ASTM A20/A20M-20

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:A20/A20M −20
Standard Specification for
General Requirements for Steel Plates for Pressure Vessels
This standard is issued under the fixed designation A20/A20M; 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.
A
1. Scope*
Title of Specification ASTM Designation
Pressure Vessel Plates, Heat-Treated, Carbon- A537/A537M
1.1 This general requirements specification covers a group
Manganese-Silicon Steel
of common requirements that, unless otherwise specified in the Pressure Vessel Plates, Alloy Steel, Quenched-and- A542/A542M
Tempered, Chromium-Molybdenum, and Chromium-
applicable product specification, apply to rolled steel plates for
Molybdenum-Vanadium
pressure vessels covered by each of the following product
Pressure Vessel Plates, Alloy Steel, Quenched and A543/A543M
specifications issued by ASTM: Tempered Nickel-Chromium-Molybdenum
Pressure Vessel Plates, Alloy Steel, Quenched and A553/A553M
A
Title of Specification ASTM Designation
Tempered 7, 8, and9%Nickel
Pressure Vessel Plates, Alloy Steel, Nickel A203/A203M
Pressure Vessel Plates, Carbon Steel, Manganese- A562/A562M
Pressure Vessel Plates, Alloy Steel, Molybdenum A204/A204M
Titanium for Glass or Diffused Metallic Coatings
Pressure Vessel Plates, Alloy Steel, Manganese- A225/A225M
Pressure Vessel Plates, Carbon Steel, High Strength, for A612/A612M
Vanadium-Nickel
Moderate and Lower Temperature Service
Stainless Chromium Steel-Clad Plate A263 1
Pressure Vessel Plates, 5 % and 5 ⁄2 % Nickel Alloy A645/A645M
Stainless Chromium-Nickel Steel-Clad Plate A264
Steels, Specially Heat Treated
Nickel and Nickel-Base Alloy-Clad Steel Plate A265
Pressure Vessel Plates, Carbon-Manganese-Silicon A662/A662M
Pressure Vessel Plates, Carbon Steel, Low- and A285/A285M
Steel, for Moderate and Lower Temperature Service
Intermediate-Tensile Strength
Pressure Vessel Plates, Carbon-Manganese-Silicon A724/A724M
Pressure Vessel Plates, Carbon Steel, Manganese-Silicon A299/A299M
Steel, Quenched and Tempered, for Welded Pressure
Pressure Vessel Plates, Alloy Steel, Manganese- A302/A302M
Vessels
Molybdenum and Manganese-Molybdenum-Nickel
Pressure Vessel Plates, Low-Carbon Age-Hardening A736/A736M
Pressure Vessel Plates, Alloy Steel, Double- A353/A353M
Nickel-Copper-Chromium-Molybdenum-Columbium
Normalized and Tempered9%Nickel
(Niobium) Alloy Steel
Pressure Vessel Plates, Alloy Steel, Chromium- A387/A387M
Pressure Vessel Plates, High-Strength Low-Alloy Steel A737/A737M
Molybdenum
Pressure Vessel Plates, Heat-Treated, Carbon- A738/A738M
Pressure Vessel Plates, Carbon Steel, High Strength A455/A455M
Manganese-Silicon Steel, for Moderate and Lower
Manganese
Temperature Service
Pressure Vessel Plates, Carbon Steel, for Intermediate- A515/A515M
Pressure Vessel Plates, Alloy Steel, Chromium- A832/A832M
and Higher-Temperature Service
Molybdenum-Vanadium
Pressure Vessel Plates, Carbon Steel, Moderate- and A516/A516M
Steel Plates for Pressure Vessels, Produced by A841/A841M
Lower-Temperature Service
Thermo-Mechanical Control Process (TMCP)
Pressure Vessel Plates, Alloy Steel, High-Strength, A517/A517M
Steel Plates, 9 % Nickel Alloy, for Pressure Vessels, A844/A844M
Quenched and Tempered
Produced by the Direct-Quenching Process
Pressure Vessel Plates, Alloy Steel, Quenched and A533/A533M
Pressure Vessel Plates, Alloy Steel, Chromium- A1017/A1017M
Tempered, Manganese-Molybdenum and Manganese-
Molybdenum-Tungsten
Molybdenum-Nickel
A
These designations refer to the latest issue of the respective specification which
appears in the Annual Book of ASTM Standards, Vol 01.04.
1.1.1 This general requirements specification also covers a
group of supplementary requirements that are applicable to
severaloftheaboveproductspecificationsasindicatedtherein.
Such requirements are provided for use if additional testing or
additional restrictions are required by the purchaser, and apply
only if specified individually in the purchase order.
1.2 Appendix X1 provides information on coil as a source
This specification is under the jurisdiction ofASTM Committee A01 on Steel, of plates for pressure vessels.
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
1.3 Appendix X2 provides information on the variability of
A01.11 on Steel Plates for Boilers and Pressure Vessels.
tensile properties in plates for pressure vessels.
Current edition approved Nov. 1, 2020. Published November 2020. Originally
approved in 1950. Last previous edition approved in 2019 as A20/A20M – 19. DOI:
1.4 Appendix X3 provides information on the variability of
10.1520/A0020_A0020M-20.
Charpy-V-Notch impact test properties in plates for pressure
ForASME Boiler and Pressure Vessel Code applications, see related Specifica-
tion SA-20/SA-20M in Section II of that Code. vessels.
*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
A20/A20M−20
1.5 Appendix X4 provides information on cold bending of A285/A285M Specification for Pressure Vessel Plates, Car-
plates, including suggested minimum inside radii for cold bon Steel, Low- and Intermediate-Tensile Strength
bending.
A299/A299M Specification for Pressure Vessel Plates, Car-
bon Steel, Manganese-Silicon
1.6 These materials are intended to be suitable for fusion
A302/A302M Specification for PressureVessel Plates,Alloy
welding. When the steel is to be welded, it is presupposed that
Steel, Manganese-Molybdenum and Manganese-
aweldingproceduresuitableforthegradeofsteelandintended
Molybdenum-Nickel
use or service will be utilized.
A353/A353M Specification for PressureVessel Plates,Alloy
1.7 In case of any conflict in requirements, the requirements
Steel, Double-Normalized and Tempered 9 % Nickel
oftheapplicableproductspecificationprevailoverthoseofthis
A370 Test Methods and Definitions for Mechanical Testing
general requirements specification.
of Steel Products
1.8 Additional requirements that are specified in the pur-
A387/A387M Specification for PressureVessel Plates,Alloy
chase order and accepted by the supplier are permitted,
Steel, Chromium-Molybdenum
provided that such requirements do not negate any of the
A435/A435M Specification for Straight-Beam Ultrasonic
requirements of this general requirements specification or the
Examination of Steel Plates
applicable product specification.
A455/A455M Specification for Pressure Vessel Plates, Car-
bon Steel, High-Strength Manganese
1.9 For purposes of determining conformance with this
A515/A515M Specification for Pressure Vessel Plates, Car-
general requirements specification and the applicable product
bon Steel, for Intermediate- and Higher-Temperature Ser-
specification, values are to be rounded to the nearest unit in the
vice
right-hand place of figures used in expressing the limiting
values in accordance with the rounding method of Practice A516/A516M Specification for Pressure Vessel Plates, Car-
bon Steel, for Moderate- and Lower-Temperature Service
E29.
A517/A517M Specification for PressureVessel Plates,Alloy
1.10 The values stated in either SI units or inch-pound units
Steel, High-Strength, Quenched and Tempered
are to be regarded separately as standard. The values stated in
A533/A533M Specification for PressureVessel Plates,Alloy
each system may not be exact equivalents; therefore, each
Steel, Quenched and Tempered, Manganese-Molybdenum
system shall be used independently of the other. Combining
and Manganese-Molybdenum-Nickel
values from the two systems may result in non-conformance
A537/A537M Specification for PressureVessel Plates, Heat-
with the standard.
Treated, Carbon-Manganese-Silicon Steel
1.11 This general requirements specification and the appli-
A542/A542M Specification for PressureVessel Plates,Alloy
cable product specification are expressed in both inch-pound
Steel, Quenched-and-Tempered, Chromium-
unitsandSIunits;unlesstheorderspecifiestheapplicable“M”
Molybdenum, and Chromium-Molybdenum-Vanadium
specification designation (SI units), the plates are to be
A543/A543M Specification for PressureVessel Plates,Alloy
furnished to inch-pound units.
Steel, Quenched and Tempered Nickel-Chromium-
1.12 This international standard was developed in accor-
Molybdenum
dance with internationally recognized principles on standard-
A553/A553M Specification for PressureVessel Plates,Alloy
ization established in the Decision on Principles for the
Steel, Quenched and Tempered 7, 8, and 9 % Nickel
Development of International Standards, Guides and Recom-
A562/A562M Specification for Pressure Vessel Plates, Car-
mendations issued by the World Trade Organization Technical
bon Steel, Manganese-Titanium for Glass or Diffused
Barriers to Trade (TBT) Committee.
Metallic Coatings
A577/A577M Specification for Ultrasonic Angle-Beam Ex-
2. Referenced Documents
amination of Steel Plates
2.1 ASTM Standards:
A578/A578M Specification for Straight-Beam Ultrasonic
A203/A203M Specification for PressureVessel Plates,Alloy
Examination of Rolled Steel Plates for Special Applica-
Steel, Nickel
tions
A204/A204M Specification for PressureVessel Plates,Alloy
A612/A612M Specification for Pressure Vessel Plates, Car-
Steel, Molybdenum
bon Steel, High Strength, for Moderate and Lower Tem-
A225/A225M Specification for PressureVessel Plates,Alloy
perature Service
Steel, Manganese-Vanadium-Nickel
A645/A645M Specification for Pressure Vessel Plates, 5 %
A263 Specification for Stainless Chromium Steel-Clad Plate
and 5 ⁄2 % Nickel Alloy Steels, Specially Heat Treated
A264 Specification for Stainless Chromium-Nickel Steel-
A662/A662M Specification for Pressure Vessel Plates,
Clad Plate
Carbon-Manganese-Silicon Steel, for Moderate and
A265 Specification for Nickel and Nickel-Base Alloy-Clad
Lower Temperature Service
Steel Plate
A700 Guide for Packaging, Marking, and Loading Methods
for Steel Products for Shipment
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
A724/A724M Specification for Pressure Vessel Plates,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Carbon-Manganese-Silicon Steel, Quenched and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Tempered, for Welded Pressure Vessels
A20/A20M−20
A736/A736M Specification for PressureVessel Plates, Low- plate-as-rolled that does not define the actual condition of a
Carbon Age-Hardening Nickel-Copper-Chromium- plate,butdefinesthesingularproductofaslaboringotthathas
Molybdenum-Columbium (Niobium) Alloy Steel been hot-rolled
A737/A737M SpecificationforPressureVesselPlates,High-
3.1.2 coil—hot-rolled steel in coil form for processing into
Strength, Low-Alloy Steel
finished plates.
A738/A738M Specification for PressureVessel Plates, Heat-
3.1.3 exclusive—when used in relation to ranges, as for
Treated, Carbon-Manganese-Silicon Steel, for Moderate
ranges of thicknesses in the tables of permissible variations in
and Lower Temperature Service
dimensions, the term is intended to exclude only the greater
A751 Test Methods, Practices, and Terminology for Chemi-
value of the range. Thus, a range from 60 to 72 in. [1500 to
cal Analysis of Steel Products
1800 mm] exclusive includes 60 in. [1500 mm], but does not
A770/A770M Specification for Through-Thickness Tension
include 72 in. [1800 mm].
Testing of Steel Plates for Special Applications
3.1.4 heat treatment terms—see 3.1.11, and Terminology
A832/A832M Specification for PressureVessel Plates,Alloy
A941.
Steel, Chromium-Molybdenum-Vanadium
A841/A841M Specification for Steel Plates for Pressure
3.1.5 hot forming—a forming operation producing perma-
Vessels, Produced by Thermo-Mechanical Control Pro-
nent deformation, performed after the plate has been heated to
cess (TMCP)
the temperature required to produce grain refinement.
A844/A844M Specification for Steel Plates, 9 % Nickel
3.1.6 hot-rolled (hot rolling)—for plates, the process de-
Alloy, for Pressure Vessels, Produced by the Direct-
scribed for a plate that has been rolled from a slab or ingot
Quenching Process
whose starting temperature is suitably above the recrystalliza-
A941 TerminologyRelatingtoSteel,StainlessSteel,Related
tion temperature of the metal to be rolled.
Alloys, and Ferroalloys
3.1.6.1 Discussion—Hot-rolled may be used in conjunction
A1017/A1017M Specification for Pressure Vessel Plates,
with any rolling process to more effectively describe a specific
Alloy Steel, Chromium-Molybdenum-Tungsten
condition, for example; hot-rolled as-rolled; hot-rolled control-
E21 TestMethodsforElevatedTemperatureTensionTestsof
rolled, etc.
Metallic Materials
3.1.7 manufacturer—the organization that directly controls
E29 Practice for Using Significant Digits in Test Data to
the conversion of steel ingots or slabs, by hot rolling, into
Determine Conformance with Specifications
plate-as-rolled or into coil; and for plates produced from
E112 Test Methods for Determining Average Grain Size
plate-as-rolled, the organization that directly controls, or is
E208 Test Method for Conducting Drop-Weight Test to
responsible for, one or more of the operations involved in
Determine Nil-Ductility Transition Temperature of Fer-
finishing the plates. Such finishing operations include leveling,
ritic Steels
cutting to length, testing, inspection, conditioning, heat treat-
E709 Guide for Magnetic Particle Testing
ment(ifapplicable),packaging,marking,loadingforshipment,
2.2 American Society of Mechanical Engineers Code:
and certification.
ASME Boiler and Pressure Vessel Code, Section IX
3.1.7.1 Discussion—The finishing operations need not be
2.3 U.S. Federal Standard:
done by the organization that did the hot rolling of the plate.
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
For plates produced from coil, see also 3.1.2.
2.4 Automotive Industry Action Group Standard:
3.1.8 mill edge—the normal edge produced by rolling be-
B1 Bar Code Symbology Standard
tween horizontal finishing rolls.Amill edge does not conform
to any definite contour. Mill edge plates have two mill edges
3. Terminology
and two trimmed edges.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 as-rolled—for plates, the condition of a plate that has 3.1.8.1 Discussion—Mill edge plates may at times be side-
been hot-rolled and will not be or has not yet been heat treated. trimmed on one or both sides at the discretion of the manu-
3.1.1.1 Discussion—The term as-rolled by itself is not facturer.
meant to refer to plates that have been hot-rolled using control-
3.1.9 plate identifier—the alpha, numeric, or alphanumeric
rolling (CR), direct quench (DQT), thermo-mechanical control designation used to identify the plate.
rolling (TMCP), recrystalization control rolling (RCR), or any
3.1.10 plates—flat hot-rolled steel, ordered to thickness or
similar methods that are intended to produce a set of properties
weight and typically to width and length, commonly available
that are not normally achievable were they not employed. The
by size as follows:
term as-rolled is to be distinguished from the established term
Width, in. [mm] Thickness, in. [mm]
Over 8 [200] over 0.229 [6.0 mm and over]
Over 48 [1200] over 0.179 [4.6 mm and over]
Available from American Society of Mechanical Engineers (ASME), ASME
3.1.10.1 Discussion—Steel plates are available in various
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
thickness, width, and length combinations dependent upon
Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
equipment and processing capabilities of various manufactur-
Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
ers and processors. Historic limitations of a plate based upon
Available fromAutomotive IndustryAction Group (AIAG), 26200 Lahser Rd.,
Suite 200, Southfield, MI 48033, http://www.aiag.org. dimensions (thickness, width, and length) do not take into
A20/A20M−20
account current production and processing capabilities. To 4.1.10 Supplementary requirements, if any (test specimen
qualify any plate to a particular product specification requires heat treatment, special impact test requirements, etc.),
that all appropriate and necessary tests be performed and that
4.1.11 Provisions for delivery with mill edges and any
the results meet the limits prescribed in that product specifi- special permissible variations (see 14.4), and
cation.Ifthenecessarytestsrequiredbyaproductspecification
4.1.12 Additional requirements, if any.
can not be conducted, the plate can not be qualified to that
specification. This general requirements specification contains
5. Materials and Manufacture
permitted variations for the commonly available sizes. Permit-
5.1 Thesteelshallbemadeinanopen-hearth,basic-oxygen,
ted variations for other sizes are subject to agreement between
orelectric-arcfurnace,possiblyfollowedbyadditionalrefining
the purchaser and the manufacturer or processor, whichever is
in a ladle metallurgy furnace (LMF), or by another method; or
applicable.
secondary melting by vacuum-arc remelting (VAR), electro-
3.1.11 precipitation heat treatment—a subcritical tempera-
slag remelting (ESR), or another method.
ture thermal treatment performed to cause precipitation of
5.2 The steel may be strand cast or cast in stationary molds.
submicroscopic constituents, and so forth, to result in enhance-
5.2.1 Strand Cast Slabs:
ment of some desirable property.
5.2.1.1 If heats of the same nominal chemical composition
3.1.12 processor—the organization that directly controls, or
are consecutively strand cast at one time, the heat number
is responsible for, operations involved in the processing of coil
assigned to the cast product (slab) may remain unchanged until
into finished plates. Such processing operations include
all of the steel in the slab is from the following heat.
decoiling, leveling, cutting to length, testing, inspection,
5.2.1.2 When two consecutively strand cast heats have
conditioning, heat treatment (if applicable), packaging,
different nominal chemical composition ranges, the manufac-
marking, loading for shipment, and certification.
turer shall remove the transition material by any established
3.1.12.1 Discussion—Theprocessingoperationsneednotbe
procedure that positively separates the grades.
done by the organization that did the hot rolling of the coil. If
5.3 The ratio of reduction of thickness from a strand-cast
only one organization is involved in the hot rolling and
slab to plate shall be at least 3.0:1, except that reduction ratios
processing operations, that organization is termed the manu-
as low as 2.0:1 are permitted if all of the following limitations
facturer for the hot rolling operation and the processor for the
are met:
processing operations. If more than one organization is in-
volved in the hot rolling and processing operations, the 5.3.1 The purchaser agrees to the use of such reduction
organization that did the hot rolling is termed the manufacturer ratios.
and the organization that does one or more processing opera-
5.3.2 The applicable product specification is A299/A299M,
tions is termed a processor. A515/A515M,A516/A516M,A537/A537M,A662/A662M,or
A737/A737M.
3.2 Refer to Terminology A941 for additional terms used in
5.3.3 The specified plate thickness is 3.0 in. [75 mm] or
this standard.
more.
5.3.4 One or more of the following low hydrogen practices
4. Ordering Information
are used: vacuum degassing during steelmaking; controlled
4.1 Orders should include the following information, as
soaking of the slabs or plates; or controlled slow cooling of the
necessary, to adequately describe the desired product.
slabs or plates.
4.1.1 Quantity (weight [mass] or number of plates),
5.3.5 The sulfur content is 0.004 % or less, based upon heat
4.1.2 Dimensions,
analysis.
4.1.3 Name of product (for example, plates, carbon steel;
5.3.6 One or more of the following practices are used:
plates, alloy steel),
electromagnetic stirring during strand casting; soft reduction
4.1.4 Specification designation (including type, class, and
during strand casting; heavy pass reductions or other special
grade as applicable) and year-date,
practices during plate rolling; or combined forging and rolling
4.1.5 Condition (as-rolled, normalized, quenched and
during plate rolling.
tempered, etc. If heat treatment of plate is to be performed by
5.3.7 The plates are ultrasonically examined in accordance
the fabricator, this is to be stated.Also, if purchaser specifies a
with Specification A578/A578M, Level C based on continuous
heat-treatment cycle, this is to be stated),
scanning over 100 % of the plate surface.
4.1.6 Impact test requirements, if any (see Section 12). (For
5.3.8 The plates are through-thickness tension tested in
Charpy V-notch test, include test specimen orientation, testing
accordance with Specification A770/A770M.
temperature,andacceptancecriteria.Fordrop-weighttest,give
5.4 Unless otherwise specified in the purchase order, plates
testing temperature),
shall be produced from plate-as-rolled or from coil.
4.1.7 Exclusion of either plates produced from coil or plates
produced from plate-as-rolled, if applicable. (See 5.4 and
5.5 Coils are excluded from qualification to the applicable
Appendix X1.)
product specification until they are decoiled, leveled, cut to
4.1.8 Limits for grain refining elements other than length, and tested by the processor in accordance with the
aluminum, if applicable (see 8.3.2),
specified requirements (see Sections 9, 10, 11, 12, 13, 14, 15,
4.1.9 Paint marking (see 13.2.1), 16, and 20.)
A20/A20M−20
5.5.1 Plates produced from coil shall not contain splice applicable grade, class, and type. In addition, for elements that
welds, unless approved by the purchaser. are listed in Table 1 but are not specified or restricted in the
applicable product specification for the applicable grade, class,
6. Heat Treatment
and type, heat analyses shall conform to the applicable heat
analysis limits given in Table 1.
6.1 If plates are required to be heat treated, the heat
treatment shall be performed by the manufacturer, the
7.2 Product Analysis:
processor, or the fabricator, unless otherwise specified in the
7.2.1 Sampling for chemical analysis and methods of analy-
applicable product specification.
sis shall be in accordance with Test Methods, Practices, and
Terminology A751.
6.2 If the heat treatment required by the applicable product
specification is to be performed by the purchaser or the 7.2.2 For each plate-as-rolled, the purchaser shall have the
option of chemically analyzing a broken tension test specimen
purchaser’s agent, and the plates are to be supplied by the
manufacturer or processor in a condition other than that or a sample taken from the same relative location as that from
which the tension test specimen was obtained.
required by the applicable product specification, the order shall
so state. 7.2.3 For elements that are specified or restricted by the
applicable product specification for the applicable grade, class,
6.2.1 If plates are ordered without the heat treatment re-
and type, product analyses shall conform to the product
quired by the applicable product specification, heat treatment
analysis requirements of the applicable product specification
of the plates to conform to the requirements of the applicable
for the applicable grade, class, and type.
product specification shall be the responsibility of the pur-
chaser. 7.2.4 For elements that are listed in Table 1 but are not
specified or restricted by the applicable product specification
6.3 If heat treatment is to be performed, the plates shall be
heat treated as specified in the applicable product specification.
The purchaser may specify the heat treatment to be used,
provided it is not in conflict with the requirements of the
TABLE 1 Limits on Elements (see 7.1.3 and 7.2.4)
applicable product specification.
A
Copper, max % Heat analysis 0.40
Product analysis 0.43
6.4 If normalizing is to be performed by the fabricator, the
plates shall be either normalized or heated uniformly for hot A
Nickel, max % Heat analysis 0.40
forming, provided that the temperature to which the plates are Product analysis 0.43
heated for hot forming does not significantly exceed the
A,B
Chromium, max % Heat analysis 0.30
normalizing temperature.
Product analysis 0.34
6.5 If no heat treatment is required, the manufacturer or
A,B
Molybdenum, max % Heat analysis 0.12
processor shall have the option of heat treating the plates by
Product analysis 0.13
normalizing, stress relieving, or normalizing and then stress
C
Vanadium, max % Heat analysis 0.03
relieving to meet the requirements of the applicable product
Product analysis 0.04
specification.
D E
Columbium (Niobium), max % Heat analysis 0.02
6.6 If approved by the purchaser, cooling rates faster than
Product analysis 0.03
those obtained by cooling in air are permissible to achieve
F
Titanium, max % Heat analysis 0.03
specified mechanical properties, provided that the plates are
Product analysis 0.04
subsequently tempered in the temperature range from 1100 to
Boron, max % Heat analysis 0.0010
1300°F [595 to 705°C].
Product analysis 0.0015
A
7. Chemical Composition
In addition for each heat, based upon the heat analysis, the sum of copper,
nickel, chromium, and molybdenum shall not exceed 1.00 %, unless one or more
7.1 Heat Analysis:
ofthoseelementsarespecifiedorrestrictedbytheapplicableproductspecification
7.1.1 Sampling for chemical analysis and methods of analy- for the applicable grade, class, and type.
B
In addition for each heat, based upon the heat analysis, the sum of chromium
sis shall be in accordance with Test Methods, Practices, and
and molybdenum shall not exceed 0.32 %, unless one or both of those elements
Terminology A751.
arespecifiedorrestrictedbytheapplicableproductspecificationfortheapplicable
grade, class, and type.
7.1.2 For each heat, the heat analysis shall include determi-
C
Byagreementbetweenthepurchaserandthesupplier,theheatanalysislimitfor
nationofthecontentofcarbon,manganese,phosphorus,sulfur,
vanadium is permitted to be increased to a value not higher than 0.10 %, and the
silicon, nickel, chromium, molybdenum, copper, vanadium,
product analysis limit for vanadium is permitted to be increased to a value not
higher than 0.11 %.
columbium (niobium); any other element that is specified or
D
Columbium and niobium are interchangeable names for the same element and
restricted by the applicable product specification for the
both names are acceptable for use in A01 specifications.
E
applicable grade, class, and type; aluminum, if the aluminum
Byagreementbetweenthepurchaserandthesupplier,theheatanalysislimitfor
columbium (niobium) is permitted to be increased to a value not higher that
content is to be used in place of austenitic grain size testing of
0.05 %, and the product analysis limit for columbium (niobium) is permitted to be
the heat (see 8.3.2.1); and any other austenitic grain refining
increased to a value not higher than 0.06 %.
F
element for which limits are specified in the purchase order Byagreementbetweenthepurchaserandthesupplier,theheatanalysislimitfor
titanium is permitted to be increased to a value not higher than 0.04 %, and the
(see 8.3.2).
productanalysislimitfortitaniumispermittedtobeincreasedtoavaluenothigher
7.1.3 Heat analyses shall conform to the heat analysis
than 0.05 %.
requirements of the applicable product specification for the
A20/A20M−20
for the applicable grade, class, and type, product analyses shall by agreement with the purchaser, the metal so removed may be
conform to the applicable product analysis limits given in replaced with weld metal (see 9.4).
Table 1.
9.3 Edge Imperfections:
7.3 Referee Analysis—For referee purposes, Test Methods, 9.3.1 Laminar-type discontinuities 1 in. [25 mm] and less in
Practices, and Terminology A751 shall be used. length visible to the unaided eye on an edge of a plate as
prepared for shipment by the manufacturer or processor are
8. Metallurgical Structure
acceptable and do not require exploration.
8.1 Where austenitic grain size testing is required, such 9.3.2 All larger discontinuities shall be explored to deter-
minetheirdepthandextent.Discontinuitiesshallbeconsidered
testing shall be a McQuaid Ehn test in accordance with Test
Methods E112 and at least 70 % of the grains in the area continuous when located in the same plane within 5 % of the
plate thickness and separated by a distance less than the length
examined shall meet the specified grain size requirement.
of the smaller of two adjacent discontinuities.
8.2 Coarse Austenitic Grain Size—Where coarse austenitic
9.3.3 Indications visible to the unaided eye on the cut edges
grain size is specified one austenitic grain size test per heat
of a plate as prepared for shipment by the manufacturer or
shall be made and the grain size number so determined shall be
processor shall not exceed the limits given in Columns 1 and 2
in the range of 1 to 5 inclusive.
of Table A1.14 [A2.14].
8.3 Fine Austenitic Grain Size:
9.3.4 Larger indications shall be removed by the manufac-
8.3.1 Except as allowed in 8.3.2, and when fine austenitic
turer or processor by grinding, provided that the resultant
grainsizeisspecified,orwhentheproducerelectstodetermine
cavity does not exceed the limits given in Columns 3 and 4 of
the grain size, one McQuaid Ehn test per heat shall be made
Table A1.14 [A2.14].
and the austenitic grain size number so determined shall be 5
9.3.5 Indications of greater magnitude shall be cause for
or higher, and the chemical requirements of 8.3.2 do not apply.
rejection of the plate, except that, by agreement with the
purchaser, the defects may be removed and replaced with weld
NOTE 1—Such austenitic grain size numbers may be achieved with
lower contents of austenitic grain refining elements than 8.3.2 requires for
metal (see 9.4).
austenitic grain size testing to be waived.
9.3.6 Indications on the edges of a plate cut during the
8.3.2 Unless testing for fine austenitic grain size is specified fabrication shall be cause for rejection of the plate at the
discretion of the purchaser if the magnitude exceeds the limits
in the purchase order or the producer elects to test for fine
austenitic grain size, the austenitic grain size test need not be given in Columns 5 and 6 of TableA1.14 [A2.14]. The defects
may be removed and replaced with weld metal (see 9.4).
made for any heat that has, by heat analysis, one or more of the
following: 9.3.7 Fabricators should be aware that edge cracks may
initiate upon bending a sheared or burned edge during the
8.3.2.1 A total aluminum content of 0.020 % or more.
8.3.2.2 An acid soluble aluminum content of 0.015 % or fabrication process. This is not considered to be a fault of the
steel, but is rather a function of the induced cold work or heat
more.
8.3.2.3 A content for an austenitic grain refining element affected zone.
that exceeds the minimum value agreed to by the purchaser as
9.4 Repair by Welding:
being sufficient for austenitic grain size testing to be waived.
9.4.1 Repair welding shall be permitted only with the
8.3.2.4 Contents for the combination of two or more auste-
approval of the purchaser.
nitic grain refining elements that exceed the applicable mini-
9.4.2 Preparation for repair welding shall include inspection
mum values agreed to by the purchaser as being sufficient for
to confirm complete removal of the defect.
austenitic grain size testing to be waived.
9.4.3 Repairs shall be made utilizing welding procedures
8.3.2.5 The analysis for the elements mentioned in 8.3.2.1,
qualified in accordance with Section IX of the
8.3.2.2, 8.3.2.3,or 8.3.2.4 shall be included in the test report.
ASME Boiler and Pressure Vessel Code and repair welding
shall be done by welders or welding operators meeting the
9. Quality
qualification requirements of Section IX.
9.1 General—Plates shall be free of injurious defects and
9.4.4 The weld metal shall have the A-number analysis
shall have a workmanlike finish.
corresponding to the equivalent ASME P-number of the plate,
except that A-1 or A-2 analysis weld metal may be employed
9.2 Surface Imperfections:
9.2.1 For plates produced from plate-as-rolled, all injurious for P-1 plates. Other weld metals may be employed that are
compatible with the plate being repaired, if so approved by the
surface imperfections shall be removed by the manufacturer.
For plates produced from coil, all injurious surface imperfec- purchaser. Such weld metals shall be qualified in accordance
with the requirements of Section IX of the
tions shall be removed by the processor.
9.2.1.1 Shallow imperfections shall be ground to sound ASME Boiler and Pressure Vessel Code.
9.4.5 If Charpy impact tests of the plate are required, the
metal; the ground area shall be well faired and the thickness of
the ground plate shall not be reduced below the minimum welding procedure qualification tests shall also include Charpy
impact tests of the weld, the heat-affected zone, and the plate,
thickness permitted.
9.2.1.2 All surface imperfections, the removal of which will and the test results shall be reported to the purchaser.
reduce the plate thickness below the minimum thickness 9.4.6 If the plate is subjected to normalizing, quenching and
permitted, shall be cause for rejection of the plate, except that, tempering, hot forming, or post-weld heat treating, the welding
A20/A20M−20
procedure qualification test plates and the weld repaired plate quenchedandtemperedplates,onetensiontestcouponshallbe
shall be subjected to the thermal heat treatment as specified by taken from each coil. Two tension test coupons shall be taken
the purchaser. from each quenched and tempered plate, as heat treated.
9.4.7 In addition, repair welds shall meet the requirements
11.1.4 Plates Produced from Coil and Qualified Using Test
of the construction code specified by the purchaser.
Specimens Taken from Test Coupons Heat Treated by Other
than Stress Relieving—One tension test coupon shall be taken
10. Test Methods
from each coil.
10.1 All tests shall be conducted in accordance with Test
11.2 Orientation of Test Specimens—The longitudinal axis
Methods and Definitions A370.
of the tension test specimens shall be transverse to the final
10.2 Yield strength shall be determined by either the 0.2 %
rolling direction of the plate.
offsetmethodorthe0.5 %extensionunderloadmethod,unless
11.3 Location of Test Coupons—Tension test coupons shall
otherwise stated in the applicable product specification.
betakenfromacorneroftheplate.Forquenchedandtempered
10.3 Rounding Procedures—For purposes of determining
plates, the two tension test coupons shall be taken from
conformance with the applicable product specification, a cal-
opposite ends of the plate.
culated value shall be rounded to the nearest 1 ksi [5 MPa] for
11.4 Tests from Heat-Treated Plates:
tensile and yield strengths, and to the nearest unit in the
right-hand place of figures used in expressing the limiting 11.4.1 If heat treatment is performed by the manufacturer or
valueforothervalues,inaccordancewiththeroundingmethod processor, the test specimens shall be taken from the plate in
given in Practice E29. the heat-treated condition or from full-thickness coupons
simultaneously heat treated with the plate.
11. Tension Tests
11.4.2 If heat treatment is to be performed by the fabricator,
11.1 Number of Test Coupons:
the plates shall be accepted on the basis of tests made on test
11.1.1 Plates Produced from As-Rolled Plates—For other
specimens taken from full-thickness coupons heat treated in
than quenched and tempered plates, one tension test coupon
accordance with the requirements specified in the applicable
shall be taken from each plate-as-rolled. Two tension test
product specification or the purchase order. If the heat-
coupons shall be taken from each quenched and tempered
treatment temperatures are not specified, the manufacturer or
plate, as heat treated. If plates are furnished by the manufac-
processor shall heat treat the coupons under conditions it
turer or processor in accordance with 11.4.2 and qualified by
considers appropriate. The purchaser shall be informed of the
using test specimens taken from heat-treated test coupons
procedure followed in heat treating the specimens.
(including normalized, normalized and tempered, and
11.4.3 If approved by the purchaser, the procedures of
quenched and tempered), one tension test coupon shall be
11.4.2 may be implemented on plates heat treated by the
taken from each plate-as-rolled (see Terminology A941 for the
manufacturer or processor, except that for plates that are
definition of plate-as-rolled).
quenchedandtempered,alltestingrequiredthespecificationor
11.1.2 Plates Produced from Coil and Furnished without
the purchase order must be performed after plate heat
Heat Treatment or with Stress Relieving Only—Except as
treatment, in accordance with 11.1.1 and 11.4.4, and the results
allowed by 11.1.2.1 and 11.1.4, a minimum of three tension
reported.
coupons shall be taken from each coil as follows:
11.4.4 For plates that are heat treated with a cooling rate
11.1.2.1 The first test coupon shall be taken immediately
faster than still-air cooling from the austenitizing temperature,
prior to the first plate to be qualified to the applicable product
one of the following shall apply in addition to other require-
specification, the second test coupon shall be taken from the
ments specified herein:
approximate center lap, and the third test coupon shall be taken
11.4.4.1 The gage length of the tension test specimen shall
immediately after the last plate to be qualified to the applicable
be taken at least 1T from any as-heat treated edge, where T is
product specification. If, during decoiling, the amount of
the thickness of the plate, and shall be at least ⁄2 in. [12.5 mm]
material decoiled is less than that required to reach the next
from flame-cut or heat-affected-zone surfaces.
standard test location, a test for qualification of that particular
11.4.4.2 Asteel thermal buffer pad, 1 T by 1T by at least 3T,
portion of the coil shall be made from a test coupon taken from
shall be joined to the plate edge by a partial penetration weld
a location adjacent to the innermost portion decoiled.
completely sealing the buffered edge prior to heat treatment.
11.1.2.2 All plates between any two test locations that meet
11.4.4.3 Thermal insulation or other thermal barriers shall
the requirements of the applicable product specification are
be used during the heat treatment adjacent to the plate edge
acceptable.
where the test specimens are to be removed. It shall be
11.1.2.3 All plates between a test location that fails to meet
demonstrated that the cooling rate of the tension test specimen
the requirements of the applicable product specification and an
isnofasterthan,andnotsubstantiallyslowerthan,thatattained
adjacent test location that meets the requirements of the
by the method described in 11.4.4.2.
applicable product specification are rejectable, except that the
processor has the option to make other tests after cutting back 11.4.4.4 When test coupons cut from the plate but heat
the coil in either direction. treated separately are used, the coupon dimensions shall be not
11.1.3 Plates Produced from Coil and Furnished Heat less than 3T by 3T by T and each tension test specimen cut
Treated by Other than Stress Relieving—For other than from it shall meet the requirements of 11.4.4.1.
A20/A20M−20
11.4.4.5 If cooling rate data for the plate and cooling rate gage length is increased. The effect is not so pronounced in
control devices for the test coupons are available, the test thicker plates. For such material, if so stated in the applicable
coupons may be heat treated separately in the device, provided product specification for plates up to ⁄4 in. [20 mm], inclusive,
that this method is approved by the purchaser. in thickness, if the percentage of elongation of an 8-in.
[200-mm] gage length test specimen falls not more than 3
11.5 Test Specimen Preparation:
percentage points below the amount prescribed, the elongation
11.5.1 Tension test specimens for plates ⁄4 in. [20 mm] and
shall be considered satisfactory if the percentage of elongation
under in thickness shall be the full thickness of the plates. The
in 2 in. [50 mm] across the break is not less than 25 %.
test specimens shall conform to the requirements for either the
1 1 11.6.4 The tensile requirements tables in many of the
1 ⁄2-in. [40-mm] wide or the ⁄2-in. [12.5-mm] wide rectangular
product specifications covered by this general requirements
tension test specimen of Test Methods and Definitions A370.
1 specification specify elongation requirements in both 8-in.
The 1 ⁄2-in. [40-mm] wide test specimen may have both edges
1 [200-mm] and 2-in. [50-mm] gage lengths. Unless otherwise
parallel. The ⁄2-in. [12.5-mm] wide specimen may have a
3 provided in the applicable product specification, both require-
maximum nominal thickness of ⁄4 in. [20 mm].
ments are not required to be applied simultaneously, and the
11.5.2 For plates up to 4 in. [100 mm], inclusive, in
elongation need only be determined in the gage length appro-
thickness, tension test specimens may be the full thickness of
1 priate for the test specimen used. After selection of the
the plate and conform to the requirements for the 1 ⁄2-in.
appropriate gage length, the elongation requirement for the
[40-mm] wide rectangular tension test specimen of Test Meth-
alternative gage length shall be deemed not applicable.
ods and Definitions A370 if adequate testing machine capacity
is available.
11.7 This specification does not provide requirements for
11.5.3 For plates over ⁄4 in. [20 mm] in thickness, except as
product tension testing subsequent to shipment (see 15.1).
permitted in 11.5.2, tension test specimens shall conform to the
Therefore, the requirements of 11.1 through 11.6 and Section
requirements for the 0.500-in. [12.5-mm] diameter test speci-
16 apply only for tests conducted at the place of manufacture
menofTestMethodsandDefinitionsA370.Theaxisofthetest
prior to shipment. Compliance to Specification A20/20M and
specimen shall be located midway between the center of
the applicable product specification does not preclude the
thickness and the top or bottom surface of the plate.
possibility that product tension test results may vary outside
specified ranges. The tensile properties will vary within the
11.6 Elongation Requirement Adjustments:
same plate-as-rolled or piece, be it as-rolled, control-rolled, or
11.6.1 Due to the specimen geometry effect encountered
heat-treated. The purchaser should, therefore, be aware that
when using the rectangular tension test specimen for testing
tension testing in accordance with the requirements of Speci-
thin plate, adjustments in elongation requirements must be
fication A20/A20M does not provide assurance that all prod-
provided for thicknesses under 0.312 in. [8 mm].Accordingly,
ucts of a plate-as-rolled will be identical in tensile properties
the following deductions shall be made from the base elonga-
with the products tested. If the purchaser wishes to have more
tion requirements in the applicable product specification:
confidence than that provided by Specification A20/A20M
Elongation
Plate Nominal Thickness Range, in. [mm]
testing procedures, additional testing or requirements, such as
Deduction, %
0.299–0.311 [7.60–7.89] 0.5
Supplementary Requirement S4, should be imposed.
0.286–0.298 [7.30–7.59] 1.0
0.273–0.285 [7.00–7.29] 1.5
11.8 Appendix X2 provides additional information on the
0.259–0.272 [6.60–6.99] 2.0
variability of tensile properties in plates for pressure vessels.
0.246–0.258 [6.20–6.59] 2.5
0.233–0.245 [5.90–6.19] 3.0
0.219–0.232 [5.50–5.89] 3.5
12. Notch-Toughness Tests
0.206–0.218 [5.20–5.49] 4.0
0.193–0.205 [4.90–5.19] 4.5
12.1 Charpy V-Notch Tests:
less than 0.193 [4.90] 5.0
12.1.1 Number of Tests—If Charpy V-Notch tests are
11.6.2 Due to the inherently lower elongation that is o
...