钢制紧固件稀土镧改性渗锌层的制备与性能研究

摘要

目的 提高车辆钢制紧固件在海洋环境中的腐蚀防护能力.方法 借助稀土元素对渗锌层的改性作用,采用正交试验方法优化了渗锌剂配方和工艺参数,制备出性能更为优异的稀土改性渗锌层.结果 稀土改性优化渗锌工艺参数为(质量分数):La2(NO3)31%,Zn粉70%,CO(NH2)22%,Al2O327%,加热温度为460℃,保温时间为2 h.与常用渗锌剂制备的渗锌层相比,稀土改性渗锌层更为均匀、致密、光滑.结论渗层厚度提高了107.3%,对腐蚀介质起到更为优异的阻滞作用,耐蚀性更强.%Objective To improve the corrosion prevention ability of fasteners in marine environment.Methods With the help of modifying effects of rare earth on diffusion zinc layer, the orthogonal test method was used to optimize the sherardizing agent formulation and process parameters; and more excellent rare earth modified sherardizing layers were prepared.Results Parameters (mass fraction) of the rare earth modified optimization sherardizing technology were: La2 (NO3)3 content: 1% Zn powder content: 70%, CO (NH2)2 content: 2%, the content of Al2O3: 27%, heating temperature of 460℃, insulation time: 2 h. Compared with the diffusion zinc layer prepared by commonly used zinc impregnation agent, the modified diffusion zinc layer was more uniform, compact and smooth.Conclusion The layer thickness is im-proved by 107.3%, and it has a better effect on the corrosion medium. Its corrosion resistance is better.