ASTM A739-90a(2022)

Standard Specification for Steel Bars, Alloy, Hot-Wrought, for Elevated Temperature or Pressure-Containing Parts, or Both

ABSTRACT
This specification covers hot-wrought, ferritic alloy steel bars for elevated temperature or pressure-containing parts suitable for fusion welding or both. The bars are furnished in two grades: Grade B 11 and Grade B 22. The steel shall be made by on or more of the following primary processes: open-hearth, basic-oxygen, or electric furnace. The bars shall be normalized and tempered. The heat analysis shall conform to the limits for chemical composition specified. The bars as represented by the test specimen shall conform to the tensile requirements specified.
SCOPE
1.1 This specification2 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.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 28-Feb-2022
• ICS: 77.140.30 - Steels for pressure purposes
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.15 - Bars

Relations

• Refers: ASTM A370-24 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Mar-2024
• Refers: ASTM A370-19 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jul-2019
• Refers: ASTM A370-17a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2017
• Refers: ASTM A370-17 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jan-2017
• Refers: ASTM A370-15 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Nov-2015
• Refers: ASTM A29/A29M-15 - Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought
• Effective Date: 01-Nov-2015
• Refers: ASTM A370-14 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-May-2014
• Refers: ASTM A370-13 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2013
• Refers: ASTM A370-12a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Oct-2012
• Refers: ASTM A29/A29M-12 - Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
• Effective Date: 01-May-2012
• Refers: ASTM A29/A29M-12e1 - Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought
• Effective Date: 01-May-2012
• Refers: ASTM A370-12 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Mar-2012
• Refers: ASTM A370-11a - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 15-Nov-2011
• Refers: ASTM A29/A29M-11a - Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
• Effective Date: 01-Oct-2011
• Refers: ASTM A29/A29M-11 - Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
• Effective Date: 01-Apr-2011

Overview

ASTM A739-90a(2022) is the international standard specification issued by ASTM for hot-wrought, ferritic alloy steel bars intended for use in elevated temperature or pressure-containing parts, or for both applications. This specification ensures steel bars are suitable for fusion welding, and it covers two specific grades: Grade B 11 and Grade B 22. The steel bars outlined under ASTM A739 are hot-wrought, normalized, tempered, and must meet strict requirements for chemical composition and mechanical performance. These alloy steel bars are essential for critical service in high-temperature or high-pressure environments, commonly found in industries such as power generation and petrochemical processing.

Key Topics

• Material Grades:

  • Grade B 11: 1.25% chromium, 0.55% molybdenum
  • Grade B 22: 2.25% chromium, 1.00% molybdenum

• Manufacturing Processes:
  The steel shall be produced via open-hearth, basic-oxygen, or electric furnace methods. Additional processes such as secondary melting (electroslag remelting or vacuum arc remelting) are permitted.

• Heat Treatment:

  • Bars are normalized and tempered with specific austenitizing and minimum tempering temperature requirements for each grade.
  • Ensures structural integrity and performance at elevated temperatures.

• Mechanical Properties:

  • Specific tensile strength, yield strength, elongation, and reduction of area requirements are defined.
  • Test specimens are taken longitudinally, and multiple tests per heat and heat treatment charge are mandated.

• Quality and Workmanship:

  • Bars must be free of defects such as pipe, cracks, and flakes.
  • Descaling is required unless otherwise specified to ensure a clean finish for further processing.

Applications

ASTM A739 alloy steel bars are widely utilized in applications that demand reliable performance under high temperatures or pressure. Typical uses include:

• Boiler and Pressure Vessel Components:
  Parts that are exposed to high internal pressures or elevated temperatures in boilers, heat exchangers, and pressure vessels.
• Petrochemical and Power Generation Industries:
  Components in turbines, reactors, and high-temperature piping.
• Industrial Machinery:
  Critical structural elements requiring fusion welding and firm mechanical properties.

The specification supports design engineers and manufacturers to select materials that ensure safety, reliability, and long-term performance in demanding environments.

Related Standards

When referencing or utilizing ASTM A739-90a(2022), it is beneficial to consult related standards for comprehensive coverage and compatibility, such as:

• ASTM A29/A29M: General Requirements for Steel Bars, Carbon and Alloy, Hot-Wrought
• ASTM A370: Test Methods and Definitions for Mechanical Testing of Steel Products
• ASME Boiler and Pressure Vessel Code (Section II): Specification SA-739 for Boiler and Pressure Vessel applications

These standards provide further guidance on material requirements, testing protocols, and application-specific details to ensure product conformity and performance.

---

For companies and engineers working with pressure-containing parts in elevated temperature service, compliance with ASTM A739-90a(2022) ensures adherence to globally recognized best practices for alloy steel bars, supporting both safety and operational efficiency.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A739 −90a (Reapproved 2022)
Standard Specification for
Steel Bars, Alloy, Hot-Wrought, for Elevated Temperature or
Pressure-Containing Parts, or Both
This standard is issued under the fixed designation A739; 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 U.S. Department of Defense.
1. Scope 3. Ordering Information
1.1 This specification covers hot-wrought, ferritic alloy
3.1 Orders for material under this specification should
steel bars for elevated temperature or pressure-containing parts
include the following information:
suitable for fusion welding or both.
3.1.1 Quantity (weight or number of pieces),
3.1.2 Name of material (ferritic alloy steel bars),
1.2 The bars are furnished in the following grades:
3.1.3 Condition (hot wrought, normalized and tempered,
Grade B 11: 1.25 % chromium, 0.55 % molybdenum
Grade B 22: 2.25 % chromium, 1.00 % molybdenum machine straightened and descaled),
3.1.4 Dimensions (cross-sectional shape, size, and length),
1.3 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical 3.1.5 ASTM designation and date of issue,
conversions to SI units that are provided for information only 3.1.6 Grade (Table 1),
and are not considered standard.
3.1.7 Additions to the specification, and
3.1.8 End use.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
NOTE 1—A typical description is as follows: 10 000 lb, Ferritic Alloy
ization established in the Decision on Principles for the
Steel Bars, Hot Wrought Normalized and Tempered, and Descaled,
Development of International Standards, Guides and Recom-
1.000 in. diameter by 10 ft, ASTM A739 dated____, Grade B11, Special
mendations issued by the World Trade Organization Technical Straightened, Special Machined Fittings.
Barriers to Trade (TBT) Committee.
4. Materials and Manufacture
2. Referenced Documents
4.1 Melting Practice—The steel shall be made by one or
2.1 ASTM Standards: more of the following primary processes: open-hearth, basic-
A29/A29M SpecificationforGeneralRequirementsforSteel
oxygen, or electric-furnace. The primary melting may incor-
Bars, Carbon and Alloy, Hot-Wrought porate separate degassing or refining and may be followed by
A370 Test Methods and Definitions for Mechanical Testing
secondary melting using electroslag remelting or vacuum arc
of Steel Products
remelting. Where secondary melting is employed, the heat
shall be defined as all of the ingots remelted from a single
2.2 ASME Code:
primary heat.
ASME Boiler and Pressure Vessel Code
4.2 Condition—Unlessotherwisespecified,barsshallbehot
wrought, heat treated, and descaled.
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
4.3 Heat Treatment:
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.15 on Bars.
4.3.1 The bars shall be normalized and tempered.
Current edition approved March 1, 2022. Published March 2022. Originally
4.3.2 Austenitizing temperature shall be within the range
approved in 1976. Last previous edition approved in 2016 as A739 – 90a (2016).
from 1700 °F to 1800 °F (927 °C to 982 °C).
DOI: 10.1520/A0739-90AR22.
For ASME Boiler and Pressure Vessel Code applications, see related Specifi-
4.3.3 Cooling from the austenitizing temperature may be
cation SA-739 in Section II of that code.
accomplished by cooling in still air or moving air, at the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
producer’s option. When permitted by the purchaser, cooling
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
fromtheaustenitizingtemperaturemaybeacceleratedbyspray
the ASTM website.
or liquid quenching.
Available from American Society of Mechanical Engineers (ASME), ASME
4.3.4 Theminimumtemperingtemperatureshallbe1200 °F
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org. (649 °C) for Grade B11 and 1250 °F (677 °C) for Grade B22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A739−90a (2022)
...