S135钻杆钢表面Fe-Ni-W合金镀工艺

Electroplating process of Fe-Ni-W alloy on surface of S135 drill pipe steel

利用正交试验,选择温度、主盐浓度等4个因素,通过极差分析,确定了S135钻杆钢电沉积Fe-Ni-W合金镀层的最佳制备工艺,研究了镀液p H值、电流密度以及柠檬酸钠对镀层的组分、显微硬度和沉积速率的影响。结果表明,在本试验条件下,获得的合金镀层结构为非晶态;随着镀液PH升高,镀层显微硬度先增大后减小,沉积速率总体呈下降趋势;镀层沉积速率随电流密度增加也逐渐增大,当电流密度从6 A/dm^2提高到15 A/dm^2时,合金硬度从320 HV增加到540 HV;提高镀液中的柠檬酸钠含量时,铁和钨均呈现增加趋势,而镍却出现下降趋势,同时,镀层硬度先增大后减小,沉积速率逐渐减小。

Orthogonal experiment was used to determine the optimum process for preparing Fe-Ni-W alloy coating deposited on S135 drill pipe steel. The experiment was conducted using 4 key process parameters,including bath temperature,concentration of main salts and so on. Influences of p H value,current density and sodium citrate on the component,microhardness and deposition rate of the plating were investigated. The results show that the plating obtained under this condition is amorphous. With the increasing of p H value in the plating solution,the microhardness of coating increases first and then decreases,and the deposition rate is overall on the decline. Plating deposition rate also gradually increases with the increase of current density. When the current density changes from 6 A / dm^2 to 15 A / dm^2,hardness increase trend is bigger,from 320 HV to 540 HV. When adding sodium citrate in plating solution,contents of iron and tungsten showan increasing trend,but the nickel content decreases. At the same time,hardness of the coating increases first and then decreases,the deposition rate gradually decreases.