车身用高强钢的回弹实验与分析

Test and Analysis on Springback of High Strength Steel for Car Body

目的研究和分析身用高强钢在冲压过程中的回弹行为与规律。方法基于Wagoner的拉延弯曲实验模型,采用拉延弯曲(Draw-Bend)实验机,针对590 MPa级冷轧双相钢和420 MPa级低合金高强钢两个常用的典型车身用高强钢材料开展回弹实验研究,通过不同弯曲半径模拟不同冲压模具圆角半径,同时以不同张紧力模拟冲压压边力,讨论了两种材料的冲压成形及回弹性能与控制。结果两类钢的回弹量均随着冲压模具圆角半径的增大而减小,随着压边力的增大而减小,双相钢相比低合金能产生更大的回弹,厚板随冲压条件变化的回弹波动一般低于薄板。结论实验研究结果对高强钢在实际冲压过程中的回弹控制有着较强的指导意义。

The paper aims to study the springback behaviors and rules of high strength steel for car body during stamping. The springback of two typical materials DP590 and HSLA420 were studied through draw-bend experiment based on Wagoner’s draw-bend model. During the test, different bend radius and nominal tension were used to simulate different die radius and bank holding force, respectively. Forming and springback behavior of two materials during stamping were analyzed through this method. The analysis showed that the springback of two materials decreased with the increase of die radius and bank holding force. Springback amount of DP steel was higher than that of HSLA steel. The thicker gauge usually had less fluctuation of springback when stamping condition changed. The result could provide good guidance to control the springback during stamping process for high strength steels.