Hole expansion of twinning-induced plasticity steel

Fracture in the hole expansion test for a high-Mn twinning-induced plasticity (TWIP) steel sheet sample was investigated. The test results showed that cracking always occurred along the rolling direction (RD). The fracture behavior of the material was rationalized in terms of strain-rate sensitivity, yield surface shape and damage-producing MnS stringers aligned along the RD. In addition, according to the macroscopic constitutive modeling results, work hardening was shown to be almost isotropic for this material.