摘要
为了改善304不锈钢工件的高温耐磨性能,利用CO2激光器在其表面熔覆了Ni基高温合金层。研究了熔覆层的物相组成、显微组织、成分分布,测试了其显微硬度、高温耐磨性能等,并与基材进行了对比。结果表明:Ni基合金熔覆层的组织从熔池底部到表层为胞状晶—柱状枝晶—树枝晶;熔覆层的主要组成相是Ni3Cr2,NbC,Mo2C与Cr23C6;Ni基合金粉末中添加难熔元素Cr,Mo,Nb等对熔覆层的组织起到了固溶强化、硬质相强化和弥散强化作用;熔覆层的平均显微硬度达到了405 HV,高温耐磨性能是基体的2倍多。
Ni-based alloy cladding coating was prepared on 304 stainless steel substrate using a CO2 laser. The phase structure, microstructure and composition distribution of the laser cladding coating were investigated, and its microhardness and high-temperature wear resistance were examined. It was found that as-prepared Ni-based alloy coating consisted of cellular crystalline, columnar dendrite and fine dendrite from the bottom of the molten cell to the surface. Ni3Cr2 , NbC, Mo2C and Cr23C6 were identified in the laser cladding layer. Besides, introducing refractory element Cr, Mo and Nb into the laser cladding materials resulted in solid solution strengthening, hard phase strengthening and dispersion strengthening. As-prepared Ni-based alloy coating possessed an average microhardness of 405 HV, and its wear resistance was two times better than that of the stainless steel substrate.
出处
《材料保护》
CAS
CSCD
北大核心
2012年第2期1-4,84,共4页
Materials Protection
基金
广东省教育部产学研结合项目(2010A090200077)
关键词
激光熔覆
Ni基合金层
难熔元素
显微组织
高温耐磨性能
laser cladding
Ni-based alloy coating
refractory element
microstructure
high-temperature wear resistance
