INDUSTRIAL AND ENGINEERKNG CHEMISTRY
I798
(261) Weir, C. E., Carter, J., Newman, S. B., and Kanagy, J. R., J.
Am. Leather Chem. Assoc., 43, 69-95 (1948); cf. Maeser, Ibid., 42,390 (1947). Penetration of leather by water under
dynamic conditions.
( 2 6 2 ) Wellington Sears Co., New York, '6\7inyoi~ Fabrics for Chemical
Filtration and Other Industrial Applications," rnultigraphed bulletin, May 29,1947. (263) Whewell, C. S., Ann. Repts. SOC.Chem. I n d . Progress Applied Chem., 27, 106-20 (1942). Protein fibers. (264) Ibid., 28,88-101 (1943). Prot,ein fibers. (265) White, W. L.,and Siu, R. G . H.. ISD,ESG.CHEM., 39,1628-30 (1947). Resistance of resin-impregnated cotton fabriw to microorganisms. ( 2 6 6 ) Whitwell, J. C., and Toner, R. K., Teztile Research J., 17,99108 (February 1947). Predicting equilibrium moisture relations, with particular reference to textile fibers. (267) Wieschhaus, L. J., Southern Power and Ind., 66, No. 4 , 72-4,76 (1948); cf. C.A., 41,6778g. Application and rnaintcnance of filter-type dust collectors. Various types of clot,h filter fahrim.
VOl. 40, NO. 18
D.R.."Saran," Dow Chemical Co., Midland, Fvlich.. multigraphed, April 21, 1947. Exposition on Saran B-118. including physical and chemical properties. (269) Williams, G. C.,Akell, R. B.,and TaIbott, C. P., Chem. Eng.
(268) Williams,
43,No. 11, Trans. Am. Inat. Chem. Engrs., 685 -96 (1947). Fiberglas packing in gas-adsorbing systems. (270) Wilsdon, B.H., Times TradePng..G, vi (October 1939). Coinpetitors of wool. Technical comparisons. Table of mechanicat properties of fibers. (271) Work, R. W.,Thorne, A. M., axid Livingston, M. R., Phye. Rev., 70,803(1946). Investigation of load-deformation characteristics of Celanese and wool with partioular reference !a use in carpet pile. (272) Wright, R.E.,and Harris, Milton, Chem. Eng. News, 26, 2:-E (1948). Textile fiber developments, review for 1947. (273) Wuhrmann, K.,Schweia. Arch; angew. Wiss. Tech., 11, 138-44 (1945). Structure snd technological properties of fiboik $1: PrOQTesS,
Italian broom. REPEXVED August 113,1948.
R. B. RlEARS AKD S . C . SNYDER Carnegis-Zllinois Steel Corporation, P i t t s b u r g h , P a . HIS paper on low alloy a i d carbon steels summarizes recently published information which is believed to be of interest to chemical engineers. It supplements the article (16) written by the same authors last year. CARBOY S l E E L S
I n a paper by Kinzel ( I S ) the Factors influencing the ductility of welded steel structures are discussed. This paper is of importance to chemical engineers because welded steel vessels and structures are used under a wide variety of conditions in chemical plants. Kinael concludes that several metallurgical factors contribute to the behavior of welded steel structures when they are exposed to impact. Among these factors is the composition of the steels. Generally speaking, other factors being the same, increasing the csxbon content of the steel raises the temperature at which embrittlement under impact occurs. I n contrast to this, certain alloy additions lower the temperature at Tvliich embrittlement occurs. The rewlts of corrosion tests on a series of metals and alloys exposed to sulfuric acid of various concentrations were discussed by Wilkinson (19). He concludes that carbon steel is very resistant to 88 to 98% sulfuric acid at low velocities and a t a temperature of 35" F. He also points out that hydrocarbon emulsion streams containing concentrated sulfuric acid are not corrosive to carbon steel except a t points wliere the stream moves at high velocity relative to the steel surface. The materisls of construction used in the furfural extractive distillation process for the separation and purification of Cd hydrocarbons are discussed in a paper by Buell and Boatright (6). They find that carbon steel is entirely satisfactory for niany uses; such as for solvent transfer lines, solvent heat exchanger heads (but not for heat exchanger tubes), walls, trays, and chimneys of the butylene extractive distillation tom-er (but not for bubble caps), and for the first evaporator in the furfural repurification unit. Brown, DeLong, and Auld (5) give the results of corrosion tests on a number of metals and alloys in dry chlorine and dry hydrogen chloride a t elevated temperatures. They suggest that
carbon steel is satisfactory for continuouti service in dry chluiiue or dry hydrogen chloride a t temperatures up to 400" F. Thsy found that in t h e temperature range from 450' to 500 'F., carbon steel would ignite in contact with dry chlorine. The resistance to corrosion of' wrought carbon steel was compared to that of cast iron in a series of tests by White ( d 7 ) . T e s k included exposures to water vapor, salt spray, sulfur dioxide fumes, mixed acid fumes, and the weatherometer. White concluded that carbon steel was about 15yomore resistant to cormsion than cast iron when both were exposed in the unprotectud condition. Similarly, organic coatings proved to be more pr0tective on carbon steel than on cast iron. For many types of service the metallurgical structure of carbon steel has been found to have negligible effect on its corrosion resistance. I n a recent paper, however, Manuel (14) points out that under some oil ell conditions the metallurgical structure of the carbon steel greatly affects its corrosion resistance. hlicrostructures consisting of well formed pearlite with lamellae which are long, straight, and continuous appear t o be more resistant tc. attack than those containing pearlite which is less we!l formed 01 which is spheroidized. I n a recent article (B), it is noted that carbon steel has pesformed well in the thermal catalytic cracking unit at the Alma, Mich., refinery of Leonard Refineries, Inc., which uses crudes containing 0.9% by weight of sulfur. Carbon steel in the reactor and in the catalyst kiln suffered litlle damage. Severe corrosion was found only in the heater transfer lines and tar separator bottom lines. These lines were replaced with 4 to 6% chromium steel pipe. Phipps (12)points out that dehydration of petroleum products is an effective method of preventing corrosion on the intoriors of carbon steel pipe lines. I t may prove less expensive than going GO alloy steels or to other more costly materisls. NICKEL STEELS
It is concluded by Armstrong anid Brophy ( 4 ) after examinations of steels containing up to 13% nickel, that the 8.5% nickel steel is a promising ferritic constructional material for equipment
INDUSTRIAL AND ENGINEERING CHEMISTRY
October 1948
used in low temperature processing and storage of liquefied gases. This steel is readily weldable by commercial methods and meets mechanical property requirements after welding. It is being tried for a variety of commercial applications including oil well sucker rods, oil well tubing for deep wells, seamless tubing in black liquor evaporators, and solder rolls for the production of tin cans. Uses of nickel steels are discussed also by Morton (18)and by Newell, Manfre, and Cordovi (20). The atmospheric corrosion of low alloy steels is reviewed by Copson (8). He presents durves illustrating that nickel additions (up to 5%) decrease the rate of corrosion of steel exposed a t a marine location (Block Island). The beneficial effect of nickel additions is more pronounced after 5.0 years than after 1.1 years.
'
1799
LOW MOLYBDENUM ALLOY STEELS
A study of the graphitization of cast carbon-molybdenum steels (0.36 t o 0.90% molybdenum) was made by Smith, Urban, and Bolton (2.3, 24). They state that neither heat treatment, nor control of melting procedure or deoxidation practice ensures against graphitization of carbon-molybdenum steel. They indicate that freedom from graphitization is to be sought through the use of those alloy additions which confer greater stability to the carbide (28).
LOW CHROMIUM ALLOY STEELS
Wilder and Tyson (88)claim that steels containing 0.5% or more of chromium, regardless of the deoxidation practice used in their manufacture, are highly resistant to graphitization after prolonged exposure to carbon compounds at temperatures from 900 ' to 1200' F. They found that these chromium-containing steels were more resistant than carbon steels or than steels containing 1.7 or 3.7% nickel. The effectiveness of chromium in reducing corrosion rates of steels used a t elevated temperatures in contact with petroleum products containing sulfur was discussed by Nelson (19). This author gives the following table which lists the relative protection provided by chromium additions to steels for such applications. Chromium, yo 0 5
'7 9
18 (t8 Nil
Relative Proteotion 1.0 2.5 to 3.5 4 . 0 to 6 . 0
6 . 3 to 9 . 0 14 to high
It should be pointed out that the relative over-all cost of processing equipment made of these various steels may differ materially because the cost of fabrication of a piece of equipment may, in some cases, be many times the cost of the material used. Nelson also lists the following steels which have been found suitable for use at various temperatures in contact with petroleum products containing sulfur: Temperature of Service, O F.
Chromium in Steel, To For expensive fittings equipment None 5 7 t o 12 5tO 8 12 to 18 7 to 12 bto 8 12 to 18
For lines and
The scaling of several irons and steels at elevated temperatures was studied by Nicholson and Kwasney (21). Exposures were made to atmospheres of 100% oxygen, 100% sulfur dioxide, and various mixtures of oxygen, sulfur dioxide, and nitrogen. The temperatures investigated ranged from about 1000O F. t o about 1600' F. Under most of the conditions of exposure investigated, a steel contain'ng 4.9% chromium was definitely more resistant to scaling than was carbon steel. I n a discussion of the corrosion and oxidation of metals in contact with high pressure steam, Buster and Romer (7) conclude that chromium-molybdenum steels containing from 2 to 9% chromium and from 0.5 to 1.0% molybdenum are very satisfactory for use with metal temperatures up to 1200 'F. Above this temperature, stabilized 18-8stainless steel is reported as satisfactory. Eilerts and co-workers (9) discuss the results of laboratory tests on the reiative resistance to corrosion of various steels in high pressure gas condensate wells. They conclude that a steel containing approximately 9% chromium provides the best combination of corrosion resistance, physical strength, and cost economy of any of the steels tested. Steel containing 7% chromium also was superior t o the carbon steel now used for gas condensate well tubing, A.P.I. Grade 5-55.
Kerosene Distillate Unit Equipped w i t h Alloys Steel (7% Cr 1% Mo) Tubes
+
White (26) describes the occurrence of graphitization in carbonmolybdenum pipe, particularly in the low temperature region of the heat-affected zone of a weld. I n one case, chain type graphitization in this material led to a service failure of a steam pipe operating a t about 935' F. It has been found that practically all instances of severe graphitization occurred in steels to which appreciable amounts of aluminum had been added. No generally accepted reason for the potent effect of aluminum has been advanced so far. Since steels containing appreciable aluminum tend to be fine grained and since coarse grained steels are generally more resistant to graphitization, this may explain part of the effect. No relation has been observed between the tendency to graphitize and the amounts of silicon, manganese, or residual elements (other than aluminum) present in the steel. There is considerable evidence, however, that additions of chromium (possibly in excess of 0.5%) are beneficial in preventing graphitization. Miller (17)and co-workers report the changes in structure of 0.5% molybdenum steel exposed for prolonged periods of time under laboratory conditions a t 1000"to 1300' F. The steel they used was relatively fine grained but did not show graphitization even after 5000 hours' exposure a t those temperatures. Spheroidization did occur, however. The authors point out that steels may suffer appreciable losses in creep strength as a result of spheroidi-
INDUSTRIAL A N D E N G I N E E R I N G C H E M I S T R Y
1800
zation. Therefore, equipment designed on the basis of the strength for a given microstructure may suffer a significant loss of strength during service at temperatures which cause spheroidization. The creep properties of molybdenum, chromium-molybdenum, and molybdenum-vanadium steels were investigated by Glen (11). He concludes that a 0.5% of molybdenum plus 0.25% of vanadium steel in the normalized and tempered condition has creep and rupture properties much superior to those of a 0.5% molybdenum or a 0.5% molybdenum plus 0.8% chromium steel, GENERAL
A new type of specification for constructional steels based on hardenability bands ( 1 , 30) is now gaining prominence. I n such specifications, hardenability of the steels is specified directly, with chemical composition being of secondary importance. These specifications are probably of more importance in the case of steels used for automotive or other purely mechanical applications than they are for steels used by chemical engineers. A listing and discussion of the new and expanded steel specification tables has been presented in the S.A.E.J. (3) and will appear later in the 1948 “S.A.E. Handbook.” Hawks (19) has published hardenability, tensile, impact, grain size, and inclusion rating data on 32 of the relatively new NE cast alloy steels. Intermediate alloy steels for service at elevated temperatures: were discussed by Miller (16). The qualities required of steels for specific types of equipment used in the oil and chemical industry are described and the effect on properties of various alloying elements are discussed. A table is given which lists the steels most commonly used in petroleum refineries. The effects of various alloy additions on the corrosion of steel in outdoor atmospheres, waters, various chemicals, and gases at elevated temperatures are reviewed in the “Corrosion Handbook” (95) recent$ published by the Electrochemical Society. The data given are probably the most complete that have ever been gathered together in one publication. They are too diverse and comprehensive to summarize here. C. A. Ellinger (10) and associates conducted laboratory corrosion tests in which tap water from Washington, D. C., was circulated continuously through pipes of ten different ferrous materials for periods of time extending up to 10 years. The results obtained indicate that the average depth of pits is smallest on the samples of centrifugally cast iron, copper-molybdenum ingot iron, and nickel-bearing wrought iron (1.72c/, nickel). The copper-molybdenum ingot iron and the nickel-bearing wrought iron also exhibited the lowest losses of weight of the ten materials tested, whereas the cast iron lost more weight than seven of the materials.
Anon., Petroleum Processsng, 3 , 111-13 (1948). Anon., J. SOC.At~tomotibeEngrs., 55, 17-34, 59-61 (1947). Armstrong, T. N., and Brophy, G. R., Am. SOC.Mech. Engrs., preprint (1947). Brown, M. H., DeLong, W.B., and Auld, J. R., IND. ENQ. CHEW.,39,839-44 (1947).
Buell, C K., and Boatright, R. G., Ibid., 39, 695-705 (1947). Buster, P. H., and Romer, J. B., Trans. Electroch.em. Soc., 91,
655 (1947). Copson, H. R., Am.Soc. Testing.Materials,p1ep1intNo.20 (1948). Eilert, C. K., Green, F., Archer, F. C., Hanna, B., and Burman, L. M., Corrosion, 4, 245 (1948). Ellinger, G. A., Waldron, L. J., and Marzoff, S. B., Am. SOC. Testing Materials, preprint 21 (1948). Glen, J., J . I r o n SteelInst. (London),158, 37-80 (1948). Hawks, M. F., Trans. Am. Soc. Metals, 39, 1-40 (1947). Kinzel, A. B., Ibid., 40, 79 (1948). Manuel, R. W., Corrosion, 3,415-31 (1947). Mears, R. B., and Snyder, S. C., IND. Esc,. CHEM.,39, 1219-24 (1947). RLil!er, R. F., Petroleum Engr., 19, No. 4, 178-89 (1948). Miller, R. F., Golaszewski, E. V., and Smith, G. V., Metal Progress, 53, 83-6 (1948). Morton, B. B., Corrosion, 3, 23-4 (1947). Nelson, ’w. L., Oil Gas J . , 43, Pt. 2, 107 (1944). Newell, 13. D., Manfre, J. A., and Cordovi, M. A., Materials &. Methods, 25, 62-7, 159 (1947). Nicholson, J. H., and Kwasney, E. J., Yrana. Electrochem. SOC., 91, 681 (1947). Phipps, H. K., Corrosion, 3, 458-65 (1947). Smith, A. J., Urban, J., and Bolton, J. W.,Trans. Am. Xoc. N e c h . Engrs., 68, 609-24 (1946). Smith, A . J., Urban, J., and Bolton, J. W., WeZdkbg J . ( N . Y e ) * 25, 257s-689 (1946). Uhlig, H. H., “Corrosion Handbook,” New York, John ’Wiley &- Sons, 1948. White, A. E., Jfetal Progress, 52, 371-5 (1947). White, EL. W., Materials & Methods, 26, No 2, 82-5 (1947). Wilder, A. B., arid Tyson, J. D., Trans. A m . Soc. Metals, 40, 233 (1948). TT7ilkinson,E R , Corrosion, 3, 252-62 (1047). Wray, P. R.,I i o n A g e . 160, No. 24, 84-89 (1947). K c c a r v m JUIY 17, 1945.
LITERATURE CITED
(1) Am. Iron & Steel Inst., SOC.
Automotive Engrs., eontributions t o metallurgy of steel, 11, June 1947.
Vol. 40, No. 10
OOURTCBY MYCALEX CORPORATION OF AMERICA
Glass-Bonded Mica Parts 25, 26, 29. Spacer for telephone relay 27, 32. Clamping plate for telephone relay 28. Electrode mounting for level indicator
30. 31. 33.
Six terminal header for transformer Test jack body, for high frequency cirouits Printed circuit base, experimental
