Bake-Hardening Behaviour of High Manganese TWIP Steels: Potential and Limitations
The potential of high manganese TWIP steels for applications in high strength car body parts have been intensively pointed out during the last years.In particular,the outstanding combination of formability and great work-hardening are key features to introduce new design concepts for high strength and light weight parts based on TWIP steels.The rather low yield stress found in TWIP steels however,represents a significant drawback,particularly compared to 1st generation AHSS.In case of the latter,the bake-hardening treatment is an established approach to enhance the strength of a structural element,as it can be easily implemented in the production process as part of the coating treatment.For AHSS,the fundamental mechanism is well understood.For TWIP steels the strengthening potential and also the underlying mechanism of bake-hardening is yet unknown.As a consequence,the presented study shows a systematic investigation of the impact of bake-hardening annealing on the material behaviour of micro-alloyed TWIP steel.To identify promising process windows,several parameters like pre-strain,bake-hardening temperature and annealing time were varied and the resulting effect was evaluated in tensile tests.The results point out a significant bake-hardening behaviour that is strongly depending on pre-strain,annealing time and temperature.Best results however can be achieved at high pre-strains in combination with a standard bake-hardening annealing treatment,where an increase of the yield of ~50 MPa could be achieved.The underlying physical mechanisms may be related to short-range ordering.
high manganese steel bake hardening TWIP heat treatment short-range ordering
Wesselmecking S Ingendahl T Gospodinov I Blankart C Hofmann H Roesler T Nagel M Unruh K Bleck W
RWTH Aachen University, Steel Institute, Intzestraβe 1, 52072 Aachen, Germany ThyssenKrupp Steel Europe, Kaiser-Wilhelm-Straβe 100, 47166 Duisburg, Germany Hoesch Hohenlimburg GmbH, Oeger Str. 120, 58119 Hagen,Germany Faurecia Autositze GmbH, Nordsehler Straβe 38, 31655 Stadthagen Germany
国际会议
成都
英文
195-198
2016-11-16（万方平台首次上网日期，不代表论文的发表时间）