1. Department of Material Science and Engineering, Southeast University, Nanjing 210096, Jiangsu, China; 2. Technology Center of Jiangsu Shenyuan Special Steel Company, Ltd., Xinghua 225722, Jiangsu, China
Abstract:Grain growth and its kinetics during solid solution treatment of 6Cr21Mn10MoVNbN steel in a temperature range from 1000 ℃ to 1250 ℃ were investigated. The experimental results show that the dispersed carbonitride in the steel greatly restrains grain growth. The grain size and Rockwell hardness are decreased a little by solid solution treatment at the temperature below grain coarsening temperature(1150 ℃) due to undissolved carbonitride, but grain grow rapidly and Rockwell hardness decreases quickly by solid solution at >1150 ℃. Grain growth increases exponently with the increasing solid solution treatment temperature. At the temperature from 1050 ℃ to 1100 ℃, the activation energy value for grain growth is 189.9 kJ/mol, which means that the grain growth mechanism is self-diffusion controlling process, and the grain growth kinetics equation is given.