In this paper, weight loss and electrochemical methods were used to investigate the corrosion behavior of acidification sewage. It was testified that pH value had remarkable influence on corrosion rate. In acid media, the cathodic process was mainly controlled by hydrogen de-polarization. The lower of pH value, the bigger the corrosion rate was, which meant the more concentrated of acid, the faster of corrosion rate. While in neutral or basic solution, oxygen played a key role in cathodic reaction. Polarization curves and EIS tests showed the corrosion mechanism in different stages of acidification sewage was inconsistent. Both methods proved some of them were controlled by diffusion process. EIS tests also showed the corrosion could be controlled by electrochemical, diffusion and inductive reactance control. The electrochemical mechanism was different.% 本文采用静态失重法和电化学方法研究了不同阶段酸化返排液的腐蚀规律。两种方法均证实了pH值是影响腐蚀速率的主要因素。酸性环境中电化学阴极过程主要受氢去极化控制，因此，pH值越低介质酸浓度越大，腐蚀速率越快；而中碱性介质中电化学阴极过程主要受氧去极化控制。极化曲线和电化学阻抗谱(EIS)测试证实了不同返排阶段的介质对金属腐蚀作用的机理不一致。极化曲线显示部分组别的阳极过程受扩散控制，EIS也证实了这一点；EIS测试表明，不同返排液的腐蚀可能受到电化学控制，受扩散控制，有些还出现了感抗弧，其电化学机理有所不同。
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