ASTM G142-98(2022)
(Test Method)Standard Test Method for Determination of Susceptibility of Metals to Embrittlement in Hydrogen Containing Environments at High Pressure, High Temperature, or Both
Standard Test Method for Determination of Susceptibility of Metals to Embrittlement in Hydrogen Containing Environments at High Pressure, High Temperature, or Both
SIGNIFICANCE AND USE
5.1 This test method provides a reliable prediction of the resistance or susceptibility, or both, to loss of material strength and ductility as a result of exposure to hydrogen-containing gaseous environments. This test method is applicable over a broad range of pressures, temperatures, and gaseous environments. The results from this test method can be used to evaluate the effects of material composition, processing, and heat treatment as well as the effects of changes in environment composition, temperature, and pressure. These results may or may not correlate with service experience for particular applications. Furthermore, this test method may not be suitable for the evaluation of high temperature hydrogen attack in steels unless suitable exposure time at the test conditions has taken place prior to the initiation of tensile testing to allow for the development of internal blistering, decarburization or cracking, or both.
SCOPE
1.1 This test method covers a procedure for determination of tensile properties of metals in high pressure or high temperature, or both, gaseous hydrogen-containing environments. It includes accommodations for the testing of either smooth or notched specimens.
1.2 This test method applies to all materials and product forms including, but not restricted to, wrought and cast materials.
1.3 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.
1.4 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
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Standards Content (Sample)
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: G142 − 98 (Reapproved 2022)
Standard Test Method for
Determination of Susceptibility of Metals to Embrittlement in
Hydrogen Containing Environments at High Pressure, High
Temperature, or Both
This standard is issued under the fixed designation G142; 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 E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers a procedure for determination
G15 Terminology Relating to Corrosion and Corrosion Test-
of tensile properties of metals in high pressure or high
ing (Withdrawn 2010)
temperature, or both, gaseous hydrogen-containing environ-
G111 Guide for Corrosion Tests in High Temperature or
ments. It includes accommodations for the testing of either
High Pressure Environment, or Both
smooth or notched specimens.
G129 Practice for Slow Strain Rate Testing to Evaluate the
1.2 This test method applies to all materials and product
Susceptibility of Metallic Materials to Environmentally
forms including, but not restricted to, wrought and cast
Assisted Cracking
materials.
2.2 Military Standard:
1.3 The values stated in SI units are to be regarded as MIL-P-27201B Propellant, Hydrogen
standard. The values given in parentheses after SI units are
3. Terminology
provided for information only and are not considered standard.
3.1 Definitions:
1.4 This standard does not purport to address all of the
3.1.1 control test, n—a mechanical test conducted in an
safety concerns, if any, associated with its use. It is the
environment that does not produce embrittlement of a test
responsibility of the user of this standard to establish appro-
material.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.1.2 hydrogen embrittlement, n—hydrogen induced crack-
1.5 This international standard was developed in accor-
ing or severe loss of ductility caused by the presence of
dance with internationally recognized principles on standard-
hydrogen in the metal.
ization established in the Decision on Principles for the
3.1.3 Other definitions and terminology related to testing
Development of International Standards, Guides and Recom-
can be found in Terminology G15.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 Specimens of selected materials are exposed to a gas-
2. Referenced Documents
eoushydrogencontainingenvironmentathighpressureorhigh
2.1 ASTM Standards:
temperature, or both, while being pulled to failure in uniaxial
D1193 Specification for Reagent Water
tension. The susceptibility to hydrogen embrittlement is evalu-
E4 Practices for Force Calibration and Verification of Test-
ated through the determination of standard mechanical prop-
ing Machines
erties in tension (that is, yield strength, ultimate tensile
E8/E8M Test Methods for Tension Testing of Metallic Ma-
strength, notched tensile strength, reduction in area or
terials
elongation, or both). Comparison of these mechanical proper-
ties determined in a hydrogen-containing environment to those
This test method is under the jurisdiction of ASTM Committee G01 on
determined in a non-embrittling environment (control test)
Corrosion of Metals and is the direct responsibility of Subcommittee G01.06 on
providesageneralindexofsusceptibilitytocrackingversusthe
Environmentally Assisted Cracking.
material’s normal mechanical behavior.
Current edition approved Oct. 1, 2022. Published October 2022. Originally
approved in 1996. Last previous edition approved in 2016 as G142 – 98 (2016).
DOI: 10.1520/G0142-98R22.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
the ASTM website. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G142 − 98 (2022)
5. Significance and Use
5.1 This test method provides a reliable prediction of the
resistance or susceptibility, or both, to loss of material strength
and ductility as a result of exposure to hydrogen-containing
gaseous environments. This test method is applicable over a
broad range of pressures, temperatures, and gaseous environ-
ments. The results from this test method can be used to
evaluate the effects of material composition, processing, and
heat treatment as well as the effects of changes in environment
composition, temperature, and pressure. These results may or
may not correlate with service experience for particular appli-
cations. Furthermore, this test method may not be suitable for
the evaluation of high temperature hydrogen attack in steels
unless suitable exposure time at the test conditions has taken
place prior to the initiation of tensile testing to allow for the
developmentofinternalblistering,decarburizationorcracking,
or both.
6. Apparatus
6.1 Since this test method is intended to be conducted at
high pressures and may also involve high temperatures, the
apparatus must be constructed to safely contain the test
environment while being resistant to the embrittling effects of
hydrogen. Secondly, the test apparatus must be capable of
allowing introduction of the test gas, removal of air from the
test cell, and accurate performance of the tension test on the
test specimen. In cases where the tests are conducted at
elevated temperatures, the apparatus must provide for heating
of the specimen and the test environment in direct contact with
the specimen.
6.2 Fig. 1 shows a schematic representation of a typical test
cell designed to conduct HP/HT gaseous hydrogen embrittle-
ment experiments. The typical components include:
6.2.1 Metal Test Cell—The test cell should be constructed
from materials that have proven to have high resistance to
hydrogen embrittlement under the conditions. A list of poten-
tial materials of construction is shown in Fig. 2. Materials
FIG. 1 Hydrogen Tensions Test Autoclave for Various Alloys in
Hydrogen versus Air
with high values of tensile ratios (environment versus a control
environment) should be used. Materials with low values of this
parameter should be avoided.
6.2.4 Electrical Feed-Throughs—If very high temperature
6.2.2 Closure and Seal—To facilitate operation of the test
conditions are required it may be advantageous to utilize an
cell and tension testing, the closure should provide for rapid
internal heater to heat the test specimen and the gaseous
opening and closing of the test cell and reliable sealing
environment in the immediate vicinity of the specimen.
capabilities for hydrogen. This can include either metallic or
Therefore, a feed-through would be needed to reach an internal
nonmetallic materials with high resistance to hydrogen em-
resistance or induction heater. These feed-throughs must also
brittlement and degradation.
provide electrical isolation from the test cell and internal
6.2.3 Gas Port(s)—The gas port should be designed to
fixtures, and maintain a seal to prevent leakage of the test
promote flow and circulation of the gaseous test environments,
environment. If external heaters are used, no electric feed-
inert gas purging and evacuation as required to produce the
throughs would be required for testing.
intended test environment. Usually two ports are used so that
6.2.5 Tensile Feed-Through(s)—To apply tensile loading to
flow-through capabilities are attained to facilitate these func-
the test specimen it is necessary to have feed-through(s) which
tions.
provide linear motion and transmission of loads from an
external source. Care must be taken to design such feed-
throughs to have low friction to minimize errors due to friction
Kane, R. D., “High Temperature and High Pressure,” Corrosion Tests and
losses when using externally applied loads. These are usually
Standards, Baboian, Robert, editor, ASTM, West Conshohocken, PA.
designed to incorporate thermoplastic or elastomeric materials,
Metals Handbook, Vol 9, Corrosion, 9th Edition, ASM International, Metals
Park, OH, 1987, p. 1104. or both. If elevated temperature tests are being conducted, then
G142 − 98 (2022)
FIG. 2 Notched Tensile Strength (NTS) Ratio for Various Alloys in 35 MPa to 69 MPa Gaseous Hydrogen versus Air Tested
at Room Temperature
extreme care must be used in the selection of these materials to vicinity of the test specimen to limit power requirements and
alsoresistdeteriorationandlossofmechanicalpropertiesatthe problems with high temperature sealing and pressure contain-
test temperature. ment.
6.2.6 Pull Rod—The pull rod works in combination with the
6.2.9 Grips—Grips shall provide for efficient and accurate
tensile feed-through to provide for loading of the test speci-
transfer of load from the pull rods to the test specimen. Grips
men. It is usually attached to a tensile testing machine on one
should be designed to minimize compliance in the loading
end and the tension specimen on the other. It should be
system under the anticipated loads to pull the test specimen.
designed to have adequate cross-sectional area to minimize
6.2.10 Loading Fixture—A fixture is used to react the load
complianceintheloadingsystemundertheanticipatedloadsto
used to pull the specimen. An internal fixture is shown
be used. Also, to minimize frictional forces in the seal and
schematically in Fig. 1.
promote sealing, it should be made with a highly polished
6.2.11 Testing Machines—Tension testing machines used
surfaces [<0.25 µm (10 µin.) RMS]. It is possible to obtain pull
forconductingtestsaccordingtothistestmethodshallconform
rod systems that are pressure balanced so specimen loading
to the requirements of Practices E4. The loads used in tests
from the internal pressure in the test cell can be minimized.
shall be within the calibrated load ranges of the testing
6.2.7 Load Cell—Load cells for conducting high pressure
machines in accordance with Practices E4.
tensile tests may be two configurations:
6.2.7.1 External load cells which are attached to the pull rod
7. Reagents
outside of the test cell, and
6.2.7.2 Internal load cells which are either attached to the 7.1 Purity of Reagents—Reagent grade chemicals and ultra
pull rod or grip assembly inside of the autoclave or are low oxygen gases (<1 ppm) shall be used in all tests unless the
integrated into the pull rod.When using external load cells it is test environment is derived from a field or plant environment.
important to correct load cell readings for frictional forces in If the test is to be conducted for aerospace propulsion
the pressure seal. Additionally, if non-pressure balanced pull applications, the environment shall consist of hydrogen gas per
MIL-P-27201B.
rods are used, compensation for pressure loading of the
specimen must be also performed.
7.2 If water is to be added to any test environment, distilled
6.2.8 Electric Resistance or Induction Heater(s)—Either
ordeionizedwaterconformingtoSpecificationD1193TypeIV
internal or external heaters can be used to obtain elevated
shall be used.
temperature. For lower temperatures, and when using test
environments containing reactive constituents in addition to
8. Test Environment
hydrogen, external heating of the test cell is typically more
convenient. At high temperatures, when using non-reactive or 8.1 Test environments can consist of either field or plant
hydrogen gas environments, an internal heater can be used to samples or be prepared in the laboratory from chemicals and
heat only the test specimen and the gaseous environment in the gases as indicated in Section 7.
G142 − 98 (2022)
8.2 When testing in hydrogen containing environments,
susceptibility to hydrogen embrittlement typically increases
with decreasing oxygen content of the test environment.
Therefore, strict procedures for deaeration shall be followed
and periodically qualified for oxygen content as discussed in
Sections 9 and 11.
8.3 For purposes of standardization, suggested standardized
pressuresforhydrogengastestingshallbe7MPa,35MPa,and
69 MPa. However, for materials evaluation for specific
applications,thetestpressureshouldbeequaltoorgreaterthan
that which represents the service conditions.
9. Sampling
9.1 The procedure for sampling mill products is typically
covered in product or other specifications and is outside the
scope of this document.
9.2 Sampling of the test environment is recommended to
confirm that the test environment is in conformance with this
test method and attains the intended test conditions. Such
sampling shall be conducted immediately prior to and after
testing. The frequency of environmental sampling shall be as
required to cover applicable product, purchase or in-house
testingspecifications,orboth.Asaminimumrequirementtobe
in compliance with this test method, however, sampling of the
test environment shall be conducted at the start of testing and
againwhenanyelementofthetestprocedureortestsystemhas
been changed or modified.
FIG. 3 Standard Tension Specimens (a) Smooth and (b) Notched
10. Test Specimens
10.1 Tension specimens shall be used for evaluation of
hydrogen embrittlement.These specimens shall conform to the
11.2 The control materials for tests conducted in a hydrogen
dimensions and guidelines provided in Test Methods E8/E8M.
containing environment shall be as given below:
However, in some cases, the material size, configuration, and
11.2.1 Low Resistance—Low Alloy Steel: UNS G43400
form or the confines of various test cells may limit the actual
(austenitize at 900 °C for 1 h plus water quench and temper at
dimensions of the test specimen. In such cases, the specimen
454 °C for 2 h).
geometry and dimensions shall be fully described.Take care to
11.2.2 Intermediate Resistance—Nickel Base Alloy: UNS
only compare the results obtained from similar specimens.
N07718 (solution annealed at 954 °C for 1 h plus air cool; age
10.2 For purposes of standardizing the evaluation of mate-
at 718 °C
...
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