Time-Dependent Corrosion Behavior of High Chromium White Cast Iron in an Acidic Solution

The corrosion behavior of high chromium white cast iron was studied in 0.5 mol dm H SO + 0.01 mol dm HCl solution over time through electrochemical and immersion experiments. Potentiodynamic and potentiostatic polarizations revealed active-passivation transition behavior, with critical current densities observed at-0.27 V and 0.00 V , repectively. The former potential showed preferential dissolution of primary gamma phases, while the latter one showed preferential dissolution of eutectic gamma phases. Immersion tests showed an exponential increase in corrosion rate, with significant acceleration observed around 1000 seconds due to the onset of eutectic gamma phase dissolution. Over a 24-hour immersion period, both gamma phases exhibited extensive corrosion, leaving carbides largely intact. These findings elucidate distinct corrosion behaviors of high chromium white cast iron in acidic environments, providing critical insights into material performance evaluation. Understanding these mechanisms is essential for predicting the longevity and durability of materials in corrosive conditions, thereby informing better material design and application strategies.