Correlation between Mechanical and Geometrical Characteristics of Shot and Residual Stress Induced by Shot Peening

Author:  Marconi, Citran, Gregorat
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002023
Year of Publication:  2002
Abstract:  
Authors Paolo Marconi, 2Effe Engineering S.r.l., Manerba del Garda, Italy Giorgio Citran and Giovanni Gregorat, Pometon S.p.A., Venice, Italy Abstract Accurate measurement of induced residual stress is necessary in order to evaluate the validity of peening process parameters. Among these parameters, a fundamental role is played by size and hardness of shot. Both of these characteristics are governed by specifications. Another important aspect is the use of "conditioned" shot. The scope of our analysis is to verify if it is possible to achieve greater process repeatability and reliability by using shot with a narrower hardness range and with more precise geometrical characteristics, compared to values found in current specifications. We have therefore measured surface and in-depth residual stress by X-ray diffraction and have analyzed the shape of the shot with a scanning electron microscope (SEM). We have also evaluated the effect on both conditioned and non conditioned shot following impact on the peening surface by SEM analysis.