Fracture behaviour of a Fe–22Mn–0.6C–0.2V austenitic TWIP steel

Julie Lorthios (1) , Matthieu Mazière (1) , Xavier Lemoine (2) , Philippe Cugy (2) , Jacques Besson (1) , Anne-Françoise Gourgues-Lorenzon (1)

1 CDM - Centre des Matériaux
2 ArcelorMittal Maizières Research SA

The mechanical behaviour of a 22Mn-0.6C-0.2V austenitic TWIP steel has been extensively characterised for a variety of strain ratios (from shear to biaxial stretching) using smooth and notched specimens. A constitutive model involving a non-isotropic yield function together with isotropic and/or kinematic hardening satisfactorily represented the experimental database. It was used to estimate local stress and strain fields and to derive a fracture criterion based on the equivalent stress and Lode angle that were expressed to be consistent with the constitutive equations describing the plastic flow behaviour. A weak dependence on hydrostatic stress further improves prediction of fracture initiation, with an average standard error of less than 5% over ten different mechanical tests.

Mots clés: Plastic yield anisotropy; ductile fracture; anisotropic fracture criterion; TWIP steels; forming limit diagram

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Julie Lorthios, Matthieu Mazière, Xavier Lemoine, Philippe Cugy, Jacques Besson, et al.. Fracture behaviour of a Fe–22Mn–0.6C–0.2V austenitic TWIP steel. International Journal of Mechanical Sciences, 2015, 101-102, pp.99-113. ⟨10.1016/j.ijmecsci.2015.07.029⟩. ⟨hal-01199574⟩