低碳钢在模拟海洋潮差区的腐蚀行为的电化学研究

利用自主设计的腐蚀实验槽模拟实海潮差,并借助恒电位仪、电化学工作站对Q235B低碳钢在潮差区不同位置以及全浸区的腐蚀过程进行原位监测.结果表明,试样处在潮差区的不同位置时的腐蚀规律不同,低碳钢在中潮区和低潮区的腐蚀速率高于最高潮区及全浸区的腐蚀速率;在一个潮差涨落周期内,低碳钢开路电位的变化与表面经历的干、湿状态及所发生的阴、阳极反应有关;在长期潮差腐蚀进程中,低碳钢开路电位的变化规律与锈层的厚、薄状态有关.

ELECTROCHEMICAL STUDY ON CORROSION BEHAVIORS OF MILD STEEL IN A SIMULATED TIDAL ZONE

The environment of the tidal zone is very complex.And the dry-wet alternation and interaction of sea erosion leads to serious corrosion of metal materials,making it difficult to adopt protective measures.Therefore,it is of great significance to study the corrosion and protection of metal materials in the tidal zone.Corrosion weight loss results showed that the corrosion behaviors of metal in different regions of tidal zone were altered,but the corrosion mechanism of metal materials in the tidal zone is not obvious.In order to study the corrosion mechanism of tidal corrosion,without considering the seawater splashing effect,a corrosion experimental trough was designed to simulation the tidal zone and immersion zone,and the corrosion behaviors of Q235B mild steel(designated) in it were monitored in situ by the potentiostat and electrochemical workstation.The results showed that the corrosion behaviors of Q235B steel at diverse positions are not the same.The corrosion rate of Q235B steel in the mid tide zone and low tide zone is higher than the highest tide zone and immersion zone.In a tidal range fluctuation cycle,the open-circuit potential variation law of the Q235B steel is related with the dry/wet state of the metal surface and the cathode/anode reactions.In the long term tidal corrosion process,the open-circuit potential variation of Q235B steel is related with the thickness of the rust layer.