Talk given by

Dr.-Ing. Christian Haase
Forschungsgruppe "Integrative Werkstoffsimulation"
Institut für Eisenhüttenkunde
RWTH Aachen University

Abstract:

High-Manganese Steels (HMnS), especially Twinning-Induced Plasticity (TWIP) steels, have gained strongly increased interest of both industry and academia during the last two decades. The main reason for this is their outstanding combination of ultra-high tensile strength, high ductility and work-hardening capacity. Especially, the resulting high energy-absorption capacity makes these steels suitable for applications, such as crash relevant structural components in automobiles, which are expected to dissipate the kinetic energy during a crash incident by deforming plastically.

Understanding the fundamentals of HMnS better and, at the same time, generating a new methodology for alloy design has been the main objective of the Collaborative Research Center (SFB) 761 ‘Steel – ab initio’ during the last 9 years. In this presentation, the general approach to use ab initio calculations to support alloy design will be introduced for the design of a TWIP steel crash box. The focus will be put on alloy selection based on deformation-mechanism maps and on the microstructure-texture correlation during deformation and annealing. A new method was applied to determine the optimal processing parameters for the thermomechanical treatment of TWIP steel with improved yield strength-elongation ratio by texture analysis. Further possibilities to tailor the microstructure and, thus, the mechanical properties by varying the chemical composition and/or processing route will be presented.