Dislocation motion at a fatigue crack tip in a high-nitrogen steel clarified through in situ electron channeling contrast imaging

Kishan Habib, Motomichi Koyama, Toshihiro Tsuchiyama, Hiroshi Noguchi

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

The dislocation motion was observed at the tip of a fatigue crack in the high nitrogen steel (HNS) by in situ test through electron channeling contrast imaging. No dislocation motion was observed near the crack tip even at a stress amplitude higher than the fatigue limit. In contrast, dislocation pileup was observed a bit from the crack tip with very narrow dislocation spacing. In addition, with increasing number of cycles, the dislocations were extended to stacking fault. The stacking fault showed a reversible behavior of shrink and expansion, which may influence in enhancing the crack growth resistance of the HNS.

Original languageEnglish
Article number109930
JournalMaterials Characterization
Volume158
DOIs
Publication statusPublished - 2019 Dec

Keywords

  • Crack coalescence
  • Dislocations motion
  • Electron channeling contrast imaging
  • High nitrogen steel
  • In situ test

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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