The roles of CO2 and water vapour on the high temperature corrosion of a type 430 stainless steel as an interconnect of bio-gas fuel intermediate temperature SOFCs

Abstract

A Type 430 stainless steel was exposed to Ar-20 %CO2 without and with water vapour at 800 °C up to 96 h. Increasing water vapour content from 5 % to 40 % helped reduce mass gain, enhance volatilisation, and improve scale adhesion with fewer pores at scale/steel interface. Mechanisms for Cr and Mn volatilisations including the direct reactions between Cr-containing oxide and CO2 were suggested with the aid of the XPS results. Mathematical relations that express the role of water vapour on concentrations of defects responsible for scale growth were proposed to help explain the reduced oxidation rate.