Original paper(Vol.48 No.7 pp.705)

Abstract:The commonly used X-ray stress measurement, so-called sin²ƒÕ method, is valid for the stress determination from the X-ray diffraction data. However, the method fails if the samples are anisotropic because the method is constructed from some assumptions, one of which is that the samples are regarded as isotropic and homogeneous polycrystalline materials. Therefore, in order to be applicable the polycrystalline materials withsHKLtpreferred orientation, the method was improved by the introduction of the rotation symmetry about the normal axis to the X-ray diffraction plane in this paper. The basic equation in the X-ray stress measurement i.e. the X-ray stress-lattice strain relation was derived forsHKLtpreferred orientation in result. Then, the method applied to a centrifugal casting part, and was discussed in comparison with the sin²ƒÕ method.

Key Words:X-ray diffraction, Residual stress, Preferred orientation, Polycrystalline materials, Casting parts