EFFECT OF RARE EARTH ADDITIONS ON THE SCALE MORPHOLOGY OF AN Fe-Cr-Al ALLOY
Li Pei;Luo Jiqun Baotou Institute of Metallurgy Research
Cite this article:
Li Pei;Luo Jiqun Baotou Institute of Metallurgy Research. EFFECT OF RARE EARTH ADDITIONS ON THE SCALE MORPHOLOGY OF AN Fe-Cr-Al ALLOY. Acta Metall Sin, 1980, 16(4): 401-496.
Abstract Scales on Fe-23Cr-6Al alloy wrinkle rapidly in air at 1300℃. Cavities andvoids are formed at the scale/substrate interface. For pre-polished specimens, cav-ities are found at the grain boundaries on the metal surface in the form of net-work, and voids occur at places originally occupied by inclusions and carbides.For alloys containing 0.15% La, 0.15% Ce or 0.60% Y, the scales are flat andfree from cavities and voids at the scale/substrate interface. The grains in theinner layer of the scale are columnar in form and adhere tightly to each other.It is considered that the capability of the RE in suppressing the formation of hotcorrosion pits on the alloy surface during the early stage of oxidation and inreducing the creep deformation due to the growth stress in the scale may accountfor the fact that RE addition inhibits the formation of cavities and voids at thescale/substrate interface and improves the adhesion between the scale and the sub-strate.
[1] Felten, E. J., J. Electrochem. Soc., 108 (1961) , 490． [2] Wukusick, C. S. and Collins, J. F., Mater. Res. Stand., 4 (1964) , 637． [3] Hillinger, H., Werkst. Korros., 22 (1971) , 504． [4] Tien, J. K. and Pettit, F. S., Met. Trans., 3 (1972) , 1587． [5] Golightly, F. A., Stott, F. H. and Wood, G. C., Oxid. Metals, 10 (1976) , 163． [6] 天野忠照,矢岛圣使,斋藤安俊,日本金属学会志,41(1977) ,1074． [7] 未发表资料.
