ASTM G168-17
(Practice)Standard Practice for Making and Using Precracked Double Beam Stress Corrosion Specimens
Standard Practice for Making and Using Precracked Double Beam Stress Corrosion Specimens
SIGNIFICANCE AND USE
5.1 Precracked specimens offer the opportunity to use the principles of linear elastic fracture mechanics (1)4 to evaluate resistance to stress corrosion cracking in the presence of a pre-existing crack. This type of evaluation is not included in conventional bent beam, C-ring, U-bend, and tension specimens. The precracked double beam specimen is particularly useful for evaluation of materials that display a strong dependence on grain orientation. Since the specimen dimension in the direction of applied stress is small for the precracked double beam specimen, it can be successfully used to evaluate short transverse stress corrosion cracking of wrought products, such as rolled plate or extrusions. The research applications and analysis of precracked specimens in general, and the precracked double beam specimen in particular, are discussed in Appendix X1.
5.2 The precracked double beam specimen may be stressed in either constant displacement or constant load. Constant displacement specimens stressed by loading bolts or wedges are compact and self-contained. By comparison, constant load specimens stressed with springs (for example, proof rings, discussed in Test Method G49, 7.2.1.2) or by deadweight loading require additional fixtures that remain with the specimen during exposure.
5.3 The recommendations of this practice are based on the results of interlaboratory programs to evaluate precracked specimen test procedures (2, 3) as well as considerable industrial experience with the precracked double beam specimen and other precracked specimen geometries (4-8).
SCOPE
1.1 This practice covers procedures for fabricating, preparing, and using precracked double beam stress corrosion test specimens. This specimen configuration was formerly designated the double cantilever beam (DCB) specimen. Guidelines are given for methods of exposure and inspection.
1.2 The precracked double beam specimen, as described in this practice, is applicable for evaluation of a wide variety of metals exposed to corrosive environments. It is particularly suited to evaluation of products having a highly directional grain structure, such as rolled plate, forgings, and extrusions, when stressed in the short transverse direction.
1.3 The precracked double beam specimen may be stressed in constant displacement by bolt or wedge loading or in constant load by use of proof rings or dead weight loading. The precracked double beam specimen is amenable to exposure to aqueous or other liquid solutions by specimen immersion or by periodic dropwise addition of solution to the crack tip, or exposure to the atmosphere.
1.4 This practice is concerned only with precracked double beam specimen and not with the detailed environmental aspects of stress corrosion testing, which are covered in Practices G35, G36, G37, G41, G44, and G50.
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.
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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.
Designation: G168 − 17
Standard Practice for
Making and Using Precracked Double Beam Stress
1
Corrosion Specimens
This standard is issued under the fixed designation G168; 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* 2. Referenced Documents
2
1.1 This practice covers procedures for fabricating, 2.1 ASTM Standards:
preparing, and using precracked double beam stress corrosion D1193 Specification for Reagent Water
test specimens. This specimen configuration was formerly E8/E8M Test Methods for Tension Testing of Metallic Ma-
designated the double cantilever beam (DCB) specimen. terials
Guidelines are given for methods of exposure and inspection. E399 Test Method for Linear-Elastic Plane-Strain Fracture
Toughness K of Metallic Materials
Ic
1.2 The precracked double beam specimen, as described in
E1823 TerminologyRelatingtoFatigueandFractureTesting
this practice, is applicable for evaluation of a wide variety of
G15 Terminology Relating to Corrosion and Corrosion Test-
metals exposed to corrosive environments. It is particularly
3
ing (Withdrawn 2010)
suited to evaluation of products having a highly directional
G35 Practice for Determining the Susceptibility of Stainless
grain structure, such as rolled plate, forgings, and extrusions,
Steels and Related Nickel-Chromium-Iron Alloys to
when stressed in the short transverse direction.
Stress-Corrosion Cracking in Polythionic Acids
1.3 The precracked double beam specimen may be stressed
G36 Practice for Evaluating Stress-Corrosion-Cracking Re-
in constant displacement by bolt or wedge loading or in
sistance of Metals and Alloys in a Boiling Magnesium
constantloadbyuseofproofringsordeadweightloading.The
Chloride Solution
precracked double beam specimen is amenable to exposure to
G37 Practice for Use of Mattsson’s Solution of pH 7.2 to
aqueous or other liquid solutions by specimen immersion or by
Evaluate the Stress-Corrosion Cracking Susceptibility of
periodic dropwise addition of solution to the crack tip, or
Copper-Zinc Alloys
exposure to the atmosphere.
G41 Practice for Determining Cracking Susceptibility of
Metals Exposed Under Stress to a Hot Salt Environment
1.4 This practice is concerned only with precracked double
beam specimen and not with the detailed environmental G44 PracticeforExposureofMetalsandAlloysbyAlternate
Immersion in Neutral 3.5 % Sodium Chloride Solution
aspects of stress corrosion testing, which are covered in
Practices G35, G36, G37, G41, G44, and G50. G49 Practice for Preparation and Use of Direct Tension
Stress-Corrosion Test Specimens
1.5 This standard does not purport to address all of the
G50 Practice for Conducting Atmospheric Corrosion Tests
safety concerns, if any, associated with its use. It is the
on Metals
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
3. Terminology
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
3.1 Definitions of Terms Specific to This Standard:
dance with internationally recognized principles on standard- 3.1.1 stress corrosion cracking (SCC) threshold stress
ization established in the Decision on Principles for the
intensity, K —the stress intensity level below which stress
Iscc
Development of International Standards, Guides and Recom- corrosioncrackingdoesnotoccurforaspecificcombinationof
mendations issued by the World Trade Organization Technical
material and environment when plane strain conditions are
Barriers to Trade (TBT) Committee. satisfied.
1 2
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion For referenced ASTM standards, visit the ASTM website, www.astm.org, or
of Metals and is the direct responsibility of Subcommittee G01.06 on Environmen- contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
tally Assisted Cracking. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2017. Published December 2017. Originally the ASTM website.
3
approved in 2000. Last previous edition approved in 2013 as G168 – 00 (2013). The last approved version of this historical standard is referenced on
DOI: 10.1520/G0168-17. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
...
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: G168 − 00 (Reapproved 2013) G168 − 17
Standard Practice for
Making and Using Precracked Double Beam Stress
1
Corrosion Specimens
This standard is issued under the fixed designation G168; 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 Scope*
1.1 This practice covers procedures for fabricating, preparing, and using precracked double beam stress corrosion test
specimens. This specimen configuration was formerly designated the double cantilever beam (DCB) specimen. Guidelines are
given for methods of exposure and inspection.
1.2 The precracked double beam specimen, as described in this practice, is applicable for evaluation of a wide variety of metals
exposed to corrosive environments. It is particularly suited to evaluation of products having a highly directional grain structure,
such as rolled plate, forgings, and extrusions, when stressed in the short transverse direction.
1.3 The precracked double beam specimen may be stressed in constant displacement by bolt or wedge loading or in constant
load by use of proof rings or dead weight loading. The precracked double beam specimen is amenable to exposure to aqueous or
other liquid solutions by specimen immersion or by periodic dropwise addition of solution to the crack tip, or exposure to the
atmosphere.
1.4 This practice is concerned only with precracked double beam specimen and not with the detailed environmental aspects of
stress corrosion testing, which are covered in Practices G35, G36, G37, G41, G44, and G50.
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1193 Specification for Reagent Water
E8/E8M Test Methods for Tension Testing of Metallic Materials
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K of Metallic Materials
Ic
E1823 Terminology Relating to Fatigue and Fracture Testing
3
G15 Terminology Relating to Corrosion and Corrosion Testing (Withdrawn 2010)
G35 Practice for Determining the Susceptibility of Stainless Steels and Related Nickel-Chromium-Iron Alloys to Stress-
Corrosion Cracking in Polythionic Acids
G36 Practice for Evaluating Stress-Corrosion-Cracking Resistance of Metals and Alloys in a Boiling Magnesium Chloride
Solution
G37 Practice for Use of Mattsson’s Solution of pH 7.2 to Evaluate the Stress-Corrosion Cracking Susceptibility of Copper-Zinc
Alloys
G41 Practice for Determining Cracking Susceptibility of Metals Exposed Under Stress to a Hot Salt Environment
G44 Practice for Exposure of Metals and Alloys by Alternate Immersion in Neutral 3.5 % Sodium Chloride Solution
1
This practice is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subcommittee G01.06 on Environmentally
Assisted Cracking.
Current edition approved May 1, 2013Nov. 1, 2017. Published July 2013December 2017. Originally approved in 2000. Last previous edition approved in 20062013 as
G168 – 00 (2006).(2013). DOI: 10.1520/G0168-00R13.10.1520/G0168-17.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
G168 − 17
G49 Practice for Preparation and Use of Direct Tension Stress-Corrosion Test Specimens
G50 Practice for Conducting Atmospheric Corrosion Tests on M
...
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