On the applicability of local approach models for the determination of the failure behavior of steels of different toughness

For the description of the failure behavior of ductile steels so-called local approach models can be used. These models describe numerically the process developing microscopically and finally leading to fracture (void initiation, void growth, void coalescence → fracture) by means of continuum mechanical approaches in order to calculate the macroscopical failure behavior. This contribution deals with the possibility of calculating the deformation and failure behavior of specimens and comment-like specimens using finite-element-calculations on the basis of local approach models. Three structural steels of different toughness have been investigated: (1) the ferritic reactor pressure vessel steel 20 MnMoNi 5 5 (similar to A508 C13); (2) the austenitic pipe steel X10 CrNiNb 189 (1.4550, similar to TP304) and (3) the reactor pressure vessel steel 22 NiMoCr 37 (similar to A508 C12), the chemical composition of which was slightly modified to decrease the upper shelf toughness. The quality of the calculation is assessed by a comparison between experimental and numerical results