Ni/c-BN对激光熔覆316L不锈钢熔覆层组织与耐蚀性的影响

Effect of Ni/c-BN on the Microstructure and Properties of Laser Cladding 316L Stainless Steel Coating

采用激光熔覆技术在马氏体不锈钢(ZG06Cr13Ni4Mo)表面制备了Ni/c-BN增强316L不锈钢复合熔覆层。通过XRD、SEM、EDS、电化学试验和冲蚀试验分析了不同Ni/c-BN含量对熔覆层的显微组织和和耐蚀性影响。结果表明,复合熔覆层的物相由FeCr_(0.29)Ni_(0.16)C_(0.06)固溶体组成,随着Ni/c-BN添加量的增加,其顶部组织的等轴晶数量减少,胞状树枝晶的数量增多。复合熔覆层的耐蚀性随Ni/c-BN添加量的增加呈先升高后降低的趋势,当Ni/c-BN添加量为5wt.%时,熔覆层的耐蚀性最好。过量的Ni/c-BN使得熔覆层表面存在气孔,且导致熔覆层内部存在少量大尺寸残留c-BN,降低了熔覆层的耐腐蚀性和耐冲蚀性。

The Ni/c-BN reinforced 316L stainless steel composite cladding layer was prepared on the surface of martensitic stainless steel(ZG06Cr13Ni4Mo) using laser cladding.The effects of different Ni/c-BN contents on the microstructure and corrosion resistance of the coating were analyzed by XRD,SEM,EDS,electrochemical test,and erosion test.The results show that with increased Ni/c-BN content,the number of equiaxed crystals in the top tissue decreased and the number of Cellular dendritic crystals increased.As the amount of Ni/c-BN addition increased,the corrosion resistance of the composite coating tended to increase and then decrease.The coating had the best corrosion resistance when the Ni/c-BN content was 5 wt.%.The excess Ni/c-BN results in the presence of pores on the surface of the coating and leads to a few large residual c-BN inside the coating,which reduces the corrosion and erosion resistance of the coating.