NaCl溶液pH值对5083铝合金腐蚀的影响研究

摘要

采用电化学试验方法,结合金相组织观察、SEM、腐蚀形貌观察等,研究了在不同pH值时3％(质量分数)NaCl溶液中5083铝合金的点蚀电位、自腐蚀电位及腐蚀质量损失.研究结果表明,5083铝合金点蚀电位基本接近,自腐蚀电位存在差异,而且在强酸、强碱溶液中会发生全面均匀的腐蚀溶解；在弱酸、弱碱或偏中性溶液中由于在夹杂物及基体间发生局部点蚀而表现出较低的腐蚀质量损失.%Effect of solution pH on corrosion behavior of alloy AA5083 immersed in NaCl solutions was investigated using measurements of weight loss, potentiodynamic polarization, combined with techniques of metallographic structure, scanning electron micrograph (SEM) and corrosion morphology. The results showed that the pitting potentials in different pH were similar, but the corrosion potentials were different. The corrosion behavior was found to be dependant of the solution pH. In acidic or alkaline chloride solutions, general corrosion occurred. In contrast, exposure to slightly neutral and slight acidic or alkaline solutions resulted in pitting corrosion.