E28.13 - Residual Stress Measurement

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 types3,4  
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.
SCOPE
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
5.1 This test method covers a procedure for experimentally determining macroscopic residual stress tensor components of quasi-isotropic bearing steel materials by XRD. Here the stress components are represented by the tensor σij as shown in Eq 1 (1,5 p. 40). The stress strain relationship in any direction of a component is defined by Eq 2 with respect to the azimuth phi(φ) and polar angle psi(ψ) defined in Fig. 1 (1, p. 132).
5.1.1 Alternatively, Eq 2 may also be shown in the following arrangement (2, p. 126):
5.2 Using XRD and Bragg’s law, interplanar strain measurements are performed for multiple orientations. The orientations are selected based on a modified version of Eq 2, which is dictated by the mode used. Conflicting nomenclature may be found in literature with regard to mode names. For example, what may be referred to as a ψ (psi) diffractometer in Europe may be called a χ (chi) diffractometer in North America. The three modes considered here will be referred to as omega, chi, and modified-chi as described in 9.5.  
5.3 Omega Mode (Iso Inclination) and Chi Mode (Side Inclination)—Interplanar strain measurements are performed at multiple ψ angles along one φ azimuth (let φ = 0°) (Figs. 2 and 3), reducing Eq 2 to Eq 3. Stress normal to the surface (σ33) is assumed to be insignificant because of the shallow depth of penetration of X-rays at the free surface, reducing Eq 3 to Eq 4. Post-measurement corrections may be applied to account for possible σ33 influences (12.12). Since the σij values will remain constant for a given azimuth, the s1{hkl} term is renamed C.
FIG. 2 Omega Mode Diagram for Measurement in σ11 Direction  
FIG. 3 Chi Mode Diagram for Measurement in σ11 Direction
Note 1: Stress matrix is rotated 90° about the surface normal compared to Fig. 2 and Fig. 14.  
5.3.1 The measured interplanar spacing values are converted to strain using Eq 24, Eq 25, or Eq 26. Eq 4 is used to fit the strain versus sin2ψ data yiel...
SCOPE
1.1 This test method covers a procedure for experimentally determining macroscopic residual stress tensor components of quasi-isotropic bearing steel materials by X-ray diffraction (XRD).  
1.2 This test method provides a guide for experimentally determining stress values, which play a significant role in bearing life.  
1.3 Examples of how tensor values are used are:  
1.3.1 Detection of grinding type and abusive grinding;  
1.3.2 Determination of tool wear in turning operations;  
1.3.3 Monitoring of carburizing and nitriding residual stress effects;  
1.3.4 Monitoring effects of surface treatments such as sand blasting, shot peening, and honing;  
1.3.5 Tracking of component life and rolling contact fatigue effects;  
1.3.6 Failure analysis;  
1.3.7 Relaxation of residual stress; and  
1.3.8 Other residual-stress-related issues that potentially affect bearings.  
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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
5.1 The techniques described provide for the measurement of change in length of a fastener. Such measurements are made from one end of the specimen without requiring access to the rear surface.  
5.2 The Ultrasonic Pulse Echo technique is used to monitor changes in length of fasteners and as a tool for industrial quality control. Applications include fasteners used in turbines, petrochemical pressure vessels, aircraft, automotive manufacturing, general bolting within the nuclear industry, structural steel connections, and laboratory testing.
SCOPE
1.1 This practice covers a procedure for measuring changes in length of threaded bolts using the ultrasonic pulse-echo technique.  
1.2 This procedure is normally intended for metal bolting 6.3 mm or more in nominal diameter with effective length-to-diameter ratios of 2:1 or greater.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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.  
1.5 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
5.1 Summary:  
5.1.1 Residual stresses are present in almost all materials. They can be created during the manufacture or during the life of the material. Residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical general-purpose method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination:  
1.1.1 This test method specifies a hole-drilling procedure for determining in-plane residual stresses near the surface of an isotropic linearly elastic material. It is applicable to residual stress determinations where the stresses do not vary significantly across the diameter of the drilled hole. The measured stresses are the in-plane residual stresses that exist within the depth of the drilled hole. Stress sensitivity rapidly decreases with depth from the measured surface and deep interior stresses cannot be evaluated. The measured residual stresses are described as “uniform” if they remain approximately constant within the hole depth, “non-unifom” if they vary significantly.  
1.1.2 In general, “blind” holes are used, where the depth of the drilled hole and therefore the depth of the residual stress evaluation is less than the workpiece thickness. However, for a thin workpiece, it is also possible to do through-thickness measurements of uniform (membrane) stresses using a through-hole.  
1.2 Stress Measurement Range:  
1.2.1 This test method applies in cases where material behavior is linear-elastic. When near-yeild residual stresses are present, it is possible for local yielding to occur due to the stress concentration around the drilled hole. Satisfactory measurement results can be achieved providing the residual stresses do not exceed about 80 % of the material yield stress for blind-hole drilling and about 50 % of the material yield stress for through-hole drilling.  
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.  
1.4 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.  
1.5 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.
SCOPE
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 S2hkl and S1 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
4.1 Residual stresses in tubing may be detrimental to the future performance of the tubing. Such stresses may, for example, influence the susceptibility of a tube to stress corrosion cracking when the tube is exposed to certain environments.  
4.2 Residual stresses in new thin-walled tubing are very sensitive to the parameters of the fabrication process, and small variations in these parameters can produce significant changes in the residual stresses. See, for example, Table 1, which shows the residual stresses measured by this practice in samples from successive heats of a ferritic Cr-Mo-Ni stainless steel tube and a titanium condenser tube. This practice provides a means for estimating the residual stresses in samples from each and every heat.  
4.2.1 This practice may also be used to estimate the residual stresses that remain in tubes after removal from service in different environments and operating conditions.  
4.3 This practice assumes a linear stress distribution through the wall thickness. This assumption is usually reasonable for thin-walled tubes, that is, for tubes in which the wall thickness does not exceed one tenth of the outside diameter. Even in cases where the assumption is not strictly justified, experience has shown that the approximate stresses estimated by this practice frequently serve as useful indicators of the susceptibility to stress corrosion cracking of the tubing of certain metal alloys when exposed to specific environments.  
4.3.1 Because of this questionable assumption regarding the stress distribution in the tubing, the user is cautioned against using the results of this practice for design, manufacturing control, localized surface residual stress evaluation, or other purposes without supplementary information that supports the application.  
4.4 This practice has primarily been used to estimate residual fabrication stresses in new thin-walled tubing between 19 mm (0.75 in.) and 25 mm (1 in.) outside diameter and 1.3 mm (0.05 ...
SCOPE
1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of thin-walled tubing. This practice assumes a linear stress distribution through the tube wall thickness and will not provide an estimate of local stress distributions such as surface stresses. (Very high local residual stress gradients are common at the surface of metal tubing due to cold drawing, peening, grinding, etc.) The Hatfield and Thirkell formula, as later modified by Sachs and Espey,2 provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing.  
1.2 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.  
1.3 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 test method provides a means of verifying the alignment of an X-ray diffraction instrument in order to quantify and minimize systematic experimental error in residual stress measurement. This method is suitable for application to conventional diffractometers or to X-ray diffraction instrumentation designed for residual stress measurement of either the diverging or parallel beam types.3,4  
4.2 Application of this test method 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 residual stress measurement. The specimen shall be sufficiently fine-grained, homogeneous, isotropic, and of sufficient depth such that incident X-rays interact with and diffract from an adequate number of individual coherent domains and or grains such that a near random grain orientation distribution is sampled. The crystals shall provide intense diffraction at all angles of tilt, ψ, which will be employed (see Note 1).  
Note 1: Complete freedom from preferred orientation in the stress free specimen is, however, not critical in the application of the technique.
SCOPE
1.1 This test method covers the procedure for preparation and usage of a stress-free test specimen for the purpose of verifying the systematic error caused by instrument misalignment and/or sample positioning during X-ray diffraction residual stress measurement.  
1.2 This test method is applicable to all X-ray diffraction instruments that measure diffracted X-rays from the crystal structure of a polycrystalline specimen and is applicable to single, double, and multiple exposure techniques. Through measurement of a high-angle back-reflection, these techniques are used to derive the interatomic spacing (d-spacing) and the macroscopic strain and to 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  
1.3 This test method describes the use of iron powder for fabrication of the stress-free test specimen that is used to verify the systematic error for residual stress measurement of ferritic or martensitic steels. This test method is easily adapted to other alloys and ceramics through use of powder having a similar diffraction angle as the material to be measured.  
1.4 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.  
1.5 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 test method provides a means of verifying instrument alignment in order to quantify and minimize systematic experimental error in X-ray diffraction residual stress measurement. This method is suitable for application to conventional diffractometers or to X-ray diffraction instrumentation of either the diverging or parallel beam types.3, 4  
4.2 Application of this test method requires the use of a flat specimen of stress-free material that produces diffraction in the angular region of the diffraction peak to be used for stress measurement. The specimen must be sufficiently fine-grained and isotropic so that large numbers of individual crystals contribute to the diffraction peak produced. The crystals must provide intense diffraction at all angles of tilt, ψ, which will be employed (see Note 1).  
Note 1: Complete freedom from preferred orientation in the stressfree specimen is, however, not critical in the application of the technique.
SCOPE
1.1 This test method covers the preparation and use of a flat stress-free test specimen for the purpose of checking the systematic error caused by instrument misalignment or sample positioning in X-ray diffraction residual stress measurement, or both.  
1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in polycrystalline samples employing measurement of a diffraction peak position in the high-back reflection region, and in which the θ, 2θ, and ψ rotation axes can be made to coincide (see Fig. 1).  
1.3 This test method describes the use of iron powder which has been investigated in round-robin studies for the purpose of verifying the alignment of instrumentation intended for stress measurement in ferritic or martensitic steels. To verify instrument alignment prior to stress measurement in other metallic alloys and ceramics, powder having the same or lower diffraction angle as the material to be measured should be prepared in similar fashion and used to check instrument alignment.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

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.
SCOPE
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 S2hkl and S1 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 are mathematical conversions to inch-pound units that 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 Residual stresses in tubing may be detrimental to the future performance of the tubing. Such stresses may, for example, influence the susceptibility of a tube to stress corrosion cracking when the tube is exposed to certain environments.  
4.2 Residual stresses in new thin-walled tubing are very sensitive to the parameters of the fabrication process, and small variations in these parameters can produce significant changes in the residual stresses. See, for example, Table 1, which shows the residual stresses measured by this practice in samples from successive heats of a ferritic Cr-Mo-Ni stainless steel tube and a titanium condenser tube. This practice provides a means for estimating the residual stresses in samples from each and every heat.
4.2.1 This practice may also be used to estimate the residual stresses that remain in tubes after removal from service in different environments and operating conditions.  
4.3 This practice assumes a linear stress distribution through the wall thickness. This assumption is usually reasonable for thin-walled tubes, that is, for tubes in which the wall thickness does not exceed one tenth of the outside diameter. Even in cases where the assumption is not strictly justified, experience has shown that the approximate stresses estimated by this practice frequently serve as useful indicators of the susceptibility to stress corrosion cracking of the tubing of certain metal alloys when exposed to specific environments.  
4.3.1 Because of this questionable assumption regarding the stress distribution in the tubing, the user is cautioned against using the results of this practice for design, manufacturing control, localized surface residual stress evaluation, or other purposes without supplementary information that supports the application.  
4.4 This practice has primarily been used to estimate residual fabrication stresses in new thin-walled tubing between 19-mm (0.75-in.) and 25-mm (1-in.) outside diameter and 1.3-mm (0.05-in...
SCOPE
1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of thin-walled tubing. This practice assumes a linear stress distribution through the tube wall thickness and will not provide an estimate of local stress distributions such as surface stresses. (Very high local residual stress gradients are common at the surface of metal tubing due to cold drawing, peening, grinding, etc.) The Hatfield and Thirkell formula, as later modified by Sachs and Espey,2 provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing.  
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The techniques described provide for the indirect measurement of change in length of a fastener. Such measurements are made from one end of the specimen without requiring access to the rear surface.  
5.2 The equipment is field portable and should be used in the manner prescribed by the manufacturer. Common uses include monitoring changes in length of fasteners and as a tool for industrial quality control. Current applications include fasteners used in turbines, petrochemical pressure vessels, aircraft, automotive manufacturing, general bolting within the nuclear industry, structural steel connections, laboratory testing, and so forth.
SCOPE
1.1 This practice covers a procedure for measuring changes in length of threaded fasteners using conventional ultrasonic pulse-echo bolt-measuring instrumentation which has been properly calibrated.  
1.2 This procedure is normally intended for metal bolting 6.3 mm or more in nominal diameter with effective length-to-diameter ratios of 2:1 or greater.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Summary:
5.1.1 Residual stresses are present in almost all materials. They may be created during the manufacture or during the life of the material. If not recognized and accounted for in the design process, residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination :
1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces.  
1.2 Stress Measurement Range:  
1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the residual stresses within the boundaries of the drilled hole.  
1.2.2 This test method applies in cases where material behavior is linear-elastic. In theory, it is possible for local yielding to occur due to the stress concentration around the drilled hole. Satisfactory measurement results can be achieved providing the residual stresses do not exceed about 80 % of the material yield stress for hole drilling in a “thick” material and about 50% of the material yield stress in a “thin” material.  
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Summary:
5.1.1 Residual stresses are present in almost all materials. They may be created during the manufacture or during the life of the material. If not recognized and accounted for in the design process, residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination :
1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces.  
1.2 Stress Measurement Range:  
1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the residual stresses within the boundaries of the drilled hole.  
1.2.2 This test method applies in cases where material behavior is linear-elastic. In theory, it is possible for local yielding to occur due to the stress concentration around the drilled hole. Satisfactory measurement results can be achieved providing the residual stresses do not exceed about 80 % of the material yield stress for hole drilling in a “thick” material and about 50% of the material yield stress in a “thin” material.  
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method covers a procedure for experimentally determining macroscopic residual stress tensor components of quasi-isotropic bearing steel materials by XRD. Here the stress components are represented by the tensor σij as shown in Eq 1 (1, p. 40). The stress strain relationship in any direction of a component is defined by Eq 2 with respect to the azimuth phi(ϕ) and polar angle psi(ψ) defined in Fig. 1 (1, p. 132).
Alternatively, Eq 2 may also be shown in the following arrangement (2, p. 126):
Using XRD and Bragg’s law, interplanar strain measurements are performed for multiple orientations. The orientations are selected based on a modified version of Eq 2, which is dictated by the mode used. Conflicting nomenclature may be found in literature with regard to mode names. For example, what may be referred to as a ψ (psi) diffractometer in Europe may be called a χ (chi) diffractometer in North America. The three modes considered here will be referred to as omega, chi, and modified-chi as described in 9.5.
Omega Mode (Iso Inclination) and Chi Mode (Side Inclination)—Interplanar strain measurements are performed at multiple ψ angles along one ϕ azimuth (let ϕ = 0°) (Figs. 2 and 3), reducing Eq 2 to Eq 3. Stress normal to the surface (σ33) is assumed to be insignificant because of the shallow depth of penetration of X-rays at the free surface, reducing Eq 3 to Eq 4. Post-measurement corrections may be applied to account for possible σ33 influences (12.12). Since the σij values will remain constant for a given azimuth, the s1{hkl} term is renamed C.
The measured interplanar spacing values are converted to strain using Eq 24, Eq 25, or Eq 26. Eq 4 is used to fit the strain versus sin2ψ data yielding the values σ11, τ13, and C. The measurement can then be repeated for multiple phi angles (for example 0, 45, and 90°) to determine the full stress/strain tensor. The value, σ11, will influence the overall slope of the data, while τ13 is related ...
SCOPE
1.1 This test method covers a procedure for experimentally determining macroscopic residual stress tensor components of quasi-isotropic bearing steel materials by X-ray diffraction (XRD).
1.2 This test method provides a guide for experimentally determining stress values, which play a significant role in bearing life.
1.3 Examples of how tensor values are used are:
1.3.1 Detection of grinding type and abusive grinding;
1.3.2 Determination of tool wear in turning operations;
1.3.3 Monitoring of carburizing and nitriding residual stress effects;
1.3.4 Monitoring effects of surface treatments such as sand blasting, shot peening, and honing;
1.3.5 Tracking of component life and rolling contact fatigue effects;
1.3.6 Failure analysis;
1.3.7 Relaxation of residual stress; and
1.3.8 Other residual-stress-related issues that potentially affect bearings.
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method provides a means of verifying instrument alignment in order to quantify and minimize systematic experimental error in X-ray diffraction residual stress measurement. This method is suitable for application to conventional diffractometers or to X-ray diffraction instrumentation of either the diverging or parallel beam types. ,  
Application of this test method requires the use of a flat specimen of stress-free material that produces diffraction in the angular region of the diffraction peak to be used for stress measurement. The specimen must be sufficiently fine-grained and isotropic so that large numbers of individual crystals contribute to the diffraction peak produced. The crystals must provide intense diffraction at all angles of tilt, ψ, which will be employed (see Note 1).
Note 1—Complete freedom from preferred orientation in the stressfree specimen is, however, not critical in the application of the technique.
SCOPE
1.1 This test method covers the preparation and use of a flat stress-free test specimen for the purpose of checking the systematic error caused by instrument misalignment or sample positioning in X-ray diffraction residual stress measurement, or both.
1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in polycrystalline samples employing measurement of a diffraction peak position in the high-back reflection region, and in which the θ, 2θ, and ψ rotation axes can be made to coincide (see Fig. 1).
1.3 This test method describes the use of iron powder which has been investigated in round-robin studies for the purpose of verifying the alignment of instrumentation intended for stress measurement in ferritic or martensitic steels. To verify instrument alignment prior to stress measurement in other metallic alloys and ceramics, powder having the same or lower diffraction angle as the material to be measured should be prepared in similar fashion and used to check instrument alignment.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Summary:
5.1.1 Residual stresses are present in almost all materials. They may be created during the manufacture or during the life of the material. If not recognized and accounted for in the design process, residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination :
1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces.  
1.2 Stress Measurement Range:  
1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the residual stresses within the boundaries of the drilled hole.  
1.2.2 This test method applies in cases where material behavior is linear-elastic. In theory, it is possible for local yielding to occur due to the stress concentration around the drilled hole, for isotropic (equi-biaxial) residual stresses exceeding 50 % of the yield stress, or for shear stresses in any direction exceeding 25 % of the yield stress. However, in practice it is found that satisfactory results can be achieved providing the residual stresses do not exceed about 60 % of the material yield stress.  
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method provides standard procedures for experimentally determining the effective elastic parameter for X-ray diffraction measurement of residual and applied stresses. It also provides a standard means of reporting the precision of the parameter.
This test method is applicable to any crystalline material which exhibits a linear relationship between stress and strain in the elastic range.
This test method should be used whenever residual stresses are to be evaluated by an X-ray diffraction technique and the effective elastic parameter of the material is unknown.
SCOPE
1.1 This test method covers a procedure for experimentally determining the effective elastic parameter, Eeff, for the evaluation of residual and applied stresses by X-ray diffraction techniques. The effective elastic parameter relates macroscopic stress to the strain measured in a particular crystallographic direction in polycrystalline samples.  Eeff   should not be confused with  E, the modulus of elasticity. Rather, it is nominally equivalent to  E/(1 + ν) for the particular crystallographic direction, where ν is Poisson's ratio. The effective elastic parameter is influenced by elastic anisotropy and preferred orientation of the sample material.  
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 inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Summary:
Residual stresses are present in almost all materials. They may be created during the manufacture or during the life of the material. If not recognized and accounted for in the design process, residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination:
1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces.
1.2 Stress Measurement Range:  
1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the residual stresses within the boundaries of the drilled hole.
1.2.2 This test method applies in cases where material behavior is linear-elastic. In theory, it is possible for local yielding to occur due to the stress concentration around the drilled hole, for isotropic (equi-biaxial) residual stresses exceeding 50 % of the yield stress, or for shear stresses in any direction exceeding 25 % of the yield stress. However, in practice it is found that satisfactory results can be achieved providing the residual stresses do not exceed about 60 % of the material yield stress.
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Summary:
Residual stresses are present in almost all materials. They may be created during the manufacture or during the life of the material. If not recognized and accounted for in the design process, residual stresses can be a major factor in the failure of a material, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial, for example, the compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses.
SCOPE
1.1 Residual Stress Determination:
1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces.
1.2 Stress Measurement Range:  
1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the residual stresses within the boundaries of the drilled hole.
1.2.2 This test method applies in cases where material behavior is linear-elastic. In theory, it is possible for local yielding to occur due to the stress concentration around the drilled hole, for isotropic (equi-biaxial) residual stresses exceeding 50 % of the yield stress, or for shear stresses in any direction exceeding 25 % of the yield stress. However, in practice it is found that satisfactory results can be achieved providing the residual stresses do not exceed about 60 % of the material yield stress.
1.3 Workpiece Damage:  
1.3.1 The hole-drilling method is often described as “semi-destructive” because the damage that it causes is localized and often does not significantly affect the usefulness of the workpiece. In contrast, most other mechanical methods for measuring residual stresses substantially destroy the workpiece. Since hole drilling does cause some damage, this test method should be applied only in those cases either where the workpiece is expendable, or where the introduction of a small shallow hole will not significantly affect the usefulness of the workpiece.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of the tubing. This practice assumes a linear stress distribution through the tube wall thickness and will not provide an estimate of local stress distributions such as surface stresses. (Very high local residual stress gradients are common at the surface of metal tubing due to cold drawing, peening, grinding, etc.) The Hatfield and Thirkell formula, as later modified by Sachs and Espey, provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The techniques described provide for the indirect measurement of change in length of a fastener. Such measurements are made from one end of the specimen without requiring access to the rear surface.
The equipment is field portable and should be used in the manner prescribed by the manufacturer. Common uses include monitoring changes in length of fasteners and as a tool for industrial quality control. Current applications include fasteners used in turbines, petrochemical pressure vessels, aircraft, automotive manufacturing, general bolting within the nuclear industry, structural steel connections, laboratory testing, and so forth.
SCOPE
1.1 This practice covers a procedure for measuring changes in length of threaded fasteners using conventional ultrasonic pulse-echo bolt-measuring instrumentation which has been properly calibrated.
1.2 This procedure is normally intended for metal bolting 0.25 in. (6.4 mm) or more in nominal diameter with effective length-to-diameter ratios of 2:1 or greater.
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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method provides standard procedures for experimentally determining the effective elastic parameter for X-ray diffraction measurement of residual and applied stresses. It also provides a standard means of reporting the precision of the parameter.
This test method is applicable to any crystalline material which exhibits a linear relationship between stress and strain in the elastic range.
This test method should be used whenever residual stresses are to be evaluated by an X-ray diffraction technique and the effective elastic parameter of the material is unknown.
SCOPE
1.1 This test method covers a procedure for experimentally determining the effective elastic parameter, Eeff, for the evaluation of residual and applied stresses by X-ray diffraction techniques. The effective elastic parameter relates macroscopic stress to the strain measured in a particular crystallographic direction in polycrystalline samples.  Eeff should not be confused with E, the modulus of elasticity. Rather, it is nominally equivalent to E/(1 + ν) for the particular crystallographic direction, where ν is Poisson's ratio. The effective elastic parameter is influenced by elastic anisotropy and preferred orientation of the sample material.
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 inch pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Residual stresses are present in almost all structures. They may be present as a result of manufacturing processes or they may occur during the life of the structure. In many cases residual stresses are a major factor in the failure of a structure, particularly one subjected to alternating service loads or corrosive environments. Residual stress may also be beneficial as, for example, compressive stresses produced by shot peening. The hole-drilling strain-gage technique is a practical method for determining residual stresses. See Table 1.
SCOPE
1.1 This test method covers the procedure for determining residual stresses near the surface of isotropic linearly-elastic materials. Although the concept is quite general, the test method described here is applicable in those cases where the stresses do not vary significantly with depth and do not exceed one half of the yield strength. The test method is often described as "semi-destructive" because the damage that it causes is very localized and in many cases does not significantly affect the usefulness of the specimen. In contrast, most other mechanical methods for measuring residual stress substantially destroy the specimen. Since the test method described here does cause some damage, it should be applied only in those cases either where the specimen is expendable or where the introduction of a small shallow hole will not significantly affect the usefulness of the specimen.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the procedure for determining residual stresses near the surface of isotropic linearly-elastic materials. Although the concept is quite general, the test method described here is applicable in those cases where the stresses do not vary significantly with depth and do not exceed one half of the yield strength. The test method is often described as "semi-destructive" because the damage that it causes is very localized and in many cases does not significantly affect the usefulness of the specimen. In contrast, most other mechanical methods for measuring residual stress substantially destroy the specimen. Since the test method described here does cause some damage, it should be applied only in those cases either where the specimen is expendable or where the introduction of a small shallow hole will not significantly affect the usefulness of the specimen.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the procedure for determining residual stresses near the surface of isotropic linearly-elastic materials. Although the concept is quite general, the test method described here is applicable in those cases where the stresses do not vary significantly with depth and do not exceed one half of the yield strength. The test method is often described as "semi-destructive" because the damage that it causes is very localized and in many cases does not significantly affect the usefulness of the specimen. In contrast, most other mechanical methods for measuring residual stress substantially destroy the specimen. Since the test method described here does cause some damage, it should be applied only in those cases either where the specimen is expendable or where the introduction of a small shallow hole will not significantly affect the usefulness of the specimen.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This practice covers a procedure for measuring changes in length of threaded fasteners using conventional ultrasonic, pulse-echo bolt-measuring instrumentation which has been properly calibrated.  
1.2 This procedure is normally intended for metal bolting 0.25 in. (6.4 mm) or more in nominal diameter with effective length-to-diameter ratios of 2:1 or greater.  
1.3 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 A qualitative estimate of the residual circumferential stress in thin-walled tubing may be calculated from the change in outside diameter that occurs upon splitting a length of the tubing. The Hatfield and Thirkell formula, as later modified by Sachs and Espey, provides a simple method for calculating the approximate circumferential stress from the change in diameter of straight, thin-walled, metal tubing.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This practice provides a means for evaluating both systematic and random errors for ultrasonic speed-of-sound measurement systems which are used for evaluating material characteristics associated with residual stress and which may also be used for nondestructive measurements of the dynamic elastic moduli of materials. Important features and construction details of a reference block crucial to these error evaluations are described. This practice can be used whenever the precision and bias of sound speed values are in question.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers a procedure for experimentally determining the effective elastic parameter, Eeff , for the evaluation of residual and applied stresses by X-ray diffraction techniques. The effective elastic parameter relates macroscopic stress to the strain measured in a particular crystallographic direction in polycrystalline samples. Eeff should not be confused with E, the modulus of elasticity. Rather, it is nominally equivalent to E/(1 + [nu]) for the particular crystallographic direction, where [nu] is Poisson's ratio. The effective elastic parameter is influenced by elastic anisotropy and preferred orientation of the sample material.  
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 inch pound units are to be regarded as the standard. The SI units given in parentheses are for information only.  
1.5 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
This test method provides a means of verifying instrument alignment in order to quantify and minimize systematic experimental error in X-ray diffraction residual stress measurement. This method is suitable for application to conventional diffractometers or to X-ray diffraction instrumentation of either the diverging or parallel beam types.3 , 4  
Application of this test method requires the use of a flat specimen of stress-free material that produces diffraction in the angular region of the diffraction peak to be used for stress measurement. The specimen must be sufficiently fine-grained so that large numbers of individual crystals contribute to the diffraction peak produced. The crystals must provide intense diffraction at all angles of tilt, ψ, which will be employed (see Note 1).
Note 1—Complete freedom from preferred orientation in the stressfree specimen is, however, not critical in the application of the technique.
SCOPE
1.1 This test method covers the preparation and use of a flat stress-free test specimen for the purpose of checking the systematic error caused by instrument misalignment or sample positioning in X-ray diffraction residual stress measurement, or both.
1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in polycrystalline samples employing measurement of a diffraction peak position in the high-back reflection region, and in which the , 2, and rotation axes can be made to coincide (see ).
1.3 This test method describes the use of iron powder which has been investigated in round-robin studies for the purpose of verifying the alignment of instrumentation intended for stress measurement in ferritic or martensitic steels. To verify instrument alignment prior to stress measurement in other alloys, base metal powder having the same crystal structure as the alloy should be prepared in similar fashion and used to check instrument alignment at the appropriate diffraction angle.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This test method covers the preparation and use of a flat stress-free test specimen for the purpose of checking the systematic error caused by instrument misalignment or sample positioning in X-ray diffraction residual stress measurement, or both.  
1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in polycrystalline samples employing measurement of a diffraction peak position in the high-back reflection region, and in which the [theta], 2[theta], and [psi] rotation axes can be made to coincide (see Fig. 1).  
1.3 This test method describes the use of iron powder which has been investigated in round-robin studies for the purpose of verifying the alignment of instrumentation intended for stress measurement in ferritic or martensitic steels. To verify instrument alignment prior to stress measurement in other alloys, base metal powder having the same crystal structure as the alloy should be prepared in similar fashion and used to check instrument alignment at the appropriate diffraction angle.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The use of sound speed values to determine changes in the elastic constants due to applied or residual stress requires that such measurements be of high precision and low bias. For that reason, special evaluation tests to determine a representative precision and bias for the specific technique, method, and equipment setup used are given.
Speed of sound is a measure that depends on the accurate measurements of length of path of travel and transit time or other related parameters such as frequency, etc. Both measurements are subject to certain interpretations and assumptions and are highly dependent on laboratory expertise. This practice provides a means of checking overall technique.
This practice shall be used when it is necessary to assess the systematic and random errors associated with a particular speed of sound measurement in a solid medium. It can be used to check both equipment performance and measurement technique for these errors. It can also be used to study inherent errors in a particular method. It can also be used to assess proposed corrections to sound speed measurements such as the phase corrections of Papadakis (3, 4).
The resultant precision and bias determined by the use of the described block represents a more ideal situation than the same measurement performed in practice, in the field. Thus, the error for the specific field measurement may be larger than indicated by this test. This test represents the best error condition for a given technique and practice.
SCOPE
1.1 This practice provides a means for evaluating both systematic and random errors for ultrasonic speed-of-sound measurement systems which are used for evaluating material characteristics associated with residual stress and which may also be used for nondestructive measurements of the dynamic elastic moduli of materials. Important features and construction details of a reference block crucial to these error evaluations are described. This practice can be used whenever the precision and bias of sound speed values are in question.
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This practice provides a means for evaluating both systematic and random errors for ultrasonic speed-of-sound measurement systems which are used for evaluating material characteristics associated with residual stress and which may also be used for nondestructive measurements of the dynamic elastic moduli of materials. Important features and construction details of a reference block crucial to these error evaluations are described. This practice can be used whenever the precision and bias of sound speed values are in question.  
Formerly under the jurisdiction of Committee E28 on Mechanical Testing, this practice was withdrawn in April 2012 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees , which requires that standards shall be updated by the end of the eighth year since the last approval date.