目的 探究激光熔覆薄板W6Mo5Cr4V2高速钢刀具材料过程中扫描速度对刀具基材热影响程度、基材热积累翘曲变形和微观组织、熔覆层物相组成的影响规律，找出适合于薄板高速钢刀具材料的扫描速度参数选择范围。方法 采用单一控制变量的实验，制备出一组单道熔覆样件，分析不同扫描速度对基材热影响形貌、基材翘曲变形、显微组织及硬度的影响特性。结果 热影响区随着扫描速度的提高而不断减小，沿着熔覆方向，其热量累积程度逐渐加大，热影响区面积沿着熔覆方向往两侧扩散。扫描速度为2 mm/s时，基材底面的变形量为0.077 mm，且变形从中心向边缘扩展，以熔覆道对应中心部位最为凸出；当扫描速度为3 mm/s以上时，变形量减少到0.03 mm以内；当扫描速度为4 mm/s时，熔覆层与基材左右结合边界的最大裂纹宽度降低为0.013 mm，且裂纹长度明显减少。不同的扫描速度只影响熔覆层的组织细化程度和最高硬度区间，对熔覆层强化机理和组织成分没有较大的影响。结论 在熔覆薄板高速钢刀具材料时，较快的扫描速度可以减少基材表面的热影响程度，较慢的扫描速度容易引起基材的“鞍型”翘曲变形。当选用3 mm/s以上的扫描速度时，基材的翘曲变形量可以有效的控制在0.03 mm以内，且提高扫描速度可以在一定程度上有效降低结合边界裂纹尺寸。

The work aims to investigate the effect laws of scanning speed on the degree of cutter substrate thermal influence, the heat accumulated warping deformation and microstructure of substrate, and the phase composition of cladding layer during laser cladding of thin plate W6Mo5Cr4V2 high-speed steel and then find the appropriate parameter selection range of speed scanning for thinner high-speed steel cutter. A series of single-pass cladding layers were prepared by single control variables. The influence characteristics of different scanning speed on the morphology of thermal influence, the deformation of structure, the microstructure and the microhardness of substrate were analyzed. With the increase of scanning speed, the heat-affected zone decreased, the heat accumulation increased gradually along the cladding direction, and the area of the heat-affected zone spread to both sides along the cladding direction. When the scanning speed was 2 mm/s, the deformation of the substrate bottom was 0.077 mm, the deformation expanded from the center to the edge and the central part corresponding to the cladding path was the most prominent. When the scanning speed was above 3 mm/s, the deformation was reduced to within 0.03 mm. When the scanning speed was 4 mm/s, the maximum crack width between the cladding layer and the left and right boundaries of the substrate was reduced to 0.013 mm, and the crack length was significantly reduced. Different scanning speed only affected the microstructure refinement degree and the maximum microhardness range of the cladding layer, but had no significant influence on the strengthening mechanism and phase composition of the cladding layer. During the laser cladding of thin plate high-speed steel cutter material, faster scanning speed can reduce thermal influence degree on the surface of the substrate material, but slow scanning speed is easy to cause the "saddle" warping deformation of substrate. When scanning speed is more than 3 mm/s, the warping deformation of the substrate can be effectively controlled within 0.03 mm and the size of crack on combined boundary can be effectively reduced by increasing the scanning speed.