Self‐piercing riveting (SPR) has been used to joint steel to aluminum alloy sheets in multimaterial car body. It is a challenge to joint high strength steel to aluminum alloy by SPR process, especially for materials with high strength and large thickness. Herein, the SPR process for 1500 MPa hot stamped steel and aluminum alloy sheets is studied by experiment and simulation method. The laser heat treatment process is applied to the hot stamped steel sheet before joining. The relationship between heat treatment process and hardness distribution is studied and the softening zone with hardness less than 300 HV is obtained. Furthermore, the local softening zone is joined to an aluminum alloy sheet by SPR process. In the process, the rivets with high hardness are used to pierce the steel sheet. The failure mode and maximum tensile shear force of the joint are studied. At the same time, the joints without laser heat treatment are compared. The results show that the interlock and the maximum shear force for laser heat treatment increase by 91% and 26%, respectively.

中文翻译：

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基于局部软化区的热冲压钢板和铝合金板的自穿孔铆接

自冲铆接（SPR）已用于在多材料车体中将钢与铝合金薄板连接起来。通过SPR工艺将高强度钢与铝合金连接起来是一个挑战，特别是对于高强度和大厚度的材料而言。在本文中，通过实验和模拟方法研究了1500 MPa的热冲压钢和铝合金板的SPR工艺。接合前，对热冲压后的钢板进行激光热处理。研究了热处理工艺与硬度分布之间的关系，得到了硬度小于300 HV的软化区。此外，通过SPR工艺将局部软化区连接到铝合金薄板上。在此过程中，使用高硬度的铆钉刺穿钢板。研究了接头的破坏模式和最大拉伸剪切力。同时，对未进行激光热处理的接头进行了比较。结果表明，激光热处理的互锁和最大剪切力分别增加了91％和26％。