中文摘要：

采用脉冲电镀法在Q235钢表面制备Ni-Cr-Mo合金镀层。利用辉光放电光谱仪（GDS）、扫描电镜（SEM）、Tafel曲线和电化学阻抗谱（EIS）考察了pH值对镀层元素含量、沉积速率、表面形貌和耐蚀性的影响。结果表明：随着pH值的增大,镀层中镍含量先减小后增大,铬先增大后减小,钼含量减小;镀层沉积速率先增大后减小;在3.5%NaCl溶液中,镀层耐蚀性先增强后减弱。pH值为3.5时,镀层均匀致密,具有最大的自腐蚀电位（-0.535V）、最小的腐蚀电流密度（0.123μA·cm-2）和最大的电荷转移电阻（2550Ω·cm2）,此时镀层耐蚀性最好。

英文摘要：

Ni-Cr-Mo alloy coatings were prepared on the surface of Q235 steel by pulse electroplating meth. The effects of pH value on the element content, deposition rate, surface morphology and corrosion resistance of the coating were investigated by glow discharge spectroscopy （GDS）, scanning electron microscopy （SEM）, Tafel curve and electrochemical impedance spectroscopy （EIS）. The results show that with the increase ofpH value, Ni content in the coating decreases firstly and then increases, Cr content increases firstly and then decreases, Mo content decreases. The deposition rate of the coating increases firstly and then decreases; in 3.5 % NaCl solution, the corrosion resistance of the coatings strengthens firstly and then weakens. The coating prepared in 3.5 pH bath is uniform and compact, which has the biggest corrosion potential （-0.535 V）, the smallest corrosion current density （0.123 μA·cm2） and the biggest charge transfer resistance （2550 Ω· cm2）, then, the coating exhibits the best corrosion resistance.