42CrMo钢加热时奥氏体晶粒长大演化规律

Austenite grain growth behaviour of 42Cr Mo steel during heating

对42CrMo钢在不同加热温度(850~1150℃)和保温时间(0~1200 s)下的奥氏体晶粒长大规律进行了研究。采用金相定量法对加热后材料的奥氏体晶粒度进行测量,建立42CrMo钢加热时奥氏体晶粒长大演化模型。结果表明:奥氏体晶粒尺寸随加热温度升高呈指数关系长大,随保温时间的延长呈近似抛物线形式长大;利用基于唯象理论的Sellars模型,通过非线性回归方法建立42CrMo钢加热时奥氏体晶粒长大演化模型;将该模型导入有限元软件中预报42Cr Mo钢加热时奥氏体晶粒变化,预报结果与实验结果吻合,验证了该模型的正确性。

Austenite grain growth behaviour of 42 CrMo steel in the process of heating at different temperatures for different holding time was investigated. The austenite grain size of 42 CrMo steel was measured by quantitative metallography method,and the austenite grain growth model was established based on the experiments. The results show that austenite grain grows in an exponential law with the increase of heating temperature,while approximately in a parabolic law with the increasing of holding time. According to the Sellars model of phenomenological theory and the nonlinear regression method,the austenite grain size growth model of 42 CrMo steel during heating is obtained. The austenite grain size of 42 CrMo steel during heating is predicted by FEM simulation based on the model. The prediction result agrees well with the experimental result.