石油钻杆激光增材制备耐磨带的组织结构及性能研究

Research on the Microstructure and propertiess of Oil Drill Pipe Prepared by Laser Additive Manufacturing

利用6kW高功率半导体激光器,在42CrMo基体上制备Fe基Co/WC复合陶瓷涂层及Stellite 12耐高温合金涂层,分别用光学显微镜(OM)、扫描电镜(SEM)、显微硬度计及摩擦磨损试验机对熔覆层的显微组织、硬度及耐磨性进行研究。结果表明,涂层与基体呈冶金结合;涂层底部晶粒以近似垂直于基体界面的胞状晶的形态生长,中部以柱状晶过渡到树枝晶,上部是具有一定生长方向的细小枝晶;Fe^(-9)+30%Co/WC涂层组织均匀致密、晶粒细小,WC颗粒保存完整,耐磨性相较于42CrMo涂层提高18.6倍;Fe^(-3)+30%Co/WC涂层平均显微硬度最高达到489 HV0.5,是基体硬度的3.25倍,耐磨性也最好,相较于42CrMo涂层提高220倍。

Fe-CoAVC composite coatings and Stellite 12 high temperature resistant coatings were prepared on 42CrMo substrate by using 6kW high power diode laser. The morphology, microhardness and wear resistance of laser cladding layers were studied by optical microscope（OM）,scaiming electronic microscope （SEM）, microhardness tester and friction wear testing machine. The results show that the cladding layer has a metallurgical bonding with substrate. The morphology of crystal grain at the bottom of lading layer is cell structure, whose growth is perpendicular to the interface of cladding and substrate. Then the columnar grain transits to dendrite structure at the central,the morphology of crystal grain at the top zones of layer is dendritic structure and grows with a single direction. When composite coating is Fe-9＋30% CoAVC, microstructure of cladding layer is uniform and compact, with WC particles preserved intact, and it＇s wear resistance is more than 18.6 times compared with 42CrMo coating. When composite coating is Fe-3＋30% CoAVC, the highest hardness 489 HV0 5 of cladding layer is 3.25 times than substrate and i t＇s wear resistance is more than 220 times compared with 42CrMo coating.s：