| Oxidation behavior of Fe-Ni alloys added by small amount of Ni was studied, under the exposure to the temperatures up to 1100℃, 1150℃, and 1200℃, respectively. The slope of mass change curve representing an oxidation rate was 1 or 2 up to 20 seconds and decreased to 1/2 after 20 seconds in a parabolic shape. The temperature of the initial stage of oxidation increased more quickly at the furnace inside than at the surface of the specimen, and its behavior was reversed due to oxidation heat after 20 seconds later. Oxide layer was mainly composed of FeO. And particle of Fe_3O_4 and Fe_2O_3 was distributed in FeO layer. The order of the composition ratio for the oxide was Fe_2O_3,·Fe_3O_4,·FeO at the oxide surface, FeO,·Fe_3O_4,·Fe_2O_3 at the internal oxide, and FeO,·Fe_3O_4,·Fe_2O_3 at the surface of metal after stripping oxide layer. |
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