GB/T 26140-2023 Active

This document specifies the method for measuring residual stress in polycrystalline materials by neutron diffraction. This document is applicable to the detection of samples of uniform, non-uniform, and materials containing different crystal phases.
This document briefly describes the principle of neutron diffraction technology and provides the following recommendations:
—— Selection of suitable diffraction crystal planes for measurement of different types of materials;
—— Selection of sample orientation in appropriate measurements;
—— Selection of the volume to be measured related to the grain size and stress state of the tested materials.
This document specifies the process of accurately locating and correcting the detection site within the neutron beam, as well as the process of accurately defining the material sampling volume during measurement.
This document specifies the precautions for calibrating neutron diffraction devices and the technical methods for obtaining stress-free reference values.
This document specifies various methods for conducting neutron diffraction measurements, provides the process of analyzing the results and determining their statistical correlation, and provides recommendations for determining reliable estimates of residual stress from strain measurement data and evaluating the uncertainty of the results.