针对热成形前Usibor1500 钢板激光拼焊时Al-Si镀层对焊缝的影响进行研究，对比分析了保留Al-Si镀层与去除顶层镀层后的激光拼焊焊缝金相特征，通过能量色散X-射线光谱(EDS)的方法分析了镀层元素在焊缝中的分布特征，采用室温拉伸实验研究了去除顶层镀层前后力学性能的差异。研究结果表明: Al元素分布于焊缝各个部位并存在局部偏聚，Al在不同合金相中质量百分比分别为1.76%和2.65%；Al-Si镀层进入焊缝形成的脆性相降低焊缝力学性能，焊缝断裂的抗拉强度为458~479 MPa，而断裂于母材时为500 MPa 左右；去除顶层镀层可以改善焊缝力学性能，拉伸断裂位置均为母材。

The metallographic phases and tensile strength of tailored fiber laser welded blanks of Al-Si coated Usibor1500 and Usibor1500 without coating are investigated, and the distribution of Al in the weld seams is investigated by energy- dispersive X- ray spectroscopy (EDS). Ambient tensile strength is tested to study the difference with or without top coating layer. The results show that, Al enters the weld seam and distributes in the whole area of weld seam and be with local segregation, the mass percent of Al in two phases are 1.76% and 2.65% , respectively. Al- Si coating which entering the weld seam decreases the mechanical properties of weld seam due to the formation of brittle phase, whose strength is 458~479 MPa, while the strength of base metal is around 500 MPa. After removing the top layer of the coating, the mechanical properties increase distinctly, whose fracture locations are consistently at the base metal.