Advanced Hadfield steel with Cr-optimization resists against corrosion and erosion-corrosion

Abstract

This study investigated the effects of Cr-optimization on the corrosion and erosion-corrosion behaviors of Hadfield steel with 1.1 wt% C-13 wt% Mn in a neutral aqueous environment. A variety of experimental and analytical results showed that adding Cr can enhance the corrosion and erosion-corrosion resistance. However, the extent of improvement is limited under non-optimized alloying conditions, specifically when the Cr content is below or above 2 wt%. Only at the optimized Cr content of approximately 2 wt%, the superior corrosion and erosion-corrosion resistances are manifested by excluding coarse M7C3 and forming a thin oxide layer enriched with Cr primarily composed of Fe3-xCrxO4 on the surface during corrosion. The inhibiting characteristics of the corrosion scale contribute to have lower corrosion kinetics with higher polarization resistance and corrosion-enhanced erosion rates compared to conventional Hadfield steel and commercial carbon steels. With its favorable combination of long-term environmental stability in harsh corrosive and erosive environments, along with high-strength, hardness, ductility, and commercial availability, the newly designed Hadfield steel is a promising alternative to commonly used metallic materials in various industrial applications.