A continuum damage analysis of hydrogen attack in a 2.25Cr–1Mo pressure vessel

M.W.D. van der Burg, E. van der Giessen, V. Tvergaard

OnderzoeksoutputAcademic

12 Citaten (Scopus)
325 Downloads (Pure)

Samenvatting

A micromechanically based continuum damage model is presented to analyze the stress, temperature and hydrogen pressure dependent material degradation process termed hydrogen attack, inside a pressure vessel. Hydrogen attack (HA) is the damage process of grain boundary facets due to a chemical reaction of carbides with hydrogen, thus forming cavities with high pressure methane gas. Driven by the methane gas pressure, the cavities grow, while remote tensile stresses can significantly enhance the cavitation rate. The damage model gives the strain-rate and damage rate as a function of the temperature, hydrogen pressure and applied stresses. The model is applied to study HA in a vessel wall, where nonuniform distributions of hydrogen pressure, temperature and stresses result in a nonuniform damage distribution over the vessel wall. Stresses inside the vessel wall first tend to accelerate and later decelerate the cavitation rate significantly. Numerical studies for different material parameters and different stress conditions demonstrate the HA process inside a vessel in time. Also, the lifetime of the pressure vessel is determined. The analyses underline that the general applicability of the Nelson curve is questionable.
Originele taal-2English
Pagina's (van-tot)1-13
Aantal pagina's13
TijdschriftMaterials Science and Engineering A
Volume241
DOI's
StatusPublished - 1998

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