1.1 本规程描述了用于残余应力测量的X射线衍射仪校准的验证程序。 1.2 本规程进一步描述了使用铁粉制造无应力试样，用于量化铁素体或马氏体钢残余应力测量中可能出现的系统误差。通过使用与待测材料具有类似衍射角的粉末，该实践很容易适用于其他合金和陶瓷。 1.3 本规程适用于测量多晶样品晶体结构衍射X射线的所有X射线衍射仪器。它适用于测试方法中定义的残余应力测量的可接受多次暴露技术 E2860 . 通过测量平面的高角度背反射集，这些技术用于推导原子间距（d）- 然后计算残余应力，其中θ、2θ和ψ旋转轴可以重合（参见 图1 ). 图1 定义的X射线衍射残余应力测量几何形状和角度 1.4 单位- 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、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（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 本规程提供了一种验证X射线衍射仪校准的方法，以量化和最小化残余应力测量中的系统实验误差。本规程适用于常规X射线衍射仪器或发散或平行光束类型的X射线衍射残余应力测量仪器 3. , 4. 4.2 本规程的应用要求使用在衍射峰角度范围内衍射X射线的平坦无应力试样，用于后续残余应力测量。试样应具有足够小的相干畴或晶粒，准均匀、准各向同性，并具有足够的厚度，以使入射X射线与足够数量的单个相干畴或晶粒相互作用并从中衍射，从而使近- 对随机晶粒取向分布进行采样。晶体应在将采用的所有倾斜角度ψ下提供强烈的衍射。 注1: 晶体结构取向中的大偏差是不可取的，但在应用该技术时，完全不受无应力试样中首选取向的影响并不关键。

1.1 This practice describes the procedure for verifying the alignment of X-ray diffraction instruments used for residual stress measurements. 1.2 This practice further describes the use of iron powder for fabrication of a stress-free test specimen to be used to quantify the systematic error that can occur in residual stress measurement of ferritic or martensitic steels. This practice is easily adapted to other alloys and ceramics by the use of a powder having a similar diffraction angle to the material to be measured. 1.3 This practice is applicable to all X-ray diffraction instruments that measure diffracted X-rays from the crystal structure of a polycrystalline specimen. It is applicable to the acceptable multiple exposure techniques of residual stress measurement as defined in Test Method E2860 . Through measurement of a high-angle back-reflection set of planes, these techniques are used to derive the interatomic spacing (d-spacing) and the crystallographic strain, and then calculate residual stress in which the θ, 2θ, and ψ rotation axes can be made to coincide (see Fig. 1 ). FIG. 1 X-Ray Diffraction Residual Stress Measurement Geometry and Angles Defined 1.4 Units— 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 ====== 4.1 This practice provides a means of verifying the alignment of an X-ray diffraction instrument so as to quantify and minimize systematic experimental error in residual stress measurements. This practice is suitable for application to conventional X-ray diffraction instruments or to X-ray diffraction residual stress measurement instruments of either the diverging or parallel beam types 3 , 4 4.2 Application of this practice requires the use of a flat stress-free specimen that diffracts X-rays within the angular range of the diffraction peak to be used for subsequent residual stress measurements. The specimen shall have sufficiently small coherent domains or grains, be quasi-homogeneous, quasi-isotropic, and be of sufficient thickness such that incident X-rays interact with and diffract from an adequate number of individual coherent domains or grains such that a near-random grain orientation distribution is sampled. The crystals shall provide intense diffraction at all tilt angles ψ that will be employed. Note 1: A major bias in crystal structure orientation is undesirable, but complete freedom from preferred orientation in the stress-free specimen is not critical in the application of the technique.