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Title: Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels

Abstract

Localized deformation mechanisms and strain-hardening behaviors in irradiated 316 and 316LN stainless steels were investigated, and a theoretical model was proposed to explain the linear strain-hardening behavior during the localized deformation. After low temperature irradiation to significant doses the deformation microstructure changed from dislocation tangles to channels or to mechanical twins. It was also observed that irradiation hardening straightened gliding dislocations and increased the tendency for forming pileups. Regardless of these microstructural changes, the strain-hardening behavior was relatively insensitive to the irradiation. This dose-independent strain-hardening rate resulted in dose independence of the true stress parameters such as the plastic instability stress and true fracture stress. In the proposed model, the long-range back stress was formulated as a function of the number of pileup dislocations per slip band and the number of slip bands in a grain. The calculation results confirmed the experimental observation that strain-hardening rate was insensitive to the change in deformation mechanism because the long-range back stress hardening became as high as the hardening by tangled dislocations.

Authors:
 [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Flux Isotope Reactor; Shared Research Equipment Collaborative Research Center
Sponsoring Org.:
Work for Others (WFO)
OSTI Identifier:
931940
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of ASTM International; Journal Volume: 4; Journal Issue: 8
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHANNELING; DEFORMATION; DISLOCATIONS; FRACTURES; HARDENING; INSTABILITY; IRRADIATION; MICROSTRUCTURE; PLASTICS; SLIP; STRAIN HARDENING; STAINLESS STEEL-316; STAINLESS STEEL-316L

Citation Formats

Byun, Thak Sang, and Hashimoto, Naoyuki. Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels. United States: N. p., 2007. Web.
Byun, Thak Sang, & Hashimoto, Naoyuki. Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels. United States.
Byun, Thak Sang, and Hashimoto, Naoyuki. Mon . "Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels". United States. doi:.
@article{osti_931940,
title = {Strain hardening during mechanical twining and dislocation channeling in irradiated 316 stainless steels},
author = {Byun, Thak Sang and Hashimoto, Naoyuki},
abstractNote = {Localized deformation mechanisms and strain-hardening behaviors in irradiated 316 and 316LN stainless steels were investigated, and a theoretical model was proposed to explain the linear strain-hardening behavior during the localized deformation. After low temperature irradiation to significant doses the deformation microstructure changed from dislocation tangles to channels or to mechanical twins. It was also observed that irradiation hardening straightened gliding dislocations and increased the tendency for forming pileups. Regardless of these microstructural changes, the strain-hardening behavior was relatively insensitive to the irradiation. This dose-independent strain-hardening rate resulted in dose independence of the true stress parameters such as the plastic instability stress and true fracture stress. In the proposed model, the long-range back stress was formulated as a function of the number of pileup dislocations per slip band and the number of slip bands in a grain. The calculation results confirmed the experimental observation that strain-hardening rate was insensitive to the change in deformation mechanism because the long-range back stress hardening became as high as the hardening by tangled dislocations.},
doi = {},
journal = {Journal of ASTM International},
number = 8,
volume = 4,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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