The short-term (4 h) high-temperature oxidation behavior of 444Nb and 444NbTi stainless steel at 1100℃ is investigated by X-ray Diffraction

Scan Electron Microscopy and Energy Dispersive Spectrometer to analyze the phase

microscopic morphology and chemical composition distribution of the oxide film. The results show that the oxidation weight gain per cm

2

of the 444NbTi steel is twice that of the 444Nb steel

which is related to the Ti changing the defect structure of the Cr

2

O

3

oxide film. Spallation of oxide film happens to the 444Nb steel sample

it may be that the rapid diffusion of Mn promotes the diffusion of Nb to the interface between oxide film and metal matrix

and the formation of endogenous Nb oxide increases the internal stress and thermal stress of steel. There is a dendritic matrix in the oxide film of the 444NbTi steel sample

whi

ch increases the interfacial strength

and the Ti and Al undergo obvious internal oxidation.