Significance and Use
5.1 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).
5.2 For plating processes, the value of σ th-IHE is used to specify quantitatively the maximum operating stress for a given structure or product.
5.3 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).
5.4 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.
5.5 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.
5.6 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.
5.7 Annex A1 describes the application of this standard test method to hydrogen embrittlement testing of fasteners.
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 (2) (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 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.
—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.
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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A490 Specification for Structural Bolts, Alloy Steel, Heat Treated, 150 ksi Minimum Tensile Strength
A574 Specification for Alloy Steel Socket-Head Cap Screws
B602 Test Method for Attribute Sampling of Metallic and Inorganic Coatings
E4 Practices for Force Verification of Testing Machines
E6 Terminology Relating to Methods of Mechanical Testing
E8 Test Methods for Tension Testing of Metallic Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E399 Test Method for Linear-Elastic Plane-Strain Fracture Toughness K Ic of Metallic Materials
E812 Test Method for Crack Strength of Slow-Bend Precracked Charpy Specimens of High-Strength Metallic Materials
E1681 Test Method for Determining Threshold Stress Intensity Factor for Environment-Assisted Cracking of Metallic Materials
F519 Test Method for Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service Environments
F606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
F2078 Terminology Relating to Hydrogen Embrittlement Testing
G5 Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements
G129 Practice for Slow Strain Rate Testing to Evaluate the Susceptibility of Metallic Materials to Environmentally Assisted Cracking
J1237 Metric Thread Rolling Screws
B18.18.4M Inspection and Quality Assurance for Fasteners for Highly Specialized Engineering Applications, 1987
decreasing loading rate; delayed brittle failure; displacement control; fasteners; hydrogen embrittlement threshold; hydrogen induced stress cracking; rising step load; slow strain rate;
ICS Number Code 77.040.10 (Mechanical testing of metals)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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