Recrystallization of 55KhGR steel during high temperature thermomechanical treatment

Abstract

1. High temperature thermomechanical treatment of 55KhGR steel at 950–1100°C results in recrystallization of austenite which is determined by the temperature and the degree of deformation. 2. Deformation of 55KhGR steel at 850 and 900°C does not lead to recrystallization of austenite due to rolling regardless of the degree of swaging. 3. Deformation at 950°C is accompanied by recrystallization due to rolling when the degree of swaging is higher than the critical degree (>5–15%) and to collecting recrystallization when the degree of swaging is in the critical range. 4. Deformation at 1050–1100°C results in collecting recrystallization of austenite regardless of the degree of swaging. 5. The cooling rate in water or in oil used in high temperature thermomechanical treatment has no effect on the grain size of the austenite. 6. The maximum ultimate strength results from recrystallization due to rolling. Collecting recrystallization resulting from high temperature thermomechanical treatment considerably decreases the ultimate strength of 55KhGR steel.