0
RESEARCH PAPERS

Changes in State Variables at Elevated Temperatures

[+] Author and Article Information
Huseyin Sehitoglu

Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801

J. Eng. Mater. Technol 111(2), 192-203 (Apr 01, 1989) (12 pages) doi:10.1115/1.3226453 History: Received February 18, 1988; Online September 15, 2009

Abstract

Two state variables, strength and internal (back) stress, were determined during cyclic deformation by rapid unloading-reloading experiments. The experiments were performed at different temperatures and strain rates, Considerable increases in strength at low temperatures (20°C–300°C) due to cyclic deformation and due to strain aging were measured. The variation of internal stresses at elevated temperatures (600°C) with strain rate was identified. Regions of high back stress rates were established on stress-back stress diagrams. High strain rates during unload-reload excursions are needed to minimize changes in back stress during measurements. The results (state variables) and the stress-strain response were compared to predictions based on a unified constitutive model. The capabilities of the model under cyclic loading, decrease in strength at high temperatures due to spheroidization, and increase in strength due to strain aging at lower temperatures, were found to be satisfactory. The extension of the unloading-reloading technique to multiaxial loading is outlined.

Copyright © 1989 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In