CO_2气体保护焊/喷射送粉法制备Fe基耐磨堆焊层研究

Fe-based Hardfacing Layer Prepared by CO_2 Gas-shielded Welding with Spraying Powder

将传统CO2气体保护焊与喷射送粉法复合，在Q235碳钢表面堆焊Fe-C-Cr-B-Ni系合金，研究了Ni元素含量变化对堆焊层组织和硬度的影响．利用金相显微镜观察堆焊层组织，结合EDS、XRD分析堆焊层的相成分，采用洛氏硬度计测试堆焊层表面的硬度．研究结果表明：堆焊层由马氏体、奥氏体以及（Fe，Cr）7C3和（Fe，Cr）2B硬质化合物组成．堆焊层熔合区由固溶体组成，过热区晶粒粗大，母材区组织均匀．堆焊层的HRC值范围为51．1～56．5，随着Ni含量的增加，堆焊层的硬度缓慢降低．

The hardfacing with Fe -C-Cr-B-Ni alloy was prepared on Q235 steel by traditional CO 2 gas shielded welding in combination of spraying powder .The effect of Ni element on the microstructure and hard-ness of surfacing layer was investigated .The microstructure of surfacing layer was observed using metallographic microscope , and the composition was analyzed by EDS and XRD .The surface hardness was tested using Rock-well apparatus.Results showed that the surfacing layer comprised martensite and austenite as well as hard （Fe, Cr）7C3 and （Fe,Cr）2B.The fusion zone of surfacing layer was composed of solid solution .The grains at the o-verheated zone were coarse , while the microstructure of base metal was uniform .The hardness of surfacing layer was HRC 51.1-56.5.With the increase of Ni content , the hardness decreased slowly .