管线钢在干湿交替环境下的腐蚀

Corrosion of Pipeline Steel in Dry and Wet Alternative Environment

在模拟土壤的NS4溶液中,采用腐蚀失重、极化曲线和产物形貌观察等方法研究了X80钢在干湿交替环境下的腐蚀行为。结果表明,腐蚀速率随干/湿交替时间比降低先增加后减小,当干/湿交替时间比为9h/15 h时,腐蚀速率最高,为全浸腐蚀速率的1.8倍;在此条件下,腐蚀速率随pH值增大而降低;随着Cl^-浓度增大,腐蚀速率先降低后增加;采用灰关联度法分析影响间浸腐蚀的因素排序为干/湿交替时间>pH值>Cl^-浓度。

Corrosion behaviors of X80 steel in alternating wet and dry environment were studied by the means of weight loss, electrochemical polarization curves and morphology observation in the NS4 solution. The results showed that the corrosion rate first increased and then decreased with decreasing the time ratio of dry to wet. When the time ratio of dry to wet was 9 h/15 h, the corrosion rate reached 0.56 mm/a which was 1.8 times of the corrosion rate under the condition of full immersion. Under the condition of interval immersion, the corrosion rate decreased with pH value increase. As the concentration of Cl- increased, the corrosion rate first decreased and then increased. The influence sequence on the interval immersion corrosion was time of wet-dry alternating, pH and Cl concentration on the basis of analysis using gray relational theory.