Experiments supporting the corrosion enhanced plasticity model

Critical experiments have been performed to test the corrosion enhanced plasticity model. Slow strain rate test and four points bending test on <110> and <410> 316L alloy single crystals clearly show that the macroscopically brittle fracture on the average (110) and (100) plane is in fact achieved by microcracking on (111) facets in zigzag which is in perfect agreement with the model. The first stage of the model is also confirmed: cracks initiate inside the (111) slip band as a consequence of a localised dissolution in the (111) slip lines. Finally the hypothesis of an entranced plasticity due to the anodic dissolution is verified. A corrosion fatigue test on 3161 shows that when anodic dissolution is favoured then, at a a macroscopic scale, a softening effect can be detected: it is due to vacancies which entranced dislocations mobility. (author). 5 refs., 4 figs