模具参数对304不锈钢圆筒拉深件残余应力的影响

Influence of die parameters on residual stresses of stainless steel 304 cylindrical drawing parts

过大的残余应力容易导致圆筒拉深件应力腐蚀开裂失效。通过7组切环实验及有限元模拟研究了模具参数(凹模圆角半径和凸凹模间隙)对304不锈钢圆筒拉深件残余应力的影响,测得了各圆环的张开距离,采用ABAQUS有限元软件计算出圆筒件中的残余应力。结果表明:环向残余应力先随着凸凹模间隙的增大而增大,但当凸凹模间隙大于1.06t时,环向残余应力基本不受凸凹模间隙的影响;凹模圆角半径对筒形拉深件环向残余应力几乎没有影响;中部径向残余应力随着凸凹模间隙和凹模圆角半径的增大而增大。因此,选择较小的拉深间隙对减小304不锈钢圆筒拉深件中的残余应力是有效的。

Huge residual stress leads to stress corrosion cracking of the cylindrical drawing cups easily. The influences of die parameters （Die corner radius and punch-die clearance） on the residual stress of stainless steel 304 cylindrical drawing parts were investigated by seven sets of split-ring experiments and numerical simulations. The opening distances of rings were measured, the residual stresses were calculated by FEM numerical simulations of software ABAQUS. The results show that the circumferential residual stress increases firstly with the increase of the drawing punch-die clearance, then almost keeps constant when the clearance is bigger than 1.06t. The die corner radius is not affected by the circumferential residual stress. Radial residual stress in the middle of thickness increases with the increase of the drawing punch-die clearance and the die corner radius. As a result, a smaller punch-die clearance is more effective to reduce the re- sidual stress in the wall of stainless steel 304 cylindrical drawing cups.