摘要
Abstract
The work aims to prepare a hard and wear-resistant Fe-based ceramic particles-strengthened coating on surface of structural low-alloy steels by studying microstructure and properties of the cladding layer.Mixed powder of Fe58 alloy and B4C ceramic was cladded on the substrate 16Mn steel by applying plasma cladding technique.A coating strengthened by wear-resistant and ultrahardFe-based ceramic particles was fabricated on the surface of 16Mn steel successfully,and microstructure,microhardness and wear resistance of the Fe58-B4C coating were investigated.The coating was dense,uniform,pore-free and crack-free,and was of good coating-substrate adhesion.Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to observe coating morphology and phase composition.The results suggested that fine and uniform carbides and borides-reinforced phases,the cladding layer was compatible with the substrate,interface exhibited metallurgical bonding,reinforced phases were mainly Fe2B,FeB,Cr7BC4,Cr7C3 and B4C.In addition,ferroboron compounds (Fe2B and FeB) spread over (Fe,Ni) solid solution phase along grain boundary in chain-like manner,and formed reticular structure together with (Fe,Ni) solid solution on the grain boundary.Chromic carbon,boride Cr7BC4,Cr7C3 and incompletely reacting B4C ceramic phase spread over in the grains in the form of irregular bulk and dot scope.Sectional microhardness and abrasive wear test results of the cladding layer showed that the sectional microhardness spread over uniformly,and average hardness was up to 11.9 GPa,which was over 7.95 times that of 16Mn steel;abrasive wear resistance of the coating was over 7 times that of 16Mn steel.As hard phases Cr7BC4,Cr7C3 and B4C dispersed in the grains jointly work with ferroboron compound (Fe2B and FeB) spreading over grain boundary in chain-like manner,microhardness and wear resistance of the cladding layer are increased dramatically.关键词
等离子熔敷/铁基合金/碳化硼/耐磨涂层/显微硬度/微观结构Key words
plasma cladding/Fe-based alloy/boron carbide/wear-resistant coating/microhardness/microstructure分类
矿业与冶金
