汽车板抗凹刚度试验

Experimental investigation on dent resistance stiffness for automotive panels

针对汽车板的特点,利用IF钢DC04、含磷钢170P1、烘烤硬化钢180BH冲压成形的胀形件及某车型翼子板零件,系统分析了屈服强度、成形条件、烘烤硬化特性等对汽车板抗凹刚度的影响。研究结果表明:高的屈服强度可有效提高汽车板的抗凹刚度,试验中烘烤硬化钢180BH的抗凹刚度最大,170P1次之,DC04的抗凹刚度最小;在合理范围内,可通过增加变形量、增大压边力等工艺手段增加零件的加工硬化程度,从而增大汽车板的抗凹刚度,但零件的抗凹刚度并非随着材料的硬化程度的增加呈线性增强,若增加过量,则引起板料过度变薄,抗凹刚度反而下降;利用烘烤硬化钢板180BH的烘烤硬化特性可显著提高材料的抗凹刚度。

For the characteristics of automotive panels,using bulging parts and automotive fenders produced by IF steel DC04,P-added steel 170P1 and BH steel 180 BH,influences of yield strength of steel,forming condition and bake-hardening characteristics on dent resistance stiffness were analyzed systematically. The results show that the dent resistance stiffness can be improved by increasing yield strength of materials,and the dent resistance stiffness of BH steel 180 BH reaches the maximum value,steel 170P1 is the second as well as IF steel DC04 is the smallest. Therefore,in a reasonable range,the work hardening of the automobile panel is enhanced by increasing the deformation amount and the blank holder force in order to increase dent resistance stiffness of automotive panel. However,the dent resistance stiffness of automotive panel does not increase linearly with the increase of work hardening. If it is over-increased,sheet material will become too thin,and the dent resistance stiffness of the automotive panel will decrease on the contrary. Thus,the dent resistance stiffness can be improved significantly by the bake-hardening feature of the BH steel 180 BH.