Koichi Akita

Progress in Bulk Texture Measurement Using Neutron Diffraction

Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan; J-PARC Center, Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan; Research Center for Neutron Science and Technology, Comprehensive Research Organization for Science and Society, Tokai, Ibaraki, 319-1106, Japan; Department of Neutron Application Technology, Radiation Application Development Association, Tokai, Ibaraki, 319-1106, Japan; College of Engineering, Ibaraki University, Hitachi, Ibaraki, 316-8511, Japan; Department of Materials Engineering and Industrial Technologies, University of Trento, 7738123 Trento, Italy.

Non-destructive Measurement of Residual Stress Depth Profile in Laser-peened Steel at SPring-8

We investigated the residual stress depth profile near the surface of steel treated by laser peening without coating using X‐ray diffraction at SPring‐8. This investigation was carried out using a constant penetration depth sin2ψ method. In this method, the sin2ψ diagram is measured controlling both the ψ angle and the X‐ray penetration depth simultaneously with a combination of the ω and χ axes of the 4‐circle goniometer. This method makes it possible to evaluate the residual stress and its depth profile in material with a stress gradient precisely and non‐destructively. As a result, we confirmed that a compressive residual stress was successfully formed all over the range of the depth profile in the steel treated properly by laser peening without coating.