n111416SE Academic Article uri icon

abstract

  • The brittle-ductile transition for a high nitrogen steel is investigated by numerical analyses of the Charpy impact test. The material is described in terms of an elastic-viscoplastic constitutive model that accounts for the nucleation and growth of micro-voids, leading to ductile fracture, as well as for cleavage failure by micro-crack nucleation. The temperature dependence of flow strength and strain hardening is included in the model, and this leads to the prediction of a transition from cleavage fracture to predominantly ductile fracture as the temperature increases. For the particular steel considered it is found that the variation of strain hardening with temperature has a strong effect on the failure mode transition. Both slow loading and impact loading of the Charpy specimen are analyzed. Most of the computations are based on a quasi-static formulation since, even at the strain rates encountered in the Charpy impact test, material strain rate sensitivity is the main time effect. The influence of material inertia is investigated in a few transient analyses. 1989 Kluwer Academic Publishers.

published proceedings

  • International Journal of Fracture

author list (cited authors)

  • Tvergaard, V., & Needleman, A.

publication date

  • January 1, 1988 11:11 AM