文档介绍：International Journal of Fatigue 25 (2003) 1259–1269
ate/ijfatigue
Residual stress modification by post-weld treatment and its
beneficial effect on fatigue strength of welded structures
Xiaohua Cheng a,∗, John W. Fisher a,b, Henry J. Prask c, Thomas Gna¨upel-Herold c,d,
Ben T. Yen a,b, Sougata Roy b
a ATLSS Research Center, Lehigh University, 117 ATLSS Drive, Bethlehem, PA 18015, USA
b Department of Civil and Environmental Engineering, Lehigh University, 13 E. Packer Avenue, Bethlehem, PA 18015, USA
c Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
d Department of Materials and Nuclear Engineering, University of Maryland, College Park, MD 20742, USA
Abstract
High tensile weld residual stress is one important factor contributing to fatigue crack development even under reversal -
pressive cyclic loadings. pressive stress induced by post-weld treatment is beneficial by eliminating the tensile residual
stresses and pressive residual stresses, which improves fatigue strength of welded structures. A study is underway
to characterize the magnitude and subsurface distribution of residual stresses produced by post-weld treatments, particularly by
Ultrasonic Impact Treatment (UIT), and to establish the post-weld treatment effect on fatigue resistance. Two post-weld treatments,
UIT and shot peening, are involved in the present study. Internal stresses were investigated on three base metal samples treated
by UIT and shot peening and on one welded sample treated by UIT through neutron diffraction and X-ray diffraction techniques.
This paper presents the experimental conditions and the results of these stress measurements. It is revealed that the pressive
residual stress induced by both treatments exceeded the yield stress of the base material near the sample surface. The depth of
compressive stress layer in base metal was – mm for UIT and ~ mm for shot peening. The pres