ALUMINUM ALLOYS R. H. BROWN AND E. 13. VERISIC, JR. Aluminum Company os America, New Kensington, P a .
I
aluminum for the production of ammonium nitrate fertilizers from natural gas and petroleum, another group of tank cars for shipping these fertilizers is in the course of construction. alloys in the chemical industry was included t o summarize the Aluminum alloys have been used for a number of years to developments in this field. Since t h a t time there has been a handle and ship nitric acid in concentrations greater than 80% marked increase in the use of aluminum for many of the applicaby weight "0,. Recent increased use of red fuming nitrie tions referred t o in t h a t article. The purpose of the present brief acid has resulted in a need for suitable shipping containers for article is t o call attention t o additional developments during the this product, and aluminum alloy drums (30 gallons) are being past year. used Lo ship this strong oxidizing agent. Another product, Because aluminum alloys do not discolor many chemicals, possessing strong oxidizing properties which has recently become they are employed for many products for which water-whiteness commercially available, is hydrogen peroxide in concentrations is a desirable property. The first of a n order of 36 tank cars conof 90% (by weight). As is the case with commercial concenstructed of 6 1 S T 4 aluminum alloy are now in service for the trations available in the past, long term storage containers for shipping of synthetic glycerol ( 1 1 ) . These cars are all of welded 90% hydrogen peroxide are best made from 99.6% alumiconstruction, have 8000-gallon capacity, and are equipped with num ( I S ) . Pumps, piping, and heat exchangers for this product 61ST4 heating coils to facilitate unloading. Aluminum tanks are usually made of aluminum. are used for the storage of molten phthalic anhydride produced Anothe; oxidizing agent whose utility is expanding t o from petroleum o-xylene (6). I n addition to the expanded use of a marked degree is oxygen, as evidenced by plants constructed t o prepare oxygen by low pressure fractionation of air (by LindeFrank1 processes, 10) Recause of their successful operation in relatively large scale pilot plants, harp type air-nitrogen and air-nitrogen-oxygen reversing heat exchangers, shell and tube-type exchangers, as well as high and low pressure toners of all-welded aluminum design are under construction for use in full scale plants (14). The niechanical properties at temperatures of - 320 O F. of aluminum alloys such as are used in the above equipment are at least equivalent, and in some cases superior, t o those a t room temperature as regards tensile strength, yield strength, elongation, and resistance to impact ( 2 ) . It has been demonstrated t h a t aluminum is one of the most suitable materials for equipmenh used to process vegetable oils by several methods, including the Tm itchell, the pressure batch, and solvent extraction (4,9). I n Germany high purity aluminum is used in the construction of reaction towcrs. in which molten wax and air are intimately njixed t o form fatty acids ( 7 ) . The reaction is initiated at 265 O t o 320 O I?., n-hich is lowered t o 212" to 250" F. as the reaction proceeds. Because i t is nontoxic torrard many microorganisms, aluminum has been used in equipment for producing chemicals by microbiological processes. Aluminum has been found t o be nontoxic t o molds producing penicillin (15) and for this reason is used in considerable amounts for equipment in penicillin plants. Rotary type fermenters used in the production of gluconic acid are constructed of aluminum alloys. One such fermenter which operates a t 30 pounds per square inch is a horizontal aluminum drum fitted with aluminum baffles (5). Aluminum has been used in the food inArgon Arc Welding of All-.iluminum Alloy Harp-Type Reversing dustry for the construction of much equipHeat Exchanger Used for Production of Oxygen by Low Pressure ment. A recent installation includes a largo Fractionation of L4ir. Insert Shows Completed Exchanger
N 1947 as part of a review of Chemical Engineering Materials of Construction (3) a four-page article on the use of aluminum
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$976
October 1948
INDUSTRIAL AND ENGINEERING CHEMISTRY
1777
COURTESY STAGEY BROTHERS QAS CONSTRUCTION COMPANY
Aluniinum Alloy Tower 5 Feet in Inside Diameter and 29 Feet 8 Inahes Over-All Height Employs Plates 1.25 Inches Thick for Shells and Is of All-Welded Construction aluminum cone-bottomed flash t a n k for the production of powdered milk ( I ) . This tank has a n over-all diameter of 16 feet 6 inches and a n over-all height of 45 feet. The newly developed agar industry in Australia employs aluminum evaporators t o concentrate filtered agar liquors (8). Work a t the Aluminum Research Laboratories led t o the development of a new product for the fabrication of beer barrels. This product consists of a core alloy of 535 coated on one side with high purity aluminum. The superior resistance t o corrosion of the high purity coating is utilized by drawing the shells with the coating on the inside. These Alclad 535 containers offer considerable promise for handling chemicals with a minimum of contamination. Experimental aluminum roofs for tanks storing sour crude oil are still in service after 20 years in a n area where the normal life of steel roofs is 4 to 5 years. Because of the trend toward the increased use of sour crudes, a number of oil producers have purchased aluminum roofs constructed mainly of aluminum alloy 61 5-T6. Because of its low emissivity, resistance t o atmospheric weathering, and suitable mechanical properties, thin 35 aluminum alloy sheet 0.015 t o 0.032 inch in thickness is now being widely used t o protect the nonmetallic thermal installation in large pipes and towers handling hot liquids and gases. During the year Alcoa industrial roofing sheet became available for industrial roofing and siding. This product not only is resistant to a variety of industrial atmospheres corrosive t o other structural metals but has mechanical properties similar t o 45. T o fill the need for nails t h a t possess a resistance t o weathering in many industrial atmospheres a n aluminum alloy nail of suitable mechanical properties has been developed from 6 1 s composition. There has been much interest in the experimental installation
by the Interstate Pipe Line Company of 4- and 6-inch buried aluminum pipe line t o handle both sour and sweet crude oils (1%). T h e 40-foot lengths of &inch diameter 63S-T6 aluminum alloy pipe weighing 262 pounds, about one third t h e weight of steel for the same service, were joined by argon arc welding in the field. A 1200-foot section of this 6-inch aluminum alloy line has been successfully tested at 1000 pounds per square inch hydraulic pressure. ACKNOWLEDGMENT
The aid of J. P. Balash in compiling data for the tabular section on aluminum alloys is gratefully acknowledged. LITERATURE CITED
(1) Alcan Ingot, p. 4 (March 19, 1948). (2) ArFy and Navy Commercial Handbook, “ANC-5 Handbook,” in
press.
(3) Brown, R. H., and Verink, E. D., Jr., IND. ENG.CHEM.,39, 1198
(1947). (4) Chem. Eng., 54, 109 (1947). ( 5 ) Ibid., p. 141 (1947). (6) Chern. Inds., 59, 68 (July 1946). (7) Zbid., 60, 64 (January 1947). (8) Food Inds., 18, 101 (October 1946). (9) Kenyan, R. L., Kruse, N. F., and Clark, S. P.. IND. ENG.CHEM., 40, 186 (1948). (10) Lobo, W. E., Chem.Inds., 59,53 (July 1946). (11) Oil,Paint Drua Rem?.. 153. 54 (1948). (12) Reed, Paul, Oil GasJ.;46,141 (Aprii29, 1948). (13) Shanley, E. S., and Greenspan, F. P., IND.EN^. CHEM.,39, 15-36 (1947). (14) Stacey Bros. G‘as Construction Co., Cincinnati, Ohio, BdZ. A-48 (preliminary). (15) Stefanik, J. J., Gailey, F. B., Brown, C. S., and Johnson, M. F., IND.ENG.CHEM.,38,666 (1946). RECEIVED July 12, 1948.
