Author(s)

O. KUWAZURU, K. ODE & W. LIU

Abstract

The corrosion electric field around the surface of stainless steel under tensile stress is addressed through the experiment and simulation. When the stress is applied, the passive film is locally damaged on the grain boundaries causing microscopic stress and strain concentrations. In a corrosive environment, the plastic strain induced by the strain concentration breaks the passive film and generates a new surface without the passive film. This causes a galvanic corrosion between the intact surface with passive film and the damaged surface without passive film. The effect of stress on the polarization curve was observed by electrochemical and mechanical experiments, and we found that the spontaneous potential decreased as the applied stress increased. To evaluate the electrochemical property of stressed stainless steel, the electric field analysis is formulated by the boundary element method (BEM) with the damaged passive film model and the empirical polarization curve model.

Keywords

boundary element method, electrochemistry, nonlinear boundary, passive film, potential problem, stainless steel, stress corrosion.