Experimental and numerical analysis of mechanical fields on cross-shaped specimens for stress corrosion cracking of cold-worked austenitic stainless steels exposed to primary environment

A stress corrosion cracking (SCC) test was performed on a cold-worked austenitic stainless steel in simulated primary water, using a cross-shaped specimen permitting sequential loading. Crack density and location were investigated by scanning electron microscopy after the SCC test. To analyse the mechanical fields in the cracking areas, finite element simulations of the whole mechanical loading were conducted, involving both strain-path and temperature changes. Combined isotropic-kinematic hardening was used as constitutive equation and identified with tensile tests performed at room temperature and at 340 degrees C. Partial validation of the model was obtained by comparison of numerical strain fields with experimental measurements obtained by digital image correlation performed on a representative "ex-situ" test in air. Variations of the strain and stress fields during this test were discussed in relation with the cracking network observed at the end of the SCC test.