Static Recrystallization Behavior of Nitrogen Alloyed HRB500E Steel

In order to provide necessary theoretical basis for hot rolling process, the static recrystallization behavior of nitrogen alloyed HRB500E steel was studied by using stress relaxation method. The effects of various strain capacity, strain temperature and strain rate on the static recrystallization of samples were analyzed with Gleeble-1500D thermal simulation machine. Besides, the results were compared with those of vanadium microalloyed HRB500E steel. Based on the experimental results and Avrami equation, the kinetic models of static recrystallization were established in terms of two kinds of experimental steels, and the static recrystallization fraction curve was compared with the predicted one of the model. The results show that when the strain is increased in the range of 0.4−1.0, the strain temperature in the range of 950−1 100 ℃, and the strain rate in the range of 0.1−1.0 s⁻¹, t_0.5 (time for 50% recrystallization) decreases and the recrystallization speed increases. In particular, the static recrystallization of the experimental steels is more notably affected by strain capacity and strain temperature than strain rate. Under the same strain conditions, the static recrystallization process of the nitrogen alloyed HRB500E steel lags behind that of the vanadium microalloyed HRB500E steel. The verification results show that the prediction results of the kinetic models were in good agreement with the experimental results.