激光熔化沉积修复40CrNiMoA高强钢的组织与性能

Microstructure and Properties of 40CrNiMoA High-strength Steel Repaired by Laser Melting Deposition

采用激光熔化沉积技术对40CrNiMoA高强钢表面进行沉积修复,利用光学显微镜、扫描电镜、显微硬度仪和周期浸润腐蚀试验,对40CrNiMoA高强钢基体及其修复区的微观组织、显微硬度和耐腐蚀性能进行研究。结果表明:经激光熔化沉积高Co-Ni二次沉淀硬化合金钢修复后,40CrNiMoA高强钢表面的耐磨损和耐腐蚀性能得到显著提高。修复区组织是由C元素过饱和的铁素体、残余奥氏体、M_3C渗碳体和M_2C型碳化物组成;热影响区组织由最初的回火索氏体转变为片状马氏体。

40CrNiMoA high-strength steel plates were repaired by laser melting deposition.The microstructure,micro-hardness and corrosion resistance of the 40CrNiMoA high-strength steel substrate and repaired zone were studied by optical microscopy,scanning electron microscopy,micro-hardness testing and corrosion testing.The results show that the wear and corrosion resistance of the 40CrNiMoA steel substrate were greatly improved after laser melting deposition repair with high Co-Ni secondary hardening alloy steel powders.The repaired zone is composed of carbon-supersaturated ferrite,lath retained austenite,M3C cementite and M 2C carbides.The heat-affected zone in the 40CrNiMoA steel substrate is plate martensitic structure transformed from the original tempered sorbite.