热浸镀高铬铸铁层热处理前后的组织及耐冲蚀磨损性能

Microstructure and Erosion Wear Behavior of Hot-Dipping High-Chromium Cast-Iron Coatings before and after Heat Treatment

通过热浸镀技术制备高铬铸铁涂层来提高材料的耐冲蚀磨损性能未见研究报道。采用热浸镀技术在碳钢表面制备了高铬铸铁涂层,利用光学显微镜、扫描电镜(SEM)和X射线衍射仪分析了涂层热处理前后的组织和物相,对涂层热处理前后的抗冲蚀磨损性能进行了比较,并观察了涂层冲蚀后的表面形貌。结果表明:涂层主要由γ-Fe,CrC和CrB组成,热处理后涂层中硬质相类型由CrC和CrB转变为Cr7C3和Cr23C6;热处理后涂层的抗冲蚀磨损性能与热处理前相比明显提高,磨损量仅为热处理前的60%。

High-chromium cast-iron coatings were prepared on carbon steel substrate by hot dipping so as to improve the wear resistance.The microstructure of the coatings before and after heat treatment was analyzed by means of optical microscopy,scanning electron microscopy and X-ray diffraction.The erosion wear behavior of the coatings before and after heat treatment was comparatively investigated,and the morphology of the coatings after erosion was observed.It was found that the coatings were mainly composed of γ-Fe,CrC and CrB.Hard phases CrC and CrB were transformed to Cr7C3 and Cr23C6 when the coatings were heat-treated.At the same time,the erosion wear resistance of the coatings was greatly increased after heat treatment,and the erosion wear volume of the heat-treated coatings was only about 60%of that of the untreated coatings.