热处理对铁基TiC复合涂层的组织及磨损性能的影响

Influence of Heat Treatment on Microstructure and Wear Behavior of Fe-TiC Composite Coatings

采用电弧喷涂技术在低碳钢Q235基体上制备铁基TiC复合涂层,利用箱式电阻炉对涂层进行400、500、600、700和800℃的热处理,研究其对铁基TiC复合涂层组织和磨粒磨损性能的影响。利用光学显微镜、扫描电子显微镜（SEM）和X射线衍射仪（XRD）对涂层的显微组织结构、磨损表面和相组成进了分析和研究。结果表明：热处理对Fe-TiC复合涂层的组织、硬度和耐磨性有显著影响,500~700℃热处理能够改善电弧喷涂铁基TiC涂层的耐磨性;500℃热处理后的涂层具有较好的耐磨损性能;随着热处理温度的增加,涂层中出现更多的氧化物相,涂层的磨损机理由犁沟切削和脆性脱落逐步转化为以脆性脱落为主。

The Fe-based alloy carbide composite coating was deposited onto Q235mild steel substrate using arc spray technique and then heat treated at different temperatures in a resistance stove.The coatings were then evaluated in the as sprayed and heat treated conditions.The microstructure and phase construction of composite coating were analyzed by scanning electron microscope（SEM）and X-ray diffraction（XRD）.Tribological properties were studied under wet condition by using pin on the disc machine.The results show that heat treatment has a significant impact on the microstructure,hardness and wear resistance of Fe-TiC composite coating.Heat treatment at 500-700℃ can improve the wear resistance of arc sprayed TiC coatings,as sprayed deposit and heat treatment at 500℃ has the best wear resistance.The oxide phase in heat treatment samples increases by increasing the heat treatment temperature and the wear mechanism gradually changes from micro-ploughing and brittle fracture to gouging abrasion.