Q345钢在模拟海洋温跃层环境下的电偶腐蚀行为研究  

Study on Galvanic Corrosion Behavior of Q345 Steel in Simulated Ocean Thermocline Environment

作　　者：刘文娟 袁建都 胡杰珍[2] 曹星慧 郭勤 马彪 LIU Wenjuan;YUAN Jiandu;HU Jiezhen;CAO Xinghui;GUO Qin;MA Biao(College of Energy and Chemical Engineering,Xinjiang Institute of Technology,Aksu 842008,China;Zhanjiang Key Laboratory of Marine Engineering and Equipment Corrosion and Protection,Guangdong Ocean University,Zhanjiang 524088,China)

机构地区：[1]新疆理工学院能源化工工程学院,新疆阿克苏842008 [2]广东海洋大学湛江市海洋工程及装备腐蚀与防护重点实验室,广东湛江524088

出　　处：《材料保护》2024年第7期119-126,153,共9页Materials Protection

摘　　要：为研究Q345钢在海洋温跃层环境下的电偶腐蚀行为,利用自制的模拟海洋温跃层装置和可拆卸阵列电极,各可拆卸电极之间通过盐桥连接,采用浸泡法和电化学方法,对海洋跃温层环境下Q345材料的腐蚀形貌和腐蚀产物进行分析。结果表明:在实验初期,利用电化学噪声技术测得的链式电极电偶电流表现为两端为正值、中间为负值的特征,说明链式电极之间形成了两端为阳极、中间为阴极的宏观腐蚀电池。随着浸泡时间的延长,链式电极之间的电偶电流密度变化较大,最大差值达到1.71μA/cm^(2),且电极极性发生反转。从金属的腐蚀速率可以得出链式电极顶部和底部的平均腐蚀速率明显高于中部的,这与电偶电流密度的变化规律具有良好的一致性。通过腐蚀产物形貌和XRD分析发现,链式电极顶部和底部表面腐蚀产物覆盖较厚,结构疏松且出现分层,且腐蚀产物中Fe_(3)O_(4)和γ-FeOOH的相对含量较高,而中部的腐蚀产物覆盖较少且致密,锈层中α-FeOOH的相对含量较高,γ-FeOOH的相对含量较低。In order to study the galvanic corrosion behavior of Q345 steel in an ocean thermocline environment,a self-made simulated ocean thermocline device and detachable array electrodes were used.The detachable electrodes were connected via a salt bridge.The corrosion morphology and corrosion products of Q345 material in the ocean thermocline environment were analyzed using immersion and electrochemical methods.Results showed that at the initial stage of the experiment,the galvanic current of the chain electrode measured by electrochemical noise technology was positive at both ends and negative in the middle,indicating that a macro corrosion cell with anodes at both ends and a cathode in the middle had formed between the chain electrodes.With the increase in immersion time,the galvanic current density between the chain electrodes varied significantly,with the maximum difference reaching 1.71μA/cm^(2),and the electrode polarity was reversed.From the corrosion rate of the metal,it was concluded that the average corrosion rate of the top and bottom electrodes of the chain electrode was significantly higher than that of the middle electrode,which was consistent with the variation in galvanic current density.Through the analysis of corrosion product morphology and XRD,it was found that the corrosion products on the top and bottom surfaces of the chain electrode were covered with thick layers,exhibiting a loose structure and delamination,with relatively high contents of Fe3 O4 andγ-FeOOH in corrosion products,whereas the corrosion products on the middle electrode were less covered and denser,with relatively high contents ofα-FeOOH and lower contents ofγ-FeOOH in the rust layer.

关 键 词：海洋温跃层 电偶腐蚀 温度 Q345钢 电化学噪声 

分 类 号：TG172[金属学及工艺—金属表面处理]