Characterization of hot corrosion of Fe-20Cr coated with a fused (Na,K)(2)SO4 film by electrochemical impedance spectroscopy

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	Characterization of hot corrosion of Fe-20Cr coated with a fused (Na,K)(2)SO4 film by electrochemical impedance spectroscopy
	C. L. Zeng; J. Li; G. M. Liu
	2007
发表期刊	High Temperature Materials and Processes
ISSN	0334-6455
卷号	26 期号:3 页码:167-176
摘要	Electrochemical studies of hot corrosion were conducted mostly in deep molten salts, which are not identical to a fused salt film in service conditions. In order to establish electrochemical measurements under a fused salt film, a two-electrode probe was proposed for electrochemical impedance studies of hot corrosion of Fe-20Cr alloy induced by a fused 0.9Na(2)SO(4)-0.1K(2)SO(4) (mole fraction) film at 1173K in air. The corrosion of the alloy was characterized by an initial incubation stage with a relatively low corrosion rate and a later stage with rapid material degradation, accompanied with quite different impedance features. In the initial stage, the alloy formed a protective Cr-rich oxide scale, and the corresponding impedance spectra were composed of two capacitive loops. With extended exposure, the electrochemical impedance spectra showed the typical characteristics of a diffusion-controlled reaction, which-was associated with the degradation of Cr-rich scale and the formation of a no-protective mixed scale of oxides and sulfides owing to fluxing of oxide scale as well as internal sulfidation of Cr. Two equivalent circuits were proposed to fit the impedance spectra in two stages. Based on the transport of molecular O-2 in the melt, Warburg impedance was introduced to calculate the product (C-O2 root D-O2) of solubility and diffusion coefficient for oxygen in the melt, and the main reduction reaction was also discussed.
部门归属	nanchang inst aeronaut technol, dept mat sci & engn, nanchang 330034, peoples r china. chinese acad sci, inst met res, state key lab corros & protect, shenyang 110016, peoples r china.;zeng, cl (reprint author), nanchang inst aeronaut technol, dept mat sci & engn, 173 shanghai rd, nanchang 330034, peoples r china;clzen2@imr.ac.cn
关键词	Fe-20cr Alloy (Na k)(2)So4 Hot Corrosion Electrochemical Impedance Spectroscopy Molten Sodium-sulfate Salt Corrosion Na2so4 Film Degrees-c Carbonate Ni Oxygen 0.38k)(2)Co3 Reduction Mechanism
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WOS记录号	WOS:000250544600001
引用统计	被引频次：1[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/321006/34014
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	C. L. Zeng,J. Li,G. M. Liu. Characterization of hot corrosion of Fe-20Cr coated with a fused (Na,K)(2)SO4 film by electrochemical impedance spectroscopy[J]. High Temperature Materials and Processes,2007,26(3):167-176.
APA	C. L. Zeng,J. Li,&G. M. Liu.(2007).Characterization of hot corrosion of Fe-20Cr coated with a fused (Na,K)(2)SO4 film by electrochemical impedance spectroscopy.High Temperature Materials and Processes,26(3),167-176.
MLA	C. L. Zeng,et al."Characterization of hot corrosion of Fe-20Cr coated with a fused (Na,K)(2)SO4 film by electrochemical impedance spectroscopy".High Temperature Materials and Processes 26.3(2007):167-176.