超高强QP980钢冲压成形性能

目的研究宝钢新一代先进高强钢QP980与第一代先进高强钢DP980的冲压成形性能。方法采用单向拉伸、光学应变分析和帽型拉弯成形等试验方法,分析两种超高强钢在加工硬化、成形极限、拉弯成形侧壁减薄和回弹等性能特性。结果 QP980的伸长率达到21.6%,与DP980钢相比有更高的强塑积,在变形过程中能够维持较高的瞬时n值,进而提高了材料的成形极限。帽型拉弯试验中,在不同的流入距离条件下,QP980钢的侧壁减薄率均低于DP980钢。在不同压边力条件下,QP980(厚度1.0 mm)材料的回弹量大于DP980(厚度1.2 mm)材料。结论 QP980在梁型件成形过程中具有优良的抗减薄特性,采用QP980钢进行冲压成形时应考虑比同级别DP980钢更大的回弹补偿量,或者采用更大变形量的工艺设计。

Stamping Formability of Ultra High Strength QP980 Steel

The work aims to study forming characteristics of new generation AHSS QP980 and first generation AHSS DP980- developed in Baosteel. Uniaxial tension, optical strain analysis, hat-shaped stretch-bending test, etc. were carried out to analyze work hardening, forming limit, side wall thickness reduction, springback, etc. in the two types of steel. QP980 has elongation of 21.6% and higher product of strength and elongation compared with DP980. QP980 remained relative high instantaneous n value during deformation and thus increased the forming limit. In hat-shaped stretch-bending test, side wall thickness reduction of QP980 was lower than that of DP980 under different flow-in distances. Springback amount of QP980- t1.0 was larger than that of DP980-t1.2 under different blank holder forces. QP980 has good anti-thinning characteristics in beam forming process. QP980 has larger springback amount compared with DP980 thus needs larger amount of springback compensation or larger deformation in process design.