BS EN 15305:2008 - Page 3

Non-destructive testing. Test method for residual stress analysis by X-ray diffraction. | Status: Confirmed, Current

1 Scope This European Standard describes the test method for the determination of macroscopic residual or applied stresses non-destructively by X-ray diffraction analysis in the near-surface region of a polycrystalline specimen or component. All materials with a sufficient degree of crystallinity can be analysed, but limitations may arise in the following cases (brief indications are given in Clause 12):

• — Stress gradients;
• — Lattice constants gradient;
• — Surface roughness;
• — Non-flat surfaces (see 5.1.2);
• — Highly textured materials;
• — Coarse grained material (see 5.1.4);
• — Multiphase materials;
• — Overlapping diffraction lines;
• — Broad diffraction lines.

The specific procedures developed for the determination of residual stresses in the cases listed above are not included in this document. The method described is based on the angular dispersive technique with reflection geometry as defined by EN 13925‑1. The recommendations in this document are meant for stress analysis where only the diffraction line shift is determined. This European Standard does not cover methods for residual stress analyses based on synchrotron X-ray radiation and it does not exhaustively consider all possible areas of application. Radiation Protection. Exposure of any part of the human body to X-rays can be injurious to health. It is therefore essential that whenever X-ray equipment is used, adequate precautions should be taken to protect the operator and any other person in the vicinity. Recommended practice for radiation protection as well as limits for the levels of X-radiation exposure are those established by national legislation in each country. If there are no official regulations or recommendations in a country, the latest recommendations of the International Commission on Radiological Protection should be applied.