Abstract：The isothermal oxidation tests of the low chromium（409L）and medium chromium（439）titanium stainless steel were carried out at 900 ℃. The oxidation kinetic curves of the two steels were obtained and the structure of oxide scale was analyzed by EPMA, SEM and XRD. The results indicated that the curves of the 409L and 439 stainless steel both followed the parabolic curve. But the parabolic velocity constant for 409L stainless steel was much higher than that for 439 stainless steel. The oxide layer of 409L stainless steel was formed by (Fe,Cr,Mn)3O4 and Fe2O3 after oxidation of 80 h. The outside layer of the oxide layer of 439 stainless steel was formed by Cr2O3 and (Cr,Mn)3O4, the inner layer of the oxide layer was SiO2 and the internal oxidation of Ti was accompanied in the matrix. The higher content of Cr can ensure the stable existence of the oxide particles in the TiO2, and the TiO2 oxidation particles can prevent the ion migration and reduce the oxidation rate significantly.
2018, Vol. 28 
