论文部分内容阅读
采用直流、单脉冲和换向脉冲三种不同电沉积方式在Q235钢表面电镀制备Ni-Cr-Mn合金镀层。利用辉光放电光谱仪、形状测量激光显微系统、Tafel曲线和电化学阻抗谱,研究了电沉积方式对镀层元素含量、沉积速率、3D形貌和耐蚀性的影响。结果表明:按照直流、单脉冲和换向脉冲的顺序,镀层中镍含量减小,铬、锰含量增大,沉积速率先增大后减小,表面粗糙度降低,耐蚀性增强。直流方式制备的镀层表面存在个别较大的颗粒,单脉冲方式制备的镀层表面颗粒大小较为均匀,但仍存在个别较大颗粒,换向脉冲方式制备的镀层总体均匀致密。换向脉冲方式制备的镀层表面粗糙度最低,在3.5%NaCl溶液中,该镀层具有最大的腐蚀电位(-0.305 V)、最小的腐蚀电流密度(7.467×10~(-8)A·cm~(-2))和最大的电荷转移电阻(5972Ω·cm~2),耐蚀性最佳。
The Ni-Cr-Mn alloy coating was prepared on the surface of Q235 steel by three different electrodeposition methods of DC, single pulse and commutation pulse. The effects of electrodeposition method on the content of element, deposition rate, 3D morphology and corrosion resistance of the coating were studied by means of glow discharge spectrometer, shape measurement laser microscopy, Tafel curve and electrochemical impedance spectroscopy. The results show that the content of nickel and nickel in the coating decreases and the deposition rate increases firstly and then decreases, the surface roughness decreases and the corrosion resistance increases in the order of DC, single pulse and commutation pulse. There are some larger particles on the surface of the coating prepared by direct current method. The surface of the coating prepared by the single pulse method is relatively uniform in size, but there are still some larger particles. The coatings prepared by the commutation pulse method are generally uniform and compact. The surface roughness of the coating prepared by the commutation pulse method is the lowest. In 3.5% NaCl solution, the coating has the maximum corrosion potential (-0.305 V) and the minimum corrosion current density (7.467 × 10 -8 A · cm ~ (-2)) and the maximum charge transfer resistance (5972Ω · cm ~ 2), the best corrosion resistance.