脉冲电镀Ni-Cr-Mn合金镀层工艺与性能研究
发布时间：2018-11-02 15:45
【摘要】：近年来,工业生产中得到的Ni-Cr合金镀层中Cr含量较低,厚度薄,难以很好的满足材料在恶劣环境中的要求。研究发现,锰元素能够提高不同合金体系的耐蚀性能。为提高Q235钢的耐蚀性,采用脉冲电镀法在Q235钢表面制备Ni-Cr-Mn合金镀层。利用辉光放电光谱仪、扫描电镜、Tafel曲线和电化学阻抗谱,研究镀液组分、配位剂、添加剂、镀液温度、pH值、电流密度、电镀时间、占空比和电沉积方式对镀层元素组成、沉积速率、表面形貌和耐蚀性的影响,确定了最优镀液组成和最优工艺参数。最优镀液组成:NiSO_4·6H_2O、CrCl_3·6H_2和MnSO_4·H_2O摩尔比为3:5:10,最优复合配位剂A含量为0.35 mol/L。最优工艺参数:温度40℃,pH值2.6,电流密度13 A/dm~2,时间30 min,占空比20%。采用直流、单脉冲和换向脉冲三种电沉积方式制备的合金镀层中,换向脉冲方式制备的合金镀层表面粗糙度最低,耐蚀性最好。利用极化曲线、循环伏安曲线和计时电流曲线研究了硫酸盐-氯化物体系NiCr-Mn合金的电沉积行为。表明Ni-Cr-Mn合金沉积为不可逆过程,合金镀层具有较好的耐蚀性。
[Abstract]:In recent years, the content of Cr in the coating of Ni-Cr alloy obtained in industrial production is relatively low and the thickness is thin, so it is difficult to meet the requirements of the materials in the harsh environment. It is found that mn can improve the corrosion resistance of different alloy systems. In order to improve the corrosion resistance of Q235 steel, Ni-Cr-Mn alloy coating was prepared on Q235 steel surface by pulse electroplating. By means of glow discharge spectrometer, scanning electron microscope, Tafel curve and electrochemical impedance spectroscopy, the composition of plating solution, coordination agent, additive, bath temperature, pH value, current density, electroplating time, duty cycle and electrodeposition mode were studied. The effects of deposition rate, surface morphology and corrosion resistance on the optimum bath composition and process parameters were determined. The optimum composition of plating bath is: NiSO_4 6H _ 2O _ 2O _ CrCl _ 3 6H_2 and MnSO_4 H _ 2O molar ratio is 3: 5: 10, and the optimum compound coordination agent A content is 0.35 mol/L. The optimum process parameters are as follows: temperature 40 鈩，
本文编号：2306226
[Abstract]:In recent years, the content of Cr in the coating of Ni-Cr alloy obtained in industrial production is relatively low and the thickness is thin, so it is difficult to meet the requirements of the materials in the harsh environment. It is found that mn can improve the corrosion resistance of different alloy systems. In order to improve the corrosion resistance of Q235 steel, Ni-Cr-Mn alloy coating was prepared on Q235 steel surface by pulse electroplating. By means of glow discharge spectrometer, scanning electron microscope, Tafel curve and electrochemical impedance spectroscopy, the composition of plating solution, coordination agent, additive, bath temperature, pH value, current density, electroplating time, duty cycle and electrodeposition mode were studied. The effects of deposition rate, surface morphology and corrosion resistance on the optimum bath composition and process parameters were determined. The optimum composition of plating bath is: NiSO_4 6H _ 2O _ 2O _ CrCl _ 3 6H_2 and MnSO_4 H _ 2O molar ratio is 3: 5: 10, and the optimum compound coordination agent A content is 0.35 mol/L. The optimum process parameters are as follows: temperature 40 鈩，
本文编号：2306226
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