中碳钢热变形行为

Evaluation of deformation behavior of medium carbon steel

对普通中碳钢在轧制过程中各种变形参数对组织演变规律的影响进行了系统的热模拟实验研究。探讨变形参数对形变储存能和组织演变规律的影响,重点考察珠光体球化过程的规律。通过实验数据计算得到变形激活能为262.57 k J·mol-1;形变储存能随变形温度降低和变形速率增加而加大,拟合出变形储存能与Z参数的关系式为:ΔGD=252.95-19.24ln Z+0.38(ln Z)2。确定了实验钢发生形变诱导铁素体相变临界形变储存能为24.28 J·mol-1。实验钢形变诱导铁素体含量随变形温度的降低而增加。为中碳钢热变形工艺优化提供了理论依据。

Thermal simulation experiment were performed to study the influence of various deformation parameters on the evolution of microstructure during the rolling process of medium carbon steel. The influence of the deformation parameters on the stored energy and the microstructure evolution; especially on the rule of the spheroidization of pearlite was investigated. From the data obtained from this experiment,it is found that the deformation activation energy is 262. 57 k J·mol- 1,and it increased with the decreasing of deformation temperature and the increasing of deformation rate. The relation between the stored energy and parameter Z is as follows: ΔGD= 252. 95-19. 24 ln Z + 0. 38( ln Z)2. The critical deformation stored energy is 24. 28 J·mol- 1when the experimental steel deformation induce ferrite phase transformed. The deformation induce ferrite content in experimental steel increases with deformation temperature decreasing. This finding provides a theory for the medium carbon steel hot deformation process optimization.