Abstract
The oxidation behavior of 17Cr-1.2Mo-0.3Ti and 16-19Cr ferritic stainless steels containing up to 2 percent Mo in air at 1000 and 1050°C was studied, and the main results obtained are as follows: (1) The longer the time from polishing of specimens to oxidation tests, the better the oxidation resistance of 17Cr-1.2Mo-0.3Ti steel. (2) Cr2O3 scales were observed in the specimen that was oxidized after a long period of exposure in air at room temperature. On the other hand, the specimen oxidized immediately after polishing developed (Cr, Mn)3O4 scales, (3) Cr concentration in the passive film increased with time elapsed after polishing, (4) Mo addition to ferritic stainless steels promoted the formation of Cr2O3 at the early stage of oxidation, improving their oxidation resistance, (5) The passive film became thinner with increasing Mo content.
