【摘要】 借助DEFORM软件对4Cr9Si2楔横轧成形过程进行了数值模拟,分析了工艺参数对楔横轧4Cr9Si2轧件表面螺旋痕影响规律.结果表明:轧件表面螺旋痕是轧件在成形过程中产生应力状态改变而产生的缺陷.随着成形角增大,表面螺旋痕深度将增加;随着楔尖圆角增大,表面螺旋痕将迅速降低;展宽角对表面螺旋痕影响较小;断面收缩率减小,塑性变形量小,表面螺旋痕将减轻.通过实验验证了有限元模拟的正确性.最后对某型气门进行了模拟和实验,当Ψ=70.84%时,在α=32°,β=7.5°,R=12 mm下得到了表面无螺旋痕气门.更多还原

【Abstract】 Cross wedge rolling process of 4Cr9Si2 was simulated by DEFORM software,and the influence of process parameters on surface spiral on cross wedge rolling of 4Cr9Si2 was analyzed.The results showed that the surface spiral was resulted from the variation of stress state which was generated in the process of rolling. As the forming angle increased,the depth of surface spiral increased. The surface spiral decreased after increasing of wedge tip fillet. Effect of stretching angle on the surface spiral was not obvious. When the area reduction decreased, plastic deformation was smaller and the surface spiral reduced. These simulated results were verified by experiments. The process parameters for a certain type of valve were determined to be α = 32°,β = 7. 5°,R = 12 mm,when area reduction is 70. 84%,and valves without surface spiral were experimentally achieved.更多还原