ASTM A645/A645M-10(2022)

Standard Specification for Pressure Vessel Plates, 5 % and 5<fraction><num>1</num> <den>2</den></fraction> % Nickel Alloy Steels, Specially Heat Treated

ABSTRACT
This specification covers specially heat treated 5% and 5 1/2% nickel alloy steel plates intended primarily for welded pressure vessels for service at low or cryogenic temperatures. Plates are classified as Grade A and Grade B. The steel shall be killed and shall conform to the fine austenitic grain size requirements specified. Plates shall be heat treated in accordance with the required specifications. The steel shall conform to the chemical requirements specified. Tensions tests and impacts tests shall be made to meet the mechanical requirements specified.
SCOPE
1.1 This specification2 covers specially heat treated 5 % and 5 1/2 % nickel alloy steel plates intended primarily for welded pressure vessels for service at low or cryogenic temperatures.  
1.2 The maximum thickness of plates which can be supplied under this specification is limited only by the capacity of the material to meet the specified requirements.  
1.3 This material is susceptible to magnetization. Use of magnets in handling after heat treatment should be avoided if residual magnetism would be detrimental to subsequent fabrication or service.  
1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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-2022
• ICS: 77.140.30 - Steels for pressure purposes
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.11 - Steel Plates for Boilers and Pressure Vessels

Relations

• Refers: ASTM A578/A578M-17(2023) - Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications
• Effective Date: 01-Nov-2023
• Refers: ASTM A435/A435M-17(2023) - Standard Specification for Straight-Beam Ultrasonic Examination of Steel Plates
• Effective Date: 01-Nov-2023
• Refers: ASTM A577/A577M-17(2023) - Standard Specification for Ultrasonic Angle-Beam Examination of Steel Plates
• Effective Date: 01-Nov-2023
• Refers: ASTM A20/A20M-18 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Mar-2018
• Refers: ASTM A20/A20M-17 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 15-Nov-2017
• Refers: ASTM A578/A578M-17 - Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications
• Effective Date: 01-Nov-2017
• Refers: ASTM A20/A20M-15 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Nov-2015
• Refers: ASTM A20/A20M-14 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Oct-2014
• Refers: ASTM A20/A20M-13 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Oct-2013
• Refers: ASTM A577/A577M-90(2012) - Standard Specification for Ultrasonic Angle-Beam Examination of Steel Plates
• Effective Date: 01-Mar-2012
• Refers: ASTM A435/A435M-90(2012) - Standard Specification for Straight-Beam Ultrasonic Examination of Steel Plates
• Effective Date: 01-Mar-2012
• Refers: ASTM A578/A578M-07(2012) - Standard Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications
• Effective Date: 01-Mar-2012
• Refers: ASTM A20/A20M-11 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Nov-2011
• Refers: ASTM A20/A20M-10 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Oct-2010
• Refers: ASTM A20/A20M-09 - Standard Specification for General Requirements for Steel Plates for Pressure Vessels
• Effective Date: 01-Oct-2009

Overview

ASTM A645/A645M-10(2022) is a recognized ASTM standard specification focused on pressure vessel plates made from 5% and 5 1/2% nickel alloy steels. These steel plates are specially heat treated and are intended primarily for welded pressure vessels requiring excellent performance at low or cryogenic temperatures.

This standard applies to both Grade A and Grade B steel plates, with requirements for chemical composition, mechanical properties, and specific heat treatment processes. The steel is required to be killed and to conform to defined austenitic grain size criteria. Rigorous mechanical and impact testing ensures the reliability and quality of materials used in critical pressure vessel applications.

Key Topics

• Material Types and Grades: Covers specifically designed 5% and 5 1/2% nickel alloy steel plates in two grades, enabling use in demanding operating environments such as cryogenic conditions.
• Heat Treatment: Details precise heat treatment protocols for both grades to ensure optimal toughness and ductility at low temperatures.
• Mechanical and Impact Testing: Specifies tension and impact (Charpy V-notch) testing to guarantee mechanical properties and resistance to brittle fracture at low or cryogenic temperatures.
• Chemical Composition: Establishes strict requirements for elements such as carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, aluminum, and nitrogen to deliver consistent performance.
• Thickness and Size: No upper limit on plate thickness other than the manufacturer's ability to meet all heat treatment and testing standards.
• Handling Precautions: Notes susceptibility to magnetization after heat treatment, advising careful handling if residual magnetism could impact subsequent fabrication or service.
• Measurement Systems: Standard recognizes both inch-pound and SI units, but each must be used independently for compliance.

Applications

ASTM A645/A645M-10(2022) steel plates are widely used in the fabrication of welded pressure vessels, especially where operation at low or cryogenic temperatures is required. Key application areas include:

• Cryogenic Storage Vessels: Used for storing liquefied gases like oxygen, nitrogen, or LNG due to high impact strength and ductility at very low temperatures.
• Low-Temperature Pressure Vessels: Suitable for chemical, petrochemical, and energy industries where safe operation under low temperature and pressure cycling demands reliable materials.
• Welded Tanks and Structural Components: Applicable in critical infrastructure requiring plates with high toughness and controlled metallurgy.
• Customized Pressure Components: Offers flexibility with supplementary testing and requirements for applications demanding enhanced quality control (e.g., vacuum treatment, specialized impact testing).

The reliable performance of these nickel alloy steels under extreme conditions underscores their practical value for safety-critical engineering applications.

Related Standards

ASTM A645/A645M references and aligns with several related standards, making it part of a comprehensive suite for pressure vessel steel plates:

• ASTM A20/A20M - General Requirements for Steel Plates for Pressure Vessels (outlines testing and retesting, quality, marking, loading, and ordering).
• ASTM A435/A435M - Straight-Beam Ultrasonic Examination of Steel Plates.
• ASTM A577/A577M - Ultrasonic Angle-Beam Examination of Steel Plates.
• ASTM A578/A578M - Straight-Beam Ultrasonic Examination for Special Applications.
• ASME SA-645 - The ASME Boiler and Pressure Vessel Code (Section II) includes related requirements suitable for code-compliance in boiler and pressure vessel applications.

For organizations specifying materials for critical service pressure vessels, especially under low or cryogenic temperatures, adherence to ASTM A645/A645M-10(2022) helps ensure material quality, regulatory compliance, and safe operational performance.

Keywords: pressure vessel plate, nickel alloy steel, cryogenic steel, low temperature steel plate, ASTM A645, welded pressure vessel standards, steel plate requirements.

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: A645/A645M −10 (Reapproved 2022)
Standard Specification for
Pressure Vessel Plates, 5 % and 5 ⁄2 % Nickel Alloy Steels,
Specially Heat Treated
This standard is issued under the fixed designationA645/A645M; 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 specially heat treated 5 % and
1 A20/A20M SpecificationforGeneralRequirementsforSteel
5 ⁄2 % nickel alloy steel plates intended primarily for welded
Plates for Pressure Vessels
pressure vessels for service at low or cryogenic temperatures.
A435/A435M Specification for Straight-Beam Ultrasonic
1.2 The maximum thickness of plates which can be supplied
Examination of Steel Plates
under this specification is limited only by the capacity of the
A577/A577M Specification for Ultrasonic Angle-Beam Ex-
material to meet the specified requirements.
amination of Steel Plates
A578/A578M Specification for Straight-Beam Ultrasonic
1.3 This material is susceptible to magnetization. Use of
Examination of Rolled Steel Plates for Special Applica-
magnets in handling after heat treatment should be avoided if
tions
residual magnetism would be detrimental to subsequent fabri-
cation or service.
3. General Requirements and Ordering Information
3.1 Plates supplied to this material specification shall con-
1.4 The values stated in either inch-pound units or SI units
form to Specification A20/A20M. These requirements outline
are to be regarded separately as standard. Within the text, the
the testing and retesting methods and procedures, permitted
SI units are shown in brackets. The values stated in each
variations in dimensions and mass, quality and repair of
system are not exact equivalents; therefore, each system must
defects, marking, loading, and ordering information.
be used independently of the other. Combining values from the
two systems may result in nonconformance with the specifi-
3.2 In addition to the basic requirements of this
cation.
specification, certain supplementary requirements are available
when additional control, testing, or examination is required to
1.5 This standard does not purport to address all of the
meet end use requirements. The purchaser is referred to the
safety concerns, if any, associated with its use. It is the
listed supplementary requirements in this specification and to
responsibility of the user of this standard to establish appro-
the detailed requirements in Specification A20/A20M.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.3 If the requirements of this specification are in conflict
with the requirements of Specification A20/A20M, the require-
1.6 This international standard was developed in accor-
ments of this specification shall prevail.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Materials and Manufacture
Development of International Standards, Guides and Recom-
4.1 Steelmaking Practice—The steel shall be killed and
mendations issued by the World Trade Organization Technical
shall conform to the fine austenitic grain size requirements of
Barriers to Trade (TBT) Committee.
Specification A20/A20M.
5. Heat Treatment
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
5.1 Grade A plates shall be heat treated in accordance with
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
5.2.GradeBplatesshallbeheattreatedinaccordancewith5.3.
A01.11 on Steel Plates for Boilers and Pressure Vessels.
Current edition approved Sept. 1, 2022. Published September 2022. Originally
approved in 1971. Last previous edition approved in 2016 as A645/A645M – 10 For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(2016). DOI: 10.1520/A0645_A0645M-10R22. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
For ASME Boiler and Pressure Vessel Code applications see related Specifi- Standards volume information, refer to the standard’s Document Summary page on
cation SA-645 in Section II of that Code. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A645/A645M − 10 (2022)
TABLE 1 Chemical Requirements
Shell plates and other parts, including heads and reinforcing
pads that are heated above 1125 °F [605 °C] for forming, shall Composition, %
Element
be heat treated after forming, Grade A Grade B
Carbon, max
5.2 Grade A, Procedure and Sequence:
Heat Analysis 0.13 0.13
5.2.1 Hardening—The plates shall be heated to a tempera-
Produce Analysis 0.15 0.15
Manganese
ture within the range from 1575 °F to 1675 °F [855 °C to
Heat Analysis 0.30–0.60 0.90–1.50
915 °C], held within that temperature range for a minimum of
Product Analysis 0.25–0.66 0.84–1.59
1 h/in. [2.4 min/mm] of thickness, but in no case less than 15
Phosphorus, max
Heat Analysis 0.025 0.020
min, and then water-quenched to below 300 °F [150 °C].
Product Analysis 0.025 0.025
5.2.2 Intermediate Heat Treatment—The plates shall be
Sulfur, max
reheated to a temperature within the range from 1275 °F to
Heat Analysis 0.025 0.010
Product Analysis 0.025 0.015
1400 °F [690 °C to 760 °C], held within that temperature range
Silicon
for a minimum of 1 h/in. [2.4 min/mm] of thickness, but in no
A
Heat Analysis 0.20–0.40 0.15–0.30
A
case less than 15 min, and then water-quenched to below
Product Analysis 0.18–0.45 0.13–0.33
Nickel
300 °F [150 °C].
Heat Analysis 4.8–5.2 5.0–6.0
5.2.3 Tempering—The plates shall be reheated to a tempera-
Product Analysis 4.7–5.3 4.9–6.1
ture within the range from 1150 °F to 1225 °F [620 °C to
Chromium
Heat Analysis . 0.10–1.00
665 °C], held within that temperature range for a minimum of
Product Analysis . 0.06–1.05
1 h/in. [2.4 min/mm] of thickness, but in no case less than 15
Molybdenum
min, and then water-quenched or air cooled to below 300 °F
Heat Analysis 0.20–0.35 0.10–0.30
Product Analysis 0.17–0.38 0.09–0.33
[150 °C].
Aluminum, total
5.3 Grade B, Procedure and Sequence: Heat Analysis 0.02–0.12 0.02–0.05
Product Analysis 0.01–0.16 0.015–0.06
5.3.1 Hardening—The plates shall be heated to a tempera-
Nitrogen, max
ture within the range from 1470 °F to 1600 °F [800 °C to
Heat Analysis 0.020 0.010
Product Analysis 0.025 0.010
870 °C],heldwithinthattemperaturerangeforasufficienttime
A
to obtain uniform temperature throughout the plate thickness,
The specified minimum limit does not apply if the total aluminum is 0.030 % or
more, ore if the acid soluble aluminum content is 0.025 % or more.
...