100Cr6轴承钢镦粗过程的微观组织模拟研究

Simulation Study on Microstructure of 100Cr6 Bearing Steel During Upsetting Process

为获得合理的100Cr6轴承钢镦粗工艺和优良的成形质量,通过simufact.forming软件对100Cr6轴承钢的镦粗过程进行数值模拟,得到坯料镦粗过程的等效应变、等效应力及温度分布等场量信息,并研究了坯料温度、上模速度、模具温度、摩擦因数等不同工艺参数对其镦粗成形的动态再结晶及晶粒尺寸等微观组织的影响。结果表明:坯料变形大的心部区域晶粒尺寸最小,坯料周边自由变形表层区域晶粒尺寸次之,与上下模具接触的坯料难变形表层区域晶粒尺寸最大;在其他条件相同的情况下,升高坯料温度,坯料平均晶粒尺寸减小,动态再结晶体积分数增大;提高上模速度,坯料平均晶粒尺寸增大,动态再结晶体积分数减小;增大摩擦因数,坯料平均晶粒尺寸减小,动态再结晶体积分数增大;升高模具温度,坯料平均晶粒尺寸减小,动态再结晶体积分数减小。

In order to obtain reasonable upsetting process and excellent forming quality of 100Cr6 bearing steel,the numerical simulation of upsetting process for 100Cr6 bearing steel is carried out by using simufact.forming software.The field information are obtained,such as equivalent strain,equivalent stress and temperature distribution during upsetting of billet.The effect of billet temperature,upper die speed,die temperature,friction coefficient and other different process parameters on microstructure such as dynamic recrystallization of upsetting forming and grain size is studied.The results show that the grain size is the smallest in center area with large deformation of billet,the grain size is the second in free deformation surface area around billet,and grain size is the largest in difficult deformation surface area of billet which is in contact with upper and lower dies.Under same other conditions,with the increase of billet temperature,the average grain size of billet decreases and the dynamic recrystallization volume fraction increases;with the increase of upper die speed,the average grain size of billet increases and the dynamic recrystallization volume fraction decreases;with the increase of friction coefficient,the average grain size of billet decreases and the dynamic recrystallization volume fraction increases;with the increase of die temperature,the average grain size of billet decreases and the dynamic recrystallization volume fraction decreases.