Compressive Residual Stress Evolution Process by Laser Peening

Koichi Akita; Hirotomo Tanaka; Yuji Sano; Shin Ichi Ohya

doi:10.4028/www.scientific.net/MSF.490-491.370

Paper Titles

Influence of Grinding Conditions on Residual Stress Profiles after Induction Surface Hardening
p.346

Residual Stresses Induced by Robotized Hammer-Peening
p.352

Residual Stresses due to Deep-Drawing of Pre-Coated Aluminum-Alloy Sheets
p.358

Residual Stress in a Quenched Gear Shaft Treated by Water Cavitation Peening
p.364

Compressive Residual Stress Evolution Process by Laser Peening
p.370

Residual Stress State and Cyclic Deformation Behaviour of Deep Rolled and Laser-Shock Peened AISI 304 Stainless Steel at Elevated Temperatures
p.376

Approach of Residual Stress Generated by Deep Rolling Application to the Reinforcement of the Fatigue Resistance of Crankshafts
p.384

An Investigation into Work Hardening of Shot Peening Affected Layer Using X-Ray Stress Analysis Technique
p.390

Calculation of Relaxation of Residual Stress and Change of Yield Strength in Shot Peened Layer
p.396

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Compressive Residual Stress Evolution Process by Laser Peening

Abstract:

Microscopic residual stress distribution on laser-irradiated materials was measured using a synchrotron radiation source. Intense laser pulses were irradiated in water to high tensile strength steel and austenitic stainless steel without any surface coating. Residual stress was measured in a laser-irradiated spot (0D), line (1D) and area (2D) on the materials in order to clarify the evolution process of residual stress. Tensile residual stresses were observed in the laser single pulse irradiated spot (0D). In the line (1D) and area (2D) irradiation, however, the tensile residual stress gradually changed into compressive side as the density of irradiated laser pulses increased. In case of laser irradiation in water, resulting residual stress is considered to be the sum of a tensile stress component by thermal effect and a compressive one by plastic deformation due to shock wave. The tensile stress component remains constant even if the laser pulse density increases, because the thermal effect may be reset every pulse, whereas the compressive stress component increases with laser pulse density, until the saturation of plastic deformation. As a result, the surface residual stress changes into compression with increasing the laser pulse density.