工艺参数对楔横轧球头销球头成形质量的影响

Influence of process parameters on forming quality of ball head of cross wedge rolling ball head pin

为了研究球头销微观组织晶粒分布规律以及工艺参数对成形质量的影响,通过DEFORM-3D有限元分析软件建立了楔横轧球头销有限元模型,对球头销成形过程及微观组织变化进行了模拟。结果表明,随着展宽角β的增大,平均晶粒尺寸和最大间隙比先减小后增大,最大间隙比增大到9.25%后逐渐趋于稳定;随着成形角α和楔尖圆角r的增大,平均晶粒尺寸与最大间隙比均先减小后增大;随着轧制温度T的升高,平均晶粒尺寸和最大间隙比逐渐减小,而最大间隙比减小至2.33%后逐渐趋于稳定。通过正交试验设计得到主次影响顺序为:展宽角β、轧制温度T、成形角α和楔尖圆角r;最佳工艺参数组合为:展宽角β=11°、成形角α=29°、轧制温度T=1140℃、楔尖圆角r=9.5°。通过球头销轧制试验得到球头销轧件,测量了其成形尺寸与微观组织晶粒;通过试验与模拟对比,得到外形尺寸误差在5%以内,平均晶粒尺寸最大误差不超过15%,进一步验证了有限元模型的准确性。

To study the grain distribution laws of microstructure of ball head pin and the influence of process parameters on forming quality,the finite element model of cross wedge rolling ball head pin was established by DEFORM-3D finite element analysis software,and the forming process and microstructure change of ball head pin were simulated.The results show that with the increase of widening angleβ,the average grain size and the maximum gap ratio first decrease and then increase,and the maximum gap ratio gradually becomes stable after increasing to 9.25%.With the increase of forming angleαand the wedge tip fillet r,both the average grain size and the maximum gap ratio first decrease and then increase.With the increase of rolling temperature T,the average grain size and the maximum gap ratio gradually decrease,while the maximum gap ratio becomes stable after decreasing to 2.33%.The primary and secondary impact order through orthogonal test design is as follows:widening angleβ,rolling temperature T,forming angleα,wedge tip fillet r.The optimal process parameters combination scheme is obtained as follows:widening angleβ=11°,forming angleα=29°,rolling temperature T=1140℃,wedge tip fillet r=9.5°.Through the ball head pin rolling tests,the ball head pin rolling part was obtained,and its forming dimension and microstructure grain were measured.Through the comparison between the tests and the simulation,the dimensional error is less than 5%,and the maximum average grain size error is less than 15%,which further verifies the accuracy of the finite element model.