Austenite grain growth behavior of V and Nb-V microalloyed high-carbon steels

Effect of Nb addition on austenite grain growth behavior of V microalloyed high-carbon steel at different elevated temperatures for different time was experimentally studied. The results show that no obvious coarsening of the austenite grain size of the steel containing Nb is observed at the temperature below 1100 and a large amount of NbC precipitates disperses in matrix, and the activation energy for migration of austenite grain boundary is 44.2 kJ/mol. The austenite grain size of Nb-free steel continuously coarsens with increasing heating temperature and no anti-coarsening ability below a specific temperature is found, and a small amount of VC precipitates disperses in matrix, and the activation energy for migration of austenite grain boundary is 197.2 kJ/mol. V decreases the dissolution temperature of NbC at a given austenitizing temperature for the high-carbon steel. ©, 2015, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.