Estimation of residual stresses induced by shot-peening. Measurement of the thermal dissipation with an infrared camera

The plasticization induced by the shot-peening treatment is an exothermic transformation. One can imagine to link the induced residual stress level to the thermal behaviour of the sample during the treatment or, at least, to propose some means of process monitoring control via temperature measurements. Steel samples were submitted to shot-peening under various conditions, both with a compressed air machine and a turbine machine. The temperature of the sample rear face was measured by IR thermography during the treatment. The thermal behaviour of the samples during the treatment have been compared to Almen intensity measurements and to residual stress measurements by the hole-drilling method. We conclude to the feasibility of process monitoring by temperature measurements. More academic experiments are being set up in order to derive quantitative relations between the thermal dissipation and the stress level. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.