ASTM F1624-06
(Test Method)Standard Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique
Standard Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique
SIGNIFICANCE AND USE
This test method is used for research, design, service evaluation, manufacturing control, and development. This test method quantitatively measures stress parameters that are used in a design or failure analysis that takes into account the effects of environmental exposure including that which occurs during processing, such as plating (8) (ASTM STP 962).
For plating processes, the value of σth-IHE is used to specify quantitatively the maximum operating stress for a given structure or product.
For quality control purposes, an accelerated test is devised that uses a specified loading rate, which is equal to or lower than the loading rate necessary to determine the threshold stress (see 8.1).
For fasteners, the value of σth-IHE is used to specify quantitatively the maximum stress during installation and in service to avoid premature failure caused by residual hydrogen in the steel as a result of processing.
For fasteners, the value of σth-EHE is used to specify quantitatively the maximum stress during installation and in service to avoid failure from hydrogen absorbed during exposure to a specific environment.
To measure the relative susceptibility of steels to hydrogen pickup from various fabrication processes, a single, selected, discriminating rate is used to rank the resistance of various materials to hydrogen embrittlement.
SCOPE
1.1 This test method establishes a procedure to measure the susceptibility of steel to a time-delayed failure such as that caused by hydrogen. It does so by measuring the threshold for the onset of subcritical crack growth using standard fracture mechanics specimens, irregular-shaped specimens such as notched round bars, or actual product such as fasteners () (threaded or unthreaded) springs or components as identified in SAE J78, J81, and J1237.
1.2 This test method is used to evaluate quantitatively:
1.2.1 The relative susceptibility of steels of different composition or a steel with different heat treatments;
1.2.2 The effect of residual hydrogen in the steel as a result of processing, such as melting, thermal mechanical working, surface treatments, coatings, and electroplating;
1.2.3 The effect of hydrogen introduced into the steel caused by external environmental sources of hydrogen, such as fluids and cleaners maintenance chemicals, petrochemical products, and galvanic coupling in an aqueous environment.
1.3 The test is performed either in air, to measure the effect if residual hydrogen is in the steel because of the processing (IHE), or in a controlled environment, to measure the effect of hydrogen introduced into the steel as a result of the external sources of hydrogen (EHE) as detailed in ASTM STP 543.
1.4 The values stated in acceptable inch-pound units shall be regarded as the standard. The values stated in metric units may not be exact equivalents. Conversion of the inch-pound units by appropriate conversion factors is required to obtain exact equivalence.
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.
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Designation: F1624 – 06
Standard Test Method for
Measurement of Hydrogen Embrittlement Threshold in Steel
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by the Incremental Step Loading Technique
This standard is issued under the fixed designation F1624; 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.
INTRODUCTION
Hydrogen embrittlement is caused by the introduction of hydrogen into steel that can initiate
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fracture as a result of residual stress or in service when external stress is applied (1). The hydrogen
can be generated during cleaning or plating processes or the exposure of cathodically protected steel
parts to a service environment including fluids, cleaning treatments, or maintenance chemicals that
maycontactthesurfaceofsteelcomponents.Thismethodcanbeusedtorapidlydeterminetheeffects
ofresidualhydrogeninapartcausedbyprocessingorquantifytherelativesusceptibilityofamaterial
under a fixed set of hydrogen-charging conditions.
The combined residual and applied stress above which time-delayed fracture will occur (finite life)
orbelowwhichfracturewillneveroccur(infinitelife)iscalledthethresholdstressorthresholdstress
intensity (K) for precracked specimens. Historically, sustained load time-to-failure tests have been
conductedonnotchedbarstodeterminethethresholdstressfortheonsetofhydrogenstresscracking.
This technique may require 12 to 14 specimens and several high-load capacity machines. For
precrackedspecimens,therun-outtimecanbeaslongasfourtofiveyearsperU.S.Navyrequirements
for low-strength steels at 33 to 35 HRC. In Test Method E1681, more than 10000 h (> one year) are
specified for low-strength steel (< 175 ksi) and 5000 h for high-strength steel (> 175 ksi).
This standard provides an accelerated method to measure the threshold stress or threshold stress
intensityasdefinedinTestMethodE1681fortheonsetofhydrogenstresscrackinginsteelwithinone
week on only one machine.
1. Scope 1.2.2 The effect of residual hydrogen in the steel as a result
of processing, such as melting, thermal mechanical working,
1.1 This test method establishes a procedure to measure the
surface treatments, coatings, and electroplating;
susceptibility of steel to a time-delayed failure such as that
1.2.3 Theeffectofhydrogenintroducedintothesteelcaused
caused by hydrogen. It does so by measuring the threshold for
by external environmental sources of hydrogen, such as fluids
the onset of subcritical crack growth using standard fracture
and cleaners maintenance chemicals, petrochemical products,
mechanics specimens, irregular-shaped specimens such as
and galvanic coupling in an aqueous environment.
notched round bars, or actual product such as fasteners (2)
1.3 The test is performed either in air, to measure the effect
(threadedorunthreaded)springsorcomponentsasidentifiedin
if residual hydrogen is in the steel because of the processing
SAE J78, J81, and J1237.
(IHE), or in a controlled environment, to measure the effect of
1.2 This test method is used to evaluate quantitatively:
hydrogen introduced into the steel as a result of the external
1.2.1 The relative susceptibility of steels of different com-
sources of hydrogen (EHE) as detailed in ASTM STP 543.
position or a steel with different heat treatments;
1.4 The values stated in acceptable inch-pound units shall
be regarded as the standard. The values stated in metric units
may not be exact equivalents. Conversion of the inch-pound
units by appropriate conversion factors is required to obtain
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This test method is under the jurisdiction of ASTM Committee F07 on
exact equivalence.
Aerospace andAircraft and is the direct responsibility of Subcommittee F07.04 on
1.5 This standard does not purport to address all of the
Hydrogen Embrittlement.
Current edition approved April 1, 2006. Published May 2006. Originally
safety concerns, if any, associated with its use. It is the
approved in 1995. Last previous edition approved in 2000 as F1624–00. DOI:
responsibility of the user of this standard to establish appro-
10.1520/F1624-06.
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priate safety and health practices and determine the applica-
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
this standard. bility of regulatory limitations prior to use.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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F1624 – 06
2. Referenced Documents 3. Terminology
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2.1 ASTM Standards: 3.1 Symbols—Termsnotdefinedinthissectioncanbefound
B602 Test Method for Attribute Sampling of Metallic and in Terminologies F2078 and E6 and shall be considered as
Inorganic Coatings
...
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