ASTM A304-05(2011)
(Specification)Standard Specification for Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements
Standard Specification for Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements
ABSTRACT
This specification covers carbon and alloy steel bars subject to end-quench hardenability requirements. The methods for estimating the hardness value of the material are presented. Method A is the minimum and maximum hardness values at any desired distance, Method B is the minimum and maximum distances at which any desired hardness value occurs, Method C is the two maximum hardness values at two desired distances, Method D is the two minimum hardness values at two desired distances, and Method E is any minimum hardness plus any maximum hardness. The heat analysis shall conform to the requirements as to chemical composition. The fine austenitic grain size requirements of the steel material are presented in details. The end-quench hardenability shall conform to the requirements specified on the purchase order. The test specimen requirements indicates that, the number and location of test specimens shall be in accordance with the manufacturers standard practice and shall adequately represent the hardenability of each heat, also, all forged or rolled hardenability test specimens must be normalized prior to testing. The grain size and end-quench hardenability test methods are presented in details.
SCOPE
1.1 This specification covers hot-worked alloy, carbon, and carbon-boron steels in a variety of compositions and sizes, which may attain specified depth of hardening in the end quench test. These steel compositions are identified by the suffix letter “H” added to the conventional grade number.
1.2 This specification provides for analyses other than those listed under Tables 1 and 2. Special hardenability limits are also permissible when approved by the purchaser and manufacturer.
1.3 The values stated in inch-pound units are to be regarded as the standard.
1.3.1 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: A304 – 05 (Reapproved 2011)
Standard Specification for
Carbon and Alloy Steel Bars Subject to End-Quench
Hardenability Requirements
This standard is issued under the fixed designation A304; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* 3.1.1 hardenability—the relative ability of a steel to harden
under heat treatment becomes apparent in the degree to which
1.1 This specification covers hot-worked alloy, carbon, and
the material hardens when quenched at different cooling rates.
carbon-boron steels in a variety of compositions and sizes,
It is measured quantitatively, usually by noting the extent or
which may attain specified depth of hardening in the end
depth of hardening of a standard size and shape test specimen
quench test. These steel compositions are identified by the
in a standardized quench. In the “end-quench” test the “depth
suffix letter “H” added to the conventional grade number.
of hardening” is the distance along the specimen from the
1.2 This specification provides for analyses other than those
quenched end to a given hardness.
listed under Tables 1 and 2. Special hardenability limits are
also permissible when approved by the purchaser and manu-
4. Ordering Information
facturer.
4.1 Orders for material under this specification should
1.3 The values stated in inch-pound units are to be regarded
include the following information, in proper sequence:
as the standard.
4.1.1 Quantity (weight),
1.3.1 The values stated in inch-pound units are to be
4.1.2 Name of material (alloy, carbon, or carbon-boron
regarded as standard. No other units of measurement are
steel),
included in this standard.
4.1.3 Cross-sectional shape,
2. Referenced Documents 4.1.4 Size,
4.1.5 Length,
2.1 ASTM Standards:
4.1.6 Grade,
A29/A29M Specification for Steel Bars, Carbon and Alloy,
4.1.7 End-quenched hardenability (see Section 9),
Hot-Wrought, General Requirements for
4.1.8 Report of heat analysis, if desired (see Section 7),
A108 Specification for Steel Bar, Carbon and Alloy, Cold-
4.1.9 Special straightness, if required,
Finished
4.1.10 ASTM designation and date of issue,
A255 Test Methods for Determining Hardenability of Steel
4.1.11 End use or special requirements, and
E112 Test Methods for Determining Average Grain Size
4.1.12 Leaded steel, when required.
E527 Practice for Numbering Metals and Alloys in the
Unified Numbering System (UNS)
NOTE 1—A typical ordering description is as follows: 10 000 lb, alloy
bars, round, 4.0 in. dia by 10 ft, Grade 1340H, J 40/56 = ⁄16 in., heat
3. Terminology
analysis required, ASTM A304, dated ________, worm gear.
3.1 Definitions of Terms Specific to This Standard:
4.2 The purchaser shall specify the desired grade, including
the suffix letter “H,” in accordance with Table 1 or Table 2.
4.3 Band limits are shown graphically and as tabulations in
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
Figs. 2-87, inclusive. For specifications purposes, the tabulated
A01.15 on Bars.
values of Rockwell C hardness are used. Values below 20
Current edition approved April 1, 2011. Published June 2011. Originally
´2
Rockwell C hardness (20 HRC) are not specified because such
approved in 1947. Last previous edition approved in 2005 as A304 – 05 . DOI:
10.1520/A0304-05R11. values are below the normal range of the C scale. The graphs
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
are shown for convenience in estimating the hardness values
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
obtainable at various locations on the end quench test bar and
Standards volume information, refer to the standard’s Document Summary page on
for various locations in oil or water quenched rounds. The
the ASTM website.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A304 – 05 (2011)
relationship between end-quench distance and bar diameter is Specification A29/A29M or A108, unless otherwise provided
approximate and should be used only as a guide. for in this specification.
4.4 Two points from the tabulated values are commonly
7. Chemical Composition
designated according to one of Methods A, B, C, D, or E,
which are defined in the following paragraphs. Those various 7.1 The heat analysis shall conform to the requirements as
to chemical composition prescribed in Tables 1 and 2 for the
methods are illustrated graphically in Fig. 1.
4.4.1 Method A—The minimum and maximum hardness grade specified by the purchaser.
7.2 When a steel cannot be identified by a standard grade
valuesatanydesireddistance.ThismethodisillustratedinFig.
1 as points A-A and would be specified as 43 to 54 HRC at J3. number in accordance with Tables 1 and 2, other compositions
may be specified, as agreed upon between the purchaser and
Obviously the distance selected would be that distance on the
end quench test bar that corresponds to the section used by the the manufacturer. Generally, hardenability bands will not be
available for such compositions.
purchaser.
4.4.2 Method B—The minimum and maximum distances at 7.3 When requested by the manufacturer, and approved by
the purchaser, other steels capable of meeting the purchaser’s
which any desired hardness value occurs. This method is
illustrated in Fig. 1 as points B-B and would be specified as 39 specified hardenability may be furnished in place of the grade
HRC at J4 minimum and J9 maximum. If the desired hardness specified by the purchaser.
does not fall on an exact sixteenth position, the minimum
8. Grain Size Requirements
distance selected should be the nearest sixteenth position
8.1 The steel shall conform to the fine austenitic grain size
toward the quenched end and the maximum should be the
nearest sixteenth position away from the quenched end. requirement of Specification A29/A29M.
8.2 Hardenability values specified in this specification are
4.4.3 Method C—Two maximum hardness values at two
desired distances, illustrated in Fig. 1 as points C-C. basedonfine-grainsteelsandarenotapplicabletocoarse-grain
material. In case coarse-grain steel is desired, the hardenability
4.4.4 Method D—Two minimum hardness values at two
desired distances, illustrated in Fig. 1 as points D-D. values shall be negotiated between the purchaser and the
manufacturer.
4.4.5 Method E—Any minimum hardness plus any maxi-
mum hardness. When hardenability is specified according to
9. End-Quench Hardenability Requirements
one of the above Methods A to E, the balance of the
9.1 The end-quench hardenability shall conform to the
hardenability band is not applicable.
requirements specified on the purchase order.
4.5 In cases when it is considered desirable, the maximum
9.2 The hardenability values shall be specified in accor-
and minimum limits at a distance of ⁄16 in. from the quenched
dance with the applicable values in Figs. 2-87 inclusive for the
end can be specified in addition to the other two points as
grade specified. See Fig. 1 for method of specifying harden-
previously described in 4.4.1-4.4.5, inclusive.
ability.
4.6 In cases when it is necessary to specify more than two
9.3 When agreed upon between the purchaser and manufac-
points on the hardenability band (exclusive of the maximum
and minimum limits at a distance of ⁄16 in.), a tolerance of two turer, special hardenability limits may be ordered and shall be
reflected on the purchase order.
points Rockwell C (HRC) over any small portion of either
curve (except at a distance of ⁄16 in.) is customary. This
10. Test Specimens
tolerance is necessary because curves of individual heats vary
10.1 Number and Location—The number and location of
somewhat in shape from the standard band limits and thus
test specimens shall be in accordance with the manufacturer’s
deviateslightlyatoneormorepositionsinthefulllengthofthe
standard practice and shall adequately represent the harden-
curves.
ability of each heat.
5. Manufacture
10.2 Thermal Treatment—All forged or rolled hardenability
5.1 Melting Practice—The steel shall be made by one or test specimens must be normalized prior to testing. Cast
more of the following primary processes: open-hearth, basic- specimens need not be normalized.
oxygen, or electric-furnace. The primary melting may incor-
11. Test Methods
porate separate degassing or refining and may be followed by
11.1 Grain Size—Test Methods E112.
secondary melting using electroslag remelting or vacuum arc
remelting. Where secondary melting is employed, the heat 11.2 End-Quench Hardenability—Test Method A255.
shall be defined as all of the ingots remelted from a single
12. Certification and Reports of Testing
primary heat.
12.1 When the full H-band is specified for alloy steels, the
5.2 Slow Cooling—Immediately after hot working, the bars
hardenability can be reported by listing hardness values at the
shallbeallowedtocoolwhennecessarytoatemperaturebelow
following distances from the quenched end of the test speci-
thecriticalrangeundersuitableconditions,topreventinjuryby
men: 1 through 16 sixteenths, then 18, 20, 22, 24, 28, and 32
too rapid cooling.
sixteenths of an inch.
6. General Requirements
12.2 Tables 2-18 in Test Methods A255 are to be used to
6.1 Material furnished under this specification shall con- calculatehardenabilityfromthechemicalidealdiameterforthe
form to the applicable requirements of the current edition of grades shown in 10.1 of Test Methods A255. Hardenability
A304 – 05 (2011)
results are to be reported for the first 10 sixteenths (16 mm), sixteenths rather than thirty-seconds are followed for all steels
then 12, 14, 16, 18, 20, 24, 28, and 32 sixteenths of an inch. to avoid misunderstanding. When the full H-band is specified
half sixteenths through 8 may be reported, as well as the
NOTE 2—The reporting hardenability using the calculated method
distances listed in 12.1.
differs from the procedure shown in 6.4 of Test Methods A255.
13. Keywords
12.3 For carbon H-steels, distances from the quenched end
may be reported by listing sixteenths or half sixteenths (rather 13.1 alloy steel bars; carbon steel bars; end quench harden-
than full sixteenths only as with alloy steels). Units of ability; steel bars
SUMMARY OF CHANGES
Committee A01 has identified the location of selected changes to this specification since the last issue,
A304 - 04, that may impact the use of this specification (Approved March 1, 2005).
(1) Changed Manganese on H 51300 in Table 1.
Committee A01 has identified the location of selected changes to this specification since the last issue,
A304 - 96, that may impact the use of this specification (Approved March 1, 2004).
(1) New section 12.2 added. (2) Previous section 12.2 renumbered as 12.3.
A
TABLE 1 Chemical Requirements of Alloy H Steels
NOTE 1— Phosphorus and sulfur in open-hearth steel is 0.035 %, max, and 0.040 %, max respectively. Phosphorus and sulfur in electric-furnace steel
(designated by the prefix letter “E”) is 0.025 %, max.
NOTE 2—Small quantities of certain elements are present in alloy steels that are not specified or required. These elements are considered as incidental
and may be present to the following maximum amounts: copper, 0.35 %; nickel, 0.25 %; chromium, 0.20 %; molybdenum, 0.06 %.
NOTE 3—ChemicalrangesandlimitsshowninthistablearesubjecttothepermissiblevariationforproductanalysisshowninSpecificationA29/A29M.
NOTE 4—Standard “H” Steels can be produced with a lead range of 0.15–0.35 %. Such steels are identified by inserting the letter “L” between the
second and third numerals of the grade designation, for example, 41L40H. Lead is generally reported as a range of 0.15–0.35 %.
UNS Desig- Grade Designation Chemical Composition, %
A
nation
Carbon Manganese Silicon Nickel Chromium Molybdenum
H 13300 1330 H 0.27–0.33 1.45–2.05 0.15–0.35 . . .
H 13350 1335 H 0.32–0.38 1.45–2.05 0.15–0.35 . . .
H 13400 1340 H 0.37–0.44 1.45–2.05 0.15–0.35 . . .
H 13450 1345 H 0.42–0.49 1.45–2.05 0.15–0.35 . . .
H 40270 4027 H 0.24–0.30 0.60–1.00 0.15–0.35 . . 0.20–0.30
B
H 40280 4028 H 0.24–0.30 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40320 4032 H 0.29–0.35 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40370 4037 H 0.34–0.41 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40420 4042 H 0.39–0.46 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 40470 4047 H 0.44–0.51 0.60–1.00 0.15–0.35 . . 0.20–0.30
H 41180 4118 H 0.17–0.23 0.60–1.00 0.15–0.35 . 0.30–0.70 0.08–0.15
H 41300 4130 H 0.27–0.33 0.30–0.70 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41350 4135 H 0.32–0.38 0.60–1.00 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41370 4137 H 0.34–0.41 0.60–1.00 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41400 4140 H 0.37–0.44 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41420 4142 H 0.39–0.46 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41450 4145 H 0.42–0.49 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41470 4147 H 0.44–0.51 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41500 4150 H 0.47–0.54 0.65–1.10 0.15–0.35 . 0.75–1.20 0.15–0.25
H 41610 4161 H 0.55–0.65 0.65–1.10 0.15–0.35 . 0.65–0.95 0.25–0.35
H 43200 4320 H 0.17–0.23 0.40–0.70 0.15–0.35 1.55–2.00 0.35–0.65 0.20–0.30
H 43400 4340 H 0.37–0.44 0.55–0.90 0.15–0.35 1.55–2.00 0.65–0.95 0.20–0.30
H 43406 E4340 H 0.37–0.44 0.60–0.95 0.15–0.35 1.55–2.00 0.65–0.95 0.20–0.30
H 44190 4419 H 0.17–0.23 0.35–0.75 0.15–0.35 . . 0.45–0.60
H 46200 4620 H 0.17–0.23 0.35–0.75 0.15–0.35 1.55–2.00 . 0.20–0.30
H 46210 4621 H 0.17–0.23 0.60–1.00 0.15–0.35 1.55–2.00 . 0.20–0.30
H 46260 4626 0.23–0.29 0.40–0.70 0.15–0.35 0.65–1.05 . 0.15–0.25
H 47180 4718 H 0.15–0.21 0.60–0.95 0.15–0.35 0.85–1.25 0.30–0.60 0.30–0.40
A304 – 05 (2011)
TABLE 1 Continued
UNS Desig- Grade Designation Chemical Composition, %
A
nation
Carbon Manganese Silicon Nickel Chromium Molybdenum
H 47200 4720 H 0.17–0.23 0.45–0.75 0.15–0.35 0.85–1.25 0.30–0.60 0.15–0.25
H 48150 4815 H 0.12–0.18 0.30–0.70 0.15–0.35 3.20–3.80 . 0.20–0.30
H 48170 4817 H 0.14–0.20 0.30–0.70 0.15–0.35 3.20–3.80 . 0.20–0.30
H 48200 4820 H 0.17–0.23 0.40–0.80 0.15–0.35 3.20–3.80 . 0.20–0.30
C
H 50401 50B40 H 0.37–0.44 0.65–1.10 0.15–0.35 . 0.30–0.70 .
C
H 50441 50B44 H 0.42–0.49 0.65–1.10 0.15–0.35 . 0.30–0.70 .
H 5
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