Institute of Engineering Science of the Ural Branch of the Russian Academy of Sciences (Ekaterinburg, Russia):

Potapov A. V., Cand. Eng., Senior Research Fellow, e-mail: potapovai@list.ru

Ural State Federal University (Ekaterinburg, Russia):

Shestakova E. N., Post-graduate, e-mail: shestakova001@mail.ru

Orlov G. A., Dr. Eng., Prof., e-mail: grorl@mail.ru

Belikov S. V., Cand. Eng., Ass. Prof., e-mail: S.V.Belikov@urfu.ru

The article presents 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: fi nite temperature deformation should not be be-low 900 °C, the temperature of the forging — 1150 °C . The range of pearlite to austenite transformation have been determined. It has been established that the transformation range is located in the temperature 750–790 °C. The recommended austenitizing temperature is in the range 880–920 °C. The increased hardness of the hot rolling rolls of the steel (250–350 HB) should be provided by the normalization with tempering. The steel hardenability has been determined by Jominy test after heating to temperatures up to 850 and 900 °C. It has been shown that the increasing the amount of alloying elements in steel enhances 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. According to its properties steel C1,4Cr2NiMoWNb can be recommended for manufacturing solid-forged rolls and bandages for composite rolls of hot rolling process from ingots weighing up to 10 tons.

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