ABSTRACT

Electrochemical corrosion thermodynamics of an X52 pipeline steel under plastic stresses was studied by measurements of corrosion potential and Volta potential with a scanning Kelvin probe in an anaerobic near-neutral pH and an aerobic high pH corrosive environments, where the steel was under active dissolution and passivity, respectively. The stress-corrosion thermodynamics of the stressed steel in both environments was studied by Volta potential measurements. While the corrosion potential shifts negatively due to a stress-enhanced corrosion activity in both solutions, the shift of Volta potential is more indicative of the corrosion thermodynamics under identical stresses. Volta potential measurements provide a more promising method than corrosion potential to indicate the stress corrosion thermodynamics of the steel. The relationships between Volta potential and corrosion potential in both active and passive solutions deviate from linearity in the presence of stress. However, the difference between the two potentials increases linearly with stress .

摘要

X52管线钢在塑性应力作用下的电化学腐蚀热力学通过在厌氧近中性pH和好氧高pH腐蚀环境中用扫描开尔文探针测量腐蚀电位和伏特电位来研究，其中钢处于活性溶解和钝化状态， 分别。通过伏特电位测量研究了两种环境中受应力钢的应力腐蚀热力学。虽然由于两种溶液中的应力增强腐蚀活性，腐蚀电位发生负向移动，但伏特电位的移动更能反映相同应力下的腐蚀热力学。伏特电位测量提供了一种比腐蚀电位更有前途的方法来指示钢的应力腐蚀热力学。在存在应力的情况下，主动和被动解决方案中的伏特电位和腐蚀电位之间的关系偏离线性。然而，两个电位之间的差异随着应力线性增加。