304不锈钢壳级进模变薄拉深工艺及数值模拟

Ironing process and numerical simulation of progressive die for stainless steel 304 shell

根据经验公式和理论数据对某304不锈钢壳进行直径减小、壁厚变薄的变薄拉深级进模设计,并运用Deform-3D对连续变薄拉深成形过程进行数值模拟,揭示了成形过程等效应力和行程载荷曲线的分布规律。模拟与试验结果表明:成形过程中,坯料的最大应力集中在与凹模圆角和凹模工作带相接触的区域;随着凸模圆角减小,凸模圆角与直壁连接处应力增大,出现危险区域;为防止最后一道拉深过程中凸模容易磨损及产品被拉伤,应合理设计拉深系数、变薄量及凹模圆角;直径减小壁厚变薄拉深件的直壁壁厚均匀。

According to empirical formula and theoretical data, ironing progressive die with reducing in diameter and thinning in wall thickness for stainless steel 304 shell was designed. The forming process of continuous ironing was numerically simulated by Deform-3D software. The equivalent stress fields and the regulation of load-stroke curves in the ironing process were revealed. The results of simulation and test show that the maximum stress of the blank focuses on the contacting areas of the die radius and the die work location. The hazardous areas will appear with the decrease of punch radius because the contact stress between the vertical wall and punch radius increases. In order to prevent the last drawing punch from wearing, the product strain, drawing coefficient, thinning and die radius should be reasonably designed. The vertical wall thickness of the drawn parts with reducing in diameter and thinning in wall thickness is homogenizing.