热变形对42CrMo钢奥氏体晶粒尺寸影响的试验研究

Experimental research on the effect of hot deformation on the growth of austenite grain size of 42CrMo steel

采用热压缩试验与有限元模拟相结合的方法,研究42CrMo钢热加工过程中临界变形、多道次压下、道次间隔时间和完全再结晶后的保温时间对奥氏体晶粒长大的影响规律。结果显示,在热变形过程中,增大道次压下量,缩短道次间隔时间,有利于晶粒细化。在热变形的最后工序中,应尽量避免容易引起晶粒粗大的临界变形;热变形完成后,应尽量缩短保温时间,防止再结晶后的晶粒异常长大;在1050℃温度附近,42CrMo钢的保温时间不应超过30min。

Hot compression experiments and finite element method were used to study the effect of critical deformation,multi-pass reduction,pass interval and holding time after complete recrystallization on the growth of austenite grain of 42CrMo steel during hot working.The results show that increase the reduction per pass and decrease the pass interval are beneficial to grain refinement during the hot deformation of 42CrMo steel.The critical deformation which can lead to coarse grain should be avoided at the last hot deformation procedure.After hot deformation,the holding time should be as short as possible to prevent abnormal growth of grain size after recrystallization.The holding time for 42CrMo steel near 1050℃ should not beyond 30min.