ASTM F2328M-04
(Test Method)Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws and Studs [Metric]
Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws and Studs [Metric]
SCOPE
1.1 This test method covers procedures for measuring, classifying, and determining the presence of decarburization and carburization in the threaded section of hardened and tempered metric steel bolts, screws, studs, and similar parts which have been heated to facilitate fabrication or to modify its mechanical properties. This test method is not intended to address products which are intentionally carburized to achieve specific results.
1.2 Two routine methods are described for measuring the limits of and determining the presence of decarburization or carburization; the Optical Method and the Microindentation Method 1. Either method is appropriate for routine examinations. The Microindentation Method 2 shall be considered the referee method.
1.3 For the purpose of these tests, there are three classes of hardened and tempered steel products for which specific measurements must be made with respect to their physical properties.
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F 2328M – 04
METRIC
Standard Test Method for
Determining Decarburization and Carburization in Hardened
and Tempered Threaded Steel Bolts, Screws and Studs
1
[Metric]
This standard is issued under the fixed designation F 2328M; 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.
1. Scope F 1789 Terminology for F16 Mechanical Fasteners
1.1 This test method covers procedures for measuring,
3. Terminology
classifying, and determining the presence of decarburization
3.1 Definitions:
and carburization in the threaded section of hardened and
3.1.1 carburization—process or result of increasing the
tempered metric steel bolts, screws, studs, and similar parts
carbon content of the surface layers of the steel fastener
whichhavebeenheatedtofacilitatefabricationortomodifyits
product.
mechanical properties. This test method is not intended to
3.1.2 decarburization—in accordance with Terminology
address products which are intentionally carburized to achieve
F 1789, is a loss of carbon from the surface layer of the
specific results.
fastener, normally associated with heat treatment.
1.2 Two routine methods are described for measuring the
3.1.3 gross decarburization—also known as complete de-
limits of and determining the presence of decarburization or
carburization, is characterized by a sufficient carbon loss to
carburization; the Optical Method and the Microindentation
show only clearly defined ferrite grains.
Method 1. Either method is appropriate for routine examina-
3.1.4 partial decarburization—characterized as a loss of
tions. The Microindentation Method 2 shall be considered the
carbon sufficient to cause a lighter shade of tempered marten-
referee method.
site than that of the immediately adjacent base metal, but as
1.3 For the purpose of these tests, there are three classes of
being of insufficient carbon loss to show clearly defined ferrite
hardened and tempered steel products for which specific
grains.
measurements must be made with respect to their physical
properties.
4. Class of Decarburization
1.4 This standard does not purport to address all of the
4.1 Class Determination—These measurements by Class
safety concerns, if any, associated with its use. It is the
arepredicatedupontheirrelationshipbetweentheheight(H)of
responsibility of the user of this standard to establish appro-
the external thread at its maximum boundary, disregarding any
priate safety and health practices and determine the applica-
surface coating, and N, which is the minimum thread height in
bility of regulatory limitations prior to use.
the non-decarburized zone (see Figs. 1-3). The dimensions for
2. Referenced Documents N and H are listed in Table 2 for each Class. Dimension G
2 (Table 1 and Fig. 1) represents the maximum depth of gross or
2.1 ASTM Standards:
complete decarburization.
E 3 Practice for Preparation of Metallographic Specimens
E 384 Test Method for Microindentation Hardness of Ma-
NOTE 1—Refer to the product standard for specific requirements.When
terials limits are not specified, use Table 1 as a suggested reference.
5. Preparation
1
This test method is under the jurisdiction of ASTM Committee F16 on
5.1 The use of either the optical or microindentation hard-
Fasteners and is the direct responsibility of Subcommittee F16.01 on Test Methods.
ness method requires the finished product to be longitudinally
Current edition approved July 1, 2004. Published July 2004.
2
cross-sectioned, approximately through the threaded axis, and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mounted for grinding and polishing in any suitable medium
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
F 2328M – 04
FIG. 1 Decarburization Zones
FIG. 2 Position for Microindentation Measurements
FIG. 3 Microindentation Measurements for Class 3 Products
TABLE 1 Classes of Decarburization: Guide
which will provide edge retention of the specimen. This shall
Class N G max Typical Applications
beperformedinaccordancewithgoodmetallographicpractice.
1
1 ⁄2 H 0.015 mm For heat treated products which have tensile
See Practice E 3.
strengths up to 830 MPa and those with a
specified minimum tensile strength of 830
MPa or a hardness range of 24 to 34 HRC,
6. Evaluation by the Optical Method
or both.
2
6.1 Etch the mounted specimen (Sect
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.