Evaluation of Residual Stresses Introduced by Laser Shock Peening in Steel using Different Measurement Techniques

The development of a residual stress engineering technology such as laser shock peening (LSP) requires evaluation of the process by quantification of the desired effect. Applications of LSP for turbine blade integrity enhancement due to expected deeper compressive residual stresses with lower surface roughness compared to conventional shot peening (SP), have resulted in the analysis of LSP on 12CrNiMoV steel samples. The investigation compares different residual stress measurement techniques such as energy dispersive synchrotron X-ray diffraction (SXRD), laboratory X-ray diffraction (XRD) with sequential electro-polishing, neutron diffraction (ND), incremental-hole drilling (IHD), and the contour method (CM). This study highlights the benefits and opportunities of using complimentary residual stress measurement techniques in order to gain insight into the residual stresses within a material.