The mechanism of bcc α′ nucleation in single hcp ε laths in the fcc γ → hcp ε → bcc α′ martensitic phase transformation

Xusheng Yang, Sheng Sun, Tong Yi Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

65 Citations (Scopus)

Abstract

High Resolution Transmission Electron Microscopy (HRTEM) and Molecular Dynamics (MD) simulations were conducted here to study the plastic deformation induced γ (fcc) → ε (hcp) → α′ (bcc) martensitic transformation in 304 stainless steels for the α′ nucleation from single hcp-ε laths. Results elucidate that the underlying microscopic mechanism for the α′ nucleation from single hcp-ε laths obeys the Bogers-Burgers-Olson-Cohen "3T/8-T/3" model. In particular, the atomic-scale observations clearly show the Kurdyumov-Sachs (K-S) lattice orientation relation (OR) and Pitsch OR at the γ/α′ interfaces, the lattice rotation inside an α′ martensitic inclusion, the transition lattice and the reverse shear-shuffling induced continuous lattice elastic deformation at the diffuse ε/α′ interface, which caters the 3T/8 and T/3 shears and sheds atomic process insight into the mechanism of the martensitic transformation.
Original languageEnglish
Pages (from-to)264-273
Number of pages10
JournalActa Materialia
Volume95
DOIs
Publication statusPublished - 16 Jun 2015
Externally publishedYes

Keywords

  • Austenite-to-martensite phase transformation
  • Austenitic stainless steels
  • HRTEM
  • Molecular Dynamics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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