HYDROGEN DIFFUSION IN THE VICINITY OF A CRACK TIP AFTER CYCLIC PRE-LOADING

V. Kharin  J. Toribio       

Anales de la Mecánica de la Fractura, nº 21 . 2004 . Pág. -
Ver (.pdf): 1-03-f

Resumen: In this paper, a numerical analysis is performed of the effect of cyclic pre-loading regime on the posterior hydrogen assisted cracking behaviour of high-strength steel, considering mechanical items (stress-strain evolution) and chemical aspects (hydrogen diffusion). With regard to mechanical issues, a high resolution numerical modelling is carried out of the elastoplastic stress-strain field in the near-tip area under cyclic loading (to simulate fatigue pre-cracking) and posterior monotonic loading (to simulate a slow strain rate test), considering the role of large near-tip deformations. In the matter of chemical aspects, a quantitative modelling of hydrogen diffusion is performed near the crack tip, accounting for the transient stress-strain field that evolves from the compressive one after pre-cracking to the tensile one during the test. Results show that hydrogen accumulation in fracture sites depends on residual stress distributions produced by cyclic pre-loading.

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Department of Materials Engineering, University of Salamanca E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora
Department of Materials Engineering, University of Salamanca E.P.S., Campus Viriato, Avda. Requejo 33, 49022 Zamora