INFLUENCE OF THE COMBINATION OF MICROSTRUCTURE AND MECHANICAL FIELDS ON STRESS CORROSION CRACKING INITIATION OF COLD-WORKED AUSTENITIC STAINLESS STEELS

摘要

This work aims to understand the influence of bothmicrostructure and mechanical fields on stress corrosioncracking (SCC) initiation in cold-worked austeniticstainless steels. To this aim, a SCC test is performed on a316L stainless steel previously tensile pre-strained atroom temperature. The experimental local displacementfields are measured after each loading step, using digitalimage correlation (DIC) based on microgrids, and fromwhich the strain fields are also derived. In the meantime,a numerical finite element (FE) model is developed withAbaqus, aiming to reproduce the polycrystal features inthe microgrid area (grain geometries and orientations).This model is submitted to the DIC-obtaineddisplacement, allowing to simulate the strain and stressfields from polycristalline elastoplasticity constitutiveequations. The experimental microstructure, as well asthe numerical and experimental mechanical fieldsobtained at the end of the SCC test is then analyzed,compared and correlated to the cracking network.