|
|
|
| THE EFFECT OF Ce ADDITION ON HIGH TEMPERATURE OXIDATION OF Fe-Cr ALLOYS |
| Li Bei Yan Yuxin Gau Huaisun Du Zhenfang Guo Ciukun Wang Limin (Baolou Research Institute of Metallurgy) |
|
|
|
|
Abstract The influence of 0.15 or 0.70wt% Ce addition on the oxidation of Fe-15Cr and Fe-30Cr alloys in air at the temperature range between 800 and 1300℃ up to 500hr was studied.The oxidation kinetics indicated that the oxidation rates of Fe-15Cr alloy at 1000℃ and 1100℃ and that of Fe-30Cr alloy at the tem peratures from 1000 to 1200℃ reduced remarkablely owing to the 0.7wt%Ce added.However,the effect of 0.15wt%Ce was much less. The morphology observation,X-ray diffraction analyses and EPMA were carried out for the oxide layers on test alloys.The studies showed that Cr_2O_3 films could be formed rapidly on the surfaces of all test alloys at an early stage of oxidation,and then the Fe-ion concentration in Cr_2O_3 remained somewhere about 1wt% for a long time.However,the 0.7wt%Ce addition decreased the growth rate of Cr_2O_3 layer slightly.The most obvious effect of Ce was to inhibit Cr_2O_3 layer degeneracy in which Cr_2O_3 was replaced gra- dually by rapidly growing Fe-rich oxide,and to delay the breakaway of oxide film. The concentration of oxygen diffused into alloy from Cr_2O_3 layer is reduced by a factor of 10~7 owing to internal oxidation of Ce.With the reduction of oxygen concentration in alloy,internal oxidation of Si in Fe-15Cr alloys which contained about 0.2wt%Si took place in the vicinity of the Cr_2O_3 layer/alloy interface,so that a SiO_2 interface layer was formed in the Fe-15Cr-0.7Ce alloy.
|
|
Received: 25 April 1985
|
[1] 永井宏等,日本金属学会志,43,479(1979)
[2] Y.Nakamura,Met.Trans.,5,909(1974)
[3] H.Nagai,Y.Takebayashi and H.Mitani,Met.Trans.,12A,435(1981)
[4] E.J.Eelten,J.Electrochem.Soc.,108,499(1961)
[5] G.C.Wood and J.Boustead,Corros.Sci.,8,719(1968)
[6] J.M.Francis and W.H.Whitlow,Corros.Sci.,5,701(1965)
[7] 永井宏,村井照幸,三谷裕康,日本金属学会志,42,1138(1978)
[8] 永井宏,村井照幸,三谷裕康,日本金属学会志,42,756(1978)
[9] 中山忠行,渡辺靖,日本金属学会志,31,385(1967)
[10] 叶大伦,无机物热力学数据手册.冶金工业出版社,北京,(1982)
[11] C.E.Birchenall,Oxidation of Metals and Alloys Papers Presented at Seminar of the ASM(Oct.17and18,1970) ,ASM,Ohio,181(1971) |
| No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
