抄録
The cleavage fracture toughness of steels was analyzed on the basis of the statistical local criterion approach. Statistical stress criterion at the crack tip region suggests that the cleavage fracture toughness can be described as a function of the yield stress and the cleavage fracture stress of the materials. In the present work, the formulation of the cleavage fracture toughness was examined in order to analyze mezzo-scopically the mechanical and metallurgical factors. Good correlation between the cleavage fracture toughness, and the yield stress and the cleavage fractue stress which evaluated by round bar specimens was obtained for 47 kinds of low carbon steels and low alloy steels. Based on the correlation, the fracture toughness can be predicted from the tensile test properties.
