REVIEW OF THE MECHANICAL PROPERTIES OF HIGH STRENGTH, HIGH-Mn TWIP STEELS FOR AUTOMOTIVE APPLICATIONS

摘要

Recent trends in automotive industry towards improved passenger safety and reduced weight have led to a great interest in AHSS (Advanced High Strength Steel), and DP, TRIP, CP, MA, and high-Mn TWIP (TWinning Induced Plasticity) steels are particularly promising due to their superior toughness and ductility. The properties of low SFE (Stacking Fault Energy) austenitic high Mn FeMnC steel exhibiting twinning-induced plasticity have recently been analyzed in detail. At low strain rates, the plastic deformation of TWIP steels is often controlled by the movement of very few well-defined localized deformation bands. The formation and propagation of these Portevin-LeChatelier (PLC) bands lead to serrated stress-strain curves. The present contribution offers a critical analysis of the mechanical properties of high-Mn TWIP steels and focuses on their potential as automotive materials. In addition, the challenges related to the production and applications of high-Mn TWIP steels are discussed. The new insights in the properties of TWIP steels result from the use of new experimental techniques combining high sensitivity infrared thermo-graphic imaging and optical in-situ strain analysis.