Modelling the early development of secondary side stress corrosion cracks in steam generator tubes using incomplete random tessellation Original Research Article

A thorough understanding of the secondary side stress corrosion cracking of Inconel 600 in steam generator (SG) tubes seems to be still somewhat in the future. Especially the early phase of the development of cracks, also called the initiation phase, is beyond the present state-of-the-art explanations. An effort was, therefore, made to propose modelling and visualisation of the kinetics of secondary side stress corrosion crack initiation and growth on the grain-size scale: • An incomplete random tessellation is used to approximate the random planar grain structure. • The crack initiation is modelled by random processes, taking into account the most important factors such as proximity of the aggressive medium and the orientation of the grain boundaries relative to the stress field. • The stochastic process describing crack growth accounts for crack branching, coalescence and interference between neighbouring cracks. Several numerical examples are provided to demonstrate the versatility of the proposed method. Reasonable qualitative agreement with metallographic results is shown.