Microstructure and strengthening mechanism of light beam cladding layer with iron-based self-fluxing alloy powder

The 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 analysis and Rockwell hardness analysis. The results show that the microstructure of Fe-Ni-Cr-Si-B alloy powder light beam cladding layer is composed of γ(Fe,Ni) dendrite which dissolves 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 reaches HRC 47.3, which is higher than that of spraying layer or TIG cladding layer with the same powder. The main reason of strengthening of the light beam cladding layer is the solution of Cr, Si elements of γ phase and the precipitation of high hardness (Cr,Fe)7(C,B)3.