Significance and Use
5.1 Plating/coating Processes—This test method provides a means by which to detect possible hydrogen embrittlement of steel parts during manufacture by verifying strict controls during production operations such as surface preparation, pretreatments, and plating/coating. It is also intended to be used as a qualification test for new plating/coating processes and as a periodic inspection audit for the control of a plating/coating process.
5.2 Service Environment—This test method provides a means by which to detect possible hydrogen embrittlement of steel parts (plated/coated or bare) due to contact with chemicals during manufacturing, overhaul and service life. The details of testing in a service environment are found in Annex A5.
1. Scope
1.1 This test method describes mechanical test methods and defines acceptance criteria for coating and plating processes that can cause hydrogen embrittlement in steels. Subsequent exposure to chemicals encountered in service environments, such as fluids, cleaning treatments or maintenance chemicals that come in contact with the plated/coated or bare surface of the steel, can also be evaluated.
1.2 This test method is not intended to measure the relative susceptibility of different steels. The relative susceptibility of different materials to hydrogen embrittlement may be determined in accordance with Test Method F1459 and Test Method F1624.
1.3 This test method specifies the use of air melted AISI E4340 steel per SAE AMS-S-5000 (formerly MIL-S-5000) heat treated to 260 to 280 ksi (pounds per square inch ×1000) as the baseline. This combination of alloy and heat treat level has been used for many years and a large database has been accumulated in the aerospace industry on its specific response to exposure to a wide variety of maintenance chemicals, or electroplated coatings, or both. Components with ultimate strengths higher than 260 to 280 ksi may not be represented by the baseline. In such cases, the cognizant engineering authority shall determine the need for manufacturing specimens from the specific material and heat treat condition of the component. Deviations from the baseline shall be reported as required by 12.1.2. The sensitivity to hydrogen embrittlement shall be demonstrated for each lot of specimens as specified in 9.5.
1.4 Test procedures and acceptance requirements are specified for seven specimens of different sizes, geometries, and loading configurations.
1.5 Pass/Fail Requirements—For plating/coating processes, specimens must meet or exceed 200 h using a sustained load test (SLT) at the levels shown in Table 3.
TABLE 1 Lot Acceptance Criteria for Notched Specimens
| Type | Item | Sampling of
Each Lot | Requirement/Method |
| 1 | Tensile Strength | 4 each | Test Method E8. Tensile strength of each specimen must be within 10 ksi of the average. |
| 1 | HardnessA | 5 % | 51 to 53 HRC per Test Methods E18.
Round the average of
three readings per
specimen per Practice
E29. |
| 1 | Dimensions | 100 % | Meet tolerances of
corresponding
drawings. Notch
dimension verified with
shadow graphic
projection at 50 to
100× or equivalent. |
| 1 | Notched Fracture Strength (NFS) | 10 ea | Test Methods E8/E8M. NFS of each specimen
must be within 10 ksi
of the average. |
| 1c | Self-loading
notched round
specimen bend
fixture, Fig. A2.7 | 10 ea | Alternate: The number of
turns of the loading
bolt, which is required
to produce fracture in
each specimen, must be
within 5 % of the
average. |
| 1d | Self-loading
notched C-Ring
bend fixture,
Fig. A2.8 | 10 ea | Alternate: The change in
diameter at fracture
load for each specimen
must be within 0.008
inches of the average. |
TABLE 2 Electroplating Bath Compositions and Operating Conditions for Sensitivity Test
| Item | Treatment A | Treatment B |
| Bath composition: | Range | Optimum | |
| Cadmium (as CdO) | 2.9 to 5.5 oz/gal (22 to 41 g/L) | 4.5 oz/gal (33.7 g/L) | same as Treatment A |
| Total Sodium cyanide
(NaCN) | 12.0 to 16.0 oz/gal (89.9 to 120 g/L) | 14 oz/gal (104 g/L) | same as Treatment A |
| Ratio NaCN to CdO | 2.8/1 to 6.0/1 | 3.0/1 | same as Treatment A |
| pH | 12.0 or greater | 12.0 | same as Treatment A |
| Temperature | 70–90°F (21–32°C) | 75°F (24°C) | same as Treatment A |
| Sodium hydroxide
(NaOH)A | 1.0 to 3.2 oz/gal (7.5 to 24.0 g/L) | 2.5 oz/gal (18.7 g/L) | same as Treatment A |
| Brightener such as
Colcad 100B or
equivalent | Manufacturer's suggested range | None |
| Electroplating current | 10 A/ft2 (108 A/m2) | 60 A/ft2 (645 A/m 2) |
| Electroplating time | 30 minutes | 6 minutes |
| Baking | | | |
| Baking temperature | 375 ± 25°F (190 ± 14°C) | same as Treatment A |
| Baking time: Type 1
Specimen | Do Not Bake | 23 h |
| Baking time: Type 2a
Specimen | 8 h | 23 h |
| Chromate TreatmentC | Yes | same as Treatment A |
TABLE 3 Pass/Fail Loading Requirements of Test Specimens
| Type 1a, 1b, 1c, 1d, 1e | 75 % of the tensile or bend NFS (Table 1). |
| Type 2a | 92 % of the Test Methods E8/E8M, E4 ultimate strength, obtained by deflecting a 2.300-inch diameter O-Ring specimen with a 2.525-inch stressing bar. |
1.5.1 The loading conditions and pass/fail requirements for service environments are specified in Annex A5.
1.5.2 If approved by the cognizant engineering authority, a quantitative, accelerated (≤ 24 h) incremental step-load (ISL) test as defined in Annex A3 may be used as an alternative to SLT.
1.6 This test method is divided into two parts. The first part gives general information concerning requirements for hydrogen embrittlement testing. The second is composed of annexes that give specific requirements for the various loading and specimen configurations covered by this test method (see section 9.1 for a list of types) and the details for testing service environments.
1.7 The values stated in the foot-pound-second (fps) system 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.
1.8 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.
ASTM Standards
B374 Terminology Relating to Electroplating
B851 Specification for Automated Controlled Shot Peening of Metallic Articles Prior to Nickel, Autocatalytic Nickel, or Chromium Plating, or as Final Finish
D1193 Specification for Reagent Water
E4 Practices for Force Verification of Testing Machines
E8 Test Methods for Tension Testing of Metallic Materials
E18 Test Methods for Rockwell Hardness of Metallic Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E709 Guide for Magnetic Particle Testing
E1417 Practice for Liquid Penetrant Testing
E1444 Practice for Magnetic Particle Testing
E1823 Terminology Relating to Fatigue and Fracture Testing
F1459 Test Method for Determination of the Susceptibility of Metallic Materials to Hydrogen Gas Embrittlement (HGE)
F1624 Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique
F2078 Terminology Relating to Hydrogen Embrittlement Testing
G5 Reference Test Method for Making Potentiostatic and Potentiodynamic Anodic Polarization Measurements
G38 Practice for Making and Using C-Ring Stress-Corrosion Test Specimens
SAE AMS Standard
AMS-S-5000 Steel, Chrome-Nickel-Molybdenum (E4340) Bars and Reforging Stock
Military and Federal Standards and Commercial Item Descriptions
CommercialItemDescri Chromium Trioxide, Technical
Keywords
cleaner; coating; delayed failure; fluids; hydrogen embrittlement; maintenance chemicals; plating/coating; steel; stress cracking; threshold;
ICS Code
ICS Number Code 25.220.40 (Metallic coatings)
DOI: 10.1520/F0519-12A
ASTM International is a member of CrossRef.
Citing ASTM Standards
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