|SHESTAKOVA Elena||Ural Federal University|
|Spoluautoři POTAPOV Alex, ORLOV Gregory|
The article present high-carbon hypereutectoid steel for the production of hot rolling forged rolls. The steel contains 1.2 - 1.4 % carbon, carbide forming alloying elements Cr, Mo, V and Nb to improve the wear resistance of the roll, and Ni to increase the hardenability. Hot ductility of the steel has been investigated considering segregation of chemical elements in ingots weighing up to 20 tons. It has been found that the possesses steel presented ductility sufficient for hot deformation (forging) with small single compressions. The temperature range of deformation ingot has been found: finite temperature deformation should not be below 900 °C , the temperature of the forging - 1150 °C . The critical points of steel have been determined. It has been established that the transformation range is located in the AC1 temperature 750 – 790 °C. The optimum austenitizing temperature is in the range 850-880 (900) °C. The increased hardness of the hot rolling rolls of the steel (250 - 350 HB) should be provided by the normalization with temper. The steel hardenability has been determined by the end-quench-test due to Jominy method using specimens 25 mm in diameter and 100 mm length after heating to temperatures up to 850 and 900oC. It has been shown that the introduction of Nb in steel increases the depth of the hardened layer. The study of mechanical properties within the temperature range from 20 to 600 °C showed that the addition of niobium increases the heat resistance of the steel. The steel resistance to abrasion steel has been investigated. According to its properties steel C1,4Cr2NiMoWB can be recommended for manufacturing solid-forged rolls and bandages for composite rolls of hot rolling process from ingots weighing up to 10 tons.