Effect of Carbon Addition on Corrosion Resistance of High-Si Ferritic Heat-resistant Cast Steel in Chlorine Gas Environment

Abstract

Heat-resistant stainless steel castings （SCH materials as specified in JIS G 5122） are commonly used for fire grates that transport waste inside waste incinerators. However, in chlorine gas environments generated from waste containing large amounts of plastic, the protective Cr₂O₃ scale proves insufficient, potentially leading to premature failure. In this study, it was demonstrated that ferritic heat-resistant cast steel with an increased Si content, compared to conventional heat-resistant cast steel, exhibits improved corrosion resistance due to the formation of a protective Si-based scale. Furthermore, it was confirmed that increasing the carbon content significantly enhances corrosion resistance.