耐热耐腐蚀氨基磺酸盐镀镍工艺的改进

Improvement on heat- and corrosion-resistant sulfamate nickel plating process

针对螺母零件局部镀镍的质量要求,通过强化镀前处理(如增加应力消除工序及采用腐蚀/预镀镍处理)、优化镀液组成(如降低主盐浓度,提高硼酸浓度,适量添加十二烷基硫酸钠)及工艺条件(如缩窄pH范围,严格控制电流密度,适当搅拌),提高了氨基磺酸盐镀镍层的附着强度,改善了镀层的致密性。对于厚度为15～20μm及20～40μm的镀层而言,538℃下保温2h后无起泡或剥离,再中性盐雾试验48h后无锈蚀。

Aiming at the quality requirement of partially nickel plated nut, the sulfamate nickel plating process was improved as follows： （1） the pretreatment was strengthened by applying stress relief treatment and etching/nickel pre-plating; （2） the bath composition was optimized by decreasing nickel sulfamate concentration, increasing boric acid concentration, and adding a proper amount of sodium dodecyl sulfate; and （3） the process conditions were optimized by narrowing the pH range, strictly controlling the current density, and properly agitating. The adhesion strength and compactness of nickel coating were thus improved. Both 15-20 μm-thick and 20-40μm-thick nickel coatings do not blister or peel off after maintaining at 538 ℃ for 2 h, and even not rust after further neutral salt spray test for 48 h.