Microstructures of surface modification layer on Q235 steel produced by laser melt injection of WC  

作　　者：李福泉 陈彦宾 李俐群 

机构地区：[1]State Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology

出　　处：《中国有色金属学会会刊：英文版》2009年第S3期558-562,共5页Transactions of Nonferrous Metals Society of China

摘　　要：WC powder was injected onto the surface of Q235 steel by laser melt injection (LMI). The influence of process parameters was studied. The microstructure and composition of the coatings were analyzed by SEM, XRD and EDS. The hardness and wear-resistant property of the coatings and Q235 steel were measured. The results show that LMI layer can be achieved only under the condition that process parameters meet the strict requirements. By optimizing the process parameter, excellent coatings can be acquired by injecting WC powder onto the surface of Q235 steel. The microstructure in the coatings is complex, which consists of WC, W2C and M6C(Fe3W3C-Fe4W2C) phases. The difference of Fe3W3C microstructure in different zones of the coatings is obvious. Both the compositions of the reaction layers around the particle and dendrite precipitation carbides in the upper coating are Fe3W3C. The average hardness of LMI layer is above HV 900, which is about four times that of Q235 steel. The friction coefficient of LMI layer is only one quarter that of the substrate, which indicates that the wear resistance of the coatings is enhanced sharply.WC powder was injected onto the surface of Q235 steel by laser melt injection (LMI). The influence of process parameters was studied. The microstructure and composition of the coatings were analyzed by SEM, XRD and EDS. The hardness and wear-resistant property of the coatings and Q235 steel were measured. The results show that LMI layer can be achieved only under the condition that process parameters meet the strict requirements. By optimizing the process parameter, excellent coatings can be acquired by injecting WC powder onto the surface of Q235 steel. The microstructure in the coatings is complex, which consists of WC, W2C and M6C(Fe3W3C-Fe4W2C) phases. The difference of Fe3W3C microstructure in different zones of the coatings is obvious. Both the compositions of the reaction layers around the particle and dendrite precipitation carbides in the upper coating are Fe3W3C. The average hardness of LMI layer is above HV 900, which is about four times that of Q235 steel. The friction coefficient of LMI layer is only one quarter that of the substrate, which indicates that the wear resistance of the coatings is enhanced sharply.

关 键 词：laser MELT injection(LMI) WC surface modification LAYER WEAR-RESISTANT property 

分 类 号：TG142.41[一般工业技术—材料科学与工程]