CeO_2对等离子喷焊铁基涂层组织和性能的影响

Effect of CeO_2 on microstructure and properties of Fe-based coating produced by plasma arc cladding process

采用光学显微镜、扫描电镜(SEM)、X射线衍射(XRD)以及磨损试验,研究了质量分数为1%的CeO2对等离子喷焊高铬铸铁型铁基合金组织和耐磨性的影响.结果表明,加入1%的CeO2,并未改变喷焊层的相组成,主要都是由面心立方的γ(Fe,Ni)固溶体和六方结构的M7C3型碳化物(M=Cr,Fe,Mo)构成,但使γ(Fe,Ni)固溶体的{111}和{002}择优取向明显转变为以{002}为主.由于CeO2的加入,稀土氧化物作为异质形核核心,细化了组织,抑制了碳化物的生长,弥散分布于共晶组织中,提高了喷焊层的显微硬度和耐磨性能.

The effect of addition of 1%CeO2 on the microstructure and wear resistance of high chromium cast iron coating produced by plasma arc cladding process was investigated by means of optical microscope(OM),scanning electron microscope(SEM),X-rays diffraction(XRD)and sliding wear testing.The results show that the phases composition of the alloy coating compared with the Fe-iron coating was not changed,both consisted ofγ-(Ni,Fe)solid solution with a face-centered cubic lattice and M7C3(M=Cr,Fe,Mo)carbides with a hexagonal structure.Heterogeneous nucleation of the alloy coating modified with rare earth oxide CeO2 that leads to the microstructure refinement and restrains the growth of carbides.And it changes the crystal growth direction ofγ-(Fe,Ni)solid solution from both {111}and{002}to single{002}.Meanwhile,the rare earth oxides homogeneously distribute in eutectic microstructure,thus improving the microhardness and wear resistance of the coating.