ASTM A739.pdf
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Designation: A 739 – 90a (Reapproved 2006)
Standard Specification for
Steel Bars, Alloy, Hot-Wrought, for Elevated Temperature or
Pressure-Containing Parts, or Both
1
This standard is issued under the fixed designation A 739; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This specification
2
covers hot-wrought, ferritic alloy
steel bars for elevated temperature or pressure-containing parts
suitable for fusion welding or both.
1.2 The bars are furnished in the following grades:
Grade B 11: 1.25 % chromium, 0.55 % molybdenum
Grade B 22: 2.25 % chromium, 1.00 % molybdenum
1.3 The values stated 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.
2. Referenced Documents
2.1 ASTM Standards:
3
A 29/A 29M Specification for Steel Bars, Carbon and Alloy,
Hot-Wrought, General Requirements for
A 370 Test Methods and Definitions for Mechanical Testing
of Steel Products
3. Ordering Information
3.1 Orders for material under this specification should
include the following information:
3.1.1 Quantity (weight or number of pieces),
3.1.2 Name of material (ferritic alloy steel bars),
3.1.3 Condition (hot wrought, normalized and tempered,
machine straightened and descaled),
3.1.4 Dimensions (cross-sectional shape, size, and length),
3.1.5 ASTM designation and date of issue,
3.1.6 Grade (
Table 1),
3.1.7 Additions to the specification, and
3.1.8 End use.
NOTE 1—A typical description is as follows: 10 000 lb, Ferritic Alloy
Steel Bars, Hot Wrought Normalized and Tempered, and Descaled,
1.000-in. diameter by 10 ft, ASTM A 739 dated____, Grade B 11, Special
Straightened, Special Machined Fittings.
4. Materials and Manufacture
4.1 Melting Practice—The steel shall be made by one or
more of the following primary processes: open-hearth, basic-
oxygen, or electric-furnace. The primary melting may incor-
porate separate degassing or refining and may be followed by
secondary melting using electroslag remelting or vacuum arc
remelting. Where secondary melting is employed, the heat
shall be defined as all of the ingots remelted from a single
primary heat.
4.2 Condition—Unless otherwise specified, bars shall be
hot wrought, heat treated, and descaled.
4.3 Heat Treatment:
4.3.1 The bars shall be normalized and tempered.
4.3.2 Austenitizing temperature shall be within the range
from 1700 to 1800°F (927 to 982°C).
4.3.3 Cooling from the austenitizing temperature may be
accomplished by cooling in still air or moving air, at the
producer’s option. When permitted by the purchaser, cooling
from the austenitizing temperature may be accelerated by spray
or liquid quenching.
4.3.4 The minimum tempering temperature shall be 1200°F
(649°C) for Grade B 11 and 1250°F (677°C) for Grade B 22.
1
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.15 on Bars.
Current edition approved March 1, 2006. Published March 2006. Originally
approved in 1976. Last previous edition approved in 2000 as A 739 – 90a (2000).
2
For ASME Boiler and Pressure Vessel Code applications see related Specifi-
cation SA-739 in Section II of that code.
3
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
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
TABLE 1 Chemical Requirements
Element Composition, %
Grade B 11 Grade B 22
Carbon, max 0.05–0.20 0.05–0.15
Manganese 0.40–0.65 0.30–0.60
Phosphorus, max 0.035 0.035
Sulfur, max 0.040 0.040
Silicon 0.50–0.80 0.50 max
Chromium 1.00–1.50 2.00–2.50
Molybdenum 0.45–0.65 0.90–1.10
1
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