角型截面不锈钢型材拉弯成形起皱缺陷控制

Wrinkling defect control for stainless steel profile with angle section in stretch-bending process

对某地铁车辆用角型截面变曲率不锈钢车顶弯梁的拉弯成形工艺进行了数值模拟研究,分析了此类构件产生起皱缺陷的原因,研究了型材立边高度、模具间隙及拉伸量对起皱趋势变化的影响规律,找到了最优的模具参数和工艺参数,最终通过试验进行了验证,获得了高质量的拉弯件。结果表明:立边高度对起皱缺陷影响显著,在固定弦边长度的情况下,增大立边高度将加重起皱缺陷;模具间隙对起皱情况有一定影响,减小模具间隙能够减轻起皱缺陷,但不能完全消除;拉伸量对起皱缺陷影响很大,增大拉伸量可以有效控制起皱缺陷,当拉伸量增加至7.5%时起皱缺陷基本消失。

The stretch-bending process of stainless steel roof bending beam with angle section and variable curvature for a subway vehicle was studied by numerical simulation,and the causes of wrinkle defects in such components were analyzed.Then,the influences of sidewall height,die clearance and stretching amount on wrinkling trend were studied,and the optimum parameters of die and process were found.Finally,the verification test was carried out,and the high quality stretrch-bending parts were obtained.The results show that the sidewall height has a significant influence on the wrinkling defect,and increasing the sidewall height can aggravate wrinkling defect when the length of flange is fixed.However,the die elearance has a certain influence on the wrinkling defect,and reducing the die clearance can reduce the wrinkling defect,but the wrinkling cannot be completely eliminated.The stretching amount has a great influence on the wrinkling defect,and increasing the stretching amount can effectively control the wrinkling.When the stretching amount increases to 7.5%,the wrinkling substantially disappears.