Feasibility of the ($4\delta_t,\sigma_{22c}$) criterion to predict fracture toughness of ferritic steel using specified specimen types

An improved Ritchie–Knott–Rice failure criterion, namely ($4\delta_t,\sigma_{22c}$) criterion, for the A515-70 steel is studied with allowance for the specimen geometry, specimen temperature, and initial crack length. The results show that the ($4\delta_t,\sigma_{22c}$) criterion can effectively predict the cleavage fracture. Results of studying the possibility of using a dimensionless function for determining the fracture toughness are reported.