Experimental Mechanics

, 49:775 | Cite as

Evaluation of Residual Stresses Induced by Robotized Hammer Peening by the Contour Method

  • L. Hacini
  • N. Van Lê
  • P. Bocher


Welded components suffer from high tensile residual stresses close to the weld beads. These stresses seem to be the origin of premature cracking which could result in a catastrophic rupture during operation and a reduction of the lifespan of these components. In this context, the Hydro-Québec’s Research Institute (IREQ) developed a technique of residual stresses relaxation by robotized hammer peening which makes it possible to release stresses close to surface and preserve the mechanical and dimensional properties of manufactured components. Robotized hammer peening was used to induce compressive residual stresses on initially stress free samples of austenitic stainless steel 304L. Hammer peening layers from one to nine were performed and the resulting residual stresses were evaluated thanks to the contour technique. Complete 2D residual stress fields on samples cross sections were obtained. The ability of hammer peening to relax residual stresses within welded plates was then quantified on austenitic stainless steel 304L plates welded with a 308 steel and hammer peened. These tests show the efficiency of hammer peening as a method to relax tensile residual stresses and induce compressive ones to a depth of a few millimetres. Process parameters were optimized such as the number of hammer peening layers to be applied to reduce processing time and maximization of the intensity and spatial distribution of the compressive residual stresses.


Residual stresses relaxation Welding Hammer peening Stress measurement Contour technique 



The authors would like to thank the CRSNG and the IREQ for their financial support and Dr Jean-Luc Fihey, Dr Jacques Lanteigne, Dr Raynald Simoneau and Denis Thibault for their help. They are also grateful to Stéphane Godin and Carlo Baillargeon for their help in the experimental tasks of this work.


  1. 1.
    Thibault D, Simoneau R, Lanteigne J, Fihey JL (2005) Residual stresses induced by robotized hammer-peening. Proceedings 7th International Conference on Residual Stresses, pp 352–357Google Scholar
  2. 2.
    Hertzberg RW (1996) Deformation and fracture mechanics of engineering materials, , th ed, 4th edn. Wiley, New York, pp 261–263.Google Scholar
  3. 3.
    Hacini L, Lê NV, Bocher P (2008) Effect of impact energy on residual stresses induced by hammer peening of 304L plates. J Mater Process Tech 208:542–548CrossRefGoogle Scholar
  4. 4.
    Valentin MD (1994) Hammer peening effects on the fatigue life of welded T-plate joints. Dissertation. Carleton University, CanadaGoogle Scholar
  5. 5.
    Hassan AF (1994) Fatigue strength of tapered partial-length cover plates. Dissertation. Purdue University, United StatesGoogle Scholar
  6. 6.
    Kirkhope KJ, Bell R, Caron L, Basu RI, Ma KT (1999) Weld detail fatigue life improvement techniques: part 2: application to ship structures. Marine Struct 12:477–496. doi: 10.1016/S0951-8339(99)00031-3.CrossRefGoogle Scholar
  7. 7.
    Infante V, Branco CM, Baptista R, Gomes E (2002) A residual stresses and fracture mechanics analysis of welded joints repaired by hammer peening. Proceedings 8th Portuguese Conference on FractureGoogle Scholar
  8. 8.
    Branco CM, Infante V, Baptista R (2004) Fatigue behaviour of welded joints with cracks, repaired by hammer peening. Fatigue Fract Eng Mater Struct 27:785–798. doi: 10.1111/j.1460-2695.2004.00777.x.CrossRefGoogle Scholar
  9. 9.
    Knight JW (1978) Improving the fatigue strength of fillet welded joints by grinding and peening. Welding Res Int 8:519–540.Google Scholar
  10. 10.
    Maddox SJ (1998) Fatigue of steel fillet welds hammer peened under load. Welding in the World 414:343–349.Google Scholar
  11. 11.
    Takamori H (2000) Improving fatigue strength of welded joints. Dissertation. Lehigh University, United StatesGoogle Scholar
  12. 12.
    Simoneau R (2004) Déformation de plaques d'aciers par le martelage multi-passe robotisé. Technical report, Institut de recherche d'Hydro-Québec, Varennes, Québec, CanadaGoogle Scholar
  13. 13.
    Fihey JL, Simoneau R, Lanteigne J, Thibault D, Laroche Y (2005) Controlled hammer-peening on a restrained A514 (S690Q) weldment. Proceedings High Strength Steels for Hydropower Plants, JulyGoogle Scholar
  14. 14.
    Thibault D, Simoneau R (2001) Technologie d'amélioration en place des roues de turbines hydrauliques. Technical report, Institut de recherche d'Hydro-Québec, Varennes, Québec, CanadaGoogle Scholar
  15. 15.
    Hacini L, Lê NV, Bocher B (2007) Traitement de surfaces par impacts : Évaluation des contraintes résiduelles induites par martelage. Proceedings 18ème Congrès Français de Mécanique, AugustGoogle Scholar
  16. 16.
    Hacini L, Lê NV, Bocher B, Thibault D (2006) Residual stresses induced by robotized hammer peening: The effect of impact energy. Proceeding COM2006(October), 759–767Google Scholar
  17. 17.
    Lanteigne J (2004) Simulation élasto-plastique 2D du martelage: Application à l'acier au carbone A-516 et à l'acier inoxydable 304. Technical report, Institut de recherche d'Hydro-Québec, Varennes, Québec, CanadaGoogle Scholar
  18. 18.
    Nasri H (2007) Mesure des contraintes résiduelles par micro profils de surface. Dissertation, Université du Québec, École de technologie supérieure, CanadaGoogle Scholar
  19. 19.
    Prime MB (2001) Cross-sectional mapping of residual stresses by measuring the surface contour after a cut. J Eng Mater Technol 123:162–168. doi: 10.1115/1.1345526.CrossRefGoogle Scholar
  20. 20.
    Prime MB, Martineau RL (2002) Mapping residual stresses after foreign object damage using the contour method. Mater Sci Forum 404–407:521–526.CrossRefGoogle Scholar
  21. 21.
    Prime MB, Sebring RJ, Edwards JM, Hughes DJ, Webster PJ (2004) Laser surface-contouring and spline data-smoothing for residual stress measurement. Experimental Mech 442:176–184. doi: 10.1007/BF02428177.CrossRefGoogle Scholar
  22. 22.
    Grant PV (2003) 2D Residual stress mapping using the contour method: a technique review. NPL Technique Review Document. National Physical Laboratory, Middlesex, United Kingdom, 2003Google Scholar
  23. 23.
    Hacini L (2007) Application de la technique des micro-profils à la mesure des contraintes résiduelles dues au soudage et au martelage de plaques en acier austénitique inoxydable 304L. Technical report, Institut de recherche d'Hydro-Québec, Varennes, Québec, CanadaGoogle Scholar
  24. 24.
    Thibault D, Bocher B, Thomas M, Garghouri M (2008) Neutron diffraction measurements of residual stresses in 13%Cr–4%Ni weld (in press)Google Scholar
  25. 25.
    Busby JT, Hash MC, Was GS (2005) The relationship between hardness and yield stress in irradiated austenitic and ferritic steels. J Nucl Mater 336:267–278. doi: 10.1016/j.jnucmat.2004.09.024.CrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics 2008

Authors and Affiliations

  1. 1.École de Technologie Supérieure (Université du Québec)MontréalCanada

Personalised recommendations