Water vapor effect on high-temperature oxidation behavior of Fe₃Al intermetallics

Abstract

Nb) were oxidized at 950• C in dry and humid (11 vol% water) synthetic air. Thermogravimetric measurements showed that the oxidation rates of the tested intermetallics were lower in humid air than in dry air (especially for Fe 3 Al-Zr,Mo and Fe 3 Al-Zr,Mo,Nb). The addition of small amounts of Zr, Mo or Nb improved the kinetics compared with that of the undoped Fe 3 Al. Fe 3 Al showed massive spallation, whereas Fe 3 Al-Zr, Fe 3 Al-Zr,Mo and Fe 3 Al-Zr,Mo,Nb produced a flat, adherent oxide layer. The rapid transformation of transient alumina into alpha alumina may explain the decrease in the oxidation rate in humid air.

Performance Characteristics of Hot-dip and Plasma Spray Aluminide Coated Nickel-Based Superalloy 718 under Cyclic Oxidation in Water Vapour

“…This could be likely as a result of the crack formation either on the surface scale or within the aluminium layer which allowed access of H2O to penetrate through paths of such cracks or voids. Reaction of H2O and aluminum forms an alumina oxide with increased mass gain [24,25]. Nevertheless, the plasma spray coatings have slightly high mass gain than the hot-dip coating.…”

Effect of Water Vapor on Alumina Scale Growth Based on First-Principles Calculations

“…Therefore, much effort has been made toward understanding the effect of water vapor on the oxidation of metallic materials. In particular, the impact of water vapor on the high-temperature oxidation behavior of alumina-forming alloys has received considerable attention because of their increasing use in emerging energy technologies such as power generation, jet engines, petrochemical processing, and solid oxide fuel cells. − Most of these applications encounter a relatively high level of humidity or steam and rely on the ability of the alloys to form a protective oxide scale under the harsh service conditions. Therefore, water vapor plays a significant role in influencing the sustained use of the metallic components.…”

Effect of environmental sulfur on the structure of alumina scales formed on Ni-base alloys

“…a-Al 2 O 3 transformation; whereas, Zr [8], La, Hf [14], Si [15], Pt [16,17], Y [18][19][20][21] have been reported to delay this transformation. A few investigations have dealt with the environmental effects such as water vapor [22][23][24][25] and the results are not conclusive. Chevalier et al [23] and Zhou et al [22] reported that the presence of water vapor promoted the h ?…”

“…A few investigations have dealt with the environmental effects such as water vapor [22][23][24][25] and the results are not conclusive. Chevalier et al [23] and Zhou et al [22] reported that the presence of water vapor promoted the h ? a on the Fe 3 Al intermetallic and NiAl.…”