1Cr13不锈钢应力腐蚀裂缝内的电化学机制研究

CIESC Journal

1Cr13不锈钢应力腐蚀裂缝内的电化学机制研究

刘幼平,迟芳,左景伊

北京化工学院应用化学系,北京化工学院应用化学系,北京化工学院应用化学系北京100029 ,北京100029 ,北京100029

出版日期:1993-10-25 发布日期:1993-10-25

ELECTROCHEMICAL BEHAVIOURS INSIDE STRESS CORROSION CRACKS OF 1Cr13 STAINLESS STEEL

Liu Youping, Chi Fang and Zuo Jingyi (Department of Applied Chemistry, Beijing Institute of Chemical Technology, Beijing 100029)

Online:1993-10-25 Published:1993-10-25

摘要/Abstract

摘要： 模拟1Cr13不锈钢在0.5mol/L NaCl溶液中应力腐蚀裂缝尖端的环境变化和受力状态,进行腐蚀及电化学测试,绘制了描述该体系应力腐蚀裂缝内各阶段热力学和动力学行为的实验电位～pH图.腐蚀率～pH曲线、电位～时间曲线和电位～pH图等均表明上述体系应力腐蚀裂缝内存在1个临界pH值(90℃时约为4.1).低于临界值,裂缝尖端发生钝态向活态的转变,腐蚀速度骤增,电位下降.应力和微区酸化都使裂缝内的钝化效果变差,腐蚀率增大.应力使裂缝尖端开始加速腐蚀的临界pH值升高.

Abstract: Specimens stressed at yieiding point in acidic occluded solutions were tested to simulate the mechanical and environmental states within stress corrosion cracks for "1Cr13 steel /0.5mol/L Cl-" system, and to determine the corrosion rates as well as the electrochemical behaviour of crack tips at different propagating stages. The experimental potential / pH diagrams depicting kinetic and thermodynamic behaviours inside cracks as well as mechanical and environmental effects on occluded cell corrosion were constructed. A critical pH value (about 4.1 at 90℃) was found from the "corrosion rate/pH" curve, "potential / time" curves, and potential / pH diagrams, below which passive-active transition occurred at crack tips and corrosion rate increased rapidly. Both stress and acidification caused a higher corrosion rate and a greater critical pH value.

刘幼平,迟芳,左景伊. 1Cr13不锈钢应力腐蚀裂缝内的电化学机制研究 [J]. CIESC Journal.

Liu Youping, Chi Fang and Zuo Jingyi (Department of Applied Chemistry, Beijing Institute of Chemical Technology, Beijing 100029). ELECTROCHEMICAL BEHAVIOURS INSIDE STRESS CORROSION CRACKS OF 1Cr13 STAINLESS STEEL[J]. .