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TechnologyProduction of coke Wet and dry quenched coal coke made in the integrated works is produced from low sulfur coals (0.3–1.0% content) found in Kuznetsk, Pechersk and Yakutsk coal fields with high level of stability of coke quality indices by ash content — 84.9%, sulfur — 100%, moisture — 87.2%, volatile matter — 94.3% and strength coefficient — 99.2%. Recovered from the coke-oven gases are coal tar, ammonia sulfate and benzol. Production of sinter Today the automated batching of the charge components is introduced in the sinter shop and the technology of fluxed sinter production is mastered and that greatly increased blast furnace output and improved pig iron quality. Blast Furnaces Four blast furnaces produce steelmaking pig iron, foundry pig iron, chromium-nickel pig iron and blast furnace ferromanganese. The main initial product for pig iron production is the integrated works’ own sinter, pellets from ore mining and concentration plants of Kursk Magnetic Anomaly and from the Urals and local chromium-nickel ores. The initial product for ferromanganese melting is manganese ore and concentrates of Kazakhstan deposits. Steel making industry Open Hearth Furnace Shop (OHF-Shop) There are four one-type open hearth furnaces with nominal charge of 450 tons and two tandem furnaces with charge of 2X250 tons. All the furnaces are fixed basic furnaces and operate using scrap ore process with hot metal. There are four casting platforms in the casting bay where steel top casting into slab molds (ingot weight is 11.7, 13 and 14.5 tons) and bottom casting into bloom ingots (ingot weigh is 8.3 tons) are performed. Mixers departments №1 and 2 accommodate two mixers with capacity of 1,300 tons each for steelmaking pig iron storage. A specific feature of the “Ural Steel”’s product range is that with the huge production volumes it melts exclusively killed steel, including quality carbon, low alloyed and alloyed steels. Steel containing less than 0.025 % sulfur by mass accounts for more than one half of the total output. Such technologies as slag cut off when steel is tapped from the furnace into ladles with basic lining, inert gas (argon or nitrogen) stirring in the ladle, aluminum wire feeding to alloy steel and casting with inert gas shielding of the metal stream against oxidation are widely used in OHF Shop to improve the quality of steel. Implementation of this integrated secondary treatment technology has ensured steel homogeneity in chemistry, improved the quality of melted steel and finally has provided high quality rolled products to be produced. Electric Arc Furnace Shop (EAF Shop) Technological procedure used in EAF Shop provides for the production of clean steel with sulfur mass content less than 0.005% and phosphor less than 0.015%; as well as steel cleanliness is high in relation to nonmetallic inclusions. This technology guarantees production of rolled steel products with mechanical properties which exceed the requirements of Russian and International standards. Rolling mills 1,250 mm mill rolls ingots weighing 8.3–13.0 tons into 300 x 320, 330 x 510 mm blooms and slabs 130–300 mm thick, 600–1,150 mm wide and 1,300–6,000 mm long. The adjustage bays accommodate unheated and heated pits for slow cooling of blooms and slabs made of alloyed and high-alloyed steel grades. Depending on alloying degree the metal is subject to slow cooling in unheated pits or special thermal treatment in heated pits to avoid flake and crack formation. Plate rolling mill №1 The purpose of this shop is to roll slabs in 2,800mm mill into plates 8–50 mm thick, 1,500–2,500 mm wide and 4,500–12,000 mm long from low-alloyed and carbon steel grades, including high-strength steel grades for special applications. The technology of plate rolling, developed at “Ural Steel”, ensures stable mechanical properties and high tensile properties of final products due to introduction of the following up-to-date techniques: Reheating of slabs is done in four furnaces heated with the mix of blast furnace and natural gases; rolling is done in roughing two-high stand and finishing four-high stand. Heat treatment of metal is done in four heating furnaces with roller hearths. Ultrasonic inspection of rolled plates is performed in automated plants “Nukem” and “Sever-6-08-2800 VT” installed in flow line of the 2,800 rolling mill which provide 100% continuity control of rolled plates. Plate rolling mill №2 The shop is designed to produce strip still of 5–25 mm thick, 200–600 mm width and 4,000–12,000 length out of low-alloyed and carbon steel on the 800 mill. For heat treatment and pickling the strips are delivered to heat treatment and pickling department for normalizing, hardening with tempering and descaling the strips by mechanical means or pickling. Cut-to-length strips are stacked. Maximal weight of transported strips is 1,400 kg and maximal length is 2.0–12.0 m. Strips are stacked 150–500 mm high on piling tables. The technology of strip rolling, developed at “Ural Steel” ensures stability of mechanical properties and high tensile properties of final products due to the introduction of the following up-to-date techniques: - The rolling mill is equipped with modern walking-beam reheat furnaces with flat flame burners and non-impact billet discharge system. Metal reheating is performed in two continuous walking-beam furnaces heated with natural gas. Rolling is performed in universal roughing stand and in a group of four finishing stands: universal stands №1 and 2 and four-high stands №3 and 4. The heat treatment and pickling department provides for heat treatment and strip pickling in the solution of hydrochloric acid. Strips reheating is performed in two through-type roller-hearth furnaces with multi-row charge. Pickling line includes four pickling baths located in sequence, two tanks for rinsing and neutralizing bath. Section-rolling mill The shop is designed to produce square billets of 90 x 90 mm to 220 x 220 mm in cross-section, round billets 90 to 250 mm in diameter, I-beams of Standard №36, equal angles with flange widths from 200 to 230 mm and channel section №40 on the mill950/800. The rolled stock heating is performed in four continuous heating furnaces. Then they are rolled in 950mm two-high stand, in two three-high non-reversible stands and 850mm two-high non-reversible stand. Heat treatment is done in two walking beam furnaces. Stamped profiles plant The following technological processes are applied in the plant: blanking in presses, hardening in through-type pusher furnaces and annealing in bell-type furnaces. Low temperature annealing technology of rolled strip made of carbon quality steel grade has been developed and mastered in this plant, which is intended for finished blanking. “Ural Steel” is the only enterprise in Russian steel industry which has an experience in manufacture of track shoe strip and finished caterpillar tracks for 330, 500 and 800 h.p. heavy industrial caterpillar tractors working under extreme conditions at temperature from 50 °С to +50°С. |
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