Recently, laser cladding has been widely investigated for the preparation of Co-based coatings for high-temperature applications. However, there is a highly cracking tendency in Co-based alloys due to the reinforcing hard phases. In this work, a single layer of CoCrMoSi coating was prepared with laser cladding on 304 stainless steel. By proper preheating, cracking was avoided during deposition. The high-temperature wear behaviors of the coating were evaluated by ball-on-disk test. In terms of morphology and chemical composition, the coating exhibited a gradient microstructure across the section. From the interface with the substrate to the top surface, the structure was characterized with three types of morphology in sequence, i.e., coarse cellular crystals in the interdiffusion zone, nanosized lamellar eutectic and Laves-phase dendrites embedded within nanosized lamellar eutectic. The surface hardness of the coating is 835HV_0.3, which was mainly attributed to the Laves phase. Compared with the 304 stainless steel, the volume loss of the coating decreased by 76.5%at 400°C. The wear mechanisms of the coating were oxidation wear and abrasive wear. The excellent coating wear resistance at high-temperature can be traced to the microstructure of Laves phase embedded within the nanosized eutectic.

最近，激光熔覆层已被广泛研究用于制备高温应用的钴基涂层。然而，由于增强的硬质相，Co基合金中存在很高的开裂趋势。在这项工作中，用激光熔覆在304不锈钢上制备了一层CoCrMoSi涂层。通过适当的预热，避免了沉积过程中的开裂。通过球盘试验评估涂层的高温磨损行为。就形态和化学组成而言，涂层在整个截面上均表现出梯度微观结构。从与基材的界面到顶面，该结构的特征依次为三种类型的形态，即互扩散区中的粗大细胞晶体，纳米层状共晶和Laves相树突嵌入纳米层状共晶内。涂层的表面硬度为835HV_0.3，这主要归因于Laves相。与304不锈钢相比，涂层在400°C时的体积损失减少了76.5％。涂层的磨损机理是氧化磨损和磨料磨损。高温下优异的涂层耐磨性可以追溯到纳米共晶内嵌入的Laves相的微观结构。