船用碳钢在电解压载水中的初期腐蚀行为

为研究压载水电解处理技术对压载舱腐蚀的规律,采用静态挂片失重、电化学测试以及扫描电镜(SEM)等方法研究低碳钢在电解压载水中的初期腐蚀行为.结果表明:低碳钢在余氯质量浓度为7.5、17和28 mg/L的压载水中的腐蚀速度分别约为其在天然海水中的1.25、1.46和1.7倍,且余氯质量浓度越高,温度对腐蚀加速的影响越大;试样在电解压载水中的腐蚀过程由阴极反应中的传质过程控制;碳钢在余氯质量浓度为7.5和17 mg/L压载水中的腐蚀形貌留有剥蚀、断裂的特征.腐蚀产物能谱分析表明:电解压载水腐蚀产物中的氯元素含量降低,产物层对氯离子的渗入具有较强的阻碍作用.

Early corrosion behavior of marine carbon steel in electrolyzed ballast water

Laboratory weight-loss measurements,electrochemical tests and SEM techniques were used to study the early corrosion behavior and mechanism of marine carbon steel in electrolyzed ballast water.Experimental results show that the corrosion rate of marine carbon steel is 1.25,1.46 and 1.7 times in ballast water more than that in natural seawater for the mass concentration of total residual chlorine(TRC) being 7.5 mg/L,17 mg/L and 28 mg/L respectively.The influence of temperature to the corrosion rate increased with the mass concentration of TRC increasing.Corrosion process was controlled by mass transfer process in cathodic reaction.The SEM observation shows that carbon steel surface was characterized with denudation and rupture corroded in electrolyzed ballast water with mass concentration of TRC 7.5 mg/L and 17 mg/L.The elemental analysis for the corrosion products shows that the content of chlorine elements decreases,which indicates that the product layers in electrolyzed ballast water has strong hindering effect on chloride ion penetration.