Deformation and fracture mechanisms in Al-added high manganese TWIP steels for automobile parts(Sang Yong Shin, Ulsan Univ.)

Sang Yong Shin
2014-05-23 pm 04:00 / EB1, E207

Deformation and fracture mechanisms in Al-added high manganese TWIP steels for automobile parts

Sangyong Shin, Ph.D.
Assistant Professor, Ulsan University
 

Abstract

TWinning Induced Plasticity (TWIP) steels are intensively studied worldwide in order to satisfy the strict requirements for automotive steels demanding high economy, environmental friendliness, and high performance. Recently, TWIP steels, in which the Mn addition is reduced while Al is added to secure high formability as well as excellent strength and ductility, have also been developed. In this study, high Mn TWIP steels and Al-added TWIP steels were fabricated, and their microstructures, tensile properties, and cup formability were analyzed to investigate effects of Al addition on deformation mechanisms in tensile and cup forming tests. The delayed fracture properties of the TWIP steels were examined by dipping tests of cup specimens in the boiled water, after which the microcrack formation behavior was analyzed. And the serration phenomena of the TWIP steels were examined by tensile tests, and were explained by the microstructural evolution including formation of localized Portevin–Le Chatelier deformation bands and twins.