The Susceptibility of Local Parameters to Steel Microstructure Evaluated Using Charpy Type Specimen

Accepting the Beremin approach to the analysis of cleavage failure criteria the local fracture parameters have been calculated using FEM for Charpy type specimen. Two types, of model fenitic microstructures have been selected for presentation differing by carbide thickness and scatter of fracture toughness data. For the microstructures investigated the Weibull stresses (location parameters) were related to cleavage fracture stresses determined supposing deterministic nature of cleavage fracture events at initiation. The results of static three point bending and low blow impact testing were used for these purposes. Microstructural and rnicrohctographic reasons for scatter of data were determined. Relation of microstructural and microfractographic features to local fracture criteria was analysed.