Deformation of single crystal hadfield steel by twinning and slip

Journal Article (Journal Article)

The stress-strain behavior of Hadfield steel (Fe, 12.34 Mn, 1.03 C, in wt%) single crystals was studied for selected crystallographic orientations ([1̄11], [001] and [1̄23]) under tension and compression. The overall stress-strain response was strongly dependent on the crystallographic orientation and applied stress direction. Transmission electron microscopy and in situ optical microscopy demonstrated that twinning is the dominant deformation mechanism in [1̄11] crystals subjected to tension, and [001] crystals subjected to compression at the onset of inelastic deformation. In the orientations that experience twinning, the activation of multiple twinning systems produces a higher strain-hardening coefficient than observed in typical f.c.c. alloys. Based on these experimental observations, a model is presented that predicts the orientation and stress direction effects on the critical stress for initiating twinning. The model incorporates the role of local pile-up stresses, stacking fault energy, the influence of the applied stress on the separation of partial dislocations, and the increase in the friction stress due to a high solute concentration. On the other hand, multiple slip was determined to be the dominant deformation mechanism in [1̄11] crystals subjected to compression, and [001] crystals deformed under tension. Furthermore, the [1̄23] crystals experience single slip in both tension and compression with planar type dislocations. Using electron back-scattered diffraction patterns, macroscopic shear bands (MSBs) were identified with a misorientation of 9° in the compressed [1̄11] single crystals at strains as low as 1%.

Full Text

Duke Authors

Cited Authors

  • Karaman, I; Sehitoglu, H; Gall, K; Chumlyakov, YI; Maier, HJ

Published Date

  • April 2, 2000

Published In

Volume / Issue

  • 48 / 6

Start / End Page

  • 1345 - 1359

International Standard Serial Number (ISSN)

  • 1359-6454

Digital Object Identifier (DOI)

  • 10.1016/S1359-6454(99)00383-3

Citation Source

  • Scopus