Influence of external mechanical loadings (creep, fatigue) on oxygen diffusion during nickel oxidation

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Oxidation of Metals

DOI:https://doi.org/10.1007/BF01046824· OSTI ID:245136

Moulin, G; Arevalo, P ^[1]; Salleo, A ^[2]

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1. Universite Paris, Orsay (France)
2. Universite de Rome La Sapienza, Rome (Italy)

This study deals with the influence of various mechanical loadings (fatigue, creep, creep-fatigue) on oxygen diffusion in a particular system, oxidizing nickel. A distinction between the behavior of the oxide layer and underlying nickel was noted during the first step of oxidation at 550{degrees}C, in P{sub O{sub 2}}= 1 atm. Mechanical loading causes a decrease of the oxygen mobility through the oxide scale (factor of 10{sup 3}). The oxide thicknesses on nickel undergoing mechanical loadings are different than for an unloaded sample, due to distinct contributions of the oxygen and nickel fluxes in the growing oxide. In the substrate, the ingress of oxygen becomes easier with a constant tensile load (creep). The intergranular-oxygen diffusion coefficient, D{sub i}, is increased by a factor of 10{sup 2} with respect to other samples. In creep, oxygen diffusion takes place along grain boundaries of a structure with smaller grains than in unstrained Ni. A short fatigue period during creep-fatigue decreases the sensitivity of nickel to intergranular-oxygen diffusion.

• Sponsoring Organization: USDOE
• OSTI ID: 245136
• Journal Information: Oxidation of Metals, Journal Name: Oxidation of Metals Journal Issue: 1-2 Vol. 45; ISSN OXMEAF; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CREEP
DIFFUSION
DYNAMIC LOADS
FATIGUE
NICKEL
OXIDATION
OXYGEN