Effects of B, Y, Ti and Zr additions on high temperature oxidation behaviors for Fe-Cr-Al alloy

摘要

Fe-Cr-Al alloys present a great resistance to hightemperature oxidation. As well known, Fe-Cr-Al alloys whichhave been studied for high temperature coating and substrate ofcatalyst honeycomb have outstanding corrosion resistance atelevated temperature. The isothermal oxidation behaviors of Fe-Cr-Al alloys containg 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 deg C were examined. Theweight gains recorded for Fe-(15, 20)%Cr-(6, 8)%Al specimensprogressively increased with oxidation time. The results of XRDfor Fe-Cr-Al alloys containing 0.03%Y + 0.5%Ti and 0.5%Zrexhibited excellent oxidation resistance. The oxide of Fe-Cr-Alalloys containing 0.03%Y and 0.05%B exhibited highlyconvoluted configuration. However, Fe-Cr-Al alloys containing0.5%Ti, 0.03%Y+0.5%Ti and 0.5%Zr exhibited noduledconfiguration. Inward penetration of scale for Fe-(15, 20)%Cr-(6,8)%Al specimens has been exhibited. For the alloy containing0.5%Zr, oxidation behavior displayed better isothermal oxidationcompared with the Zr-free alloy. And the effects of Zr are toimprove the adherence of protective layer of Al_20_3 scale by pegging effect.