| Fe-Cr-Al alloys present a great resistance to high temperature oxidation. As well known, Fe-Cr-Al alloys which have been studied for high temperature coating and substrate of catalyst honeycomb have outstanding corrosion resistance at elevated temperature. The isothermal oxidation behaviors of Fe-Cr-Al alloys contains 0.03%Y, 0.05%B, 0.5%Ti, 0.03%Y ＋ 0.5%Ti and 0.5%Zr in dry air at 1,000℃ were examined. The weight gains recorded for Fe-(15, 20)%Cr-(6, 8)%Al specimens progressively increased with oxidation time. The results of XRD for Fe-Cr-Al alloys containing 0.03%Y ＋ 0.5%Ti and 0.5%Zr exhibited excellent oxidation resistance. The oxide of Fe-Cr-Al alloys containing 0.03%Y and 0.05%B exhibited highly convoluted configuration. However, Fe-Cr-Al alloys containing 0.5%Ti, 0.03%Y ＋ 0.5%Ti and 0.5%Zr exhibited noduled configuration. Inward penetration of scale for Fe-(15, 20)%Cr-(6, 8)%Al specimens has been exhibited. For the alloy containing 0.5%Zr, oxidation behavior displayed better isothermal oxidation compared with the Zr-free alloy. And the effects of Zr are to improve the adherence of protective layer of Al₂O₃ scale by pegging effect. |
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