Microstructure and Microhardness Change of Fe-Cr-C Alloy Layer Prepared by Electron Beam Scanning before and after Heat Treatment

Fe,Cr,C powder mixtures were employed to coat the surface of a low carbon steel substrate,and the Fe-Cr-C alloy layer was prepared by electron beam scanning in vacuum condition which was heated treatment at 800 ℃ for 2.5 h.The microstructure,phase compasition and hardness of the layers before and after heat treatment were analyzed with optical microscopy,XRD analysis,SEM and microhardness test. The results show that after heat treatment,the austenite matrix transformed to ferrite with secondary carbides precipitated in it.The grain size of the carbides distributed dispers in the layer after heat treated decreased.The microhardness of the heat treated sample decreased slowly but was more even.