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Battle of the Bricks

Under the conditions of war, the Soviet tank industry, like the entire Soviet industry, faced the problem of a shortage of production resources, which did not allow the tank industry to bring the production of armored vehicles to a higher qualitative and quantitative level. Among the scarce resources that seriously complicated the work of the metallurgical industry in the tank industry, observers point to refractory materials.

Refractories were necessary for the construction and maintenance of open-hearth furnaces in the metallurgical production of enterprises of the People's Commissariat of the Tank Industry (NKTP) of the USSR. This problem was greatly enhanced by the fact that in the second half of 1942 armor-hull production of tank factories began construction of heating and thermal furnaces, which absorbed a significant part of the refractory materials allocated for NKTP.

In 1854 Henry Bessemer, a steel maker of Sheffield, England, gave to the world a successfully developed process of steel making known by his name. Aside from Watt's invention of the steam engine, no invention since that of printing had so profoundly affected the welfare of the human race as Sir Henry Bessemer's contribution. Bessemer's trials, failures and partial successes culminated in an art so well developed that all improvements made since then have been of operating or technical details and of increased scale of operations.

Bessemer steel is made by blowing air at a pressure of from 10 to 30 pounds pressure per square inch through molten cast iron by which silicon, manganese and carbon in the metal is eliminated by oxidation after which sufficient molten iron rich in manganese and carbon is added to give a steel of the desired manganese and carbon content.

There were two kinds of refractory materials used to line the vessel or converter in which the process is conducted. One of these materials, and in this country the most common one, is ground quartz rock which is mixed in a "pug" mill and moistened to the consistency of damp clay. It is rammed firmly in place on the interior of the converter. This is very largely silica (SiO2). As the silicon of the iron, undergoing conversion, is converted into SiO2, there is no chemical reaction between the vessel lining and the SiO2 from the iron. The vessel lining is subjected only to the abrasive action of the iron and slag during the "blow." The process of making steel in a converter of silicious lining is called the "acid" process.

In the conversion of a high phosphorus iron, the phosphorus is eliminated by adding a basic flux to the charge. This is usually burnt lime, as the addition of limestone or dolomite, which are carbonates, absorb heat in driving off the carbon dioxide. The use of a basic flux necessitates a similar refractory lining to the converter. This is made up in such instances of magnesite, which is used in the calcined form and chemically is the oxide of magnesia. This gives rise to the name of the "basic" process.

The production capacity of a furnace depends upon the judgment and care exercised in the selection of the correct kind and quality of brick for each of its parts, and equally upon the care with which the masons do their work. An eighty-ton furnace will contain about 1,000,000 brick, while a forty-ton furnace will require about 700,000. The expense of the masonry is a serious item, as that is the part of a furnace which most often requires renewal. The total output of the furnace is dependent on its durability.

The functions of fire brick are to form a chamber and passages to contain and conserve the heat of the fuel and hold the metal and slag of the bath. In an acid open hearth, silica brick are used for the bed, sides, roof and ports of the furnace. The hearth is made of silica sand sintered into an impervious mass. The life of a well made acid furnace will approximate one thousand heats.

For the needs of the current repair of only open-hearth furnaces in Ural-Mash, in the fourth quarter of 1942, it took 1035 tons of refractory brick, and in the first quarter of 1943, another 800 tons. But only 827.3 and 280.7 tons arrived in the indicated periods, respectively. All this meant that by the spring of 1943, the open-hearth shop of UZTM was facing a real possibility of a halt.

The report on military acceptance at Uralmash emphasized the fact that it was in 1943 that the uneven work of the [open-hearth] shop [UZTM] was observed, which experienced exceptional difficulties in obtaining various materials, especially refractories, fuel and several others. The work of open-hearth furnaces during the war years was largely complicated by the fact that the quality of refractory bricks and other materials was extremely low.

As in Uralmash, serious problems of metallurgical production arose at the Ural tank plant No. 183 (UTZ) during the second half of 1942 - early 1943 Already by the summer of 1942, the production of armor hulls for the T-34 at plant No. 183 had stopped. The main enterprise of the country for the manufacture of armored hulls and T-34 tanks could not independently increase its production. Further growth in the production of medium tanks was largely ensured by the supply of hulls from Uralmash. There was no qualitative shift that could rectify the situation.

In the first quarter of 1943, plant number 183 smelted less than 10 thousand tons of metal per month (for a quarter in total - 29.3 thousand tons). In other words, output remained approximately at the level of the third quarter of 1942. In the second quarter of 1943, steel output increased to 34.3 thousand, and in the second half of the year the plant smelted 12 thousand tons per month, which was 3-3 , 5% more than planned targets. Therefore, it can be argued that only from the second half of 1943, the UTZ began to smelt an increased volume of open-hearth metal.

In the conditions of the development of the wartime situation, the Pervouralsk Silica Plant remained for a long time the only enterprise in the system of the head furnace of the People's Commissariat of Chermet for the production of refractory bricks. The construction of new facilities in Pervouralsk allowed leveling problems, but until the end of the war the metallurgical production of the largest tank factories continued to experience a shortage of refractories.




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Page last modified: 10-04-2019 10:16:49 ZULU