高强钢板U形件热冲压技术及有限元分析

摘要

高强钢板热冲压技术是解决其冷冲压缺陷的新型加工技术.建立了U形件的热冲压有限元模型,采用热力耦合分析方法得到了热冲压过程中板料的温度、厚度及应力的分布规律,并研究板料和模具的初始温度对热冲压后制件的温度及应力分布规律的影响.结果表明,U形件压边区域、圆角处温度下降较慢,中心区域和两侧壁温度下降很快；两侧壁和圆角处减薄较大；凸模圆角处应力最大,压边区域和底部中心区域应力值最小；模具初始温度不变,板料初始温度增加,冲压结束时制件的最低温度、应变最大值随之增加,厚度最小值、应力最大值随之减小；板料初始温度不变,模具初始温度增加,冲压结束时制件的最低温度、应变最大值随之增加,厚度最小值、应力最大值随之减小.%Hot stamping of high strength steel is a new technology to solve the defects of cold stamping. The hot stamping finite element model of the U shape is established to obtain the blank temperature,thickness and stress distribution and study the influence to the temperature and stress distribution after hot stamping coursed by the initial blank and die temperature coupled thermo-mechanical analysis method. The results show that the temperature drops slowly in U shape holding area and fillet, quickly in the center area and two lateral walls. The thinning is large in the two lateral wall and fillet. The largest stress is in the fillet of the punch and the minimum stress is in the holding area and bottom center area. If the die initial temperature is unchanged, as follow as the blank initial temperature increasing, the minimum temperature and the maximum strain of the part after stamping will increase, the minimum thickness and the maximum stress will decrease. If the blank initial temperature is unchanged,as follow as the die initial temperature increasing,the minimum temperature and the maximum strain of the part after stamping will increase, and the minimum thickness and the maximum stress will decrease.