5CrNiMo钢激光熔覆再制造涂层的组织与性能  

Microstructure and Properties of Layer Remanufactured by Laser Cladding on 5CrNiMo Steel

作　　者：王程 韦习成[1] 孙中刚 张华健 郑坤 WANG Cheng;WEI Xicheng;SUN Zhonggang;ZHANG Huajian;ZHENG Kun(School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China;Shanghai Aircraft Manufacturing Co., Ltd., Shanghai 201324, China;College of Materials Science and Technology, Nanjing Tech University, Nanjing Jiangsu 210009, China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]上海飞机制造有限公司,上海201324 [3]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《上海金属》2021年第2期1-6,12,共7页Shanghai Metals

基　　金：国家重点研发计划(No.2016YFB1100501);南京市优势产业关键技术突破招标项目(201803)。

摘　　要：采用激光熔覆技术,在5CrNiMo钢表面制备了耐磨铁基梯度涂层。采用X射线衍射仪、扫描电镜、显微硬度计和摩擦磨损试验机等研究了沉积态和热处理后的不同M2含量的Fe1涂层的物相组成、微观组织和显微硬度。结果表明:含M2组分的涂层热处理后硬度提高,沉积态涂层的物相主要为γ-Fe(Cr-Ni-Fe-C)和[Fe,Ni]固溶体,热处理后α-Fe(Fe-Cr)和(Cr,Fe)_(7)C_(3)相含量增多。涂层主要由Fe和Cr元素组成,晶界富含Mo、Cr、V和Mn等元素。热处理后涂层中析出了大量弥散强化相,耐磨性提升了约1.3倍。优选耐磨层配比为20%M2,中间层和连接层配比为10%M2,热处理工艺为900℃保温1 h后空冷或水冷。优选配比的多层熔覆涂层组织致密,无裂纹和气孔等缺陷,磨损试验结果表明不同成分的涂层磨损率接近。Iron-based wear-resistant gradient layer was prepared on the 5CrNiMo steel by means of laser cladding technology.Phase constitution,microstructure and microhardness of as-deposited or heat treated Fe1 layers with different proportions of M2 were studied by using X-ray diffraction,scanning electron microscopy,microhardness measurement and wear test machine.The results showed that hardness of the layers containing M2 component increased after heat treatment,the phases of as-deposited layers were mainlyγ-Fe(Cr-Ni-Fe-C)and[Fe,Ni]solid solution,and the amounts ofα-Fe(Fe-Cr)and(Cr,Fe)_(7)C_(3)phases increased after heat treatment.The layer was mainly composed of Fe and Cr elements,and the grain boundary was rich in Mo,Cr,V and Mn elements.After heat treatment,a large amount of dispersion strengthening phase was precipitated from the layers,and the wear resistance increased by a factor of 2.3.The optimal proportions were 20%M2 for the wear-resistant layer,and 10%M2 for the intermediate layer and connecting layer,and the heat treatment process was holding at 900℃for 1 h and then air cooling or water cooling.The multilayer clad layer with the optimal proportion was dense and had no defects such as cracks and pores.From the wearing test it was seen that wear rates of the layers with different compositions were similar.

关 键 词：5CRNIMO钢 激光熔覆 梯度涂层 微观组织 耐磨性 

分 类 号：TG1[金属学及工艺—金属学]