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采用粉末等离子堆焊方法,对自制的C-Cr-Nb-Ni合金粉末进行堆焊,研究了不同堆焊电流对熔深的影响。对堆焊层进行显微硬度测试,采用金相显微镜和扫描电镜分析了堆焊层的显微组织及物相。研究结果表明,堆焊电流120 A时,母材基本不发生熔化,可得到低稀释率的堆焊层。堆焊层的显微硬度在距熔合线0.5 mm以后,硬度增加不明显。堆焊层的显微组织主要为马氏体及少量残余奥氏体,硬质相为六边形状Cr3C2,熔敷层碳含量和铌含量较高,但并未形成铌的碳化物,含铌化合物起到形核质点及细化晶粒的作用。
The homemade C-Cr-Nb-Ni alloy powder was deposited by powder plasma surfacing method, and the effect of different welding current on penetration was studied. The microhardness of the surfacing layer was tested. The microstructure and phase of the surfacing layer were analyzed by optical microscope and scanning electron microscope. The results show that when the welding current is 120 A, the base metal does not melt and the overlay with low dilution rate can be obtained. Hardness of surfacing layer after 0.5 mm away from the fusion line, the hardness increase is not obvious. The surfacing layer microstructure mainly martensite and a small amount of retained austenite, hard phase hexagonal Cr3C2, cladding layer of carbon content and high niobium content, but did not form niobium carbide, niobium The compound serves to nucleate the particles and refine the grains.