Effects of Ti Addition on Austenite Grain Growth during Reheating of As-Cast 0.2 mass% Carbon Steel

Effects of Ti addition on grain growth in reversely-transformed austenite structure during reheating of the as-cast 0.2 mass% C steel have been investigated for a Ti concentration range between 0 and 0.2 mass% and heating rates from 0.014 to 2.5°C/s. The austenite grain growth during reheating is retarded by the Ti addition and such an effect becomes stronger with the addition of higher amount of Ti. This retarding effect is ascribable to the pinning effect of fine Ti(C,N) particles which should precipitate from the as-cast structure during the reheating process. The experimental results on the grain growth behavior are well explained by the grain growth model including the Zener force and counting reduction of the pinning effect due to the existence of the coarse Ti(C,N) particles crystallized during the solidification