碳钢表面激光熔覆镍基合金涂层及其高温磨损行为

应用激光熔覆法,采用镍基NiCrSiB合金粉末,在20#碳钢表面制备了熔覆涂层.利用X射线衍射仪分析熔覆层的相组成;利用摩擦磨损实验机对熔覆层的高温耐磨性能进行了研究;利用扫描电镜观察熔覆层形貌.结果表明:所制得熔覆层组织均一、致密,与基体形成了良好的冶金结合.镍基合金激光熔覆层硬度提高到基体的4倍;高温磨损率约为基体的1/3.熔覆层耐磨能力增强的主要原因在于熔覆层与基体良好的冶金结合,固溶强化和硼化物、硼碳化物等析出相的强化作用.

Laser Cladding of Ni-based Alloy on # 20 Steel Surface and Its High-Temperature Abrasive-Wear Behavior

Laser cladding of Ni-based alloy was implemented on the surface of #20 carbon steel specimens by use of NiCrSiB powder. Then, the phase composition of the cladding was investigated by XRD, with its high-temperature wearability investigated on an abrasion-wear tester and its surface morphology observed by SEM. The results showed that cladding has even and compact microstructure that has been integrated metallurgically with #20 carbon steel substrate. The microhardness of the cladding is 3 times greater than the substrate, but its high-temperature wearability is just about one third of the substrate. The reasons why the wearability is improved are mainly the highly metallurgical integration of the cladding with substrate, strengthening due to solid solution and that due to precipitation hardening from borides and boron carbonide.