ASTM A920/A920M-97

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: A 920/A 920M – 97 An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
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Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Steel Bars, Microalloy, Hot-Wrought, Special Quality,
1
Mechanical Properties
This standard is issued under the fixed designation A 920/A 920M; 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 E 45 Practice for Determining the Inclusion Content of
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Steel
1.1 This specification covers hot-wrought, special quality
microalloyed carbon steel bars intended for use in applications
3. Terminology
where as-rolled mechanical properties are desired. A typical
3.1 Definitions of Terms Specific to This Standard:
end use is hydraulic cylinder shafts.
3.1.1 microalloyed steels—microalloyed steels are carbon
1.2 The bars shall be furnished to chemical composition and
steels to which small quantities of certain elements are added
mechanical properties as provided herein. Chemical composi-
in order to enhance mechanical properties. This enhancement
tion is based on standard carbon steel grades modified to
of mechanical properties results from control of the tempera-
include microalloying elements such as columbium (niobium),
ture and cooling rate during the hot-rolling process.
vanadium, or molybdenum. Four strength classes are available,
designated 60, 75, 80, and 100, corresponding to the minimum
4. Ordering Information
yield strength in ksi.
4.1 Orders for material supplied to this specification should
1.3 Sections and sizes of bar steels available are covered in
include the following, as required, to describe adequately the
Specification A 29/A 29M.
desired material:
1.4 Supplementary Requirements S1 to S5 are provided for
4.1.1 Quantity (weight or number of bars),
use when additional controls or requirements are desired.
4.1.2 Name of material (hot-rolled microalloyed steel bars),
These shall apply only when specified on the purchase order.
4.1.3 Dimensions,
1.5 The values stated in either inch-pound units or SI units
4.1.4 ASTM specification number and date of issue,
are to be regarded separately as standard. Within the text and
4.1.5 Grade designation or chemical composition limits (see
tables, SI units are shown in brackets. The values stated in each
Section 8),
system are not exact equivalents; therefore, each system must
4.1.6 Class,
be used independently of the other. Combining values from the
4.1.7 Type (see 7.1) to designate grain refiner,
two systems may result in nonconformance with the specifi-
4.1.8 Additions to the specification and Supplementary
cation.
Requirements, if required, and,
1.6 Unless the order specifies the applicable “M” specifica-
4.1.9 End use.
tion designation, the material shall be furnished to the inch-
pound units.
5. General Requirements
5.1 Material furnished under this specification shall con-
2. Referenced Documents
form to the applicable requirements of the current edition of
2.1 ASTM Standards:
Specification A 29/A 29M, unless otherwise provided herein.
A 29/A 29M Specification for Steel Bars, Carbon and Alloy,
Hot-Wrought and Cold-Finished, General Requirements
6. Materials and Manufacture
2
for
6.1 Melting Practice—The steel shall be produced in accor-
A 370 Test Methods and Definitions for Mechanical Testing
3 dance with the applicable methods for primary and secondary
of Steel Products
melting outlined in Specification A 576.
A 576 Specification for Steel Bars, Carbon, Hot-Wrought,
2
6.2 The steel shall be killed. Supplementary Requirements
Special Quality
S1 through S5 may be invoked upon agreement between
producer and purchaser.
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6.3 The bars shall be special quality.
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
6.4 The bars shall be hot-wrought, as wrought, unless
A01.15 on Bars.
otherwise specified.
Current edition approved March 10, 1997. Published September 1997. Originally
published as A 920/A 920M-93. Last previous edition A 920/A 920M-93.
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Annual Book of ASTM Standards, Vol 01.05.
3 4
Annual Book of ASTM Standards, Vol 01.03. Annual Book of ASTM Standards, Vol 03.01.
1

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A 920/A 920M
TABLE 2 Chemical Requirements—(Microalloy Elements)
7. Metallurgical Requirements
7.1 Grain Size—The steel shall conform to the fine grain
Element Chemical Ranges and Limits, %
size requirement of Specification A 29/A 29M. The grain
Heat Analysis Product Analysis
refining element m
...