MATHEMATICAL MODEL ON DUCTILE-BRITTLE TRANSITION OF METALLIC MATERIALS

摘要

In the present paper. according to the stress-strain criteria for initiating cleavage crack and typical ductile dimple fracture, a mathematical model on ductile-brittle transition of metallic materials has been put forward through analyzing the fracture behavior of impacted specimens at various temperatures and the stress-strain distributions ahead of the tips of notch and propagating ductile crack. From the model, the beginning temperatures of the upper and lower platform on the ductile-brittle transition curve can be deduced, and the effects of em-brittlement and loading rate on ductile-brittle transition behavior and DBTT can be explained.