碳弧堆焊和激光熔覆铁基合金粉块涂层的组织及性能

Microstructure and Properties of Fe-based Alloy Powder Block Coating by Carbon Arc Surfacing and Laser Cladding

采用碳弧堆焊和激光熔覆法将Fe-05合金粉块分别熔覆在Q235钢基体表面。分析了涂层的显微组织和物相组成。测试了涂层的显微硬度和磨损失重。研究了熔覆工艺对涂层组织、硬度及耐磨性的影响。结果表明,碳弧堆焊和激光熔覆涂层的显微组织为黑色基体相上分布着白色的物相。其中黑色物相为基体α-(Fe,Cr)固溶体,白色物相主要为(Fe,Cr)_7C_3、Cr_(23)C_6、Cr_7C_3、Fe_2B、Fe_3B、Cr_3C_2、CrFeB及Ni_3Si。碳弧堆焊和激光熔覆涂层中均有裂纹产生,裂纹类型均为穿晶裂纹。激光熔覆涂层的显微硬度高于碳弧堆焊层,平均显微硬度约为989 HV。激光熔覆涂层的耐磨性高于碳弧堆焊涂层。

Fe-05 alloy powder block was cladded on the surface of Q235 steel substrate by using carbon arc surfacing and laser cladding, respectively. The microstructure and phase component of the coating were analyzed. The microhardness and wear mass loss of the coating were tested. The effects of cladding processes on the microstrueture, hardness and wear resistance of the coating by carbon are surfacing and laser cladding were investigated. The results show that the microstructure of the coating by carbon are surfacing and laser cladding exhibits white phase distributing in black matrix. The black phase is α-（Fe,Cr） solid solution and the white phase is mainly （Fe, Cr）7C3, Cr23C6, Cr7C3, Fe2B, Fe3B, Cr3C2, CrFeB and Ni3Si. Both carbon arc surfacing and laser cladding layers have cracks, and the crack type is transcrystalline crack. The microhardness of laser cladding coating is higher than that of carbon arc surfacing coating, and the average microhardness is about 989 HV, and the wear resistance of laser cladding coating is higher than that of carbon arc surfacing coating.