超强度钢热成形车身零件性能的研究

A Research on the Performance of Auto-body Parts Made of Hot-formed Ultra-high Strength Steel

为探索超高强度钢BR1500HS的热成形性能及其在车身应用的前景,本文采用拉伸测试和金相分析方法,对超高强度钢BR1500HS热成形前后的微观结构和力学性能进行了对比分析,并通过整车正面碰撞数值仿真,对比了超高强度钢BR1500HS热成形零件和常用材料B340LA冷成形零件的抗碰撞性能。结果表明:热成形后超高强度钢BR1500HS的微观结构主要为板条状马氏体,其屈服强度和抗拉强度均达到热冲压成形前的2倍多;BR1500HS热成形零件比B340LA冷成形零件在具有更高的耐撞性能,适合用于制造车身结构件。

To explore the hot forming performance of ultra-high strength steel BR1500 HS and its application prospects as auto-body parts,the microstructure and mechanical properties of BR1500 HS before and after hot forming are comparatively analyzed by tensile test and metallographic analysis,and the crashworthiness performances of BR1500 HS hot-formed parts and common B340 LA cold formed parts are compared by a numerical simulation of vehicle frontal crash. The results show that the microstructure of hot-formed BR1500 HS is mainly lath martensite,with both its yield strength and tensile strength are as high as over 2 times of that before hot-forming and the hot-formed BR1500 HS parts have higher crashworthiness performance than B340 LA cold-formed parts,indicating that ultrahigh strength steel BR1500 HS is suitable for manufacturing the structural parts of vehicle body.