碳钢在流动3%氯化钠溶液中的腐蚀机理的探讨

本文利用自行设计的模拟流动状态的装置,研究了碳钢在流动3%NaCl溶液中的腐蚀规律及施加阴极电流后对腐蚀的影响。结果表明:随着相对流速的增大,碳钢的腐蚀随之加剧,并发现存在一个临界相对流速值。当相对流速小于此值时,腐蚀主要受电化学因素影响。而相对流速大于此值时,流体力学因素开始明显起主导作用,并与电化学因素间的协同效应增强,导致腐蚀速度急剧上升。施加阴极电流后,不仅抑制了电化学因素引起的腐蚀,而且大幅度地削弱了电化学因素与流体力学因素间的协同效应,从而使腐蚀速度大大降低。

A STUDY ON THE CORROSION MECHANISM OF CARBONSTEEL IN FLOWING 3% NaCl SOLUTION

A simulating test apparatus is Used to study the corrosion of carbon steel in flowing 3%NaCl solution and the efiect of applied cathodic current on the corrosion process. The experimental result shows that the corrosion rate of carbon steel increases with the increasing of flow Velocity, and there is a critical flow velocity. When the flow velocity is below the critical one the corrosion is mainly controlled by electrochemical factor,while over the critical flow velocity the hydrodynamic factor plays a prominent role in the corrosion of carbon steel,and the synergism between hydrodynamic factor and electrochemical factor is enhanted,causing corrosion rate of carbon steel to increase grearly.The application of cathodic current not only restrains the corrosion caused by electrochemical factor but also markedly weakens the synergism between them,thus the corrosion rate decreases rapidly.