The Effects of Water Vapor and Hydrogen on the High-Temperature Oxidation of Alloys

Journal Article · Sat Jun 01 04:00:00 EDT 2013 · OXIDATION OF METALS

DOI:https://doi.org/10.1007/s11085-012-9349-8· OSTI ID:1129854

Mu, N; Jung, K; Yanar, N M; Pettit, F S; Holcomb, G R; Howard, B H; Meier, G H

Essentially all alloys and coatings that are resistant to corrosion at high temperature require the formation of a protective (slowly-growing and adherent) oxide layer by a process known as selective oxidation. The fundamental understanding of this process has been developed over the years for exposure in pure oxygen or air. However, the atmospheres in most applications contain significant amounts of water vapor which can greatly modify the behavior of protective oxides. The development of oxy-fuel combustion systems in which fossil fuels are burned in a mixture of recirculated flue gas and oxygen, rather than in air, has caused renewed interest in the effects of water vapor and steam on alloy oxidation. The focus of this paper is on the ways the presence of water vapor can directly alter the selective oxidation process. The paper begins with a brief review of the fundamentals of selective oxidation followed by a description of recent experimental results regarding the effect of water vapor on the oxidation of a variety of chromia-forming alloys (Fe- and Ni-base) in the temperature range 600 to 700 °C. The atmospheres include air, air-H{sub 2}O, Ar-H{sub 2}O and Ar-H{sub 2}O-O{sub 2}. Then the behavior of alumina-forming alloys in H{sub 2}O-containing atmospheres is briefly described. As hydrogen is produced during oxidation of alloys in H{sub 2}O, it can be released back into the gas phase or injected into the metal (where it can diffuse through to the other side). Experiments in which hydrogen concentrations have been measured on both sides of thin specimens during oxidation by H{sub 2}O on only one side are described. Finally, it is attempted to catalogue the various experimental observations under a few general principles.

• Research Organization: National Energy Technology Laboratory - In-house Research
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• DOE Contract Number: FE0004000
• OSTI ID: 1129854
• Report Number(s): A-UNIV-PUB-054
• Journal Information: OXIDATION OF METALS, Journal Name: OXIDATION OF METALS Journal Issue: 5-6 Vol. 79
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Fe-base alloys
Ni-base alloys
oxidation
water vapor