激光熔覆Fe-Ti-V-Cr-C合金涂层的微观组织和性能

Microstructure and Property of Laser Cladding Fe-Ti-V-Cr-C Alloy Coatings

采用激光熔覆技术制备了Fe-Ti-V-Cr-C合金耐磨涂层。借助光学显微镜、XRD、扫描电镜、显微硬度计以及磨损试验机,研究了不同铬铁加入量对涂层组织及性能的影响。结果表明:在激光熔覆条件下,钛铁、钒铁、铬铁与石墨通过原位反应生成了稳定的硬质相,呈粒状或花状分布的TiC-VC复合相和断续网状分布的Cr7C3陶瓷相均匀分布于涂层,显著提高了涂层的显微硬度和耐磨性。涂层硬度随铬铁加入增多而提高。当铬铁加入为12%(质量分数),涂层组织细密,在相同磨损条件下,其磨损量仅约为母材的1/7。当铬铁加入达到15%时,涂层出现粗大莱氏体组织,易导致涂层开裂。

Fe-Ti-V-Cr-C hardfacing coatings were produced by laser cladding,the influence of ferrochromium on the microstructure and property of the coatings was investigated by optical microscope（OM）,X-ray diffraction（XRD）,scanning electron microscope（SEM）,micro-hardness tester and wear tester.The results show that the stable carbide hard phases are generated through in-situ reaction between ferrotitanium,ferrovanadium,ferrochromium and graphite.The multiple TiC-VC presented graininess or efflorescent and intermittent Cr7C3 emerged reticulation evenly disperse in the coating,which largely increase the micro-hardness and wear resistance of the coating.The micro-hardness of the coatings increases with increasing ferrochromium content.The coating,which contented 12%（mass fraction） ferrochromium,holds compact microstructure and excellent wear resistance.Under the same condition,its mass loss is only one seventh of that of the substrate.However,when the ferrochromium content is beyond 15%,coarse Ledeburite which may cause crack and failure of coating is found.