Enhancing oxidation resistance of ferritic heat-resistant stainless steel in air atmosphere at 1100 °C by self-repairing oxide layer.

The oxidation behaviors of Al-free and 1Al ferritic heat-resistant stainless steels (FHSSs) at 1100 °C were investigated. After oxidation for 100 h, the Al-free FHSS had triple oxide layers of a first layer Fe 2 O 3 + MnCr 2 O 4 , a second layer MnCr 2 O 4 + Cr 2 O 3 + MnO, a third layer SiO 2 and oxides of Nb and Ti. The 1Al FHSS had double oxide layers of a first layer Ti-bearing (Al, Cr) 2 O 3 particles, a second layer dense (Al, Cr) 2 O 3. The (Al, Cr) 2 O 3 layer with self-repairing feature can reduce the thickness of oxide layer by 515 times, and reduce the oxidation weight gain rate of the FHSS by 5 orders of magnitude. • The addition of Al reduces the oxidation weight gain rate by 5 orders of magnitude at 1100 °C. • The addition of Al reduces the thickness of oxide layer by 515 times at 1100 °C. • The addition of Al produces an oxide layer with self-repairing characteristics at 1100 °C. [ABSTRACT FROM AUTHOR]