Modification of residual stress by post-weld vibration

Previous studies have suggested that welding residual stresses can be reduc ed by the application of controlled vibration. In the present study welded specimens were processed after being cooled to room temperature, with varyi ng amplitude of applied stress and time of vibration. An increase in the ap plied stress led to a significant decrease in the residual stresses. The ef fect of time of vibration was found to be very small for a lower range of a pplied stresses (< 230 MPa); an increase in the time of vibration had no in fluence on residual stresses. At higher applied stresses (> 230 MPa), the r esidual stresses were found to redistribute with increasing time of vibrati on. It is shown that the energy concept of the vibratory stress relief mech anism was not validated. (C) 2001 IoM Communications Ltd.