Table of Contents
ISRN Thermodynamics
Volume 2012 (2012), Article ID 106051, 4 pages
http://dx.doi.org/10.5402/2012/106051
Research Article

A Note on the Kelvin Effect in 100Cr6 Steel with Application to Identification of the Elastoplastic Limit

Division of Solid Mechanics, Lund University, P.O. Box 118, 221 00 Lund, Sweden

Received 8 December 2011; Accepted 10 January 2012

Academic Editors: R. J. Abergel and P. J. Masset

Copyright © 2012 Håkan Hallberg. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Experimental and analytical results are presented regarding the temperature evolution in 100Cr6 steel under uniaxial loading. Differently heat-treated conditions of the material are studied at different strain rates. In the annealed state, the materials exhibits a pronounced initial yield stress as it passes from the elastic region to the plastic through discontinuous yielding. In contrast, the quenched and tempered material yields continuously. The focus of the paper is on the temperature decrease during elastic deformation that precedes the more pronounced heating due to inelastic dissipation once the elastoplastic limit stress is surpassed. The applicability of the maximum temperature decrease in the elastic regime as a replacement for the commonly used 0.2%-strain measure to define the elastoplastic limit is discussed. For 100Cr6 steel, the 0.2%-strain measure is found, in some cases, to overestimate the initial yield stress by 50 MPa. The drop in temperature corresponding to the shift from elastic to inelastic material behavior is experimentally determined and compared to predictions by the Kelvin formula which in the current study give a maximum 50% error.