ASTM E915-19

Standard Test Method for Verifying the Alignment of X-Ray Diffraction Instrumentation for Residual Stress Measurement

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.

General Information

• Status: Historical
• Publication Date: 14-Oct-2019
• ICS: 19.100 - Non-destructive testing
• Technical Committee: E28 - Mechanical Testing
• Drafting Committee: E28.13 - Residual Stress Measurement

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E915 −19
Standard Test Method for
Verifying the Alignment of X-Ray Diffraction Instrumentation
1
for Residual Stress Measurement
This standard is issued under the fixed designation E915; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the procedure for preparation
E6Terminology Relating to Methods of MechanicalTesting
and usage of a stress-free test specimen for the purpose of
verifying the systematic error caused by instrument misalign-
3. Terminology
ment and/or sample positioning during X-ray diffraction re-
3.1 The definitions of mechanical testing terms that appear
sidual stress measurement.
in Terminology E6 apply to this test method.
1.2 This test method is applicable to all X-ray diffraction
3.1.1 In addition, the following common term from Termi-
instruments that measure diffracted X-rays from the crystal
nology E6 is defined:
-2
3.1.2 residual stress [FL ], n—stressinabodythatisatrest
structure of a polycrystalline specimen and is applicable to
and in equilibrium and at uniform temperature in the absence
single, double, and multiple exposure techniques. Through
of external and mass forces.
measurement of a high-angle back-reflection, these techniques
are used to derive the interatomic spacing (d-spacing) and the
4. Significance and Use
macroscopic strain and to then calculate residual stress in
4.1 This test method provides a means of verifying the
which the θ,2θ, and ψ rotation axes can be made to coincide
alignment of an X-ray diffraction instrument in order to
(see Fig. 1).
quantify and minimize systematic experimental error in re-
1.3 This test method describes the use of iron powder for
sidual stress measurement. This method is suitable for appli-
fabricationofthestress-freetestspecimenthatisusedtoverify
cation to conventional diffractometers or to X-ray diffraction
the systematic error for residual stress measurement of ferritic
instrumentation designed for residual stress measurement of
3,4
ormartensiticsteels.Thistestmethodiseasilyadaptedtoother
either the diverging or parallel beam types.
alloys and ceramics through use of powder having a similar
4.2 Application of this test method requires the use of a flat
diffraction angle as the material to be measured.
stress-free specimen that diffracts X-rays within the angular
range of the diffraction peak to be used for residual stress
1.4 This standard does not purport to address all of the
measurement. The specimen shall be sufficiently fine-grained,
safety concerns, if any, associated with its use. It is the
homogeneous, isotropic, and of sufficient depth such that
responsibility of the user of this standard to establish appro-
incident X-rays interact with and diffract from an adequate
priate safety, health, and environmental practices and deter-
number of individual coherent domains and or grains such that
mine the applicability of regulatory limitations prior to use.
a near random grain orientation distribution is sampled. The
1.5 This international standard was developed in accor-
crystals shall provide intense diffraction at all angles of tilt, ψ,
dance with internationally recognized principles on standard-
which will be employed (see Note 1).
ization established in the Decision on Principles for the
NOTE1—Completefreedomfrompreferredorientationinthestressfree
Development of International Standards, Guides and Recom-
specimen is, however, not critical in the application of the technique.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
1
This test method is under the jurisdiction of ASTM Committee E28 on the ASTM website.
3
Mechanical Testing and is the direct responsibility of Subcommittee E28.13 on Ahmad, A., Prevéy, P, Ruud, C.O., , eds., Residual Stress Measurement by
Residual Stress Measurement. X-ray Diffraction,SAEHS-784,SocietyofAutomotiveEngrs.,Inc.,Warrendale,PA
Current edition approved Oct. 15, 2019. Published December 2019. Originally (2003).
4
approved in 1983. Last previous edition approved in 2016 as E915–16. DOI: “Standard Method for X-Ray Stress Measurement,” Committee on Mechanical
10.1520/E0915-19. Behavior of Materials, The Society of Materials Science, Japan, (20 April 1973).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E915 − 16 E915 − 19
Standard Test Method for
Verifying the Alignment of X-Ray Diffraction Instrumentation
1
for Residual Stress Measurement
This standard is issued under the fixed designation E915; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the procedure for preparation and useusage of a flat stress-free test specimen for the purpose of
checkingverifying the systematic error caused by instrument misalignment orand/or sample positioning induring X-ray diffraction
residual stress measurement, or both.measurement.
1.2 This test method is applicable to apparatus intended for X-ray diffraction macroscopic residual stress measurement in
polycrystalline samples employing 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
diffraction peak position in the high-back reflection region, and 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).
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 infor fabrication of the stress-free test specimen that
is used to verify the systematic error for residual stress measurement of ferritic or martensitic steels. To verify instrument alignment
prior to stress measurement in other metallic alloys and ceramics, powder having the same or lower 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 should
be prepared in similar fashion and used to check instrument alignment.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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2
2.1 ASTM Standards:
E6 Terminology Relating to Methods of Mechanical Testing
3. Terminology
3.1 The definitions of mechanical testing terms that appear in Terminology E6 apply to this test method.
3.1.1 In addition, the following common term from Terminology E6 is defined:
-2
3.1.2 residual stress [FL ], n—stress in a body that is at rest and in equilibrium and at uniform temperature in the absence of
external and mass forces.
4. Significance and Use
4.1 This test method provides a means of verifying instrument alignment the alignment of an X-ray diffraction instrument in
order to quantify and minimize systematic experimental error in X-ray diffraction residual stress measurement. This method is
1
This test method is under the jurisdiction of ASTM Committee E28 on Mechanical Testing and is the direct responsibility of Subcommittee E28.13 on Residual Stress
Measurement.
Current edition approved Aug. 1, 2016Oct. 15, 2019. Published August 2016December 2019. Originally approved in 1983. Last previous edition approved in 20102016
as E915 – 10.E915 – 16. DOI: 10.1520/E0915-16.10.1520/E0915-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E915 − 19
FIG. 1 X-Ray Diffraction Residual Stress Measurement Geometry and Angles Defined
suitable for application to conventional di
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