1.1 本试验方法涵盖了通过实验确定x射线弹性常数的程序 （XEC） 用于通过x射线衍射技术评估残余应力和施加应力。这个 XEC 将宏观应力与多晶样品中在特定结晶方向上测量的应变联系起来。这个 XEC 是弹性模量、材料泊松比和 hkl 选择用于测量的平面。有两个 XEC 这些被称为 1. / 2. S 2. hkl 和 S 1. hkl . 1.2 本试验方法适用于所有用于测量宏观残余应力的x射线衍射仪器，这些仪器使用高背反射区域衍射峰位置的测量来确定晶格间距的变化。 1.3 本试验方法适用于所有用于残余应力测量的x射线衍射技术，包括单次、双次和多次曝光技术。 1.4 以国际单位制表示的值应被视为标准值。SI单位后括号中给出的值仅供参考，不被视为标准值。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 =====意义和用途====== 6.1 本测试方法提供了实验确定 XEC 用于使用x射线衍射技术测量残余应力和施加应力。它还提供了一种标准的方法来报告 XEC . 6.2 本试验方法适用于在弹性范围内应力和应变之间呈线性关系的任何晶体材料，即仅适用于弹性载荷。 6.3 无论何时通过x射线衍射技术评估残余应力，都应使用本试验方法 XEC 材料的种类未知。

1.1 This test method covers a procedure for experimentally determining the x-ray elastic constants (XEC) for the evaluation of residual and applied stresses by x-ray diffraction techniques. The XEC relate macroscopic stress to the strain measured in a particular crystallographic direction in polycrystalline samples. The XEC are a function of the elastic modulus, Poisson’s ratio of the material and the hkl plane selected for the measurement. There are two XEC that are referred to as 1 / 2 S 2 hkl and S 1 hkl . 1.2 This test method is applicable to all x-ray diffraction instruments intended for measurements of macroscopic residual stress that use measurements of the positions of the diffraction peaks in the high back-reflection region to determine changes in lattice spacing. 1.3 This test method is applicable to all x-ray diffraction techniques for residual stress measurement, including single, double, and multiple exposure techniques. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 6.1 This test method provides standard procedures for experimentally determining the XEC for use in the measurement of residual and applied stresses using x-ray diffraction techniques. It also provides a standard means of reporting the precision of the XEC . 6.2 This test method is applicable to any crystalline material that exhibits a linear relationship between stress and strain in the elastic range, that is, only applicable to elastic loading. 6.3 This test method should be used whenever residual stresses are to be evaluated by x-ray diffraction techniques and the XEC of the material are unknown.