抄録
Based on the maximum tensile stress criterion for the cleavage fracture of steel, correlation between fracture toughness and yield stress, or cleavage fracture stress has been investigated on 13 different types of steel. By incorporating micromechanistic criteria of failure to analytical or numerical crack tip stress and strain solutions, known as the Neuber-RKR (Ritchie, Knott and Rice) model, a certain relation can be derived between fracture toughness and flow/fracture properties of materials. In the previous work, a good experimental correlation according to analytical prediction was obtained. The generality and limitation of the correlation, and the specimen size effect on fracture toughness are discussed in the present work. From the results of the previous and present works, analytical description of fracture toughness expressed in terms of tensile properties is confirmed to be valid and a possibility of the prediction of fracture toughness from the conventional round bar tensile test is shown.
