Effects of B₄C Content on Microstructure and Properties of Fe-based Alloy Remelting Coating

In order to improve the hardness and wear resistance of Fe-based alloy remelting coatings,Fe-based/B₄C composite coatings with different B₄C contents were prepared on 45 steel surface by electron beam remelting technology（EBM）,and the microstructure,phase composition,macrohardness and three-body abrasive wear tests were carried out.The results show that the remelted coatings with different B₄C contents formed firm metallurgical bonding with the steel substrate and the coatings are mainly composed of α-Fe,γ-Fe,M₂₃（C,B）₆,M₂B,Fe₃C,（Fe,Ni） and （Fe,Si）.The microstructure of the coating is obviously refined with the increase of B₄C content and the overall macrohardness of the coating also increases,from64.29 HRC at B₄C-free to 70.45 HRC at 3wt%B₄C.After three-body abrasive wear test,the wear loss of the remelted coating increases first and then decreases with the increase of B₄C content.When B₄C content is 3wt%,the wear loss is the minimum and the wear resistance is the best.