Stress corrosion cracking as evolving interface problem

摘要

It has been long recognised that stress corrosion crack initiation and propagation are triggered by the interaction between electro-chemical processes and mechanical deformation in the crack tip region. Recently, the author of the present work proposed a model for corrosion crack nucleation and growth, which allows for incorporation in a continuum mechanical theory. In the model, the corrosion is forming the geometry of the crack tip, thus creating the conditions for strain concentration. This leads to a smooth crack surface evolution represented as a problem of evolving interface, where crack growth criterion is not needed. As a start, the chemical environment of the crack tip is assumed to be constant and unaf-fected by the changing geometry as the crack is developing. This leads to a linear relationship between strain and corro-sion rate, in the sense of removed material per unit of area. This work reviews the results obtained so far on the basis of the linear model. In addition, mathematical and finite element analyses of stationary cracks with appropriate geometry are involved to explain the behaviour predicted by the model.