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采用扫描电镜、X光电子能谱、失重法和电化学交流阻抗技术研究了铝合金7A04在0.6mol/L NaCl溶液和0.6mol/L NaCl+0.02mol/LNaHSO3溶液中干湿周浸后的腐蚀行为和规律,并测试了3种材料力学性能的变化。研究结果表明,随试验时间的延长,铝合金腐蚀产物不断增多,腐蚀失重符合指数规律C=Atn,抗拉强度和延伸率呈下降趋势;表面腐蚀产物形貌呈块状,在0.6mol/LNaCl溶液中腐蚀产物主要为氢氧化铝和氯化铝,而在0.6mol/L NaCl+0.02mol/L NaHSO3溶液中腐蚀产物主要为氢氧化铝、氯化铝和硫酸铝。电化学交流阻抗谱显示铝合金7A04在0.6mol/LNaCl+0.02mol/L NaHSO3溶液中的腐蚀速率远大于在0.6mol/L NaCl溶液的腐蚀速率,并探讨了其腐蚀机理。
The corrosion behavior of aluminum alloy 7A04 in 0.6mol / L NaCl solution and 0.6mol / L NaCl + 0.02mol / LNaHSO3 solution was studied by scanning electron microscopy, X-ray photoelectron spectroscopy, weight loss method and electrochemical impedance spectroscopy And laws, and tested the mechanical properties of three kinds of changes. The results show that with the prolongation of test time, the corrosion products of aluminum alloy increase ceaselessly, the corrosion loss accords with exponential law C = Atn, the tensile strength and elongation decrease; the morphology of corrosion products is massive, Corrosive products in the solution are mainly aluminum hydroxide and aluminum chloride, while the corrosion products in 0.6mol / L NaCl + 0.02mol / L NaHSO3 solution are mainly aluminum hydroxide, aluminum chloride and aluminum sulfate. The electrochemical impedance spectroscopy showed that the corrosion rate of 7A04 in 0.6 mol / L NaCl + 0.02 mol / L NaHSO3 solution was much higher than that in 0.6 mol / L NaCl solution and its corrosion mechanism was discussed.