Symmetry Breakdown Related Fracture in 42CrMo4 Steel

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Jian Feng - , University of Applied Sciences Heilbronn (Author)
  • Stefan Barth - (Author)
  • Marc Wettlaufer - (Author)

Abstract

Austenite grains that underwent the f.c.c. to b.c.c. (or b.c.t.) transformation are typically composed of 24 Kurdjumov–Sachs variants that can be categorized by three axes of Bain transfor-mations; thus, a complete transformation generally displays 3‐fold symmetry in (001) pole figures. In the present work, crystallographic symmetry in 42CrMo4 steel austempered below martensite start temperature was investigated with the help of the orientation distribution function (ODF) analysis based on the FEG‐SEM/EBSD technique. It is shown that, upon phase transformations, the spec-imens contained 6‐fold symmetry in all (001), (011), and (111) pole figures of an ODF. The ODF analysis, verified by theoretical modeling, showed that under plane‐strain conditions cracks prefer to propagate through areas strongly offset by the high symmetry. The origin of high symmetry was investigated, and the mechanism of the symmetry breakdown was explained.

Details

Original languageEnglish
Article number344
Number of pages10
JournalMetals
Volume11
Issue number2
Publication statusPublished - 18 Feb 2021
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 85100855138

Keywords