On the Stretch-Flangeability of High Mn TWIP Steels
Edge stretching is an important formability issue when it comes to apply sheet steels to automotive industry. Anisotropy, strain hardening and toughness are closely related to hole expansion properties. In this paper, hole expansion properties of a high Mn fully austenitic Twinning Induced Plasticity (TWIP) steel are compared with three other types of single-phase sheet steels. The effects of r-value, n-value, m-value and post-uniform elongation on the edge stretch-flangeability are discussed. It was found that the post-uniform elongation and the strain rate sensitivity have a pronounced effect on hole expansion properties.
Jian-Feng Nie and Allan Morton
L. Chen et al., "On the Stretch-Flangeability of High Mn TWIP Steels", Materials Science Forum, Vols. 654-656, pp. 278-281, 2010