自保护药芯焊丝明弧堆焊Fe-Cr-C-B-W合金的组织及性能

Microstructure and properties of Fe-Cr-C-B-W alloy by self-shielded flux-cored wire open-arc surfacing

采用自保护药芯焊丝明弧堆焊技术制备五组不同钨含量的Fe-Cr-C-B-W合金.借助金相显微镜、扫描电子显微镜、X射线衍射仪、洛氏硬度计和磨损试验机分析堆焊合金的组织及性能.结果表明,合金的显微组织由马氏体、残余奥氏体、M7(C,B)3,M3(C,B),Fe3W3C和WC组成.大部分钨元素被迁移到晶界生成了比WC稳定性更好的Fe3W3C缺碳复合相,堆焊层中没有典型的初生WC硬质相颗粒生成.随着钨添加量的增多,共晶硬质相M7(C,B)3,M3(C,B)和Fe3W3C随之增多,间距减小,呈连续网状均匀分布.当钨的添加量为12%时,堆焊层的耐磨性达到最佳.

Five Fe-Cr-C-B-W alloy samples with different W contents were prepared by self-shielded flux cored wire arc surfacing technology.Microstructure and properties of surfacing alloys were analyzed by metallographic microscope,scanning electron microscope,X-ray diffractometer,Rockwell hardness tester and wear tester.The results show that the microstructure of the surfacing alloy consists of martensite,retained austenite,M7(C,B)3,M3(C,B),Fe3W3C and WC.Most of W is migrated to the grain boundary to produce Fe3W3C C deficiency composite phase which is more stable than the WC.There are no typical primary WC hard phase particles in the surfacing layer.With the increase of W content,the eutectic hard phase M7(C,B)3,M3(C,B)and Fe3W3C increase,and the spacing decreases.And they are continuous and evenly distributed.When the addition amount of W is 12%,the wear resistance of the surfacing layer is the best.