The Journal of
the Korean Journal of Metals and Materials

The Journal of
the Korean Journal of Metals and Materials

Monthly
  • pISSN : 1738-8228
  • eISSN : 2288-8241

Editorial Office

Title Brief Review of Strengthening Mechanisms in TRIP- and TWIP-Assisted Medium Manganese Steels: Microstructure Analysis Viewpoint
Authors 이초현(Cho-Hyeon Lee) ; 이민영(Min-young Lee) ; 조원희(Won-Hui Jo) ; 김장중(Jang-Jung Kim) ; 천재은(Jae-Eun Cheon) ; 한주연(Ju-Yeon Han) ; 최현주(Hyun-Joo Choi) ; 조기섭(Ki-Sub Cho) ; 이현정(Hyun-Jung Lee) ; 이영국(Young-Kook Lee) ; 설재복(Jae-Bok Seol)
DOI https://doi.org/10.3365/KJMM.2026.64.1.64
Page pp.64-81
ISSN 1738-8228(ISSN), 2288-8241(eISSN)
Keywords Twinning induced plasticity; Transformation induced plasticity; Medium Mn steel; Microstructure
Abstract Recent research on medium manganese steels has highlighted their potential for achieving an exceptional strength-to-ductility balance, primarily through the synergistic activation of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) mechanisms. Medium manganese steels, generally containing 3?12 wt.% Mn, offer a unique combination of high strength and elongation with lower alloying costs than high-Mn steels. The TRIP mechanism enhances strength by promoting the stress-induced transformation of metastable austenite into martensite, while the TWIP mechanism increases ductility through twin formation and the associated high work-hardening rate. These mechanisms are strongly influenced by stacking fault energy (SFE). Medium mn steels with SFE values in the range of 18?25 mJ/m2 can simultaneously activate both, thereby overcoming the conventional strength?ductility trade-off. TRIP tends to dominate during the early stages of deformation, providing rapid strain hardening, while TWIP becomes more active at later stages, sustaining the hardening rate and prolonging the balance between strength and ductility. This paper reviews the microstructural basis of TRIP and TWIP, focusing on analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM), as well as recent in-situ TEM observations that directly capture phase transformation and twinning. Insights into the material's potential applications and future research directions are provided to highlight medium manganese steels as a promising material for next-generation high-performance applications.