Corrosion behavior of a new alumina-forming duplex stainless steel with different surface treatment in supercritical carbon dioxide

The corrosion behavior of an alumina-forming duplex stainless steel with different surface treatment was investigated in supercritical carbon dioxide. The results showed that polished materials had higher weight gain than the ground ones. An unprotective multilayer oxide scale was formed above FCC phase, whereas protective and continuous Cr/Al-rich oxide layers were formed above BCC phase on polished materials. Similar protective Cr/Al-rich oxide layers were formed, regardless of the FCC or BCC phase on ground materials. Grinding leads to the faster diffusion of Cr and Al, which causes the easier formation of the continuous Cr/Al-rich oxide layers. •Corrosion behavior of a new AFDSS exposed to sCO2 is investigated•Effect of grinding and polishing on the corrosion behavior is examined•The polished materials exhibit poorer oxidation and carburization resistance•Multilayer oxide scales containing Fe/Cr/Al are formed on polished materials•Protective Cr/Al-rich oxide scale is formed on ground materials