ASTM B839-94

Standard Test Method for Residual Embrittlement in Metallic Coated, Externally Threaded Articles, Fasteners, and Rod-Inclined Wedge Method

SCOPE
1.1 This test method covers the determination of, on a statistical basis, the probability of the existence of hydrogen embrittlement or degradation in:  
1.1.1 A batch of barrel electroplated, autocatalytic plated, phosphated, or chemically processed threaded articles or fasteners and  
1.1.2 A batch of rack plated threaded articles, fasteners, or rod.  
1.2 Industrial practice for threaded articles, fasteners, and rod has evolved three graduated levels of test exposure to ensure reduced risk of hydrogen embrittlement (see Section 3). These levels have evolved from commercial applications having varying levels of criticality. In essence, they represent the confidence level that is required. They also represent the time that finished goods are held before they can be shipped and used. This time equates to additional cost to the manufacturer that may of necessity be added to the cost of the finished goods.  
1.3 This test method is applicable to threaded articles, fasteners, and rod made from steel with [>=]1000 MPa (with corresponding hardness values of 300 HV10kg f , 303 HB, or 31 HRc) or surface hardened threaded articles, fasteners, or rod.  
1.4 This test method shall be carried out after hydrogen embrittlement relief heat treatment in accordance with the requirements of Specification B850. It may also be used for assessing differences in processing solutions, conditions, and techniques. This test method has two main functions: first, when used with a statistical sampling plan it can be used for lot acceptance or rejection, and second, it can be used as a control test to determine the effectiveness of the various processing steps including pre- and post-baking treatments to reduce the mobile hydrogen in the articles, fasteners, or rod. While this test method is capable of indicating those items that are embrittled to the extent defined in Section 3, it does not guarantee complete freedom from embrittlement.  
1.5 This test method does not relieve the processor from imposing and monitoring suitable process control.  
1.6 This test method has been coordinated with ISO/DIS 10587 and is technically equivalent.  Note 1-Great care should be taken when applying this test method. The heads of embrittled articles, fasteners, or rod may suddenly break off and become flying projectiles capable of causing blindness or other serious injury. This hazard can occur as long as 200 h after the test has started. Hence, shields or other apparatus should be provided to avoid such injury. Note 2-The use of inhibitors in acid pickling baths does not necessarily guarantee avoidance of hydrogen embrittlement.
1.7 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-1993
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.10 - Test Methods

Relations

• Replaced By: ASTM B839-94(2003) - Standard Test Method for Residual Embrittlement in Metallic Coated, Externally Threaded Articles, Fasteners, and Rod—Inclined Wedge Method
• Effective Date: 10-May-2003

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: B 839 – 94
Standard Test Method for
Residual Embrittlement in Metallic Coated, Externally
Threaded Articles, Fasteners, and Rod—Inclined Wedge
Method
This standard is issued under the fixed designation B 839; 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 (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
When atomic hydrogen enters steels and certain other alloys, it can cause loss of ductility or load
carrying ability or cracking (usually as submicroscopic cracks), or catastrophic brittle failures at
applied stresses well below the yield strength or even the normal design strength for the alloys. This
phenomenon often occurs in alloys that show no significant loss in ductility, when measured by
conventional tensile tests, and is frequently referred to as hydrogen-induced delayed brittle failure,
hydrogen stress cracking, or hydrogen embrittlement. The hydrogen can be introduced during
cleaning, pickling, phosphating, electroplating, autocatalytic processes, and in the service environment
as a result of cathodic protection reactions or corrosion reactions. Hydrogen can also be introduced
during fabrication, for example, during roll forming, machining, and drilling due to lubricant
breakdown as well as during welding or brazing operations.
1. Scope embrittlement relief heat treatment in accordance with the
requirements of Specification B 850. It may also be used for
1.1 This test method covers the determination of, on a
assessing differences in processing solutions, conditions, and
statistical basis, the probability of the existence of hydrogen
techniques. This test method has two main functions: first,
embrittlement or degradation in:
when used with a statistical sampling plan it can be used for lot
1.1.1 A batch of barrel electroplated, autocatalytic plated,
acceptance or rejection, and second, it can be used as a control
phosphated, or chemically processed threaded articles or fas-
test to determine the effectiveness of the various processing
teners and
steps including pre- and post-baking treatments to reduce the
1.1.2 A batch of rack plated threaded articles, fasteners, or
mobile hydrogen in the articles, fasteners, or rod. While this
rod.
test method is capable of indicating those items that are
1.2 Industrial practice for threaded articles, fasteners, and
embrittled to the extent defined in Section 3, it does not
rod has evolved three graduated levels of test exposure to
guarantee complete freedom from embrittlement.
ensure reduced risk of hydrogen embrittlement (see Section 3).
1.5 This test method does not relieve the processor from
These levels have evolved from commercial applications
imposing and monitoring suitable process control.
having varying levels of criticality. In essence, they represent
1.6 This test method has been coordinated with ISO/DIS
the confidence level that is required. They also represent the
10587 and is technically equivalent.
time that finished goods are held before they can be shipped
and used. This time equates to additional cost to the manufac-
NOTE 1—Warning: Great care should be taken when applying this test
turer that may of necessity be added to the cost of the finished
method. The heads of embrittled articles, fasteners, or rod may suddenly
break off and become flying projectiles capable of causing blindness or
goods.
other serious injury. This hazard can occur as long as 200 h after the test
1.3 This test method is applicable to threaded articles,
has started. Hence, shields or other apparatus should be provided to avoid
fasteners, and rod made from steel with $1000 MPa (with
such injury.
corresponding hardness values of 300 HV , 303 HB, or 31
10 kgf
NOTE 2—The use of inhibitors in acid pickling baths does not neces-
HR ) or surface hardened threaded articles, fasteners, or rod.
c sarily guarantee avoidance of hydrogen embrittlement.
1.4 This test method shall be carried out after hydrogen
1.7 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
This test method is under the jurisdiction of ASTM Committee B-8 on Metallic
responsibility of the user of this standard to establish appro-
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
priate safety and health practices and determine the applica-
General Test Methods.
bility of regulatory limitations prior to use.
Current edition approved August 15, 1994. Published October 1994.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
B 839
2. Referenced Documents
2.1 ASTM Standards:
B 602 Test Method for Attribute Sampling of Metallic and
Inorganic Coatings
B 697 Guide for Selection of Sampling Plans for Inspection
of Electrodeposited Metallic and Inorganic Coatings
F 436 Specification for Hardened Steel Washers
B 850 Post-Coating Treatments of Iron or Steel for Reduc-
ing Risk of Hydrogen Embrittlement
2.2 ISO Standards:
ISO/DIS 10587 Residual Embrittlement in Metallic Coated,
Externally Threaded Articles, Fasteners and Rod—
Inclined Wedge Method
ISO 4519 Electrodeposited Metallic Coatings and Related
Finishes—Sampling Procedures for Inspection by At-
tributes
2.3 Military Standard:
MIL-STD-1312 Fastener Test Methods
3. Terminology
3.1 Definitions—For the purposes of this test method the
following definitions apply:
3.1.1 batch—a distinct portion of items processed collec-
tively as a single group through the same identical treatment
steps at the same time on the same rack or in the same barrel.
3.1.2 embrittled—where parts fail immediately or up to 48
h in test.
3.1.2.1 Discussion—The degree to which parts within a
single plated batch or a given lot can be embrittled can vary
over a wide range. The degree of embrittlement is a function of
the concentration of atomic hydrogen in the individual parts in
the batch or lot, measured in parts per million, and in particular
that portion of the hydrogen that is mobile or free to migrate to
FIG. 1 Example of 6° Wedge and Parallel Filler Plate
areas of high stress concentration.
3.1.3 Grade 48 proof—where there are no failures after 48
that the required length of the threaded article is placed under
h of test.
test. Other loading systems and fixtures are permissible as long
3.1.4 Grade 96 proof—where there are no failures after 96
as the same load, angle, and exposure are created for the test.
h of test.
The upper surface of the wedge is ground at an angle to the
3.1.5 Grade 200 proof—where there are no failures after
lower surface. The mating nut is tensioned by any means
200 h of test.
capable of measuring tensile load. The torque method de-
3.1.6 lot—a group of items processed through the same or
scribed in 6.4 is one such method. If the torque method of
similar steps at the same time or over a contiguous time period
tightening is used, the fasteners are torqued to the desired
and from the same heat of material. The lot may be broken
value, held for the minimum specified hours, and then checked
down into a number of batches for processing purposes and
to determine if the initial torque has been maintained. Follow-
then reassembled into the same lot.
ing this they are examined for embrittlement failures. See
Section 9.
4. Summary of Test Method
4.1 The threaded articles, fasteners, or rod are subjected to NOTE 3—Increasing the applied torque by a small percentage as a
safety factor is not recommended.
stress by tensioning with a mating nut after insertion through a
clearance hole in a hardened rectangular wedge of steel; see
5. Significance and Use
Fig. 1. Additional hardened rectangular pieces of steel with
5.1 The use of this test method can significantly reduce the
parallel faces are provided as filler plates and are inserted so
risk of sudden catastrophic failure of threaded articles and
fasteners, below their design strength, due to hydrogen em-
Annual Book of ASTM Standards, Vol 02.05. brittlement.
Annual Book of ASTM Standards, Vol 15.08.
American National Standards Institute, 11 West 42nd Street, New York, NY
6. Apparatus
10036.
5 6.1 Test Fixture comprising a hardened wedge (see Fig. 1),
Available from Standardization Documents Order Desk, Bldg. 4, Section D,
700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. one or more filler plates, and a hardened washer. The hole in
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
B 839
each shall be as close to the m
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