Superior protection by α-AlO/α-LiAlO double oxide scales against alkali carbonate corrosion

Ferritic alumina-forming alloys showed high corrosion resistance to molten carbonates by forming a protective α-LiAlO2 scale at their surface. In this work, four ferritic were pre-oxidised before exposure (Li,Na,K)2CO3-melt 800 °C for 1000 h. Only outer transient alumina, such as γ-alumina, reacts with the melt, LiAlO2. At same time, innermost α-Al2O3 remains intact. α-Al2O3, well α-LiAlO2, are slow-growing compressive stress-stabilised oxide scales. Thus, combined presence of α-Al2O3/α-LiAlO2 improves protection materials investigated in study, compared non-pre-oxidised ones, superior double scale.