Martensitic transformation as a deformation process
Constitutive relations for transformation plasticity have been derived from martensitic transformation kinetic theory, predicting flow stress as a function of strain, strain rate, temperature, and stress state. The stress-strain curve can exhibit upward curvature under the combined influence of the softening contribution of the transformation as a deformation mechanism and the hardening contribution of the transformation product. This shape provides a maximum stability of plastic flow and quantitatively accounts for observed enhancement of uniform ductility in TRIP (Transformation-Induced Plasticity) steels. In combination with transformation dilatation effects, the flow stabilizing influence also accounts for a major transformation toughening effect observed when ductile fracture is controlled by plastic shear instability. The principles have now been applied to both homogeneous and dispersed-phase alloy systems.
- Research Organization:
- Massachusetts Inst. of Tech., Cambridge (USA)
- DOE Contract Number:
- FG02-84ER45154
- OSTI ID:
- 6671869
- Report Number(s):
- CONF-860340-16; ON: DE87007068
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CARBON ADDITIONS
DEFORMATION
DUCTILITY
FRACTURE PROPERTIES
HARDENING
IRON ALLOYS
IRON BASE ALLOYS
MARTENSITE
MECHANICAL PROPERTIES
PHASE TRANSFORMATIONS
STEELS
STRAIN HARDENING
STRAINS
TENSILE PROPERTIES