Comparative Study on the Oxidation Behavior of Austenitic and Ferritic Heat-Resistant Stainless Steels at High Temperatures

摘要

A comparative study of the high-temperature oxidation behavior and mechanism of 0Cr25Ni20 austenitic heat-resistant stainless steel (AHSS) and 0Cr18AlSi ferritic heat-resistant stainless steel (FHSS) at 800 degrees C, 900 degrees C, and 1000 degrees C in air up to 140 h was performed using isothermal oxidation tests. The oxidation kinetics of 0Cr25Ni20 AHSS and 0Cr18AlSi FHSS followed the parabolic law. The oxide films on 0Cr25Ni20 AHSS were composed of continuous and dense Cr2O3, MnCr2O4, and a small amount of NiMn2O4, whereas silicon exhibited internal oxidation and deteriorated the adhesion between the oxide film and substrate. Nickel-free 0Cr18AlSi FHSS exhibited good oxidation resistance at 800 degrees C and 900 degrees C due to dense, continuous, and well-adhered multicomponent oxide films containing Al2O3, Cr2O3, MnCr2O4, and a small amount of MnFe2O4. The oxidation resistance of 0Cr18AlSi FHSS declined at 1000 degrees C, mainly due to the formation of nonprotective Fe2O3 and severe internal oxidation of aluminum.