(Left) BUBBLE T O W E RF O R FATTY ACID DISTILLATION
B U I L T OF INCONEL P L A T E S '/a,
'/le,
AND
'/d
INCH THICK
NICKEL AND CORROSION= RESISTING NICKEL ALLOYS ROBERT J. McKAY International Nickel Company, N e w York, N. Y
@T
WO separate groups of properties of materials are to be considered in the design or repair of plant equipment, whether for chemical plant or other industrial operations. One of these, the physical and mechanical property group, mainly determines the design necessary for the equipment to do the work expected of it when first installed. The other group, the chemical- or corrosion-resisting properties, determines mainly its life and ability after a period of service. The physical and mechanical group has, as an important subdivision, the working properties which determine how a machine can be made and therefore have a compelling effect on design. The purpose of this paper is to summarize recent progress in the development of nickel alloys of use to the chemical industry. The present status and trend of this progress are given rather than encyclopedic data on the alloys because such data are now quite familiar to many. In some cases present progress is in the physical and mechanical properties, while in others it is in corrosion resistance. In the main, data are included only on these points, whether in connection with mechanical properties or corrosion resistance, which show useful improvement.
This paper outlines the most useful developments in nickel alloys during the past few years. A general picture of the properties and corrosion resistance of commercially pure nickel is given, with references to detailed figures. These properties serve as a basis for the discussion of the newer alloys of nickel which makes up the body of the paper. The service properties of the monel metals (including high-strength, hardcast, and machining-quality monels), the copper-nickel alloys and nickel silvers, Inconel, nickel-clad steel, nickel electroplate, nickel and alloy welding rods, and nickel cast iron are outlined. The variation in physical properties and the abilities and limits of corrosion resistance of these alloys are drawn in general terms by the use of comparative statements.
Commercially Pure Nickel As a focal point for a rather broad subject, let us use commercially pure rolled nickel. A few of the common properties illustrative of its general position among the metals are as 1392
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INDUSTRIAL AND EXGINEERING CHEMISTRY
VOL. 28, YO. 12
corrosion rates need consideration, and where oxidizing agents exist with acids, corrosion may be quite rapid. In high temperatures nickel forms a protective scale whenever oxygen is present and is not otherwise readily acted upon except by sulfur compounds. Sulfur in its loosely bound form (that is, in other than the sulfate radical) is active on nickel both in acid solutions and a t high temperatures. d somewhat useful generalization on nickel and its principal alloys is shown in Table I. The outstanding attribute of chromium in corrosion resistance is its ability to form passive films in most oxidizing agents, and it imparts this ability to many of its alloys. The outstanding attribute of copper is its complete resistance to strong acids unless some oxidizer is present. Nickel is resistant to acids and will develop oxidation passivity, but does not reach the complete resistance to oxidation or to acids of chromium, on the one hand, and of copper on the other. TEN-THOUSAND-GALLON TANKPROTECTING PHENOL IN TR-INSIT, STORhGE, AND Chromium and copper are not mutually PROCESSING BY CONTACT WITH PURENICKELSURFACBS All joints are carbon arc welded, soluble but both are soluble in nickel. Thus, we have two major series of nickel follows: density, 8.85; melting point, 1450" C.; annealing alloys resistant to corrosion, each leaning ih corrosion resistrange, 760" to 950" C.; ultimate strength, 65,000 t o 150,000 ance toward one of the two major chemical corroders, acids pounds per square inch; yield point, 20,000 t o 100,000 and oxidizers. pounds per square inch; elongation, 5 to 53 per cent in 2 inches; Brinell hardness, 85-300. Detailed data on both T 4 B L E I. GENERAL DATAon CORROSION Of NICKEL AND physical and corrosion-resisting properties are given in literaITSALLOYS ture citations 1-4, 6, 9, 12-16, 21, 22, 24, 26, 27, 28, 31, 32. Resisted by: Agent Attack The weight of nickel is intermediate between the light and Cr Oxidizer cu very heavy metals. Its melting and annealing range is so Ni-Cr Oxidiaer ( + acid) Cu-Xi Ni Oxidizers and acids Ni high as to require the best refractory furnaces for handling Cu-Ni Acid (+ oxidizer) Ni-Cr cu Acid Cr and to make such processes as extrusion and die casting d f i cult. Its strength and hardness run higher than mild steel and its ductility makes it respond readily to most shaping and The above brief general statements give a reasonably accutting operations. curate diagram of the properties of nickel. The several exCorrosion-resisting properties have not usually been exceptions which prove the rule will be more apparent as compressed quantitatively to as great an extent as the physical parisons with the newer alloys are discussed. and mechanical properties. In a recent work (%'I), the writer attempted to bring much scattered corrosion data into a conMonel Metal crete usable form; the following data on corrosion rates (in Monel metal, possibly the best known high-nickel alloy and mg. per sq. dm. per day) are quantitative generalizations from the nearest to pure nickel in its properties, cannot be called that work: new. However, it deserves discussion from the same basic Caustic Fresh Salt Ordinary Weak Oxidieing Strong standpoint as pure nickel before considering certain new modiAtm. Alkali Water Water Acid Acid Acid fications of its properties which have been accomplished in 0-6 1-2 1,000-10,000 0-1 0-1 10-200 10-80 recent years. As compared with nickel, we may consider that bugbear In order to visualize quickly the meaning of the figures, the of technical discussions and bone of contention, the cost. unit used must be understood. It is a rate of metal weight Nickel itself, while it ranks as a common metal in cost, is in loss due to corrosion, easily determined by weighing, and exthe high cost range, and even its facility of fabrication cannot pressed in relation to exposed area and time. Zero is roughly bring machinery made of it into the low range. Monel metal, the lower limit of measurement and represents less than because of its copper and iron content and because, in the measurable corrosion. Rates below 10 are so small as to be main, it is unnecessary to make the expensive nickel from usually harmless. From 10 to 100 rates become appreciable; copper separation on the ores from which it is taken, can be and in the neighborhood of 100, they need careful consideraproduced and sold a t a real saving over nickel. The product, tion. From 100 to 500, corrosion is serious, and figures above for a great many uses, has superior properties. Thus, Monel 500 usually indicate unsuitability. metal, though similar to nickel, often gives more satisfactory In the work mentioned @ I ) , the common corrosives are service for a certain use at lower cost. classified into ten groups: air, soil, acids, oxidizing agents, The difference in properties between Monel metal and nickel natural waters, salts and brines, organic materials and foods, is not directly predictable from what would be expected by high temperatures, sulfur compounds, and alkalies. Of adding copper to nickel. Certain curves of strength and acid these, six groups, air, soil, natural waters, salts and brines, corrosion resistance, for instance, go through maxima at or organic materials and foods, and alkalies are well resisted by near the Monel composition. In physical properties, the nickel. Three others are reasonably well resisted. In acids,
DECEMBER, 1936
INDUSTRIAL AND ENGINEERING CHEMISTRY
ultimate strength, yield point, and hardness numbers for Monel metal are appreciably higher than for nickel with the same treatment. These are the major differences. As to corrosion resistance, the resistance to strong acids is distinctly better than that of nickel and the resistance to high-temperature oxidation and other oxidizing agents somewhat less. This is accompanied by a lower tendency on the part of Monel metal for the formation of passive fdms and thus often less tendency for local corrosion. Monel metal is striking for the uniform nature of such corrosion as it does undergo.
Recent Improvements in Monel Metal ALUMINUM-BEARINQ MOKEL METAL. The addition of aluminum to Monel metal, to the extent of about 3.5 per cent, improves many of the mechanical properties without substantially changing the corrosion resistance. This new alloy, known as K Monel metal (ISA)may therefore be used very much as Monel metal, as far as contact with corrosives is concerned. The major advantage of K Monel metal lies in the ability to increase its mechanical properties above those of Monel metal by heat treatment or combinations of heat treatment and cold rolling. The improved properties are obtained by precipitation hardening, and the heat treatment is typical of precipitation-hardening alloys. Cold-drawn K Monel metal in the form of rods can be made with breaking strengths as high as 165.000 pounds per square inch, and hard-drawn spring wire as high as 175,000 to 200,000 pounds. The 165,000-pound material has a yield point about 125,000 pounds per square inch, and elongation in 2 inches of 21 per cent. Figure 1 gives a general r6sum6 of the strength properties available. Pure nickel can also be alloyed for precipitation hardening, and the same or higher physical properties obtained than with K Monel metal. The necessary alloying constituents are so low in amount as to leave the corrosion resistance unchanged. HARDMONELMETALCASTINGS. The aluminum-bearing Monel metal is suitable for all applications where higher mechanical properties than Monel metal are desired in rolled shapes and forgings. For castings of high hardness and strength, it is more convenient to use silicon as the alloying
1393
element to induce precipitation hardening. In many of the uses of cast Monel metal, resistance to wear in contact with metal and also to galling or seizing is very important-for instance, in the case of valve trim. Castings made of the regular Monel metal composition but containing silicon in the neighborhood of 3.5 to 4 per cent have an unusual freedom from galling and seizure (11). The mechanical property usually used to measure or illustrate this ability to make unlubricated contact with another metal without wearing away rapidly and without seizing is the hardness. Castings of the composition mentioned in the as-cast or hardened condition may have a hardness of 300 Brinell as compared with 140 Brinell for a regular Monel casting and 130 for mild steel. Direct rubbing or wear tests which number the seconds before seizure under standardized conditions of contact and pressure have also been made; from such tests the following comparative figures on galling resistance are taken (in seconds) : Regular Monel metal S. A. E. 3140 steel, quenched 89% Cu 117 Sn Bronze Grade S ’ M o G l
1 81 175 No seizure in 20 min
Although it seems to take about 3.5 per cent silicon to produce precipitation hardening in the ordinary Monel metal composition, additions of from 2 to 3 per cent produce some hardening and are useful if it is desired to obtain intermediate hardnesses with higher ductility. Any silicon addition seems to work in the direction of better corrosion resistance with the exception of alkaline attack. Although this improvement in corrosion resistance is not great enough to be evident in every test (the results have the usual variations of corrosion tests), there is a discernible tendency toward better corrosion resistance in viewing averages of many data. The improvement is hardly positive enough to classify according to the silicon content, but it is believed to be greater with the higher silicon contents. FREE-MACHIKING MONEL METAL. The production of corrosion-resisting screws, bolts, and other small items in quantities calls for a metal which machines with greater ease than normally tough and strong Monel metal. For this purpose certain compositional changes are made in Monel metal which change its physical properties just enough to allow it to be machined by automatic machines a t high rates of speed (IO). These physical changes do not affect the corrosion resistance unfavorably, and therefore the machined parts can be used interchangeably with regular Monel metal.
Chromium-Nickel Alloys (17) A typical corrosion feature of pure nickel and of most highnickel alloys is the tarnishing by sulfur compounds. This tarnishing is evident to a small extent in ordinary atmospheres. It is quite obvious in atmospheres containing sulfur dioxide or hydrogen suliide. I n the atmospheres in which these alloys are used, this tarnishing is so slight as to be disregarded but in contact with some materials, particularly foods and food liquors, it may be a nuisance. I n the handling of milk (20), for instance, the tarnishing makes frequent abrasive cleaning necessary if a bright appearance is maintained on pure nickel. Monel metal used for holding cooked cereals for long periods will darken and may even impart a dark color to portions of the cereal in contact with it. Chromium and many chromium alloys are free from such tarnishing, and certain alloys of chromium and nickel are ... noticeably resistant to it. When chromium is added to pure B w w l Hardness - 3000 KB. nickel, the rate of formation of tarnish is gradually reduced FIQURE 1. TENSILEAND IMPACT PROPERTIES OF K MOXEL AND THEIRRELATION TO BRINELL HARDNESS (ACCORDING until, at about 10 to 12 per cent chromium, tarnishing by foods TO W. A. MUDQE) over long periods of time is unnoticeable.
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INDUSTRIAL AND ENGINEERING CHEMISTRY
The alloy Inconel (16, l 7 ) , consieting of nickel 80 per cent, chromium 14, iron 6, is in a range where tarnishing is almost nonexistent. Its general corrosion rates in acids and other corroding agents are much the same as pure nickel. Besides the resistance to tarnishing, the major corrosion difference of Inconel from pure nickel is in its resistance to attack by certain loosely bound chemicals, such as bleaching agents and photographic developers in the absence of strong acids. Inconel has been unusually resistant to various photographic solutions where Monel metal and other metals are attacked. The usual resistance of chromium alloys to direct oxidation a t high temperatures is also in evidence in this alloy. The physical properties of Inconel are considerably higher than those of pure nickel. While not quite as high as those of the alloys of nickel and Monel mentioned above as worked and heat-treated for high strength, they do approach this high range. The retention of strength a t high temperatures is of particular interest, making this one of the best alloys known for springs to be used a t elevated temperatures; in addition, it provides unusual corrosion resistance a t such temperatures.
VOL. 28, NO. 12
venting fouling by marine growths. These growths, barnacles and several other forms, attach themselves tightly to many resistant materials and by their bulk often interfere with the properties desired of a metal in salt water contact. Besides such direct interference, they encourage the localization of corrosion. A barnacle, for instance, is a good electrolytic solution cell, complete with porous cup. The copper content of these alloys is sufficient to prevent these growths and preserve a reasonably free and clean surface to the water. The nickel silvers have corrosion resistance much like that of the simpler copper-nickel alloys. They are whiter in color and furnish a better metal on which to produce a pleasing white metallic finish.
Stainless Steels W. J. Priestley gives (page 1381) a more complete survey of the wide and rapidly developing class of stainless steels. I n these alloys the remarkable stainless properties of chromium itself are transferred to alloys with iron where chromium is present in varying amounts. Here nickel has a valuable effect on the physical properties. Nickel makes the alloys more ductile and generally more workable. This affects the corrosion resistance indirectly by preventing the formation (by working) of less corrosion-resisting constituents.
Copper-Nickel Alloys The copper-nickel alloys are all highly corrosion resistant, and their corrosion-resistant properties are fairly well known. They are, in general, more corrosion resistant than either of the products from which they are made-copper or nickel. Corrosion-Resisting Joints Although it is impossible to align the alloys quantitatively as il practical method of making corrosion-resistant joints is a connecting series according t o corrosion resistance between usually one of the necessities for a corrosion-resistant alloy. copper and nickel, it is true that the differences in corrosion The simplest method of making such an alloy joint would seem resistance, as shown separately by copper and nickel, are to be to melt the alloy together, making a weld of the same gradually merged in the complete set of intermediate solid corrosion resistance and physical properties as the base metal. solution alloys. In some cases this can be done, but in usual practice the result Probably the most useful recent development has been the is not obtained so simply. Often the properties of the alloy recognition and use of the corrosion resistance of the copperare obtained only by the most careful control of the metal nickel alloys of 20 to 30 per cent nickel. In sea water, for during refining and rolling. It is manifestly impossible t o instance, these alloys show high resistance; particularly the produce this same result instantaneously under a gas torch or 30 per cent nickel alloy (33, 34) has been widely introduced the heat of an arc. Thus, the weld usually differs from the into condensers in which the cooling medium is salt water. base metal in composition and physical properties and it is Besides a good general resistance to sea water, this type of always a struggle t o obtain comparable corrosion-resisting alloy has a special resistance to the types of local corrosion, properties. impingement, and pitting, which have been usual in such conWith most of the nickel alloys (5, 6), however, methods densers. of f l u x i n g a n d Although these manipulation have alloys have suitabeen worked out bly high strength so that a welded for such use, they joint can be conare somewhat veniently made by softer and therethe u s u a l procfore easier to shape esses. The comthan the h i g h e r position of the nickel alloy, Monel completed weld is metal. This ease usually so close to of f o r m i n g into that of the original small, highly alloy that it need f i n i s h e d tubes, not be considered together with the different in COITOhigher content of sion r e s i s t a n c e . the lower priced In arc w e l d i n g metal, enables the and c a r b o n a r c manufacturers to welding, suitably furnish tubes a t a f l u x e d r o d s of price well repaid nickel, Monel b y t h e corrosion metal, Inconel, the resistance. n i ckel-b ea ri n g B e s i d e s resists t a i n l e s s steels, ance to salt and 70-30 copperwater, these alloys nickel alloy prohave the valuable INTERIOROF WELDEDMONELMETALOIL-SULFONATINQ VESSELEQUIPPED WITH duce reliable MONELMETALSHAFT AND AQITATOR property of pre-
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INDUSTRIAL AND ENGINEERING CHEMISTRY
1395
corrosive conditions but should not be relied upon in strong acids and other corrosives which may set up electrochemical solution cells.
Austenitic Cast Irons
,
20,000I-;+l
O h O h
Ni. Cr.
,
0.0 0.0
1.5 2.9 .60 .84
I I
2.0
=
5.0 6.0 1.4 1.75 2.0
4.2
FIQURE 2. PROPERTIES OF NI-HARDAND PLAIN CASTIRON Total carbon, approximately 3.5 per cent: silicon, 0.95 t o 1.0 per cent.
joints, as does proper manipulation of the welding torch. Various automatic welding jobs are successfully done where they are apropos, and their number is increasing with wider use of the alloys. The favorable properties of nickel alloys for welding are several. The high electrical resistance gives good efficiency in electrical methods. Low heat conductivity localizes heat, which prevents distortion of the work and contributes toward efficient use of heat in all welds. The “friendly” alloying tendencies of nickel make its alloys easy to reproduce instantaneously, and the wide variation in composition without change in properties gives useful leeway. The high ductility prevents cracking due to cooling strains. Fluidity of the molten metal helps to obtain good penetration. Malleability allows forging and machining of finished welds. The major influences to guard against are the, tendency for gas exudation in solidifying, lowered ductility in some alloys at high temperatures, susceptibility to attack by sulfur atmospheres, and too high fluidity which makes overhead and position welding more arduous. Brazing alloys and silver solders (19) make usefully strong and corrosion-resisting joints for many purposes. Although such joints are subject to the differences in corrosion resistance and appearance of the joining materials, the silver solders particularly are to be recommended for many places where the high heat and other requirements of autogenous welding are undesirable. Soldered joints on high-nickel alloys are practical, using a range of tin-lead solders from pure tin to pure lead. Taking the copper-nickel and nickel-chromium alloys as examples, more care is progressively necessary in surface preparation as the nickel content increases. As chromium increases and nickel decreases, the ability to obtain proper bonding and adherence becomes distinctly less. Riveted and screwed joints and other joints where corrosives can penetrate small interstices can be used under mild
The addition of nickel, nickel and copper, or nickel-copper and chromium in amounts from 20 to 30 per cent produce an austenitic structure in cast iron ($3, 85, 29, SO) with certain useful changes in properties. Possibly the most important of these is an improved corrosion resistance. The typical results are shown in Table 11. The corrosion-resistant properties are variable to some extent by variation of the alloy constituents. The figures of Table I1 were obtained on Xi-Resist, approximately 14 per cent nickel, 6 per cent copper, and 3 per cent chromium. The relative availability, reasonable price, and ease of use of the addition agents used to produce this alloy make this corrosion-resistant combination very economical. Manganese may also be employed to help in the production of the austenitic structure, but its presence means considerably less corrosion resistance. The corrosion resistance of properly alloyed material may roughly be considered between that of cast iron and bronze, but much more like bronze than cast iron. Some of the physical properties furnish useful variations from those of ordinary cast iron. The Ni-Resist composition is as machinable as ordinary cast iron. A property of distinct value in connection with corrosion resistance is a resistance to erosion superior by amounts depending on the particular type of service or test. Since in such types of service as pumps and valves the wear due to erosion and corrosion is not really distinguishable, this property is a practical asset. Although the strength and ductility figures are not very different from cast iron, Ni-Resist has an inherent toughness that is a definite improvement. The chromium content affects these properties, more chromium making for higher strength and hardness. By adjusting the chromium or the chromium-silicon content, sufficient variation in properties is available to enable considerable freedom in design. A higher heat expansion makes possible special uses in conjunction with the high expanding nonferrous alloys; high electrical resistance (with constancy under temperature change) and no response to magnetic force encourage uses in electrical machinery. %Resist is quite resistant to oxidation at high temperatures and is free from the usual volume changes caused by high heat on cast iron.
TABLE11. CORROSION RESISTANCE OF CASTIRONS
Type of Corrosive Atm. .4tm. after 30 days Atm. after 90 days Atm. after 1.5 yerqrs Water spray, vertical Water spray horizontal Aerated t a p L a t e r immersion 3% serated KaC1 12.5y0 fermented molssses soln. after 120 days C O r s a t d . hot t a p water a t 95” C.6 Ferric sulfate 5 aerated HzSOI 5 7 aerated HC1 10% aerated HC1 20% aerated HCI Hot caustic (from evaporator concentrating to 100-130 T W for 54 days) Ni-Resist, 14% Ni, 6% C u , 3% Cr. b Corresponding t o bad boiler water.
a
Weight Loss, M a . / S q . Dm./Day Austenitic Plain cast iron,a cast iron, rusts rusts superficially readily
9.5 7.9 3 to 4 6.6 17.6 50
59.7 63.5 30 to 40 207.5 244.0 67.2 190
10 110 17,000 350 507 598 1111
360 660 32,000 30,000 26,665 29,475 33,270
7.8
:10
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INDUSTRIAL AND ENGINEERING CHEMISTRY
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Special Alloy Irons An extremely hard, white cast iron, unmachinable and possessing a hardness in excess of 600 Brinell, has been developed and named “Xi-Hard.” It contains approximately 4 to 5 per cent nickel and 1.25 t o 2 per cent chromium. Its application to oil production equipment has not been developed, although it has been used for welding rods in patching worn surfaces, for sleeves in working barrels, and for caterpillar-type tractor tread idlers. The need to shape surfaces by grinding has deterred the use of this unmachinable material in favor of the alloy-hardened, as-cast or heattreated machinable compositions. Figure 2 illustrates its properties in comparison with an ordinary base composition of cast iron.
Nickel-Clad Steel In response t o a demand for heavy equipment for chemical plants, such as caustic evaporators, with corrosion-resistant interior, a practicalmethod has been worked out forthoroughly bonding a thinner nickel sheet t o heavier steel (7-9). This product can be rolled into plates or even sheets of any convenient dimensions. The resulting product is as strong and malleable as steel and can be readily joined by welding. A pure nickel welding rod is used, usually backed by a heavy steel weld. The whole process of bonding and rolling is simple, because of similar properties of nickel and steel and their similar hot-rolling temperatures. The same similarities make practicable the fabrication of nickel-surfaced equipment from the clad product. The nickel layer, usually 10 per cent of the total although this may vary, has all the corrosion-resisting properties of solid nickel. In heavy equipment it is sufficiently thick to stand any usual corrosive conditions or handling, such as bending, hammering, and polishing. It is at its best in heavy plates. Thinner sheets are under the disadvantage of high rolling costs and thinness of the nickel layer.
Nickel Electroplate ( 2 8 ) This old material has hardly received the attention it deserves as a corrosion-resisting material, because of certain phases of its development. The old fashioned plater used plating conditions empirically developed, and was satisfied .Do 1
.m
FIGURE 3 POROSITY OF COATINGS OF HOT-DIPPED TIN AND ELECTROLYTIC NICKEL AT VARYIXG THICKNESSES
.ooo8
.OW7 c
< .@I06
(Hot water) x From Slrauwr Brenner,h Blum
I-JZ
?
s
(Ferroayl) A From Mac Naughtan (200-300)
.@I05
(Hat water)
L
.0004 .c
z %--
--a,_
I l l
I I
.oOOl
0
---- ------, ---I
.0003
.0002
if he could cover an article fairly well with a coat which would polish t o a good finish and remain attached to the base metal until it had stood some indefinite period of service. The thickness of the nickel coat and the strength of its adherence were only imperfectly known, but still it could be polished to a beautiful finish and served as a mediocre protection from the weather. A more thorough understanding of the electroplating process has developed during the last ten or fifteen years, starting with the realization of the importance of proper hydrogen-ion concentration and continuing through realization of the effect of hydrogen ion, circulation rate, current density, and composition of the electrolyte on the ductility, adherence, soundness, and strength of the plate It is now possible to plate nickel on a variety of base materials, which must be properly prepared; the electroplate is perfectly adherent and sounder than furnaced metal, with a range of physical properties wider than rolled metal, and the plate can be made as thick as is desired. Such electroplates are being made commercially in England but not in this country. Their cost is no greater than for the ordinary decorative plate plus the cost of the added nickel. To double the weight of the heaviest nickel coat made today and thus chemically protect the base metal completely would require about 2.5 cents per square foot for metal, or less than five dollars for a 6-foot cubical tank.
Literature Cited ,.lj Ackernian, D. E., Metals Handbook, pp. 1241, 1246-7, 1250-1, 1252-3, 1254-5, Am. Soc. Metals, 1936. (2) Burchfield, W.F., Ibid.,pp. 1263-71. (3) Burchfield, W. F., Intern. Nickel Co., Inc., Tech. Bull. TS-5 (1933). (4) Bur. Standards, Bull. 100 (1921). (5) Flocke, F. G., Schoener, J. G . , and McKay, R. J., Intern. Nickel Co., Ino., Tech. Bull. T-2 (1932) and T-8 (1935). (6) Flocke, F. G., Schoener, J. G., and McKay, R. J., Sheet Metal Worker, 24, 260-1 (Aug., 1933). (7) Humpton, W. G., “uston, F. P., and McKay, R. J., Mining and Met., 12, 90-3 (Feb., 1931). :81 Humpton, W. G., Huston, F. P., and McKay, R. J., Steel, 88, 44-50 (June 4,1931). (9) Huston, F. P., Intern. Nickel Co., Inc., Tech. Bull. T-4 (1933). TS-2 (19321, and TS-4 (1933). (10) International Nickel Co., Inc., preliminary tech. bull on “Machining Monel Metal, Nickel, and Inconel.” (11) Ibid., on “Monel Metal Castings.” (12) International Nickel Company, Ino., data book on “Monel Metal. Rolled Nickel. and Inconel.” 1933. (13) International Nickel Co., Inc., Tech; Bull. T-5 (1932). (13A) Ibid.,T-9 (1935). (14) LaQue, F. L., Intern. Nickel Co., Inc., Tech Bull. TS-3 (1932), TS-7 (1935), and TS-8 (1935); LaQue, F. L., and Searle, H. E., Ibid., TS-1 (1933). (15) McKay, R. J., IND.ENG.CHEM.,15, 555 (1923). (16) McKay, R. J., Intern. Nickel Co., Inc., Tech. Bull. T-7 (1933). (17) McKay. R. J., Metals & Alloys, 4, 177-80, 202-4 (1933). . . (18) Ibid., 7, 193-8 (Aug., 1936). (19) McKay, R. J., Western Machinery World, 22, 256-7 (June, 1931). 3 0 ) McKay, R. J., Fraser, 0. B. J., and Searle, H. E., Am. Inst. Min. Met. Engrs., Tech. Pub. 192 (1929). 2 1 ) McKay, R. J., and Wfrthington, R., “Corrosion Resistance of Metals and Alloys, A. C. S. Monograph, New York, 71, Reinhold Publishing Corp., 1936. Merica, P. D., Metals Handbook, pp. 1257-60, Am. SOC.Metals, 1936. ,~P3)Mond Nickel Co. Ltd., tech. bull. on “Austenitic Cast Irons,” 1932. (24) Mudge, W. X., Metals Handbook, pp. 1261-2, 1273-4, Am. SOC.Metals, 1936. (25) Pearce, J. G., Metallurgia, Jan., 1932, 81. (26) Pilling, K. B., Metals Handbook, pp. 1244-5, 1248-9, Am. SOC. Metals, 1936; Pilling. N. B., and Kihlgren, T. E., Ibid.,pp. 1240, 1242-3. :27) Searle, H. E., and LaQue, F. L., Intern. Nickel Co., Inc., Tech. Bull. T-10 (1935); Searle, H. E., LaQue, F. L., and Dohrow, R. H., Ibid., TS-6 (1934); Searle, H. E., and Worthington, R., Ibid.,T-3 (1932), and T-6 (1933). ~
v) VI
f
VOL. 28, NO, 12
--A
--,.
--
----,
DECEMBER, 1936
INDUSTRIAL AND E N G I N E E R I S G CHEMISTRY
(28) Thompson, J. F., Kent's Mech. Engrs. Handbook, 10th ed., pp.
529-34, New York, John Wiley & Sons, 1923. (29) Vanick, J. S., paper presented before Am. Foundrymen's Assoc., (30)
(31) 33)
(33) (3i)
Birmingham, Ala., 1935. Vanick, J. S., and Merica, P. D., Trans. A m . SOC.Steel Treating, 18, 923-34 (1930). Wadhams, 9.J., Metals Handbook, pp. 1236-9, .4m. Soc. Metals, 1936; Wise, E. M., Ibid.,p. 1272. Worthington, R., Intern. Nickel Co., Inc., Tech. Bull. T-1 (1932). Worthington, R., Ji'arl'ne Eng. & Shipping B g e , Sept., 1931. Forthington, R., X e t n l P r o g r e s s , 24, No. 1, 20-4 (1933).
RECEIVEDOctober i , 1936.
..
Discussion I. B. McCORKLE National Tube Company, Pittsburgh, Pa.
I
S ADDITION to problems of corrosion resistance of ferrous materials and their ability to give satisfactory service a t elevated temperatures, the chemical engineer a t times must employ his materials a t subzero temperature. I n general, steels become stronger and less ductile as the temperature is lowered. -Also, as the temperature is lowered, steels in the notched condition show a rapid drop in their ability to absorb energy in the impact test. I n the unnotched condition, there is apparently little if any embrittlement due to low temperatures. However, all commercial materials are more or less notched owing to euch causes as threads, too sharp fillets, pitting from corrosion, or even carelessness in handling. Unfortunately there is no way to translate impact values directly into design, so that the engineer in his selection of materials must set himself a more or less arbit,rary value. The minimum acceptable value must be the result of experience. Some designers of low-temperature equipment consider as satisfactory a minimum of 10 foot pounds a t the working temperature. Until recently this value could not be met consistently a t -50 O F., for example, even with soft steel, unless it were quenched and tempered. Aside from the expense, heat treating is often impracticable. It has been found that' alloying with nickel will affect considerable improvement. The recent development of the so-called fine-grained steels has led to remarkable improvement in plain carbon steels with respect to low-temperature impacts. There is also indication that the improvement effected by nickel is further enhanced by the fine-grain treatment. For example, t,est results on a 0.15 carbon-0.50 chromium steel showed less than 10 foot pounds a t -50" F., whereas a steel similar in composition, but differing in that it was of the fine-grain type, gave over 120 foot pounds. Considerable advances in the ability to produce steels with good impact properties a t low temperatures may be expected in the next few years. RECEIVED October 9, 1936.
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WROUGHT COPPER BASE ALLOYS D. K. CRAMPTON Chase Brass & Copper Company, Waterbury, Conn.
Copper tubes are being increasingly used for all water supplies, for pulp lines in the paper industry, air lines, oil supply lines, vapor lines, etc. Red brass is the preferred material from the corrosion standpoint for most corrosive waters. In the condenser tube field the cupronickels are gaining ground. The silicon bronzes are being increasingly applied in many diverse fields-for instance, tanks, kettles, evaporators, bolts, springs, agitators, etc. One of the latest applications in the paper industry is for Fourdrinier wire. Some of the newer alloys comprise aluminum brass for condenser use and particularly the recent modification containing both tin and aluminum. Antimony is being used in many brasses t o prevent dezincification. An alloy of great promise is nickel-aluminum bronze of rather high nickel and aluminum content. In the welding field, coated rod for metallic arc-welding and nonfuming brazing rod are important accessories t o fabrication of chemical equipment. A recent development is that of composite tubes for withstanding serious corrosion in oil refinery tubes. EVELOPMENTS in alloys as with other products usually take place over a period of years, a n d startling innovations a r e seldom brought forth in a short time. Some of t h e comparatively recent copper alloy developments have to do with extended uses of t h e well-known established alloys and others a r e of t h e nature of new materials. A few examples from each field will be described.
Extended Uses of Older Alloys COPPERTUBES.T h e metal copper has found many new and enlarged fields of use. With t h e advent of suitable fittings of t h e flared or sweated type, copper tubes are more widely utilized t h a n formerly. I n t h e plumbing field this product is highly suited t o most 71-ater conditions and combines all of t h e
