With the speedy development and the continuous application of special alloy manufacturing nowadays, M2 high-speed (HSS) steel is difficult to meet industrial needs. For improving the red hardness and wear resistance of M2 HSS surface, 20 wt.% Co was added into NiCrCu alloy powder and preplaced it onto the surface of M2 HSS, and then, the coating was fabricated by plasma cladding. The organization structure and mechanical properties of coatings before and after Co addition were studied. The results show that the addition of Co strengthened the matrix in the form of substitutional solid solution. Co did not change the phase composition and microstructure characteristics of the coating, but it reduced the residual stress and undesirable residual austenite content of the coating. The surface quality and crack resistance of the coating were optimized. In addition, the red hardness and wear resistance of the coating were significantly improved after adding Co. The average hardness increased by 22.53%, the average friction coefficient decreased by 21.65%, and the volume wear decreased by 56.86% after the coating tempering at 550 °C for 4 h. Moreover, the average hardness of Co-containing coating decreased slowly after tempering for different times. The present work is of great significance in providing a potential guidance for broadening the HSS application fields.

随着当今特殊合金制造的快速发展和不断应用，M2高速钢（HSS）已难以满足工业需求。为提高M2 HSS表面的红硬性和耐磨性，在NiCrCu合金粉末中加入20 wt.% Co，并将其预置于M2 HSS表面，然后采用等离子熔覆制备涂层。研究了Co添加前后涂层的组织结构和力学性能。结果表明，Co的加入以置换固溶体的形式强化了基体。Co并没有改变涂层的相组成和显微组织特征，但它降低了涂层的残余应力和不希望的残余奥氏体含量。优化了涂层的表面质量和抗裂性。此外，添加Co后涂层的红硬性和耐磨性显着提高。涂层在550℃回火后平均硬度提高22.53%，平均摩擦系数降低21.65%，体积磨损降低56.86% °C 4 小时。此外，不同时间回火后，含钴涂层的平均硬度下降缓慢。目前的工作对于拓宽高速钢应用领域提供潜在的指导意义重大。不同时间回火后，含钴涂层的平均硬度下降缓慢。目前的工作对于拓宽高速钢应用领域提供潜在的指导意义重大。不同时间回火后，含钴涂层的平均硬度下降缓慢。目前的工作对于拓宽高速钢应用领域提供潜在的指导意义重大。