| High temperature oxidation behavior of 19Cr-Ti ferritic stainless steel, which is used for stud pin as a glass sealing material for TV cathode ray tube, has been studied by using thermogravimetric analysis in wet (75%H₂-25%N₂) gas mixture and air, respectively. The oxide film formed on the metal surface by oxidation treatment was investigated by means of SEM, EDS and EPMA. Oxidation rate contants in the wet gas mixture change linearly in the range of 1000℃ to 1200℃, and the activation energy for oxidation was 35.3㎉/mole. The composition of oxide films obtained in both atmosphere was similar but weight gain of oxide obtained in air was higher than that in the vet gas mixture. Around l㎛ Fe metal particles were found on the surface of the oxide film of 19Cr-Ti stainless steel oxidized at 1100℃ in the wet gas mixture. From this observation, the characteristics of scale formation at high temperature can be explained as follows. As temperature goes up, initially both Fe & Cr oxides form on the metal surface but above 950℃ Fe oxide reduction occurs despite Cr oxide prolongs its growth. (Received April 23, 1996) |
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