Strain hardening and ductility of iron: axisymmetric vs plane strain elongation. Technical progress report
The strain hardening of iron at high strains in plane strain elongation (strip drawing) is shown to fall increasingly below that of drawn iron wires at true strains above 2, going through zero strain hardening at epsilon = 3.0, and becoming strongly negative thereafter, at least up to epsilon = 4.1. High resolution selected area electron diffraction has been used to map the size, shape and crystallographic orientations of a group of about 50 contiguous cells centered around an incipient shear band in an edge section of a strip drawn to epsilon = 1.8. This map shows no textural instability or change in orientation associated with the shear band, although it does show substantial misorientations throughout the group of cells, the axis of these misorientations lying in the same direction as the trace of the shear band. No other large misorientations (i.e. 5/sup 0/ or so) are present. The only instability seen in this shear band is microstructural: the slip distances in the two primary slip directions are quite anisotropic, being much longer along the trace of the shear band. Note that this shear band has appeared during the linear hardening portion of the high-strain hardening curve of the drawn strip. It is therefore considered a direct weakening mechanism rather than a result of another weakening effect. Further such orientation maps have been or are being prepared for more highly deformed strip, and for wire and pure-shear specimens as well.
- Research Organization:
- Drexel Univ., Philadelphia, PA (USA). Dept. of Materials Engineering
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-76ER04072
- OSTI ID:
- 5351783
- Report Number(s):
- DOE/ER/04072-3
- Country of Publication:
- United States
- Language:
- English
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Strain hardening and ductility of iron: axisymmetric vs. plane strain elongation. Technical progress report
Strain hardening of iron: axisymmetric vs. plane strain elongation
Related Subjects
IRON
DUCTILITY
STRAIN HARDENING
CRYSTALLOGRAPHY
ELONGATION
MICROSTRUCTURE
ORIENTATION
SIZE
TEXTURE
CRYSTAL STRUCTURE
ELEMENTS
HARDENING
MECHANICAL PROPERTIES
METALS
TENSILE PROPERTIES
TRANSITION ELEMENTS
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies