ASTM A266/A266M-99
(Specification)Standard Specification for Carbon Steel Forgings for Pressure Vessel Components
Standard Specification for Carbon Steel Forgings for Pressure Vessel Components
SCOPE
1.1 This specification covers four grades of carbon steel forgings for boilers, pressure vessels, and associated equipment. Note 1-Designations have been changed as follows: Current: Grade 1, Grade 2, Grade 3, Grade 4. Formerly: Class 1, Class 2, Class 3, Class 4.
1.2 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.
1.3 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as the standard. Within the text and tables, 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.
1.4 Unless the order specifies the applicable "M" specification designation, the material shall be furnished to the inch-pound units.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: A 266/A 266M – 99
Standard Specification for
Carbon Steel Forgings for Pressure Vessel Components
This standard is issued under the fixed designation A 266/A 266M; 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 E 112 Test Methods for Determining the Average Grain
Size
1.1 This specification covers four grades of carbon steel
E 165 Test Method for Liquid Penetrant Examination
forgings for boilers, pressure vessels, and associated equip-
E 381 Method of Macroetch Testing Steel Bars, Billets,
ment.
Blooms, and Forgings
NOTE 1—Designations have been changed as follows:
Current Formerly
2.2 Other Standard:
Grade 1 Class 1
ASME Boiler and Pressure Vessel Code, Section IX, Weld-
Grade 2 Class 2
Grade 3 Class 3 ing Qualifications
Grade 4 Class 4
3. Ordering Information and General Requirements
1.2 Supplementary requirements are provided for use when
additional testing or inspection is desired. These shall apply 3.1 In addition to the ordering information required by
only when specified individually by the purchaser in the order.
Specification A 788, the purchaser shall include with the
1.3 The values stated in either inch-pound units or SI inquiry and order a detailed drawing, sketch, or written
(metric) units are to be regarded separately as the standard.
description of the forging.
Within the text and tables, the SI units are shown in brackets. 3.2 Material supplied to this specification shall conform to
The values stated in each system are not exact equivalents;
the requirements of Specification A 788, which outlines addi-
therefore, each system must be used independently of the other. tional ordering information, manufacturing requirements, test-
Combining values from the two systems may result in noncon-
ing and retesting methods and procedures, marking, certifica-
formance with the specification. tion, product analysis variations, and additional supplementary
1.4 Unless the order specifies the applicable “M” specifica-
requirements.
tion designation, the material shall be furnished to the inch- 3.3 If the requirements of this specification are in conflict
pound units.
with the requirements of Specification A 788, the requirements
of this specification shall prevail.
2. Referenced Documents
4. Materials and Manufacture
2.1 ASTM Standards:
A 275/A 275M Test Method for Magnetic Particle Exami- 4.1 The steel shall be made in accordance with the Melting
nation of Steel Forgings Process Section of Specification A 788. A sufficient discard
A 370 Test Methods and Definitions for Mechanical Testing
shall be made to secure freedom from injurious pipe and undue
of Steel Products segregation.
A 788 Specification for Steel Forgings, General Require-
4.2 The material shall be forged as close as practical to the
ments specified shape and size.
4.3 The finished product shall be a hot-worked forging as
defined by Specification A 788.
This specification is under the jurisdiction of ASTM Committee A-1 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
A01.06 on Steel Forgings and Billets.
Current edition approved Sept. 10, 1999. Published November 1999. Originally
published as A 266 – 43T. Last previous edition A 266/A 266M–96.
2 5
For ASME Boiler and Pressure Vessel Code applications, see related Specifi- Annual Book of ASTM Standards, Vol 03.01.
cation SA–266/ SA–266M in Section II of that code. Annual Book of ASTM Standards, Vol 03.03.
3 7
Annual Book of ASTM Standards, Vol 01.05. Available from the American Society of Mechanical Engineers, 345 East 47th
Annual Book of ASTM Standards, Vol 01.03. St., New York, NY 10017.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
A 266/A 266M – 99
TABLE 2 Tensile Requirements
5. Machining
Grade 1 Grades Grade 3
5.1 Surfaces shall be machined as designated by the pur-
2 and 4
chaser. Unmachined surfaces shall be sufficiently free of scale
Tensile strength, min, ksi 60–85 70–95 75–100
to permit inspection.
[MPa] [415–585] [485–655] [515–690]
5.2 Machining may be performed either prior to or after heat
Yield strength (0.2 % offset), 30 36 37.5
min, ksi [MPa] [205] [250] [260]
treatment at the option of the manufacturer unless specified in
Elongation in 2 in. or 50 23 20 19
accordance with Supplementary Requirement S1.
mm, min, %
Reduction of area, min, % 38 33 30
6. Heat Treatment
6.1 After forging and before reheating for heat treatment,
the forgings shall be cooled in such a manner as to prevent
8.1.1 Except when otherwise specified in accordance with
injury and to accomplish transformation.
Supplementary Requirement S2, the longitudinal axis of the
6.2 All forgings shall be annealed, normalized, or normal-
specimens shall be parallel to the direction of major working of
ized and tempered, but alternatively may be liquid quenched
the forging. For upset-disc forgings, the longitudinal axis of the
and tempered when mutually agreed upon between the manu-
test specimen shall be in the tangential direction.
facturer and the purchaser. When tempering is performed, it
8.1.1.1 The longitudinal axis of the specimen shall be
shall be at a subcritical temperature, but no less than 1100°F
located midway between the parallel surfaces of the test
[595°C].
extension if added to the periphery of disks or midway between
6.3 A multiple stage austenitizing procedure may be used
the center and surface of solid forgings. For hollow forgings,
whereby the forging is first fully austenitized and liquid
the longitudinal axis of the specimens shall be located midway
quenched, followed by reheating within the intercritical tem-
between the center and outer surfaces of the wall. When
perature range to partially reaustenitize, and again liquid
separately forged test blocks are employed as defined in 8.1.3,
quenched. On completion of the austenitizing/quenching
the tension test specimens shall be taken from a location that
cycles, tempering at a temperature between 1100°F [595°C]
represents the midwall of the heaviest section of the production
and the lower critical temperature shall follow.
forgings. When specimens are required from opposite ends,
NOTE 2—Although liquid quenching from the austenitizing tempera-
they shall be taken from the diagonal corners of an axial plane.
tures is more effective in enhancing impact properties, air cooling from the
8.1.2 Except as specified herein, tests for acceptance shall
austenitizing temperatures is also beneficial and may be used instead of
be made after heat treatment has been completed. When the
the normalizing procedure in 6.2.
ends of the cylindrical forgings are closed in by reforging, the
7. Chemical Composition cylindrical forgings may be annealed, normalized, or normal-
ized and tempered and tested prior to reforging. After reforg-
7.1 Heat Analysis—The heat analysis obtained from sam-
ing, the entire forging shall be reheat-treated in the same
pling in accordance with Specification A 788 shall comply with
manner and at the same temperature range as employed when
Table 1 except that the additional features of Supplementary
the forging was heat-treated prior to certification testing.
Requirements S11 and S12 shall also apply as individually
8.1.3 When mutually agreed upon between manufacturer
specified in the ordering information.
and purchaser, test specimens may be machined from a
7.2 Product Analysis—The purchaser may use the product
specially forged block suitably worked and heat treated with
analysis provision of Specification A 788 to obtain a product
the production forgings. Such a special block shall be obtained
analysis from a forging representing each heat or multiple heat.
from an ingot, slab, or billet from the same heat used to make
the forgings it represents. This block shall receive essentially
8. Mechanical Properties
the same type of hot working and forging reduction as the
8.1 General Requirements—Except when otherwise speci-
production forgings; however, a longitudinally forged bar with
fied in accordance with Supplementary Requirement S2, the
dimensions not less than T by T by 3T may be used to represent
material shall conform to the requirements for mechanical
a ring forging. The dimension T shall be representative of the
properties prescribed in Table 2 when tested in accordance with
heaviest effective cross section of the forging. For quenched
the latest issue of Test Methods and Definitions A 370. The
and tempered forgings for which tests are required at both ends
largest obtainable tension test specimen as specified in Test
by 8.2.2.3 and 8.2.2.4, separately forged test blocks are not
Methods and Definitions A 370 shall be used.
allowed.
NOTE 3—In using separately forged test blocks, attention is drawn to
the effect of mass differences between the production forgings and the test
TABLE 1 Chemical Requirements
blocks.
Composition, %
...
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