Abstract:
This work studied oxidation behavior of as cast 26Cr-16Ni at 800, 900 and 1000oC in dry and wet air by Thermal Gravimetric Analysis (TGA) for 100 hrs. Its oxidation behavior was compared with as cast AISI 309 and as cold rolled AISI 309. At 900oC, as cast 26Cr-16Ni performed higher oxidation resistance than as cast and as cold rolled AISI 309 in both dry and wet air due to the higher Cr and Ni contents. Oxidation rate in dry air is lower than in wet air. Oxidation rate order (n) of as cast 26Cr-16Ni in dry air is 0.42, which is nearly parabolic rate law but in wet air n is 0.36, which is nearly cubic rate law. Oxidation rate orders (n) of as cast AISI 309 in dry and wet air are 0.32, 0.54, respectively, which indicate nearly cubic rate laws. Oxidation rate orders (n) of as cold rolled AISI 309 in dry and wet air are 0.29, 0.31, respectively, which indicate nearly cubic rate laws. Oxides of as cast 26Cr-16Ni, as cast AISI 309 and as cold rolled AISI 309 composed of Cr2O3, FeO, Fe2O3, NiCr2O4 and (Fe0.6Cr0.4)2O3. The oxidation rate orders of as cast 26Cr-16Ni at 800 and 1000oC in dry air are 0.66 and 0.77, respectively.