Tese: Effect of elastic-plastic stress in the defect tolerance under stress corrosion cracking
Aluno(a) : Verônica Miquelin MachadoOrientador(a): Jaime Tupiassú
Área de Concentração: Mecânica Aplicada
Data: 04/05/2016
Link para tese/dissertação: http://doi.org/10.17771/PUCRio.acad.33679
Resumo: Stress Corrosion Cracking (SCC), which consist in the initiation and propagation of cracks due to the combined attack of mechanical stresses and a corrosive environment is a potential danger for structures and components. Moreover, SCC can be explained by different mechanisms depending on the metal environmental pair, what makes difficult to create a generalized analytical approach to predict the crack behavior in SCC. Therefore, projects often use an over-conservative design criteria that disqualify a material susceptible to SCC without properly evaluate the influence of the stress fields that drive them. The aim of this work is to evaluate the effect of elastic plastic stress in SCC. This mechanical approach assumes that all chemical effects involved in SCC problems can be appositely described and quantified by traditional material resistances to crack initiation and propagation at under specific environment. Aluminium bending specimens in Gallium environment are used to predict the effect of the residual stress induced by plastic deformation in the crack initiation under SCC conditions. Furthermore, a quantitative analysis based on the non-propagating crack behavior departing from notch tips are used to calculate the necessary stress to initiate and propagate SCC in AISI 4140 steel notched specimens under aqueous hydrogen sulphide environment. The non-propagating crack behavior and the maximum load supported by notched specimens are analysed under linear elastic and elastic plastic stress field through the proposed model that will be validated by experimental data.