Application of an electrochemical scratch technique to evaluate contributions of mechanical and electrochemical attacks to corrosive wear of materials

Corrosive wear is one of the most destructive processes encountered in industry. However, how the mechanical and electrochemical actions contribute to the material removal during corrosive wear is still not well understood. In this work, an electrochemical scratch method was applied to study the synergic attack of wear and corrosion to high-Cr cast iron, cast iron and mild steel in a 3.5% NaCl solution and tap water, respectively. Contributions of corrosion, wear and corrosion-wear synergism to the total material loss were evaluated using the technique in combination with other experiments, including polarization test, scratch profile measurement, scratch test under cathodic protection. The emphasis of the research was to evaluate how corrosion and wear mutually affected each other, which helped to understand the synergism of corrosion and wear for the materials. The contributions of mechanical and corrosion actions to corrosive wear of the materials were correlated to their mechanical and electrochemical properties. It was determined that the electrochemical scratch method was effective for investigating the synergism of wear and corrosion.