主动钻杆接头金属复合陶瓷渗镀表面强化技术研究

Study on Surface Hardening Technology of Metal Composite Ceramic Alloying Plating for Active Drill Pipe Joint

为提高主动钻杆接头表面硬度、耐磨性等各项力学性能,采用熔盐法,以TiO_(2)粉末为原料,在氮气气氛下,将TiO_(2)粉末置于NaCl-MgCl_(2)熔盐中并加入微量Ag、Cu粉末,在500~800℃下反应16 h得到接头表面梯度氮化物陶瓷相。对强化后的接头进行表面硬度、显微组织及物相和耐磨性能等的测试和分析,结果表明,渗镀层形成了TiN及Fe_(x)Ti(Ag,Cu)强化相;表面硬度提高到1710HV0.05;比磨损率下降到0.0270 mm^(3)/(N·m);耐磨性比常规氮化的提高了1.8倍,比基体材料的提高了6.8倍。这表明与常规氮化工艺相比,金属复合陶瓷渗镀工艺可在强化表面形成多梯度渗镀层结构,具备减磨、降温、自润滑的效果,能极大提高接头表面硬度及耐磨性等各项力学性能。

TiO_(2) powders are placed in NaCl-MgCl_(2) molten salt with tiny amount of Ag and Cu powders at 500-800℃ for 16 hours to prepare the gradient nitride ceramic phase on the surface of active drill pipe joint,therefore to improve the adhesion resistance,wear resistance and mechanical properties of the joint.The hardness,microstructure,phase and wear resistance of the strengthened joint are tested and analyzed.It is found out that strengthening phases of TiN and Fe_(x)Ti(Ag,Cu)are formed in the infiltration layer.The surface hardness increases to 1710HV0.05,the specific wear rate decreases to 0.0270 mm^(3)/(N·m),and the wear resistance is 1.8 times higher than that of the ordinary nitrided joint,and 6.8 times higher than that of the matrix material.Compared with the common surface nitriding process,the composite cermet infiltration process forms a multi-gradient infiltration coating structure on surface of the joint,which has the effects of reducing wear,cooling and self-lubrication,and can greatly improve the surface hardness and wear resistance of the active drill pipe joint.