Static recrystallization behaviors of non-quenched steel C38N2 for crankshafts

The effects of austenitizing procedures,deformation temperature,deformation rate,deformation amount and inter-pass time between deformations on the volume fraction of static recrystallization and the residual strain ratio of non-quenched steel C38N2 for crankshafts were carefully investigated by hot simulation tests,quantitative metallography and transmission electron microscopy. Experimental observations show that,the volume fraction of static recrystallization increases and the residual strain ratio decreases when the deformation temperature,deformation rate,deformation amount and inter-pass time between deformations rise. The situation is opposite when the austenite grain size increases,but they change inconspicuously. In addition,the volume fraction of static recrystallization decreases gently when the austenitizing temperature rises below 1250℃. However,it sharply decreases when the austenitizing temperature rises above 1250℃. A mathematical model of the relationship between the volume fraction of static recrystallization and deformation parameters was derived by linear fitting and least square method. Besides,a mathematical model of residual strain ratio concerning the deformation rate term was obtained by modifying the existent mathematical model,and it fits the experimental results better.