The effect of twinning and slip on the bauschinger effect of hadfield steel single crystals Academic Article uri icon

abstract

  • The Bauschinger effect (BE) in single crystals of Hadfield manganese steel (Fe, 12.3Mn, 1.0C in wt pct) was studied for three crystallographic orientations, [1̄11], [1̄23], and [001]. Both forward tension- reverse compression (FT/RC) and forward compression-reverse tension (FC/RT) loading schemes were used to investigate the role of deformation history on the BE. The evolution of stress-strain response and a dimensionless Bauschinger parameter were used to study the BE. The BE stems from long-range back stress generated by the dislocation pileups at the twin and localized slip boundaries. Twinning boundaries present a strong obstacle and lead to a strong BE. If localized slip followed twinning, permanent softening was evident, such as in the case of the [1̄11] FT/RC scheme. Localized slip and multiple slip in the forward loading provided a transient effect in the stress-strain response without a significant permanent softening. Hadfield steel single crystals have demonstrated a high BE for orientations conducive to combined twinning/slip deformation. The BE increased with increasing prestrain, then saturated and started to decrease, in contrast with precipitation-hardened alloys. A unique strain-hardening approach along with the back stress calculation was introduced into a viscoplastic self- consistent (VPSC) formulation. The strain-hardening formulation incorporates length scales associated with spacing between twin lamellae. The simulations correctly predicted the BE and the stress-strain response for both forward and reverse loading.

author list (cited authors)

  • Karaman, I., Sehitoglu, H., Chumlyakov, Y. I., Kireeva, I. V., & Maier, H. J.

citation count

  • 6

publication date

  • March 2001