Microstructure and Strengthening Mechanism of Light Beam Cladding Layer with Iron-based Self-fluxing Alloy Powder

Microstructure and phase structure of light beam cladding layer with iron based self fluxing alloy powder were studied by SEM,EDS,X-ray diffraction,microhardness and Rockwell hardness.The results showed that the microstructure of Fe-Ni-Cr-Si-B alloy powder light beam cladding layer was composed of γ(Fe,Ni) dendrite which dissolved a lot of Cr and little B,Si,C,and (Cr,Fe)₇(C,B)₃+γ(Fe,Ni) eutectic among dendrite.The macrohardness of the light beam cladding layer reached HRC47.3,which was higher than that of spraying layer and TIG cladding layer with the same powder.The main reason of strengthening of the light beam cladding layer was the solution of Cr,Si elements in γ phase and the precipitation of high hardness (Cr,Fe)₇(C,B)₃.