T ~ I . oxide films, and mechanisms of corrosion of stainlf+ orioka (68) determined the effect of added salts on tiir passivity of chromium-iron alloys in nitric acid solutions. A i r cording to the postulat,e of Uhlig and Wulff (fOO), passivity is r i o t due to a stable oxide film formed on the surface of stainless steel>. but it, arises from electron sharing in the lattice between chromium and iron that results in a more stable energy configuration. Eli.?trons from hydrogen in its active state tend to re-establish the original electron structure in iron and result in destruction of passivity. Osygen in the presence of hydrogen-activated stainless steel surfaces re-establishes passivity by osidizing the interstitial hydrogen from the active lattice structure, with the resu!i that the iron electrons again are normally shared with those oi chromium. Single-electrode potential data were cited in support of the theory. This hypothesis was later elaborated and defended by Uhlig (95j and criticized by Evans (26) and others. Uhlig (94) also suggested that pitting of stainless stwl was caused hy breakdonn of pmsivity in localized areas due t o electrnl! tic B C tion. 0st.rofsky (73) reported that treatment, of st,ainless steel witii bichromate solutions improved its resistance t o some corrosive solutions, particularly where pitting was involved. l l o t t (63, 70) and Vernon (102) reviewed and discussed the oxidation of inet,als and the formation of oxide films. Quarrel (80) first applied the high-temperature method of electron diffraction to stainless steel and s h o w d that a t temperatures up to 950" C. the oxidc has a spinel structure. Holm (47) reported observations on the tarnishing of stainless steel by heating in vacuo. Uhlig, Carr, and Schneider (101) determined the equilibrium potentials of iron-chromium alloys containing up to about 21:; Cr. The initial values shon-ed active potentials a t chromium content up tu about 11.5% and passive potentials with hig1ir.r chromium content. The passivation of chromium-iron alloys by the formation of an oxide film at elevated temperatures was described by iirivobok (53). Uhlig and Morrill (98) investigated the effrcts 01' severa,l variables on t,he pitting of 18-8 in sodium chloride solutions. Holm (46) reported that oxide films can be removed from ferrous alloys containing carbon above a certain minimum value (including 18-8) by heating to siiit,able temperatures in a high vacuum. Gulbransen ( 4 3 ) employed an ultrasensitive microbalance and special techniques in studying the formation and stability of oside films on 18-8. Weight gains increased in parabolic fashion during osidation a t 650" C. in oxygen st 76 mm. mercury pressure. Attempts to reduce this oxide at 600" C. and a t
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
800' C. in hydrogen a t 10 mm. mercury pressure mere unsuccessful. Uhlig and Wallace (99) reported that passivation of 18-8 under certain conditions could be produced by exposure to inhibited hydrochloric acid solution. Landau and Oldach (55) reported the results of corrosion and potential studies of various binary alloys. Landau (54) discussed mechanisms of corrosion and indicated that electrochemical factors external to the metal are principally responsible for t8hebehavior of alloys in nonpassivating media. He believed that corrosion in passivating media vyas largely a function of film stability but that the electronic structure might also be of importance. Vernon, Wormwell, and Nurse (103) described the successful isolation of oxide iilms from mechanically polished or abraded 18-8 by means of a solution of iodine in anhydrous methanol. The film was stated to be of higher chromium content than the underlying metal and to increase in t,hickness with degree of polish. Potential measurements indicated the alloy to be less passive immediately after removal of the film. Evans (86) discussed the passivation of stainless steel by nitric acid. Corrosion resistance of the chromium-iron alloys was ascribed to the formation of an oxide (for instance, by exposure to nitric acid) rich enough in chromium to stabilize the M203 condition, which apparently is highly resistant to many corrosives. Truden (93) presented data indicating that sand-blasting accelerates the corrosion of 18-8 even when followed by nitric acid passivation. Pratt (78) investigated service failures of Worthite castings in sulfuric acid solution; passivity had been destroyed because of exhaustion of the oxygen content. Akinov (1, 2, 3) studied the electrode potentials of stainless steel in nitric acid and in ferric chloride solutions, particularly with reference to the ability of the alloys to restore their protective film aft'er mechanical abrasion. 18-8-1\10 was outst,anding in its ability to regain a protect,ive film, Zappfe (109) listed qualit,ative data on the corrosion resistance of stainless steels to niany solutions. 1Iahla and Nielscn (61) evaluated the strength and stability of passire films formed on stainless steel by various methods. Passivat,ion treatments did not provide dependable prot'ection against media that are incapable of healing the prot'ective film aftcr da,mage. Evans (24) discussed the electrochemical mechanism of certain corrosion processes and it.s practical implications, and inc!uded consideration of passivity. '1 series of articles in the Alloy Castiag Bulletin (4, 6, 7 , 8) reports the resu1t.j of extensive work on the effect of variatioris in c-omposition and heat-treaunent on the corrosion resistance of cast 18-8 a,nd 18-8-110to boiling 65% nit.ric acid and to Sirauss .ii)liii ion, STRESS-CORROSION CRACKING
stress-corrosion cracking of stainless steel has been thv subject of extensive study over the past several years. 1Iodgc and Miller (48) investigated a service failure resulting from esposure of 18-8 to moist ethyl chloride. Information on testing methods, susceptibility of various alloys, and operating csperience is contained in papers by Scheil, Zmeskal, Waber, and St,ockhausen (86); Scheil and Huseby (85); Franks, Binder, and Brown (41); Scheil ( 8 4 ) ; and Ellis (23). Contact with any of several chloride solutions under certain conditions (especially hot and concentrated), combined with applied or residual tensile stresses of sufficient magnitude, promotes the cracking of all tjypes of stainless steel investigated, regardless of the heat treatment employed. A solution of boiling magnesium chloride (approximately 42% MgC12, boiling a t 309' F.) has bcen widely used for detection of susceptibility to stress-corrosion cracking. The mechanism involved has not yet been established. 'L'iit:
SIGMA PHASE
Some additional information has been developed on the occurrence and characteristics of the brittle qigma phase, which de-
Vol. 39, No. 10
velops under favorable conditions in high-chromium ferritic alloys and in austenitic stainless steels containing some ferrite Progress in this field has been slow because of the difficulties of positive identification and estimation of amount present. Franks. Binder, and Bishop (40) reported that in low-carbon s t a i n l w steel containing 16-25y0 Cr, 8-2270 Ni, and 1 4 % Mo the proportion of sigma is controlled largely by chromium and molybdenum contents. Completely austenitic structures did not develop sigma, but it was recommended that steels of high molybdenum contents containing considerable ferrite be used in the annealed condition. Gow and Harder (48) worked with cast alloys of the 25-12 heatresistant type and suggested that the ratio [Cr(%)-16 C(%)]/ Ni(%) should not exceed 1.7 if the alloy were to be maintained substantially austenitic. I n alloys of this type, silicon in excess of 1%by weight was shown to have three times the effect of au equal weight percentage of chromium, and molybdenum four times the effect of an equal weight percentage of chromium in favoring sigma formation. Avery, Cooke, and Fellows (10) also investigated cast alloys of the 25-12 type with additions of tungsten or molybdenum. Among other things, they determined the effect of heat-treating temperature on the magnetic permeability of various compositions. Cook and Jones (21) found sigma to be a stable phase in the range 26-71% Cr in the binary iron-chromium system. Foley (33, 34) contributed an excellent review of all the reported work on sigma phase and added valuable interpretations and comments. Kewell ( 7 1 ) described the results of an extensive wartime invrstigation of the characteristics of 27% Cr iron. The work ww carried out primarily to determine the best methods of fabrication for this alloy, so that it could be used for synthetic rubber process equipment. The results indicated that 25 Cr-12 Ni or 25 Cr-20 Xi welding electrodes should be used for welding 27% Cr iron for maximum freedom from cracking. Newel1 concluded that (a)material subject to either 475" C. brittleness, or t o brittleness due to the presence of massive sigma phase, could be recovered by an appropriate heat treatment, and (b) that 475" C brittleness might be due to a submicroscopic precipitation of sigma phase. WELDING
\\-ith reference to the welding of stainless steel, Ostroni snd Thomas (7'4) compared the properties of 18-8 ITeld metal with cast and wrought material of the same composition. The an:lealed properties of the d d metal and the castings were similar. Page (?5) rated and correlated the weldability of 208 heals of Type 321 and of 36 heats of Type 3.17 with chemical composition. H e concluded that increase in minimum silicon content up to 0.50 4.609$ definitely improved weldability. Campbell and Thomas (16) studied tho separate effects of the various eleinents present in 25 Cr-20 Ni weld irietal on physical properties. Carbon up to 0.2% increased strength without serious loss in ductility. Increases in sulfur, silicon, and phosphorus caused fissurez. Reasonable variations in nickel and manganese had little effect on fully austenitic material. Excessive amounts of molybdenum, chromium, or columbium resulted in ferrite formation which increased strength and reduced ductility. Inert gas arc welding of at,ainless steels was discussed by Barber and Kennedy (12) and Kyer (108). Thomas (90) reported that austenitic stainless steel veld metal containing a small amount of ferrite was less sensitivr to cracking than was similar fully austenitic alloys. The addition of molybdenum in the amounts necessary to produce frer ferrite in the matrix in the as-melded condition conferred the greatest freedom from crack sensitivity; additions of columbiur:] were not so effective in this respect. Thomas cited the following equation attributed to F. K. Bloom of the American Rolling Mill Company as a useful criterion in determining the amount of nickel required in 25 Cr-20 Xi weld metal in order to render i t
October 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY
fully austenitic, and he stated that nickel in ewess of the calculated amount has been found to contribute to increased crack aensitivity :
HIGH TEMPERATURE PROPERTIES
Information on the creep properties and other high temperature J s t a on Type 316 was presented by N e d 1 (7%);on Type 321 b:i Portevin ( 7 7 ) ; on Types 304, 347, and 316 by Clark (19); and on Types 304, 321, and 347 by Miller, Benz, and Day (66). The effect of temperature cycling on the creep rate of heat-resisting ateels was discussed by Brophy and Furman (14). Fetz (31) made dynamic hardness tests on 18-8 and found the silicon content to be the principal controlling factor. The mechanism of failure of 18-8 steel cracking tubes operating at 1200-1250° F. for periods up to 100,000 hours was discussed by Clark and Freeman (80). Failure appeared to be related to the gradual development of a grain boundary precipitate believed to be a ferritic phase that resulted in the formation of microscopic cracks. Harder (44) reviewed development, applications, and structure of heatresisting alloys. AIonypenny (67) discussed the use of austenitic stainless steels for turbine blading. Properties of various stainless types of interest in heat-resistant applications were reviewed by Lincoln (67) and Evans (85). Characteristics of 16-25-6 (16% Cr-25% Ni-6% Mo), an alloy developed for use in gas turbines, were described by Fleischmann (32). Tivo articles in the Alloy Casting Bulletin (5, 9) present information on the physical properties of chromium-nickel heat-resistant alloys, and on the corrosion of such materials by air and flue gas a t high temperatures. GENERAL
Data on the mechanical properties of stainless steel a t subzeru temperature were presented by Iirisch and Haupt (6$), Petty ( 7 6 ) , and Donaldson (28). Chernyak, Golubeva, and Steinberg ‘ 1 7 ) !isted similar data for arc-welded material. A great deal of useful information bearing on the application of high-tensile stainless steel sheet in aircraft construction was developed during the war. RIebs and NcXdam published report> on tensile and elastic properties of typical stainless steels and nonferrous metals as affected by plastic deformation and heat treatment (629, tensile elastic properties a t low temperatures of 18-8 Cr-Si steel as affected by heat treatment and slight plastic deformation (6’3),torsional elastic properties of 18-8 Cr-Si steel as affected by plastic deformation and heat treatment ( 6 4 ) , and the influence of plastic deformation and of heat, treatment on Poisson’s ratio for 1s-8 Cr-Ni steel (65). F r a n k and Binder contributed papers on the stress-strain charaderistics of cold-rolled austenitic stainless steels in compression as determined by the cylinder test method (37) and on tension and compression stressstrain characteristics of cold-rolled austenitic Cr-Si and Cr-MnNi stainless steels (38). They also described a low temperature heat treatment (36, 39) consisting of holding for 16-72 hours at 200” C.; this improved the yield strength, toughness, and resietance to fatigue of cold-worked stainless steels without impairing other properties. Articles reviewing mechanical properties with application to aircraft construction were also published by Lincoln (56), Bandel (11), and Lincoln and Mather (58). Watkinp and Franks (107) discussed stainless steel for constructional use on a strength-weight ratio basis in comparison with aluminum. Sachs and Stefan (82) found that cold-drawn 18-8 had appreciably lower chafing fatigue strength than did annealed material.
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Watkins contributed review articles on the properties of sulfur and selenium types of free-machining stainless steel (104j,t,hc corrosion resist,ance of free-machining stainless steel (1OS), and the effect of added elements on the properties of stainless st,erl (106). Cady (15 ) reviewed the properties, machinability, and heat resistance of the various austenitic stainlcss grades. Infor. mation on electropolijhing methods was given by Feild and Clingan (30), by Faust and Pray (27, 28), and by Zmeskal (110). An extensive review of the processing and fabrication of stainless steel sheet and plate, including the effect of variation in production practice, was made by Schaufus and Braun (83). iz technique employing a torsion testing device for evaluation of hot workability of metals (based on the number of turns to rupture a t the testing temperature) has been described by Ihrig (49) and Clark (18). Considerable data on the various grades of stainless steel have been given. I n a second article Ihrig (50) listed additional data and discussed the effect of each of the cont,ained ailoying elements on hot workability. Two new met’hods that have been recently developed permit the cutting or burning of stainless steel almost as easily as plain carbon steel. One of these, described by Linsley (59), is called the arc-oxygen technique and is an adaptation of the principle used in underwater cutting in salvage operations. This process uses flux-coated steel electrodes through which oxygen is passed. Not only is the electrode consumed, but it provides a source of iron or iron oxide, which serves to reduce the refractory oxides formed by the oxidation of the stainless steel. The other process, described by Bellem (13), is called powder-cutting and utilizes equipment which is an adaptation of t,he familiar burning torch used for plain carbon steel. The principal difference is that a pori-dered flux is carried by the oxygen stream int>othe kerf and serves to reduce the refractory oxides. IRON-SILICOV 4LLOYS
The iron-silicon alloys, containing approximately 14”/c silicon (with or without the addition of about 3% molybdenum), are characterized by outstanding resistance to a wide vririrty of severely corrosive conditions and by poor physical propt ri ies, especially brittleness and susceptibility to mechanical or thermd shock. They have a definite place in the field of chemical process equipment and were quite widely employed in wartime construrtion of acid-concentrating plants in the form of pumps, valve-, columns, rolumn packing, etc. Many of the requirements ful filled were of such character that they could have been niet with other materials only with conaiderable difficulty. However. n t i significant improvement in th, properties oi these alloys, o t . with the probable excrption of foundry practice, ir, trchniquus of handling them, has bccn dcwloped in this country during thir period. Extensive investigations \ v t w conducted on iron-silicon alloyin Great Britain during the war. The British Government (Ministry of Supply) undertook a detailed investigation 01 methods of production, properties, and corrosicm resistanct of t h high-silicon irons in order t o m&e this information availablrs t o the new foundries involved in supplying the high wartime delmand for this materia! ( 1 A ) . IIurst and Riley (TA, 8 A , 9 A , 11A I d A ) in an extended program made a detailed investigafiori of thc microstructure and phwe constitution of these alloys by metallographic and x-ray diffraction techniques. Studies of the samr nature were also carried out by Kcill (19.4, 20A), Lipson anti Weill (16-4),and Farquhar, Lipson, and Weill @ A ) . This work established the phases present and their reactions on heat treatment. Hurst and Riley (10.4), Hurst (5A), and Wrazej (21A), in papers published a t the same time, showed that so-called “barley shell” and cracked film patterns, previously thought to be true structural constituents, in fact reqidues fi-nm the etrhants
used.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 39, No. 10
Hurst, in the first of two ptlprrs (4Aj, presented a number of Eash (8B,9B) described methods foi the ladle inoculation of highpractical details in the preparation and handling of high-silicon alloy cast iron and reported beneficial effrcts on the physical propalloys, and in the second (6A)presented considerable information erties of the castings. on their corrosion rrsistance to a variety of media. Hurst points Klinov (IWB) made corrosion test- on Russian austenitic cast out that alloys containing less than 12% silicon do iiot chon- any iron and stated that the results compared favorably with those advantage over gray iron and that little advantage i q gained previously listed for American alloy.. I n a second paper (1IBj when silicon is carried above 15.5qc, His statcmmt that the corrosion data for two grades of austenitic cast iron and for 23Ci; optimum silic-on content is 14.25% appears t o agree with Xmerichromium-3.5yc aluminum and 18-8 typrs of cast iron in various can practice. Failure of iron-silicon alloy parts during the war in concentrations of several acids arc given. Uses for high-alloy irons applications involving severe thermal shock lrd to trial on a for petrolpum-refinery service are deqcribed by Morton ( I @ ) limited scale in this country of allols of lower silicon content for automotive parts by Austin (SB,, and for lowexpansion prr(approsimately 12.553I . This experience was not sufficiently cision parts by Sefing and Semser ($If?\. Sefing ( 2 2 s ) review4 conclusive to indicate any important advantage t o be gained by the propprtips and uses of several tvpry of austenitic cast iron the use of the lower silicon content. Gratamnskii, Fadeeva, and Vovkogon (SA J reported a potcntionietric method for evaluating 4USTEYITIC \lA\G4YESE STEEL the corrosion resistance of these allovs in aulfuric acid, and Klinov (13.4) prraeiited data on the corrosion of these mare~riaisin aul~nstenitic niaiigancsc stcrl (.onietiinei k n o m as Hadfield furic and in hydrochloric acids. These writer.j point out the mangancce +eel) is an iron-baae alloy rontaining niarigdnesc irr superior corrosion resistance of the standard alloy modified with the range of 11-14% and about 1To carbon. I t is used in applica3.5% molybdenum to the halogen acids, notably hydrochloric tions involving wear and impact resistance. Although it is ausacid, which observation is in agreement with American practice. tenitic in the annealed condition and has a hardness of only 180Vaughn and Chipnian ( I T A )studied the solubility of nitrogen in 200 B.H.K., when it is cold-worked in .ervice, as in rock-crusher alloys of the silicon-iron system up to approvimately I jvc silicon. jaws, it work-hardens rapidly and attains surface hardness of the Liang, Bever, and Floe ( I d A ) investigated the solubility of order of 150-550 B.H.S. hydrogen in these alloys up to 65y0 silicon and up to 1650' C. Niconoff (6C, TC)studied the nleehaniiiii ut strain-hardcning Ward (18A) observed the effects of composition, tcniperaturr, of the ausrenitic manganese steels in ronsiderable detail. He time, and atmosphere on the scale-metal layer formed on comfound that the mayimum hardneas obtainable with any given mercial iron-silicon alloys exposed to high temperatures. Zappfe alloy was essentially independent of variations in structure and and Clogg (2,??$) described results obtained through the applicaprior hcat tieatment. In a serie. of experiments in which specition of fractography techniques to iron-silicon allovs Reavell mens xere cold-worked by either single or multiple blows, the (16A) contrihutrd a revieiv of the properties of the- n ~ ~ i t r ~ i a l ~ hardness . of the material just under the surface in some cases AUSTEVIrIC CAST IROYS
Austeriitic cast irons are quite widely employed i n dpplicatioiib of intermediate severity, u-here improvement in corrosion resistance or other properties as compared to plain or ILW-alloy cast iron is required but where the cost of appropriate high-alloy steels or other suitable materials is not justified. The nuniber of types of austenitic cast iron to meet special purposr needs has increased during the period covered by this review. .%q a class these alloys consist of high-nickel (13-36%) east ironb, usually with one or more other alloying additions. Individual type. contain up to about 8YGcopper, up to about SCc chromium, or up to 6% silicon, or combinations of these element3 totaling up to about 12%. A research committee uf the Institution of Mechanical Engineering investigated during the war the manufacture, composition, and properties of high duty cast irons for general engineering purposes. The reports of this committee represent a compilation of detailed information on a wide variety of alloy irons ( I B , 2B, 3B, 4B). Pearce v a s associated with this committee and published several papers (163, 17B, ISR, 19B) covering the same class of alloys. The constitution of iron-rich iron-nickel a h 1 s was atudied by Bradley (7B). Owen and Sully (16Bj considered the equilibrium diagram for iron-nickel alloys bclow 1000" C. and made deductions based on investigations enlplo? ing x-ray spectra techniques. Sachs and Sprptnak (20B) studird the relation between microstructuie and physical properties. Transformations occurring in austenitic irons were investigated by Galiboury and Laurent (10B). Factors affecting the resistance of cast iron to deflection under load a t high temperature were studied by Bolton (6B). Austenitic cast irons were found to possess good properties in this respect, and increasing chromium and silicon contents were stated to be beneficial, Improvements in physical properties through hcat trratnient n-i'r(l rrported by Le Thomac (13B).
evcerded that immediately in contact with the hammer. He was thus able to eatablish that a surface stress concentration of 35,000 pounds per square inch w a b required to attain mavimum hardnesses on flat surfaces with a single blow. Goss (5C) studied the work-hardening phenomenon by cold-rolling annealed material. From u-ray diffraction studiea on cold-reduced material hr fouiiil the original austenitic Qtructure remaining and concluded that the high hwdness \vas due to grain fragmentatlon into small crystallites, as first suggested by Niconoff. Waltera, Kramei, and Loring (IOC)reported on the physical properties of austenitic manganese steels of intermediate composition and stated that most manganese alloys showed greater ductility than S A.E bteels of similar tensile strength. Uhlig (9C) found that low-carbon (Y-22c;) manganese steel* are ernbrittled by retained hydrogen when quenched from thc annealing temperature. I n the high-carbon alloys of the normal commercial composition (carbon 1%, manganese 14%) however, hydrogen retained on qurnching had no effect 01, their physical properties. Franks. Binder, and Brown ( 4 C ) studied the effects of additions of small amounts of nickel and copper and of larger amounts of chromium to 16% manganese steels, and found that as the alloy content is increased. particularly chromium, resistance to atmospheric rusting or staining materially increased. They report that all of these alloys can be cold-rolled to produce yield btiengths of 110,000-190,00(~ pounds per square inch and that thr ,tress-strain charactrristics are gpnerally improved by baking at 200" C. a% modification of the 1 4 7 manganese steel alloy with 4 5 nickel has been del eloped in order to prevent embrittlement during heating a t intermediate ttmperatures, and particularly during LTelding (IC). The use of this material for repairing railway coupling boxes has been suggehted by Rice (SC). Farlor and hlccreery (3C) investigated the use of 14"{ manganese steel as material for ube in bearing shells in place of carburized and hardened steel. Young and Goard ( I l C ) and De Bondy (2C)published articles of general information on the propprtirs and IISPS of awrrnitic niangnnesr steels.
October 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY LITER4TURE CITED
Akinuv, G. V.,Compt. rend. acad. sei. C.R.S.S., 45, 116 (1944). Ibid., 45, 379 (1945). Ibid., 46, 191 (1945). Anonymous, Alloy Casting Bidl., No. 3 (1944). Ibid., No. 4 (1944). Ibid., No. 6 (1946). Ibid., KO.7 (1946). Ibid.. S o . 8 (1946). Ibid., N o . 9 (1944). Avery, H. S.,Cooke, E., and Fellows, J. .I.,Trans. Am. Inst. Mining Met. Enyrs. (Iron & Steel Div.), 150, 373 (1942). Bandel, J. M.,IrOll Age, 148, No. 15, 45, 162 (1941). Barber, L. V., and Kennedy, H. S.,Welding J . . 24, 378 (1945). Bellew, G. F., Iron Age, 158, KO.2, 42 (1946). Brophy, G. R., and Furman, D. E., TrarLs. Am. SOC.Metals, 30, 1115 (1942). Cadk-, E. L., Materials &. Uethods, 22, 1761 (1945). Campbell, H. C., and Thomas, R. D., Jr., Welding J . , 25, 760-s (1946). Chernyak, 1.. S., Golnhel-a. Z. I., and St,einberg. L. A . , Ibid.. 22, 437-s (1933). Clark, C. L., Iron Age, 153, No. 11, 52 (1944). Clark, C. L., J-atl. Petroleum ,Yews, 35, No. 9, R120 (1943). Clark, C. L., and Freeman. J. W.,Trans. Am. SOC.Metals, 35, 298 (1945). Cook, A. J., and Jones, F. W., J. Iron Steel Inst. (London), 151, pt. 2, 217 (1943j. Donaldson, J. W., Metal Treatment, 11, 161 (1944). Ellis, 0 . B., A m . Soc. Testing Materials-Am. Insi. Mining X t t . Enlrs., Preprint 24 (1944). Evan.+, U. 11.. Corrosion and Material Protect., 3, Xo. 7. 15 (1930). Evans, C . T . , Jletal Progress, 48, 1083 (1945). Evans, U. li., Trans. Faraday Soc., 40, 120 (1944). Faust, c'. L.. and Praj-, I€. A , Proc. A m . Electroplutrix' Soc., 1941, 104. Faust, C . L., and Pray, H. -1..Steel, 109, No. 20, SO, 101 (1941). Feild, A . L., Iron Age, 156, No. 25, 60 (1945). Feild, -1.L., and Clingan, I. C., Steel, 106, No. 17, 54, 64 (1940). Feta, E., Trafis. A m . SOC.Metals, 30, 1419 (1942). Fleischmann, 11. l., Iron ,4ge, 157, KO,3. 44: S o . 4, 50 (1946). Foley, F. E., A l l o y Casting Bull., No. 5, 1 (1945). Foley, F. B., Xetallurgia, 34, 39 (1946). Franks, R. (to Electro Metallurgical Corp.), Brit. Patent 563. 765 (Aug. 29, 1944). Franks, R., and Binder, W.0.. Am. Inst. Nining M e t . Engrs., Tech. Pub. 1183 (1940). Franks, R.. and Eindei, W, O., A m . SOC.Testing ,lfcrtr,iaZs, Proc., 41, 629 (1941). Franks, R., and Binder, W.O., J . Aeronaut. Sci., 9, 419 (1942). Franks, R., and Binder, W. O., Steel, 107, No. 4, 56, 58, 78 (1940). (40) Franks, R., Binder, I\-. O., and Bishop, C. R., Trans. Am. SOC. Metals, 29, 35 (1941). (41) Franks, R., Binder, W.O., and Brown, C. M., A m . SOC.Testing Xaterials-Am. Inst. Mining Met. Engrs., Preprint 23 (1944). (42) Gow, J. T., and Harder, 0. E., Trans. A m . SOC.Metals, 30, 855 (1942). (43) Gulbransen, E. A, Trans. Electrochem. Soc., 82, 375 (1942). (44) Harder, 0. E., Metals &. Alloys, 21, 725 (1945). (45) Harder, 0. E., and Gow, J. T., Trans. Am. SOC.Metals, 32, 408 (1944). (46) Holm, V. C. F., J . Researrh .Vatl. Bur. Standards, 28, 569 (1942). (47) Holm, V. C. F., 'Vatl. Bur. Standards ( C .S.),Tech. Sews Bull., 288, 40 (1941). (48) Hodge, J. C., and Miller, J . L., Tram. A m . Soc. Metals. 28, 25 (1940). (49) Ihrig, H. K., Iron Age, 153, KO.16, 86, 170 (1944). (50) Ihrig, H. K., Metals Technol., 12, 29 (1945). (51) Kaye, -1.L., Williams, R. S.,and Wulff, J. (to The Chemical Foundation, Inc.), U. S.Patent 2,267,866 (Dec. 30, 1941). (52) Krisch, A,, and Haupt, H., Arch. Eisenhiittenrc., 13, S o . 7, 299 (1940). (53) Krivobok, 5'. N., Heat Treating and Forging, 26, 121 (1940). (54) Landau, R., Trans. Electrochem. Soc., 81, 559 (1942). (55) Landau, R., and Oldach, C. S., Ibid., 81, 521 (1942). (56) Lincoln, R. A., Iron Age, 147, S o . 5, 35 (1941). (57) Lincoln, R. 9., Ibid., 156, KO.19, 74 (1945). (58) Lincoln, K. A., and Mather. K.H., J . Aeronaut. Sci., 13, 253 (1943).
1253
(59) Linsley, H. E., Iron Age, 158, No. 20, 96 (1946). (60) Mack, D. J., Metals &. Alloys, 18, 507 (1943). (61) Mahla, E. M.,and Nielsen, N. A,, Trans. Electrochem. Soc.. 89, 167 (1946). (62) Mebs, R. W.,and McAdam, D. J., JVatZ. Advisory Comm Aeronaut., Tech. IVote, KO.696 (1940). (63) Ibid., No. 818 (1941). (64) Ibid., No. 886 (1943). 165: Ibid.. KO.928 11944). i66) Xfiller, R. F., Benz, IT. G.. mid 1 1 ~ 1M. , J., Trans. Am. Sot. Metals, 32, 351 (1944). ( 6 7 ) J1onvoenr.v. J. H. G., Enginreii?ig, 160, 432, 458, 478 (19451. (68) Moiioka, S.,AVippon Kinzoku Gakukni-Shi, 3, 231 (1939). (69) M o t t , N. F., Sature, 145, 996 (1940). (70) M o t t . N. F., Trans. Faraday Soc., 36, 472 (1940). (71) Newell, H. D., Metal Progress, 49, 977 (1946). (72) Sen-ell, H. D., Jfetals R. Alloys, 14, 173 (1941). (73) Ortrofsky, J. N., Trans. A m . SOC.Metals. 27, 739 (193J1. (74) O j t r o m , K . W., and Thomas, R. D., ,Jr.. Welding J . , 20, 3 1 7 + (1 941). (75) Page, F. H., Jr., Ibid., 24, 9'29 (1945). (76) Petty, P. B., C'hem. R. M e t . Eng., 52, 102 l(19453. (77) Portevin, A. M.,Metal Progi,ess, 41, 88 (1942). (76) Pratt, W. E., Trans. Electiochem. Soc., 86, 203 (1944). (79) Pray, H., Peoples, R. Y., and Fink, F. W.,Proc. A m . hot Testing Matprials, 41, 646 ('1941) (80) Quarrel, A. G., Heat ?'reatin,g and Forging, 27, 345 (1941i. (81) Rudorff, D. W., Xetallicrgia. 27, 68 (1942). (82) Sarhs, G., and Stefan, P., Trans. *4m.Soc. Metals, 29, 87;: (1941). ( 8 3 ) Schaufus, H. S . , and Braiin. W ,H., Steel Processing, 31. 626. 691. 770 (19463 . , .: 32.. 43 11936i. , (84'. $cheil; 11.A , A m . ~ o c .~ e s t i n g.lIatrrials-Am. I?28t. -1lirLinQ M e t . Engrs., Prepi.int 22 (1944:. (85) Scheil, XI. A., and Ruseby, R. A, R'eiding J., 23, 361-a (1944) (84) Scheil, M. -4., Zmeakal. 0.. Waher, J., and Stockhausen, F. Ihid... 22.. 493-s 119431. , , (87) Scherer, E.. Riedrich, G., and K r s ~ n e r ,El. H., Iron Age, I53 No. 13, 56 (1945j. (88) Pcherer, It., Riedijch. G., an11 Rrsr-ner, H . H., Stahl u. Eixen. 62, 347 (1932). (89) Smith R.. Wvche. E. H d i d ( i o i r . IT. W.. Metals T~rh7tnl. 13, KO.4, 'fP2006 (1946). (90) Thomas, R. D., Jr , Metal P w g i t h a , 50, 424 (1946). (91) Tofaute, W,, Z. V e r deut. Ing , 85, 690 (1941). (92) Tofautc W.,and Sc!iottsky, 11.. Arch. Eiseiihuttenv., 14. 7 . (1940). (93) Tiuden, F. A , Xetal Finishing, 42, 335 (3914). (94) Uhlig. H. H., A m . Inst. Mining M e t . Engrs., Tech. Pub. 1150 (1940). 195) Thlig, H. H., Record Chem. Progrtss, 3, 3 (1942). (96) Uhlig, H. H., Trans. Am. Soc. Metals, 30, 947 (1942). (97) Thlig, H. H., Trans. Electrochem. Soc., 87, 193 (1945). (98) Uhlig, H. H., and JIoirill, M ,c., ISD. EXG.CHEx., 33, k75 (1941). (99) Chlig, H. H., and Wallace, E . )I., Traiis. Electrochem. SOL. 81, 511 (1942). 1100) Uhlig, H. H., and Wulff, J., Trans. 47n Inst. Mining J l p i Eiagrs. (Iron & Steel Div.), 135, 494 (1939). (101) Uhlig, H. H., Carr, K. E., and Schneider P. H., Trans. E1wtrochem. SOC.,79, 111 (1941). (102) Vernon, W.H. J., Chemistry & Industry, 59, 87 (1940). (103) Vernon, W., Wormwell, F., and Nurse, J., J. Iron Steel Inst. 150. u t . 2. 81 (1944). (104) Watk& S.'P., ;%fetalProgress, 39, 452 (1041). (105) Ibid., 39, 710 (1941). (106) Watkins, S.P., Product Eng., 12, 361 (1941). (107) Watkins, S. P., and Franks, R., Jfetals &: A l l o y s , 21, 698 (1945). (10s) IVyer, R. F., Iron Age, 158, No. 18, 57 (1946). (109) Zappfe, C. A , , Metal Progress, 48, 693 (1945). (110) Zmeskal, O., Ibid., 48, 729 (1945). IROS-SILICOh ALLOYS
(1.1) .Inonymous, Iiad. Chemist, 21, No. 250, 606-12 (1945); No, 251, 649-54 (1945). (2.1) Farquhar, C. M.,Lipson, H., and Weill, A . R., Iron and SteeE (London), 18, S o . 13, 614 (1945j. (3.1) Gratsianskii, N. IC.,Fadeeva, 8. M.,arid Yovkogon, A. P., Khim. Referat. Zhur., 4, Yo. 1, 142 (1941). (4%) Hurst, J. E., Foundry Trade J . , 71, 2S3 (1043). (SA) Hurst, J . E.. Iron Age, 155, No. 20, 59 (1945). (6.1) Hurpt, J. E., Proc Iust. Brit. F o , i n d 8 . u r n ~ n37, . A-IA-54 (194i4-4); Pnpcr 813.
1254
INDUSTRIAL AND ENGINEERING CHEMISTRY
Ilurst, J. E., and Riley, R. V..Iron and Steel (Londori), 17, No. 10, 425 (1944). (SA) Ibid., 18, No. 8, 333 (1945). (9-4) H u r x , J. E., and Riley, R. V., J. Iron Steel Inst. (London) 149, I, 213 (1944). (10-1)Itid.. 149, I, 221 (1944). (11-4) Hurst, J. E., and Riley, R. V., Ifetallurgin, 29, No. 171, 14.5 (1944). (12d\ Ibid.. 29, No. 171, 427 (1944). !13A) Klinov, I. Y., Trudy Konfuents. Korrozii Metal., 2, 216 (1943). ‘:4 i) Liang, Hung, Bever, 51. B., and Floe, C. r.,Metals Technol.. 13,No. 2, TP S o 1975 (1946). ls>.i1 Lipson, H., and Weill, A. R., Tranu. Faradau Soc., 39, 13 (1943). (1ti.i’ Rcavell. B. N.. Chem. Age (London). 42. S o . 1088. 19 (1940) 11iA>.i Vaughn, J. C., Jr., and Chipman, J., Trans. -4m. Inst. J T i u i n g Met. Engrs., 140, 224-32 (1940). ( t a l l Ward. R., Ibid., 152, 141-55 (1945). ( 1 Q - 1 j Weill, A . R., Nature, 152, 3853 (1943). t20-Y) ‘Xei!l, A. R., Rev. mdt , 42, No. 8 , 2G6 (1945). (214) IT’razej, W. J., J. Iron Steel Inst. (London), i49, I, 227 (19.11). ‘ 2 2 \ 1 Zappfe, C. A , , and Clogg, >I., Jr , T?ans.Am. So,-. IlTetds 34, 71-107 (1945). < I!.:
4
AUSTENITIC CAST IRONS
lB) Anonymous, Inst. Mech. Engrs. (London), J . , 143, 218 (1940) (2B) Ibid., 147, 88 (1942). (3B) Ibid., 149, 101 (1943). 4B) Ibid., 149, 103 (1943). ,5H) -4ustin, H. S.,Metal Proy:ess, 39, 097 (1941). (6B) Bollon, L. W., J . Iron Steel Inst. (London), 144, 89 (1941,. (7B) Bradley, A. J., and Goldschmidt, H. J., Ibid., 140, 11 (1939). M 3 ) Eash, J. T., Trans. A m . Fovndr!jmen’s Assoc., 49, 887 (1942)
(9Bj (10B) (11B) (12B) (13B) (14B) (15I3) (lGB) (17B)
Vol. 39, No. 10
Ibid., 50, 815 (1913).
Galibouiy and Laurent, P., Compt. rend., 209, 105 (1939). Klinov, I. Y., Khim. Referat. Zhur., 4, No, 4, 140 (1941). Klinov, I. Y., Org. Chem. Ind. (U.S.S.R.), 7, 173 (1940). Le Thomas, A,, Rev. nickel, 10, 98 (1939). Morton, B. B., Petroleum Engr., 13, No. 8 , 13@ (1942). Owen, E. A., and Sully, A. H., Phil. Mag., 31, 314 (1941). Pcarcc, J. G., Chern. Aye (London), 45, 69 (1941). Penrce, J. G , , F’oitndry TradeJ., 65, No. 1305,121; No. 13i)G, 139: KO. 1307. 158 (1941). ( M E ) Peaice, J. G., Inst. Jfech. Engrs. (London), J . , 140, 163 (1938). (19R) ILid , 146, 61 (1941). (?OB) dsclis, G., and Spietnak, J. W.,Trans. A m . Inst. M i n i n g .Ifel Engrs., 140, 359 (1940). (21B) Sefing, F. G., and Nemser, I). A ,Product Eng., 16, 799 (194,5) (22B) Sefing. F. G., Ibid., 17, 92 (1946). AUSTENITIC MANGANESE STEEL
(1C) bnonyinous, Iron Age, 146, 40 (Oct. 17, 1940). (!E) De Boncly, J. A , , Can. Metals M e t . Inds., 2, 279 (1939). (:G) Farlow, V. It., and McCreery, L. EI., X e t a l s Alloys, 14, KO.5 , 692 (1941). (4r)Franks, It., Binder, TT. O., and Brown, C. X f . , Iron Age, 150 S o . 14. 51 (1942).
( 3 2 ) Goss, N. P., Trms.’ A m . SOC.Metals, 34, 630 (1945). i6C) Niconoff, I).Ibid., . 29, 519 (1941). (7C) Ibid., 31, 716 (1943). (8C) Rice, D. B., Iron Age, 146, 33 (Oct. 31, 1940). (9C) Uhlig, H. H., Trans. A m . Inst. Mining M e t . Engrs., 158, 183 (1944). (1OC) Walters, F.M., Jr , Kramer, J. R., and Loring, B. RI., Ibid., 150, 401 (1942). (11C‘) Young, L. P.. and Goard. D. H., Can. Mining M e t . Bull.. KO. 372,170 (1948).
Chemical Stoneware F. E. HERSTEIN, General Ceramics and Steatite Corporation, Keasbey, N. J . ERAblIC materials are among the oldest known to nian, and it may be said that the progress of a civilizat,ion can be measured by its ceramic technology. A history of the ceraniic industry in general is given by Singer (22). Chemical stoneware in Its present form is a relatively new material t,o this industry, and its historj-, starting with the first stoneware factories in England in the early part of the ninetcrnth century and continuing t o its inccption in this country and continued use and progress, is described in an article by Kingsbury ( 1 2 ) . r l r n e manufacture of chemical stoneware follows the general pattwn for all ceramic materials. The raw materials are mined. wished, prepared by deaeration, stored for a n aging period, fabricated by jiggering, casting, molding, extrusion, or turning on t t x potter’s wheel, dricd, fired, and t,hen prepnred for final u.ce in most cases by grinding to the dimensions requircd or assembling n-ith other equipment. Olive gives a flow sheet shon-ing the manufacture of chemical stoneware (17) and a description of :nanufacturing techniques in a domestic factory (16). Singer also describcs manufacture and defines chemical stoneware (bS), and British pract,ices are discussed by Hodson ( 7 ) . In considering chemical stoneFyare as a material of chemical [:onstruetion, i t is neccssary to evaluate its advantages agdilst its limitations. Chamberlain states its main advantage t o be its i,esista.ncet o corrosion by all acids rxcept hydroflucric and strong hot caustic. Except for these two, i t may be called universally corrosion-proof. It is also a comparatively inexpensive material, and, because of methods of manufacture, special shapes in sniall (limntities can be made at a fairly economical cost. Its main clisadvantage is its relative fragility, which is shared by all ceI amic materials. I n application, its st,ructural qualities, such as
very high compressive strength and low tensile strength, are taken into account in the design in order that tensile stress and mechanical shock are avoided. Although the term “chemical stoneware” is generally consideied to cover one type of material, i t is really a generic term for a w a m i c body with a high density, low porosity, and high perwntagc of vitrification. Since the uses to which this material is put vsry, properties that arc desirable for one application may be undcsirable in another, and most stoneware manufacturcrs Foiinulate various bodies for different uses. An illustration of thiq 19 the use of silicon carbide bodies for applications both involving thermal shock and requiring enhanced thermal conductivity. It has been found that these bodies have a thermal L*oriductivit>-thiee to four times greater than standard stoneware, .I discbssion of various types of bodies and heat shock resistiiig bodies in particular is found in an article b y Robitschek (21) A discussion is also given by Kingsbury (12). Besides thew bodies other types such as extremely dense bodies for electrolytic service (IS), heat resistant bodies for chlorine service ( 6 ) , and porous bodies for use as diaphragms in electrolytic processes (25) have also been developed. A description of the bodies maiiiifactured by one company is given in a company bulletin
(4). To obviate the main disadvantages of chemical htonem are-n a i n e l ~, fragility and resistance t o thermal shock-research is !wing undertaken by chemical stoneware manufacturers in this country with a view t o developing bodies which will minimize these unfavorable properties and still retain the corrosion resistance which is inherent in chemical stoneware. Some of the research being undm taken non and already completed with this
