1986
INDUSTRIAL AND E N G I N E E R I N G CHEMISTRY
(113) Schuyten, H. A., JVeaver, J. W., and Reid, J. U., Am. Dyestuf Reptr., 38, 364, 365 (1949). A method of measuring waterrepellency of textiles which is independent of the type of cloth and dependent only on surface effect. (114) Scott, R. C., Testile World, 99, No. 9, 128 (1949). A tabulation of synthetic yarn consumption in 1949. (115) Seymour, R. B., Am. DyertuJReptr., 38, 453 (1949). A discussion of the development of the bonded fabric indust,ry. 62 references. (116) Seymour, R. B., and Schroder, G. M., Paper Trade J . , 128, No. 13, 16 (1949). Wool, asbestos, cotton, viscose rayon, and like fibers used in bonded fabrics which are united by thermoplastic fibers. Manufacture and uses. 42 references. (117) Siu, R. G. H., Darby, R. T., Burkholder, P. R., and Sarghoorn, E. S., Textile Research J., 19, 484 (1949). A study of mildew resistance of substituted cellulose compounds. (118) Smith, L. H., “Report of Synthetic Fibers, Technical Industrial Intelligence Committee,” New York, Textile Reserch Institute, Inc., 1946. A review of &hedevelopment in Germany of Perlon, a capralactam-type nylon. (119) Staudinger, H., Teztile-Rundschau, 4, 3 (1949). A review of the structure of natural and synthetic fibers. 57 references. (120) Stewart, J. R., Can. Textile J . , 65, No. 22, 41, 44 (1949). A discussion of the tests and wear resistance of manmade fibers. (121) Stewart, W.D., and Standen, J. H. (to B. F.Goodrich Co.), U. S. Patent 2,485,330 (Oct. 18, 1949). The use of thiothiazyl esters as fungicidal composition for textiles. (122) Taber, C., Rayon and Synthetic Testilea, 31, No. 5, 87 (1950). A report on nylon fabric development, with special emphasis on its abrasion resistance. (123) Truhlar, J., and Pantsios, A. A. (to Rudolf F. Hlavaty), U. S. Patent 2,450,790 (Aug. 30, 1949). Flameproofing of textile fibers by treatment with an organic phosphite with added chlorinated wax and chlorinated naphthalene. (124) Van Boskirk, R. L., Modern Plastics, 27, 178 (1950). Use of a nonwoven fabric as a reinforcement for plastic laminates.
Vol. 42, No. 10
(125) Van Mater, H. L. (to National Lead Co.), U. S. Patent 2,437. 853 (Jan. 4, 1949). Water repellent textiles prepared by impregnation with a solution of a soluble double carbonate of zirconium and a soluble soap in amounts to react to form a zirconyl mono fatty acid compound. (126) Ibid., 2,482,816 (Sept. 27, 1949). Zirconium compounds used to impregnate textile fabrics for rendering them water resistant. (127) Weaver, J. M.,“Asbestos Textiles and Textile Products,” Manheim, Pa., Raybestos-Manhattan, Inc., 1949. A booklet of information concerning asbestos and asbestos products. (128) Webb, P. W., Rayon and Synthetic Textiles, 31, No. 2, 39; So. 3, 62 (1950). A comparison of the properties of various fibers. (129) Weissberg, S. G., Kline, G. M., and Hansberry, H. L., IND. ENO.CHEM.,41, 1742 (1949). Fire-retardant coatings foi, fabric-covered aircraft. (130) Wellington, Sears and Co., Modern Plastics, 26, No. 9,70 (1949). A description of Lantuck resin-bonded fabrics and their properties. (131) Wesson, A. J., and Olpin, H. C. (to Celanese Corporation of America), U. 9. Patent 2,464,360 (March 15, 1949). Fireresistant organic fibrous materials containing ethylenediamine dihydrobromide. (132) Wilson, C. C., Cudd, H. H., and Probasco, D. V. (to West Point Mfg. Co.), U. S. Patent 2,477,675 (Aug. 2, 1949). A description of a method for making nonwoven fabric, utilizing positive and direct air currents. (133) Woodruff. J. A. (to American Viscose Corp.), U. S. Patent 2,454,245 (Nov. 16, 1948). A patent on the development of R substantially wash-fast flameproofing treatment for cellulosic materials by formation on the material of a water-insoluble complex of a cyanamide-formaldehyde resin with tungsten. (134) Zart, A., Chem. Ind. Tech., 21, 305 (1949). A discussion of the most important developments in the past ten years in thc field of rayon and synthetic fibers. RECEIVRD July 31. 1950.
Iron, Mild Steels, and Low-Alloy Steels c. P.
LARRABEE
AND S. C.
SNYDER
Carnegie-Illinois Steel Corporation, Pittsburgh, Pa.
T
H I S paper summarizes information published since the previous articles were written (22, 84, 86). IRONS
I n a previous paper ( 2 2 ) , attention was called t o the development of a new type cast iron-spheroidal cast iron. Since the development was first announced a t the 1948 meeting of the American Foundryman’s Society, more information has been published regarding the properties and characteristics of this material. Fifty-one companies have been licensed for its production. I n a summary prepared by Gagnebin et al. (10) it is stated that, chemically, this material differs from ordinary cast iron by the presence of a small amount of magnesium or of some other element which produces the same effect on the form and disposition of the carbon. Physically, however, there is a large difference between spheroidal and ordinary cast iron. Addition of a small but critical amount of magnesium produces a partial conversion of graphite to the spheroidal form, and the remaining graphite takes on a compact form. A larger addition ensures that all the graphite is converted to the spheroidal form; as the amount of spheroidal graphite is increased in the iron, the strength is also increased from the base level t o a value several times that of the untreated product. Considerable data are given on mechanical properties as de-
veloped by various heat treatments.
According to Gagnebin
et aE.,it is now possible, with the elimination of harmful flakes, to
make available a low cost foundry iron which is easily produced, has excellent casting qualities, and has physical properties which hitherto have only been obtainable with cast steels. Depending upon the heat treatment employed, tensile strengths vary from 63,000 t o 166,000 pounds per square inch; yield strengths vary from 46,000 to 116,08Q pounds per square inch, and elongations vary from 0.5 to 21.5%. Some of the probkms in the commercial production of ductile cast iron are described by-Kwiansky (20). Troubles for both producer and consumer are foreseen if sufficient engineering and testing work are not done before production of sections thicker than pipe is undertaken. Eagan and James (9) discuss the possible use of ductile cast iron for compressor parts which are difficult to cast with steel. Although the new material shows promise, more work must be done before it can be adopted for these parts. Using special hydraulic pumps and gages, the bursting pressure of vessels of ductile iron was found to be twice that of Class 40 gray iron and nearly equal to that of cast steel. Although magnesium additions are used almost exclusively in this country t o bring about the ductile properties, other elements will produce the same effect. Patents have been issued to
October 1950
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
Sugar Factmy h n p n r a l n r Wade of High-Strength, I n w - A l l o y Steel
1981
1988
INDUSTRIAL A N D ENGINEERING CHEMISTRY
culties have not been reported with soft, low-carbon steels. Carbon steel equipment exposed to anhydrous hydrofluoric acid may develop a scale on its surface and cause trouble where moving p a r k are involved. Therefore, when large clearances are not permissible, the use of another metal which will not scale is recommended. Darken and Smith (8),while studying the behavior of hydrogen in steel during and after immersion in sulfuric acid, developed an equation for the diffusion rate of hydrogen from a plane surface into steel. Their experiments show that the amount of hydrogen absorbed by steel during acid pickling depends upon the surface area versus weight relationship and the time of immersion. The absorption increases linearly with square root of time until the steel is saturated with the gas. The saturation value is small for hot-rolled steel but increases markedly with cold work. Annealing decreases the saturation value. Increasing the pH does not affect its saturation value but does increase the rate of absorption. Powell and Von Lossberg ($9) state that hydrogen may cause embrittlement of high-pressure boilers when using chemically treated or evaporated make-up water. A hydrogen recorder capable of measuring the gas in parts per billion is an effective means of predicting danger of attack. Another research program on the causes for and corrective mearmres necessary to prevent cracking of boiler plates made of various steels is described by McBrian el al. (23). As a result of an extensive t a t i n g and investigational program, the use of an all-welded and stress-relieved construction of boilers is recommended, especially for steam locomotives. Riveted construction can be improved by such measure8 as stress relief, proper fitting, elimination of stress raisers, and shot peening. More research is needed before the optimum materials and practices can be definitely recommended. Bartz and Rawlins ( 4 ) report that blistering of vessel walls and ot8herrefinery equipment was caused by the absorption of atomic hydrogen released by acid corrosion. Hydrogen absorption may also lead to embrittlement of steel, particularly a t high temperatures. The use of corrosion-resistant linings is recommended as one means of controlling hydrogen blistering. This information was obtained from replies to questionnaires sent to thirteen oil companies. Only two companies reported no failures from hydrogen blisters. Some reported over fifty failures. Brittleness in mild steeel has been studied by Gurrissen (11) with special reference to the effect of grain size and structure. He found that grain boundary Cementite is not formed during heating above the A , temperature but is formed during slow cooling from above AI, particularly from a temperature between AI and AS. Steels containing 0.05 to 0.30% silicon or 1.25 to 1.50% manganese are considered more suitable than mild steel for chainmaking. The addition of aluminum is beneficial in controlling grain size and reducing susceptibility to aging. The need for controlled cooling rates, neither too fast nor too slow, is indicated. Hoyt (16), in discussing the use of metals a t low temperatures, reporta that rimmed open-hearth steel and Bessemer steel are not recommended for low temperature service. Semikilled carbon steels are cheapest, but the design and the application must be suitable for their use. Fine-grained aluminum-killed steel in the normalized condition is the best of the cheaper steels. Some low alloy steels are still better. Considerable reliance is placed upon the notched-bar impact test as a means of selecting the correct types for various applications. The results obtained from a research project on the low temperature properties of several commercially pure metals, nonferrous structural alloys, carbon steels, alloy steels, and solders all a t +63O, -321", and -424" F. are reported byKostenet5 (19) in Russian and are summarized in English. For carbon steels SAE 1010, 1020, 1025, 1035, 1040, and 1050, the tensile strength increased with decreasing temperature, and both elongation and reduction of area decreased with decreasing temperature. The yield strength approaches the tensile strength a t -321 O F.
Vol. 42, No. 10
indicating that this is near the brittle temperature. Elongation is zero at -424" F. The following eight alloy steels were tested: 3.0% nickel0.25% chromium; 1.6% nickel-O.8% chromium; 3.3% nickel1.0% chromium; 5.0% nickel-0.2% chromium; 1.2% chromium0.1% molybdenum; 9.5% chromium-2.8% silicon4.4% nickel; 1.7% nickel-0.8% chromium-0.3% molybdenum; and 18.9% chromium-9.3% nickel. The tensile strength of these steels increased as the temperature decreased. The ductility generally decreased slightly a t -321' F. and dropped to a low value a t -424" F. On the basis of the test results, the 3.0% nickel0.25% chromium steel and perhaps also the 3.3% riickel-l.O% chromium and the 5.0% nickel-0.2% chromium steels were suitable for use a t low temperature. Hopkins (14) states that the corrosion of steel water pipe is a function of dissolved oxygen. He recommends the neutralization of free carbon dioxide in low alkaline waters by lime and subsequent precipitation of a calcium carbonate-ferric oxide coating on pipe surfaces to retard corrosion. Maintaining the water a t pH 8 is recommended. The water thus treated is stable when maintained a t the calcium carbonate saturation point. Hopkins shows that the cost, including Iabor, materials, and depreciation a t Baltimore, Md., during the last 25 years, averaged $0.431 per million gallons. Palmer (27) shows the necessity of careful control when combinations of phosphates and chromates or phosphates and persulfates are used as inhibitors. Certain conditions eliminate one radical; a pitting attack results. Corrosion of gas well pipe in West Tuleta, Tex., is being controlled by the use of a semipolar organic reagent according to an anonymous report (1). The reagent is injected into the pipe a s needed. The liners for cylinders of Diesel engines may last the life of the engine if the hopes of Payne and Joachim ($8)are realized. The factors studied were bore size, piston speed, cylinder displacement, liner hardness, piston skirt clearance, fuel consumption, lubricating oil, and the operating temperatures of both lubricating oil and cooling water. Although the problem has not been definitely solved, the most hopeful solution seems to be coating of the cylinder bores with a porous coating of chromium. The factors affecting the reversal of potentials of zinc and iron are being studied by Hoxeng and Prutton (16). The presence of oxygen, sulfate, and chloride radicals decreases the probability of a reversal, whereas bicarbonates and nitrates increase this probability. Electrolyte composition is a more important factor than the temperature. Humble (17)shows the necessity of protecting steel piling when immersed in sea water if long service life is desired. The recommended procedure is the deposition of a protective coating of magnesium and calcium carbonates by the application during 1 to 2 weeks of comparatively large amounts of direct current with the piling acting m the cathode. After this coating is formed, corrosion of the steel may be almost entirely prevented by the use of only 3 ma. of current. Most of the attack on steel in the tidal zone can be prevented by cathodic protective measures; however, a t the most severely attacked area (splash zone above high tide), organic or metal coatings must be used. The use of anodes of a zinc-lithium alloy is preferred by Rodgers and Stewarts (SI)to the use of anodes of pure zinc or pure magnesium t o protect steel in SOhltiOhS of certain salts with low pH values. Synthetic natural waters (fresh and sea) and salt solutions with adjusted pH values were used in the experiments. Harlow (IS),after a study of the causes of flue gas deposits and corrosion in modern boiler plants, states that pulverized fuels give less corrosion than stoker-&ed coal or oil. A fine fly-ash from the former aids in the formation of a protective coating.
October 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY ALLOY STEELS
Constructional materials for coal hydrogenation plants present many problems, avers Harding ( 1 8 ) in a description of the Bureau of Mines installation. The pressure is 10,300 pounds per square inch, the temperature is over 900' F., and hydrogen sulfide is present. Hydrogen attack is always a problem when high temperatures are combined with high pressure. For converter shells, a 3% chromium-0.65% nickel4.3% molybdenum steel with R tensile strength of 100,OOO pounds per square inch and an elastic limit of 55,000 pounds per square inch is used. Heads of vessels which are subject to higher temperature because of the reacting fluids flowing through them are made of 4 to 6% chromium-1 to 1.25% n i c k e l 4 4 to 0.8% molybdenum steel. Pipe and Fittings. Piping materials for this pilot plant were divided into three service classifications with common dimensional standards and a maximum working stress of 22,900 pounds per square inch. For tcmperature up to 375" F., SAE 4130 with a yield strength of 60,000 pounds per square inch is used because of its weldability. Fittings were forged from billets and bar stock of SAE 1030 with a yield point of 45,000 pounds per square inch. Flanges were forged to ASTM A 10546, Grade 11, with a yield point of 36,000 pounds per square inch. For medium temperatures, 375 't o 850" F., a 9% chromium steel normalized and drawn a t 1200' F., to a yield strength of 82,000 pounds per square inch is suggested. Fittings were forged from 18-8 Type 304 stainleas steel billets with a yield strength of 30,000 pounds per square inch. Flanges are made of Type 304 or of carbon-molybdenum ASTM A 182-44, Grade F1, with a 45,000-pound-per-square-inch yield point. For the highest temperatures, above 850" F., only 16% chromium-13% nickel-3% molybdenum stainless alloy is used. T o overcome difficulties in the production of pipe, cold-drawn tubing is specified. Suppliers of standard commercial pipe fittings were unable to produce seamless fittings by conventional methods because of the heavy wall thicknesses. Fittings are confined to elbows, tees, and reducers and were forged from solid billets. Tees and reducers were forged to shape and then bored and machined to finished dimensions. Elbows were made from forged solid cylinders, slightly offset, and then bored through. The bending was completed in the direction of the original offset after boring, and the result was a short radius elbow of surprisingly uniform cross section. Valves. Low temperature valves for the installation have bodiea of carbon steel, SAE 1030, with a yield point of 45,000 pounds per square inch. For medium and high temperature service, alloy steel bodies are used-ASTM A 18244, Type F-Sm, (AIS1 Type 316)-with a yield strength of 30,000 pounds per square inch. I n almost all cases the valve seats and disks are hard-faced with a weld deposit of Stellite. I n the case of special throttling valves, the seat and disk are of Kennametal, a cemented carbide of extreme hardness. In these valves the expansion chamber is fitted with a renewable target with a concave spherical surface which is hard-faced with Stellite. Design and construction of the demonstration plant has fulfilled a primary objective. The ability of American manufacturers to produce the necessary materials and equipment haa been proved beyond doubt. Valuable knowledge in high pressure techniques has been gained by the designers, manufacturers, and constructors. The operation of the plant will undoubtedly see additional objectives attained and will test the validity of the new ideas used. Ripling (80) presents data from experiments in which specimens of a 1.8% manganese-0.240fo silicon steel (SAE 1340) were tempered a t various temperatures between room temperature and 1100' F. Groups of these specimens were then tested in static tension at room temperature, -110', -220', and -321' F. The yield strength and tensile strength decreased continuously with increasing tempering temperature. When contraction in area and fracture stress are obtained on the specimens tested at
1939
the lowest temperatures, pronounced minima are obtained; these are a function of the tempering temperature. This minimum occurred a t a tempering temperature of 600' F., the temperature at which most steels are known to become brittle. Bardgett and Reeve ( 9 )found that the presence of boron almost doubles the yield stress of a low carbon-molybdenum steel. Good ductility and toughness are retained. Warnock and Brennan (36)have reported the dynamic yield strengths for eight steels, including one mild steel, two plain carbon steels, two carbon-manganese steels, one heat-treated alloy steel, and two cast steels. Dynamic loads were applied by means of an impact machine of the falling-weight type with an attachment to enable the peak load to be reached in 3 milliseconds. Supplementary tests in which the time t o reach the peak load was 1 millisecond were carried out on three of the steels. Comparison with static values revealed an increase in yield strength from 21 to 36% for the carbon steels under dynamic l o d i g . This increase of dynamic yield strength diminishes with increase in static yield strength. The annealed cast steels behaved in a similar manner, but the heat-treated alloy steel showed no appreciable increase in yield streugth. The effect of loading the same steels at an intermediate rate is given by Brown and Edmonds (6). The rate of loading was calculated to be that which would occur in a ship under the action of an underwater explosion. The dynamic yield strength of the steels with low static strength was 20 to 30% greater than their static yield strength, but for the stronger steels the increase was less; the increase was negligible in the case of the heat-treated low alloy steel. This result agrees with the findings of other investigators. Ziegler et al. (97)give the characteristics and properties of some cast low chromium-molybdenum steels. The steels investigated contained 0.4, 0.7, 1.25, 2.0, and 3.0% chromium with molybdenum varying between 0.4 and 0.8% and carbon between 0.05 and 0.3% for each chromium composition group. The effect of changes in the amount of each of these three elements is s o m e times great and sometimes small, but trends in the meohaniaal properties and thermal behavior of low chromium-molybdenum steels are established. No attempt is made to recommend a definite composition for a specific application. HIGH-STRENGTH, LOW-ALLOY STEELS
A summary of the uses of this class of steel over a period of
years has been published (a). Advantages in cost and service life can be obtained in many applications with properly designed equipment. D a t a are tabulated and plotted. Special emphasis is given to the increased atmospheric corrosion resistance and higher strength of low alloy steels as compared to those of carbon structu?-al steels. I n order to take advantage of the increased atmospheric corrosion resistance of high strength steel, comparative increases in the mechanicd properties, such as strength and toughness, are necesaary. The forming and fabricating of these steels are also discussed. Kerensky (18) gives a summary containing the types of high tensile (low alloy) steels, methods of obtaining enhanced properties (cold working, heat treating, and alloy additions), corrosion resistance, welding Characteristics, allowable stresses, effect of fatigue, and economics of their use. It is shown that the superior atmospheric corrosion resistance of these steels over that of the structural carbon grade makes thinner sections permissible for many applications. Longer service life is frequently preferable to less weight; therefore, the use of these steels in the thicknems customary with structural carbon steel is sometimes advantageous. LlTERATURE CITED
(1) Anon., Oil Uan J., 48, 107-g,112, l l P 1 6 (1949). (2) Anon., Product Eng., 20, 89-96 (1949).
1990
INDUSTRIAL A N D ENGINEERING CHEMISTRY
(3) Bardgett, W. E., and Reeve, L., J. Iron SteelInst. (London), 163, 277-94 (1949). (4) Bartz, M. H., and Rawlins, C. E., PPtideum Processing, 4, 898901,904-6 (1949). (5) Berk, A. A., Proc. Natl. Dist. Heating Assoc., 38, 273-87 (1947). (6) Brown, A. F. C., and Edmonds, R., Inst. Mech. Engrs. (London), Proc., 159, 11-14 (1948). (7) Butlin, K. R., Adanis, Mary E., and Thomas, Margaret, Nuture, 163,26-7 (1949). (8) Darken, L. S., and Smith, R. P., Corrosion, 5, No. 1, 1-10 (1949). Eagan, T. E., and James, J. D., Iron A g e , 164, No. 24 (1040). Gagnebin, A. P., Millis, K. D., and Pilling, N. B., Ibid., 163,No. 7 (1949). Gurrissen, J., J. Iron Steel ins^. (London), 162, 18-28 (1949). Harding, A. G.. Chem. Eng., 56, No. 9, 116 (1949). Harlow, W. F., Engineer. 187, 271-3 (1949). Hopkins, E. S., Tech. Assoc. Papers, Ser. 31, 399-402 (1948). Hoxeng, R. B., and Prutton, C. F., Corrosion, 5, No. 10, 330-8 (1949). Hoyt, S. L., Metal Progress, 55, No. 6, 821--ti (1949). Humble, H. A., Corrosion, 5, No. 9, 292-300 (1949). Kerensky, 0. A,, Engineer. 187, 238-241 (1949). Kostenetz, V. I . , J. Tech. Phys. (U.S.S.H.), 16, No. 5, 515-54, (1946): English summary, Metal Progress, 55, No. 1. 82, 84, 86 (1949). Kuniansky, Max, Iiun Worker (fall 1949 issue). LaQue, F. L.. and Mogerman, W. D., World Od, 129, 153-8 (1949).
Vol. 42, No. 10
Lanabee, C. P., and Snyder, 8. C., IND. EKG.CHEM.,41, 2122-4 (19491. \
~
~
~
.
,
_
McBrian, R., et al., Master Boiler Makers' Aasoc., O&. Proc.. 220-35 (1948).
Mears, R. B., and Snyder, S. C., IND.ENG.CHEM.,39, 1219-34 (1947). Ibid., 40, 1798-800 (1948). Mortogh, Henton (to Brit. Cast Iron Rosearch Assoc.), U. S. Patents 2,488,511, 2,488,512 (Nov. 15, 1949). Palmer, W. G., J . Iron Steel Inst. (London),163, 421-31 (1949). Payne, W. G . , and Joaohim, W. F., SOC.Aiitoniotive Engrs., Quart. Trans., 3, 61-6 (1949). Powell, S. T., and Von Lossberg, L. G., Corrosion, 5, No. 3, 71-8 (1949). Ripling, E. J., Am. Soc. Metula, gi.epl.int 1 (1949). Rodgers, R. R., and Stewarts, If'. R. Q., Can. Miniug Met. Bull.. NO.445,218-21 (1949). Rozsa, J. T., Iron A g e , 164, No. 25 (1949). Spitz, A. W., Chern. Eng.,56, No. 1, 238 (1949). Ibid., No. 9, 229. 'Il'arnock, F. V., and Brennan, d. B., Inst. M r c h . Etrgrs. (London), Proc.. 159, 1-10 (1948). Young, K. B., Nichols, H. J., and Solan, M. J., Welding J . (A'. Y.), 28, 153-7 (1949). Ziegler, N. A,, Meinhart, W.t.,and Goldsmith, J. R., A m . SOC. Metcrlx, preprint 6 (1949). RECEIVED August 7, 1950.
Nickel and High-Nickel Alloys H. 0, TEEPLE, The International Nickel Company, Znc., New Y o r k , N. Y .
T
presentannual review of published references to the use of nickel and high-nickel alloys as materials of construction iu similar to the previous one (132). Alloys containing about 40% or more of nickel or appreciable quantities of cobalt comprise the materials considered in this portion of the review. As previously, the subject matter is divided into three general classifications: development of new alloys or improvements in present ones and studies of their physical properties; developments in the fabrication of these alloys, including welding, forming, and heat treatments; and developments in the applications of these alloys for both high temperature and corrosion resistance with particular reference to the chemical and process industries. COMYOSlTIONS OF ALLOYS
A number of new alloys were reported, most of them designed to achieve improved mechanical or physical properties over those currently available. Kinsey and Stewart (f 83) described preliminary studies on nickel-aluminum-molybdenum alloys to develop an alloy for use under stress a t 815' C. (1500' F.) and upward. Griffiths (142) reported improvements in high temperature performance of nickel-cobalt base alloys through suitable heat treatments. Additional modifications are reported (36, f22,I W ) leading to improvements in properties of these alloys. Doyle (109)specified improved compositions relating to nickel-, cobalt-, and chromium-base alloys for high temperature service, The alloys consist of 10 to 72% nickel, 10 to 39.5% cobalt, 15 to 20% chromium, 2.7 to 5.7% aluminum, 1.55 to 3 . 5 % titanium, and specified ranges of silicon, titanium, manganese, columbium, molybdenum, vanadium, tantalum, or tungsten either singly or in combination. Heat treatment is also specified. Scott and Gordon (263) described a precipitation hardening austenitic alloy composed of 15 to 35% uickel, 20 to 40% cobalt, 17 to 22%
chromiuni, 3 tu 15% molybdenum, 1 to 9 % tungsten, 0.5 to 3 % mauganese, 0.1 to 0.7% silicon, less than 0 . 2 % carbon, and the balance iron. Age-hardening heat treatments we described. Craighead et al. (99) reported binary alloys of titanium with nickel and cobalt and ternary alloys of titanium-chromium alloys with nickel and cobalt among others. Charts on properties and diagrams are included. Allen (2) described an alloy suitable for electrical resistor elements consisting of 10 to 30% chromium, silver and aluminum, each in amounts within the range of 3 to 5% but total amount within range of 6 to 8%, and the balance nickel. An improved electrical resistance material composed of oxides of manganese, cobalt, nickel, and copper, with manganese forming from 50 to 60% of the total metal present,, is report.ed (36). A specific composition is claimed in which the atomic proportions are 50% manganese, 16% nickel, 30% cobalt, and 4% copper. Kubaschewski and Goldbeck (f89)studied the mechanism of the oxidation of nickel-platinum alloys containing 0 to 90 atomic % platinum. Various conclusions drawn are believed to be generally applicable to other similar alloys. Elsea and McBride (111) investigated the influence of nitrogen, iron, or nickel additions upon the transformation and precipitation reactions occurring in cobalt-rich cobalt-chromium alloys. I t was found that these elements tend to promote formnt,ion of t.he gamma phase. Improvements relating to electrical resistance elements are described (SI),together with a componition of an alloy of low temperature coefficient of resistance, which contains 10 to 30% chromium, 1 to 4y0aluminum, and the balance nickel. A nickel-base alloy is described (55) suitable for use in spheroidal cast iron. A process is described (60) wherein gold is permanently bonded to a nonferrous metal base. The gold is welded to a pure nickel harrier which is subwquent,ly silver-
