Dissimilar weld joints of QP980 and TRIP800 were fabricated by a fibre laser. The microstructure and mechanical properties of dissimilar weld joints were studied. The tensile properties of weld joints were not influenced by the narrow softening zone with a less reduction in hardness of ∼25 HV from the QP980, which contributed to fracture in TRIP800. The DIC images showed that the location of maximum strain was changed from the QP980 side to TRIP800 side during the tensile test of QP980 (1.2 mm)–TRIP800 (1.4 mm) joints. The dissimilar weld joints were characterised by the limited dome height test (LDH). The LDH values were varied with the punch pole location, as a result of the softening zone and non-uniform microstructure on the heat-affected zone of joints.

QP980和TRIP800的异种焊接接头是通过光纤激光器制造的。研究了异种焊接接头的组织和力学性能。焊接接头的拉伸性能不受狭窄的软化区影响，QP980的硬度降低幅度较小，约为25 HV，这有助于TRIP800的断裂。DIC图像显示，在QP980（1.2 mm）–TRIP800（1.4 mm）接头的拉伸试验期间，最大应变的位置从QP980侧更改为TRIP800侧。不同的焊接接头的特征在于有限的圆顶高度测试（LDH）。由于接头的软化区和微观结构不均匀，LDH值随冲头位置而变化。