Trabalho

Overview

Residual stress
Part 2 – Nature and origins
P. J. Withers and H. K. D. H. Bhadeshia
Residual stress is that which remains in a body that is stationary and at equilibrium with its surroundings. It can be detrimental when it reduces the tolerance of the material to an externally applied force, as is the case with welded joints. On the other hand, it can be exploited to design materials or components which are resistant to damage, toughened glass being a good example. This paper, the second part of a two part overview, the first part having been devoted to measurement techniques, examines the nature and origins of residual stresses across a range of scales.
This extends from the long range residual stress fields in engineering components and welded structures, through the interphase stresses present in composites and coatings, to the microscale interactions of phase transformations with local stresses.
MST/4640B

Published by Maney Publishing (c) IOM Communications Ltd

Professor Withers is in the Manchester Materials Science Centre, University of Manchester and UMIST, Grosvenor Street,
Manchester M1 7HS, UK ([e-mail]). Professor Bhadeshia is in the Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK ([e-mail]). Manuscript received 3 March 2000; accepted 6 December 2000.
# 2001 IoM Communications Ltd.

Introduction

Macro residual stresses in engineering components As the design of engineering components becomes less conservative, there is increasing interest in how residual stress affects mechanical properties. This is because structural failure can be caused by the combined effect of residual and applied stresses. In practice, it is not likely that any manufactured component would be entirely free from residual stresses introduced during processing. Furthermore, in natural or artificial multiphase materials, residual stresses can arise from differences in thermal