Relationship between Transition Temperatures and Fracture Toughness Parameters of Steels.

The paper shows that by combining the physical-metallurgical knowledge of the mechanism of cleavage fracture and stress distribution in a deformed body, the conditions of brittle fracture initiation can be defined and the relations between fracture toughness parameters K//I//C, K//l//d and the nil ductility transition temperature t//N//D//T or the fracture appearance transition temperature t//5//0//% (FATT) can be derived. If any of these three parameters has been experimentally determined, the remaining two parameters can be obtained using the proposed relationships.