ASTM A920/A920M-14(2019)

Standard Specification for Steel Bars, Microalloy, Hot-Wrought, Special Quality, Mechanical Properties

ABSTRACT
This specification covers standards for hot-wrought, special quality microalloyed carbon steel bars intended for use in applications where as-rolled mechanical properties are desired. A typical end use includes hydraulic cylinder shafts. The typical chemical composition of microalloyed carbon steel shall contain carbon, manganese, phosphorus, sulfur, and vanadium. Heat and product analyses shall be conducted wherein the material shall conform to the required chemical composition for vanadium, columbium (niobium), and molybdenum. The elements and specified chemical ranges shall not exceed the required limits. The steel bars shall undergo tension test and conform to the mechanical property requirements such as yield strength, tensile strength, and elongation.
SCOPE
1.1 This specification covers hot-wrought, special quality microalloyed carbon steel bars intended for use in applications where as-rolled mechanical properties are desired. A typical end use is hydraulic cylinder shafts.  
1.2 The bars shall be furnished to chemical composition and mechanical properties as provided herein. Chemical composition is based on standard carbon steel grades modified to include microalloying elements such as columbium (niobium), vanadium, or molybdenum. Three strength classes are available, designated 75 [520], 80 [550], and 100 [690], corresponding to the minimum yield strength in ksi.  
1.3 Sections and sizes of bar steels available are covered in Specification A29/A29M.  
1.4 Supplementary Requirements S1 to S5 are provided for use when additional controls or requirements are desired. These shall apply only when specified on the purchase order.  
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.6 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.  
1.7 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: 31-Aug-2019
• ICS: 77.140.20 - Stainless steels
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.15 - Bars

Relations

• Replaces: ASTM A920/A920M-14 - Standard Specification for Steel Bars, Microalloy, Hot-Wrought, Special Quality, Mechanical Properties
• Effective Date: 01-Sep-2019
• Refers: ASTM A370-24 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Mar-2024
• Refers: ASTM A576-23 - Standard Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality
• Effective Date: 01-Nov-2023
• Refers: ASTM E45-18a(2023) - Standard Test Methods for Determining the Inclusion Content of Steel
• Effective Date: 01-Nov-2023
• 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 A576-17 - Standard Specification for Steel Bars, Carbon, Hot-Wrought, Special Quality
• Effective Date: 01-Nov-2017
• Refers: ASTM A370-17 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Jan-2017
• 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 A370-15 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• 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

Overview

ASTM A920/A920M-14(2019): Standard Specification for Steel Bars, Microalloy, Hot-Wrought, Special Quality, Mechanical Properties sets comprehensive requirements for hot-wrought, special quality microalloyed carbon steel bars. Developed by ASTM International, this standard is designed for applications where as-rolled mechanical properties-such as high yield and tensile strength-are critical. The steel bars produced in accordance with ASTM A920/A920M are commonly used in demanding applications like hydraulic cylinder shafts. The standard outlines chemical composition, mechanical properties, manufacturing methods, testing procedures, and supplementary requirements, ensuring high reliability and consistent quality across industries.

Key Topics

• Microalloyed Steel Bars: Carbon steel bars are microalloyed by adding small quantities of elements such as vanadium, columbium (niobium), and molybdenum. These additions enhance mechanical properties by influencing the microstructure during hot rolling.
• Mechanical Properties: The standard specifies three strength classes-75 [520], 80 [550], and 100 [690]-based on minimum yield strengths in ksi [MPa]. This allows users to select material matched to required performance.
  • Minimum yield strength: 75, 80, or 100 ksi [520, 550, or 690 MPa]
  • Tensile strength and elongation requirements are also defined.
• Chemical Composition: Base compositions are derived from standard carbon steel grades and modified to meet specific limits for carbon, manganese, phosphorus, sulfur, and the required microalloying elements.
• Testing and Quality Control: Bars must undergo tension tests and conform to specified mechanical properties. Heat and product analyses ensure compliance with chemical composition limits.
• Manufacturing Requirements: Only killed steel (fully deoxidized) is permitted, and the bars must be hot-wrought and meet special quality standards for surface quality and internal soundness.
• Supplementary Requirements: Optional controls for chemical composition, inclusion cleanliness, calcium treatment, and surface condition may be specified by the purchaser.

Applications

ASTM A920/A920M-14(2019) is widely used in sectors where as-rolled, high-strength steel bars are essential due to demanding mechanical requirements. Typical applications include:

• Hydraulic Cylinder Shafts: The high yield strength and toughness make these bars ideal for hydraulic systems.
• Machinery Components: Used in parts that require superior mechanical properties and reliability in service.
• Construction and Infrastructure: Employed in specialized reinforcement and support elements where enhanced mechanical performance is needed.
• Automotive and Heavy Equipment Manufacturing: Suitable for applications that demand precise mechanical performance and consistent quality.

Related Standards

Understanding ASTM A920/A920M is enhanced by familiarity with related ASTM standards, which provide further details on manufacturing processes, testing, and applicable material grades:

• ASTM A29/A29M: General requirements for steel bars, carbon and alloy, hot-wrought.
• ASTM A370: Standard test methods and definitions for mechanical testing of steel products.
• ASTM A576: Specification for special quality hot-wrought carbon steel bars.
• ASTM E45: Test methods for determining the inclusion content of steel.

ASTM A920/A920M-14(2019) supports international trade and quality assurance by aligning with WTO Technical Barriers to Trade (TBT) principles, ensuring global acceptance and reliability.

Keywords: ASTM A920, microalloyed steel bars, hot-wrought steel, special quality, mechanical properties, hydraulic cylinder shafts, carbon steel bars, industrial steel standards.

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:A920/A920M −14 (Reapproved 2019)
Standard Specification for
Steel Bars, Microalloy, Hot-Wrought, Special Quality,
Mechanical Properties
This standard is issued under the fixed designationA920/A920M; 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.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This specification covers hot-wrought, special quality
microalloyed carbon steel bars intended for use in applications A29/A29M SpecificationforGeneralRequirementsforSteel
Bars, Carbon and Alloy, Hot-Wrought
where as-rolled mechanical properties are desired. A typical
end use is hydraulic cylinder shafts. A370 Test Methods and Definitions for Mechanical Testing
of Steel Products
1.2 Thebarsshallbefurnishedtochemicalcompositionand
A576 Specification for Steel Bars, Carbon, Hot-Wrought,
mechanical properties as provided herein. Chemical composi-
Special Quality
tion is based on standard carbon steel grades modified to
E45 Test Methods for Determining the Inclusion Content of
include microalloying elements such as columbium (niobium),
Steel
vanadium, or molybdenum. Three strength classes are
available, designated 75 [520], 80 [550], and 100 [690],
3. Terminology
corresponding to the minimum yield strength in ksi.
3.1 Definitions of Terms Specific to This Standard:
1.3 Sections and sizes of bar steels available are covered in
3.1.1 microalloyed steels, n—carbon steels to which small
Specification A29/A29M.
quantities of certain elements are added in order to enhance
1.4 Supplementary Requirements S1 to S5 are provided for mechanical properties.
use when additional controls or requirements are desired.
3.1.1.1 Discussion—This enhancement of mechanical prop-
These shall apply only when specified on the purchase order.
erties results from control of the temperature and cooling rate
during the hot-rolling process.
1.5 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
4. Ordering Information
each system are not necessarily exact equivalents; therefore, to
ensure conformance with the standard, each system shall be
4.1 Orders for material supplied to this specification should
used independently of the other, and values from the two
include the following, as required, to describe adequately the
systems shall not be combined.
desired material:
4.1.1 Quantity (weight or number of bars);
1.6 Unless the order specifies the applicable “M” specifica-
tion designation, the material shall be furnished to the inch- 4.1.2 Name of material (hot-rolled microalloyed steel bars);
pound units.
4.1.3 Dimensions;
4.1.4 ASTM specification number and date of issue;
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard- 4.1.5 Gradedesignationorchemicalcompositionlimits(see
ization established in the Decision on Principles for the
Section 7);
Development of International Standards, Guides and Recom-
4.1.6 Class;
mendations issued by the World Trade Organization Technical
4.1.7 Additions to the specification and Supplementary
Barriers to Trade (TBT) Committee.
Requirements, if required; and,
4.1.8 End use.
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.15 on Bars. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2019. Published September 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1993. Last previous edition approved in 2014 as A920/A920M–14. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A0920_A0920M–14R19. 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
A920/A920M−14 (2019)
TABLE 1 Typical Chemical Compositions of Microalloyed Carbon Steels
NOTE 1—These compositions are identical to those in Specification A576, with the exception of the addition of vanadium.
Base Grade Designation Chemical Composition Limits, %
C Mn PSV
10V40 0.37–0.44 0.60–0.90 0.040 max 0.050 max 0.02–0.20
10V45 0.43–0.50 0.60–0.90 0.040 max 0.050 max 0.02–0.20
11V37 0.32–0.39 1.35–1.65 0.040 max 0.08–0.13 0.02–0.20
11V41 0.37–0.45 1.35–1.65 0.040 max 0.08–0.13 0.02–0.20
15V24 0.19–0.25 1.35–1.65 0.040 max 0.050 max 0.02–0.20
15V41 0.36–0.44 1.35–1.65 0.040 max 0.050 max 0.02–0.20
5. General Requirements 7.4 Titanium shall be added when specified for refinement
of the ferritic-pearlitic (or bainitic) or austenitic grain size.
5.1 Material furnished under this specification shall con-
When titanium is specified, the titanium limits shall be as
form to the applicable requirements of the current edition of
agreed upon between producer and purchaser. The titanium
Specification A29/A29M, unless otherwise provided herein.
content shall be reported.
6. Materials and Manufacture
7.5 Nitrogenmaybespecifiedasasupplementtovanadium,
6.1 Melting Practice—The steel shall be produced in accor- columbium, or titanium. If specified, the nitrogen content shall
not exceed 0.030 % and shall be reported.
dance with the applicable methods for primary and secondary
melting outlined in Specification A576.
7.6 Sampling for heat and product analysis shall be in
6.2 The steel shall be killed. Supplementary Requirements accordance with the requirements of Specification A29/A29M.
S1 through S5 may be invoked upon agreement between
producer and purchaser.
8. Mechanical Properties
6.3
...