1942: Metallurgy

A war economy such as the world is facing today, may well be expected to have an important repercussion upon technical developments. That is just as true in metallurgy as it is in other branches of science. Steel, copper, aluminum, manganese, all of the more commonly consumed metals, have been in such tremendous demand for the production of war goods, that very little has been left for purely civilian consumption. Some of these metals have been so scarce that unprecedented measures had to be taken to insure their being used exclusively in the war effort. The need has been so great that extra precautions have had to be taken to forestall waste, and effect conservation.

During the past year conservation and waste-saving methods have undoubtedly taught the consumer much that he would not otherwise have learned. Such war-time restraints as have been found necessary have undoubtedly also developed ingenuity which technologists may not have hitherto exercised so readily, and have hastened improvements few thought possible twelve months ago.

The scarcity of tin resulting from the loss of Malaysia by the allied nations has made it necessary not only to set up a large tin smelter in this country, but also to expand detinning establishments for the recovery of tin. It has brought into full commercial use an electroplating process which requires only approximately a third of the amount of tin per given unit of area as was used in the older processes. Welding has been adapted and its technique so improved that there is a considerable saving in the metal required in a finished article, and a tremendous saving of time in prefabrication. No more spectacular example of this can be cited than what has happened in shipbuilding. Merchant ships are today being welded throughout, with a resultant immense saving in metal and in man-hours of labor.

So great has been the war demand for so-called scarce metals (scarce only because of war consumption), that unprecedented methods have been adopted for the collection and disposition of scrap.

Approximately 50 per cent of an open-hearth melt of steel may be scrap. The percentage has, at times during the past year, fallen as low as 40 per cent, but under such conditions the time of a melt is lengthened and the steel-making process prolonged. Steels containing both low and high alloy contents are usually made in the electric furnace and by the crucible processes. It has been found possible to recover some of the alloying elements, such as nickel, copper, chromium and manganese, etc., from scrap. This has proved to be a notable development.

The steel industry is thoroughly prepared to act upon such changes, as it has set up a committee to study metallurgical standards and to recommend changes consonant with today's realities. This committee has discovered by experiment that many of the richly alloyed steels can be replaced by leaner alloyed steels without jeopardizing the results. Changes and improvements in this field are not to be disclosed at the moment because of war censorship, but it is quite obvious that armor plate is important in this struggle, and any steps taken to stretch the available quantity of armor plate, even though it means the leaning up of the metallurgical specifications, is something greatly to be desired.

Early in 1941, demand for nickel began to exceed supply by a substantial margin. Armor-plate steel is toughened with nickel and the metal is added to stainless steel to enhance the ability to resist corrosion and to impart ductility. The United States produced only 554 tons in 1940, but Canada controls 90 per cent of the world supply. Cuba's large deposits of low-grade ore are being intensively developed.

Almost a year before Pearl Harbor, Industry's Technical Committee on Alloy Steel released the results of a study which showed how delicately blended compounds of chromium and molybdenum could do much of nickel's work in the electric and open-hearth furnaces of the nation. This change was abruptly nullified when chromium was put on the ration list early in 1942. A new set of steels had to be invented, each one as lean as possible in alloys. The Committee halved and quartered the amounts of alloys all along the line. Experimental heats were melted, tested, then put to use with results even better than anticipated. Many of the new lean steels — called the N.E. (National Emergency) steels — actually proved better at their individual jobs than some of the richer alloy steels used extensively in pre-war days. The Army and Navy now specify the new low-alloy grades as fast as favorable tests are reported.

An outstanding advantage of the new steels in war time, is that they require less virgin alloy materials, and can be made almost entirely from scrap steel. Scrap piles have become alloy mines. The Committee knew that because of the generally increased use of alloy steels in recent years, the residual contents of nickel, chromium and molybdenum were rising in both steel-plant scrap and purchased scrap, and they drew their plans accordingly. The yield of alloys from scrap has far surpassed all expectations.

In the post-war period, the intrinsic merit of many of the new steels will still remain and they will be thoroughly adaptable for peace-time applications.

Chromium is needed for tool steel, for armor plate, and ammunition. To meet military and essential civilian requirements in 1943, three times the tonnage used in 1939 will be needed. Large low-grade deposits of chromite ore, helpful in the emergency, have been developed in Montana, California and Oregon. The domestic output in 1943, as a result, will be as large as the pre-war imports, but the situation remains critical.

Eighty-five per cent of the world's molybdenum supply is produced here. Molybdenum imparts some characteristics to alloy steels that no other metal does. In the early stages of the war it was widely substituted for tungsten, chromium, nickel and other scarce alloys. Now the formerly plentiful metal is also scarce. It is expected, however, that domestic supply will increase about 15 per cent in 1943.

Large imports of tungsten in 1940 and 1941 helped build a stockpile of this metal, needed for cemented carbides and tool steel. Domestic production has been stepped up sharply in the last few years and a California deposit has been developed which will yield 17 per cent of the new tungsten this year. Idaho is producing 27 per cent of the domestic tungsten. The net shortage of tungsten in 1942 was estimated at somewhat over 10 per cent.

High-speed cutting tools are made of tungsten steel, because the metal stays hard at high temperatures. Production in this country amounted to 5,120 tons in 1940, but for 1942 the amount available was about twice as great. Idaho deposits were found when the situation looked blackest. Bolivian ore is another source that helps offset the loss of China's excellent tungsten ore, once the major part of United States supplies.

Domestic production of vanadium has doubled since 1937, but imports in 1942 were down somewhat from 1940. One large domestic producer is making arrangements to mine a very low-grade marginal ore which will yield an additional 2,200,000 pounds of vanadium. In 1943 production of this metal will be doubled and WPB officials do not expect a serious shortage.

Nickel is essential for steel for armor plate — projectiles, tool steel, engine parts and guns. Nickel is produced in the United States only in negligible amounts — about 3,500 tons annually, as compared with Canadian production in 1939 of 102,000 long tons. Much nickel is gathered from scrap materials. Essential 1942 demands were about four times those of 1938, they will jump to five times in 1943. The most significant possibility of expanding American supply is increasing nickel imports from Cuba.

Added to lead, antimony makes a metal brittle enough for bullets and shrapnel. Antimony sulphide is used as a primer for shells. The United States has never produced much antimony from mines, and in 1940 the take had dropped to 494 tons. Most antimony has come from China. When that source was cut off, new smelters were set up to process ore from Mexico and Peru. Fortunately deposits in Idaho turned out to be larger than the reserves marked out in preliminary explorations.

About 12.5 pounds of manganese is needed to desulphurize and deoxidize every short ton of steel. Standard grades are made only from high-grade ore, and United States stocks of high-grade ore are small. In peace time, about 97 per cent of our supply comes from abroad, mostly from Africa, Russia and British India, so that main sources of manganese still are controlled by friendly nations, but shipping shortages make sources in this hemisphere more important. Brazil and Cuba are increasing their normal shipments to the United States. Within the continent, reserves of low-grade ores in the southwestern and eastern states are being exploited with new reduction methods.

Germany and Italy control the world's greatest supplies of mercury. Mercury is used in anti-fouling paints for ships, in fungicides, and in scientific work. Mercury fulminate is a sensitive compound used to set off the main charge in explosive shells, but lead azide is replacing it. United States mercury production amounted to 37,777 flasks of 76 lb. each in 1940. Reserves of mercury were dwindling fast until discovery of a new source in Idaho bettered the position. With output from Mexican mines increasing, and new deposits opened up in Canada, the outlook for mercury is more promising than it has been.

Magnesium in its combined state is the fifth most abundant metallic element in the earth's crust. It is present in sea water, in brines occurring in underground deposits, in magnesite, dolomite, brucite and other calcine ores which are present literally in hundred-mile patches in the United States. Magnesium is separated from ores by three processes. The first draws magnesium salts from magnesite and other ores by combining chemicals with the ores. The magnesium salts then are broken down by electric current, into magnesium metal and the by-product chemicals.

Other ore processes employ gas or other forms of reducing agent instead of electricity, and are important because they help relieve the pressure of demand for electric power. Most important in this category is the ferrosilicon process. Ferrosilicon is an iron alloy made from common sand mixed with low-grade iron ore or scrap iron. It is added to prepared dolomite, a common limestone ore, and the mixture is heated in a near-vacuum, to distil magnesium metal.

The raw material from which aluminum is made is now produced from low-grade bauxite and clay under a new refining process. This process would enable alumina plants to mix a substantial quantity of clay with high-grade bauxite, conserving the limited domestic bauxite supplies. The refining process can also be used to extract alumina from low-grade bauxite.