ISSN:
1573-4889
Keywords:
Fe(Ni)CrAlX alloys
;
chloridation resistance
;
oxide scales
;
chlorides
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The high-temperature-corrosion behavior of a series of Fe(Ni)CrAlX-type alloys (where X=Zr and Hf, e.g.) has been studied in a gas mixture of 50% HCl-10% H2O−H2 at 800°C. The experimental results obtained indicated that Ni-base alloys had superior corrosion resistance to Fe-base alloys in this gas mixture. While the exposed Ni-base alloys showed weight gains due to the formation of oxides (e.g., Al2O3, Cr2O3) as well as CrCl2, the Fe-base alloys exhibited substantial weight losses resulting from the formation and subsequent evaporation of FeCl2. This study also demonstrated that Fe(Ni)Cr8AlX-type alloys, which contained high aluminum, had better chloridation resistance than Fe(Ni)25CrAlX-type alloys, which had high chromium. The improved performance of Fe(Ni)Cr8AlX-type alloys was due to the presence of a high level of aluminum which promoted formation of protective Al2O3. Although the presence of chromium in the alloys promoted the formation of Cr2O3, the high level of chromium adversely affected the chloridation resistance of Fe(Ni)25CrAlX-type alloys, due to the development of chloride (CrCl2) at the interface of the oxide scale and alloy substrate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01046895
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