Relationships between the Brittle Fracture Behavior of Deep-drawn Cups and Deformation Texture and Facet Unit

Abstract

1) The cleavage fracture can occur along the deep drawing axis of a cup which is deep drawn from a hot-rolled or cold-rolled steel blank. This cleavage fracture can be principally explained to be brought about with the increase in (200) pole density on the fracture surface. The work hardening and circumferential tensile residual stress can cause brittle fracture, but can not explain the whole fracture behavior.
2) The reduction in the brittle fracture due to the increase in r value of blank sheet and additional ironing process can be caused by decreasing the (200) pole density on the fracture surfaces.
3) The decrease in cleavage fracture unit (d_c) which is closely related to the toughness, is in linear relationship with the decrease in the (200) pole density and grain size on the fracture surfaces.