Influences of Si content on the high-temperature oxidation behavior of X10CrAlSi18 ferritic heat-resistant stainless steel at 700 °C and 800 °C

Abstract

Abstract X10CrAlSi18 FHSS (ferritic heat-resistant stainless steel) has received a lot of attention due to its advantageous combination of creep resistance and oxidation resistance. The influence of Si content on the high-temperature oxidation resistance of X10CrAlSi18 FHSS after oxidation at 700 and 800\xa0°C for up to 180\xa0h in air was investigated in this study. According to the results, a higher Si content could coarsen the grain of ferrite and simultaneously increased the amount of (Cr, Fe)23C6 carbides, which caused cracks and reduced the adhesion between the oxide film and the matrix. After oxidation at 700\xa0°C, the oxide film of 0.77Si FHSS and 1.35Si FHSS were found to be primarily composed of Al2O3, SiO2, Cr2O3, Fe2O3, Mn2O3 and MnCr2O4, with thickness of 5.10\xa0μm and 5.56\xa0μm, respectively. The oxide films formed at 800\xa0°C were primarily composed of Al2O3, SiO2, Cr2O3, FeCr2O4, Mn2O3 and MnCr2O4 with thickness of 5.55\xa0μm and 7.37\xa0μm, respectively. A higher Si content was discovered to increase the amount of MnCr2O4 in the outer layer of the oxide film, which resulted in a looser spinel structure and reduced the oxidation resistance of X10CrAlSi18 FHSS.