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

关键词:  自保护药芯焊丝|明弧堆焊|Fe-Cr-C-B-W合金|组织及性能

Key words:  self-shielded flux cored wire|arc surfacing|Fe-Cr-C-B-W alloy|microstructure and properties

摘要:

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.

Abstract:

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.