拉深比对304不锈钢圆筒件残余应力的影响

304不锈钢圆筒拉深件在其口部易发生纵向开裂,外壁残余拉应力过大是造成其纵向开裂的根本原因之一.本文结合有限元法分析不同拉深比所得圆筒拉深件的残余应力,用纳米压痕试验研究了拉深比对304不锈钢圆筒拉深件筒壁残余应力的影响.结果表明:304不锈钢圆筒拉深件外壁的残余拉应力从筒底到口部先增大后减小,最大残余应力出现在筒壁中部约60%筒壁高度处;纳米压痕测得拉深比为1.43、1.54、1.67和1.82拉深圆筒件筒壁的最大残余应力分别为391.87、745.30、793.74和1 013.1 MPa;最大残余应力随拉深比的增大而增大.与其他文献对比分析,此研究结果是正确可靠的.

Influence of drawing ratio on the residual stress in 304 stainless steel cylindrical drawing parts

Longitudinal cracking easily happens in the mouth of 304 stainless steel cylindrical drawing parts, where one of the essential reasons is due to the large residual tensile stress in their outer wall. Combined with finite element analysis, the influence of the drawing ratio on residual stresses in 304 stainless steel cylindrical drawing cups wall was studied in this paper by nanoindentation tests. The main contents and results are as follow: The residual tensile stress in the outer wall of 304 stainless steel cylindrical drawing cup increased first and then decreased from the cup bottom to its mouth. The maximum residual stresses always appeared in the middle of the cylindrical cups wall along the height direction about at 60% wall height from the cup bottom. The maximum residual stresses in the outer wall of cylindrical cups with different drawing ratios of 1.3,1.4,1.67 and 1.82 were 391.7,5.0,3.74 and 1 013.1 MPa , respectively, which were tested by nanoindentation.. They increased with the drawing ratio. By analysis and comparison of the reported literatures, the results were correct and reliable.