Numerical Investigation of Critical Electrochemical Factors for Localized Corrosion using a Multi-species Reactive Transport Model

TL;DR

This study uses a multi-species reactive transport model to analyze electrochemical factors influencing localized corrosion in stainless steel, focusing on stable pitting and repassivation phases through simulation and calibration.

Contribution

It introduces a novel multi-species reactive transport model employing a sequential non-iterative approach to investigate corrosion stages and critical electrochemical factors.

Findings

Identified key electrochemical factors at saturation and repassivation.

Calibrated model parameters using polarization scan data.

Simulated local chemistry effects at different temperatures and concentrations.

Abstract

A multi-species reactive transport model based on the sequential non-iterative approach is employed to investigate two major stages involved in artificial pit experiments of stainless steel: I. Stable pitting under a salt film and II. Film-free dissolution that transitions to repassivation. Data of current density and electrical potential obtained from rapid polarization scans of pits with different depths are utilized to calibrate the elapsed time and the electrode kinetics of each stage. The local chemistry near the base of pits at different temperature and bulk concentrations is simulated to determine several critical electrochemical factors at saturation and repassivation.