Influence of Microstructural Anisotropy on the Hydrogen-assisted Fracture of Notched Samples of Progressively Drawn Pearlitic Steel

In this study, fracture surfaces of notched specimens of pearlitic steels subjected to constant extension rate tests (CERTs) are analyzed, in an environment causing hydrogen assisted fracture. In order to obtain general results, both different notched geometries (to generate quite distinct stress triaxiality distributions in the vicinity of the notch tip) and diverse loading rates were used. The fracture surfaces were classified in relation to four micromechanical models of hydrogen-assisted micro-damage. To this end, fractographic analysis in each fracture surface was carried out with a scanning electron microscopy. Generated results increase the number of micromechanical models found in the scientific literature.