Thick section S690 QT steel is modelled with a modified multibarrier model that is based on the weakest-link mechanism. Segregation bands are modelled as discrete layers which have different grain size, yield properties, and local fracture parameters from outside of the bands. The results show that embrittlement from segregation bands can only be adequately reflected if the inhomogeneities of the fracture parameters are accounted for. The present methodology quantitively captures the cooperation of complex microstructural features in cleavage and can facilitate the trade-off between the effects of various microstructural parameters in toughness control.
- Fracture toughness
- Microstructural inhomogeneity
- Statistical modelling