S2-对高强Cu-7Ni-3Al合金在NaCl溶液中耐蚀性能的影响

实验以铜镍系耐蚀铜合金为基础，利用真空熔炼法制备得到Cu-7Ni-3Al合金，通过静态浸泡法对Cu-7Ni-3Al在不同S^2-浓度的3.5%（w） NaCl溶液中的腐蚀速率及腐蚀形态进行了研究。结果表明，通过真空熔炼法能制备出综合力学性能良好的Cu-7Ni-3Al合金。S^2-的存在促进了Cu-7Ni-3Al合金的腐蚀，Cu-7Ni-3Al合金的腐蚀速率随S^2-浓度的增大而增大，原因在于Cu-7Ni-3Al合金在S^2-环境中会形成Cu₂S，Cu₂S会使表面钝化膜变脆，并且阻止氧化膜的生成从而使腐蚀加速，因此Cu-7Ni-3Al合金在3.5% NaCl溶液中随S^2-含量的增加，耐蚀性下降。

Effect of S2-on Corrosion Resistance of Cu-7Ni-3Al Alloy in NaCl Solutions

Cu-7Ni-3Al copper alloy is prepared by vacuum smelting based on the copper-nickel corrosion-resistant copper alloys. The corrosion rate and corrosion pattern of Cu-7Ni-3Al alloy in 3.5% (w) NaCl solutions with different concentrations of S2- are analyzed by the static total impregnation corrosion experiment. The results show that Cu-7Ni-3Al alloy with good comprehensive performance is prepared by vacuum smelting. The existence of S2- promotes the corrosion of Cu-7Ni-3Al alloy. The corrosion rate of Cu-7Ni-3Al alloy increases with the increase of S2-concentration, because in the environment of S2-, Cu-7Ni-3Al alloys will form Cu2S, and Cu2S will make the passivated film brittle and prevent the formation of oxide film, thus accelerating corrosion. Therefore, the corrosion resistance of Cu-7Ni-3Al alloy decreases with the increase of S2-content in 3.5% NaCl solution.