45钢表面激光熔覆WC/Ni基合金复合覆层的组织和性能  

Microstructure and properties of laser clad WC/Ni-based alloy composite coating on 45 steel surface

作　　者：陆海峰 潘晨阳 覃恩伟[1] 吴树辉[1] 季骅[1] 王博 Lu Haifeng;Pan Chenyang;Qin Enwei;Wu Shuhui;Ji Hua;Wang Bo(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou Jiangsu 215004,China)

机构地区：[1]苏州热工研究院有限公司

出　　处：《金属热处理》2019年第12期19-25,共7页Heat Treatment of Metals

基　　金：国家重点研发计划(2016YFB1100200)

摘　　要：基于替代镀硬铬工艺在核电硬密封领域中的应用,采用半导体激光器通过侧向送粉,在45钢表面制备了无孔洞和裂纹缺陷的WC/Ni基合金复合覆层。微观结构观察显示WC硬质相以球状和块状弥散镶嵌在韧性Ni基合金母体中,获得了高硬度和高韧性的良好匹配;覆层横截面组织呈梯度分布,底部近基体界面处为柱状晶和平面晶,逐渐过渡到中部树枝状亚共晶,表层组织为等轴晶。球磨摩擦磨损试验结果显示,复合覆层的摩擦因数及比磨损率均较45钢基体分别降低48.3%和96.4%,其磨损形式以轻微磨粒磨损和氧化磨损为主。Aimed at replacing hard chrome plating in hard sealing of nuclear plant components,a WC/Ni-based alloy composite coating was prepared on AISI 1045 steel(45 steel)substrate by semiconductor laser cladding with off-axial powder feeding.The microstructure observation shows that the WC hard phase in spherical and block dispersion is embedded in the tough Ni base alloy matrix,which obtains a good match between high hardness and high toughness.The cross section structure of the clad layer is distributed in a gradient manner:the bottom near the matrix interface is composed of columnar and planar grains,gradually transitioned to the middle dendritic hypoeutectic,and the surface structure is equiaxial grains.The results of ball milling wear test show that the friction coefficient and specific wear rate of the coating are respectively 48.3%and 96.4%lower than that of the steel substrate.The wear mechanisms of the WC/Ni-based alloy composite coating are mainly slight abrasive wear and oxidation wear.

关 键 词：激光熔覆 WC/Ni基合金复合覆层 摩擦因数 磨粒磨损 

分 类 号：TG174.44[金属学及工艺—金属表面处理]