激光熔覆Cr3C2/Fe复合涂层的组织与磨损性能

采用5kWCO2连续激光器在低碳钢表面激光熔覆Fe基合金涂层（Fe55）及添加20%Cr3C（2质量分数）的Fe基合金复合涂层（Cr3C2/Fe），研究了两种涂层的组织结构、显微硬度及耐滑动磨损性能。结果表明，Fe55涂层以亚共晶方式结晶，在初生柱状固溶体枝晶间存在大量的网状共晶组织。Cr3C2/Fe涂层中Cr3C2大部分溶解，原Fe55涂层中初生柱状固溶体枝晶产生等轴化，枝晶组织也明显细化。激光熔覆Fe55涂层主要由α-Fe和Cr23C6组成，Cr3C2/Fe涂层的主要组成相为γ-Fe；α-Fe，Cr23C6以及未熔Cr3C2。激光熔覆Cr3C2/Fe涂层的硬度和耐磨性明显优于Fe55涂层。

Microstructure and Properties of Laser Cladding Cr3C2/Fe Composite Coatings

Laser cladding Fe-based alloy coating （Fe55） and Fe-based alloy composite coating with w（Cr3C2）=20% particles（ Cr3Cz/Fe ）on low carbon steel substrate were obtained by 5 kW CO2 continuous wave laser. The microstructure, microhardness and sliding wear resistance of the coatings were studied. The results show that the Fe55 coatings are solidified in hypo-eutectic way, network eutectic structure existed in the primary dendrite solid solution. Added Cr3C2 particles are roosting dissolved. The primary dendrite solid solution of the Fe55 coatings are equiaxed in the Cr3C2/Fe coatings. The dendrite of the composite coatings became to be more finer. The main phases of the Fe55 coating were a-Fe and Cr23C6, the phases of Cr3C2/Fe composite coatings were composed of a-Fe, y-Fe, Cr23C6 and Cr3C2. The microhardness and wear resistance of the Cr3C2/Fe composite coating were obviously better than that of Fe55 coatings.