阳极电解活化前处理的电流密度对 304 不锈钢电镀镍结合力的影响

Effect of current density during anodic electrolytic activation as a pretreatment for 304 stainless steel substrate on adhesion of nickel coating subsequently electroplated thereon

为了在304不锈钢表面获得结合力良好的电镀镍层,先采用140 g/L氨基磺酸溶液对304不锈钢阳极电解活化再电镀镍。通过极化曲线测试分析了304不锈钢在氨基磺酸溶液中的电化学溶解特性,接着研究了电流密度对电解活化电流效率和活化效果的影响,最后通过奥拉法测试分析了阳极电解活化电流密度对304不锈钢表面电镀镍层结合力的影响。结果表明,在高于14 A/cm2的电流密度下电解后,不锈钢表面钝化膜被去除干净,后续所得镀镍层的结合强度显著提高。

304 Stainless steel was activated by anodic electrolysis in 140 g/L sulfamic acid solution prior to nickel electroplating for preparing well-adhered nickel coating on its surface.The electrochemical dissolution characteristics of 304 stainless steel in sulfamic acid solution was analyzed by polarization curve measurement.The effect of current density during anodic electrolytic activation on the current efficiency and activation effectiveness was studied.The dependence of the adhesion of nickel coating to 304 stainless steel on current density during anodic electrolytic activation was analyzed by Ollard method.The results showed that the passivation film on stainless steel could be removed completely after electrolytic activation at a current density higher than 14 A/cm2,and the bonding strength of the nickel coating subsequently obtained by electroplating was significantly improved.