The corrosion of a Co-15 wt% Ce alloy in mixed oxidizing-sulfidizing gases at 600-800 degrees C

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	The corrosion of a Co-15 wt% Ce alloy in mixed oxidizing-sulfidizing gases at 600-800 degrees C
	Y. Niu; G. Y. Fu; F. Gesmundo
	1999
发表期刊	Corrosion Science
ISSN	0010-938X
卷号	41 期号:9 页码:1791-1815
摘要	The corrosion behavior of a Co-Ce alloy containing approximately 15 wt% Ce has been studied at 600-800 degrees C in several H-2-H2S-CO2 mixtures, providing sulfur pressures of 10(-8) atm at 600, 700 and 800 degrees C and of 10(-7) atm at 800 degrees C, and oxygen pressures of 10(-24) atm at 600 degrees C and 10(-20) atm at 700 and 800 degrees C. At 600 degrees C, the alloy corrodes more slowly than pure cobalt but more rapidly than pure cerium while, at 700 degrees C, it corrodes at about the same rate as pure cerium, but much faster than pure cobalt. At 800 degrees C under 10(-8) atm S-2, i.e. a value below the stability of the cobalt sulfides, the alloy corrodes rather slowly but, under 10-7 atm St, the rate is very high, although slightly lower than that of pure cobalt. The scaring kinetics are generally intermediate between linear and parabolic but are sometimes irregular. The corrosion of this alloy produces multilayered scales, containing an outermost layer of almost pure cobalt sulfide, an intermediate complex layer composed of a mixture of compounds of the two metals and, finally, an innermost region of internal attack of cerium by both oxygen and sulfur. Cerium is not able to diffuse outwards and remains in the alloy consumption region. In the intermediate region cobalt sulfide forms a continuous network which allows the growth of the external CoSy layer, although at rates that are reduced with respect to those of pure cobalt. Thus, a cerium content of 15 wt% is not sufficient to prevent or even to significantly reduce the sulfidation of the base metal. These results, as well as the details of the microstructure of the scales, are interpreted by taking into account the limited solubility of cerium in the base metal and the presence of an intermetallic compound, rich in cerium, in the alloy. (C) 1999 Elsevier Science Ltd. All rights reserved.
部门归属	univ genoa, fac ingn, ist chim, i-16129 genoa, italy. acad sinica, inst corros & protect met, state key lab corros & protect, shenyang 110015, peoples r china. shenyang inst chem technol, shenyang 110021, peoples r china.;gesmundo, f (reprint author), univ genoa, fac ingn, ist chim, fiera del mare,pad d, i-16129 genoa, italy;gesmundo@unige.it
关键词	Cobalt Cerium Alloys Sulfidation Oxidation High-temperature Sulfidation 2-phase Binary-alloys Most-reactive Component Ni-nb Alloys Internal Oxidation Oxidant Pressures H2-h2s Mixtures Low-oxygen Co Behavior
URL	查看原文
WOS记录号	WOS:000082561200008
引用统计	被引频次：10[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/37458
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. Niu,G. Y. Fu,F. Gesmundo. The corrosion of a Co-15 wt% Ce alloy in mixed oxidizing-sulfidizing gases at 600-800 degrees C[J]. Corrosion Science,1999,41(9):1791-1815.
APA	Y. Niu,G. Y. Fu,&F. Gesmundo.(1999).The corrosion of a Co-15 wt% Ce alloy in mixed oxidizing-sulfidizing gases at 600-800 degrees C.Corrosion Science,41(9),1791-1815.
MLA	Y. Niu,et al."The corrosion of a Co-15 wt% Ce alloy in mixed oxidizing-sulfidizing gases at 600-800 degrees C".Corrosion Science 41.9(1999):1791-1815.