以WC为强化相颗粒,在AISI H13热作模具钢表面制备了纯铁基合金熔覆层和WC质量分数为3%、6%、9%铁基合金熔覆层。在优化工艺参数的基础上,研究了熔覆层中的WC分布以及熔覆层的组织形貌、物相和磨损行为。结果表明:熔覆层与基体之间形成了良好的冶金结合,熔覆层组织主要由枝晶和共晶组成;加入WC颗粒后,其周围区域出现了组织细化现象;熔覆层因硬质相而获得了更高的硬度,且其耐磨损性能相比于基体有明显提升;当WC质量分数为3%、6%、9%时,熔覆层的硬度和耐磨性能比铁基熔覆层有较大提升;熔覆层的磨损机制主要为磨粒磨损,并伴有不同程度的黏着磨损;随着WC质量分数的增大,熔覆层的氧化磨损程度逐渐加深。

In this study, a pure iron (Fe)-based alloy cladding layer and Fe-based alloy cladding layers containing tungsten carbide (WC) particles with mass fractions of 3%, 6%, and 9% are fabricated on an AISI H13 hot-working die steel surface, and the WC is used as reinforcing phase particle. The WC particle distribution, microstructure, phase, and wear behaviors of the cladding layers are studied based on the optimized parameters of the laser cladding layers. Results reveal the existence of a good metallurgical bond between the substrate and cladding layer. The cladding layer is mainly composed of dendrites and eutectic. Upon adding WC particles, the structure around the WC particles gets refined. The Fe-based cladding layer becomes hard because of the hard-phase formation, and its wear resistance considerably improves compared to the substrate. Hardness and wear resistance of the layer are further improved when the WC mass fraction reaches 3%, 6%, and 9%. The wear mechanism of the cladding layer is mainly abrasive wear, accompanied by different degrees of adhesion wear. The oxidation wear gradually deepens when the WC mass fraction increases.