ASTM A437/A437M-15(2021)
(Specification)Standard Specification for Stainless and Alloy-Steel Turbine-Type Bolting Specially Heat Treated for High-Temperature Service
Standard Specification for Stainless and Alloy-Steel Turbine-Type Bolting Specially Heat Treated for High-Temperature Service
ABSTRACT
This specifications covers alloy-steel bolting material specially heat treated for high-temperature service, such as steam turbine, gas turbine, and similar uses. The grades of steels covered here are: Grade B4B, Grade B4C, and Grade B4D. Steels of Grades B4B and B4C shall undergo heating, liquid quenching, reheating, tempering, and air or furnace cooling, respectively. Steels of Grade B4D shall undergo heating, oil quenching, reheating or tempering, and air of furnace cooling, respectively. Heat and product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, vanadium, tungsten, aluminum, titanium, and tin. The steels shall undergo tensile, impact, and hardness tests, and shall conform to the following mechanical requirements: tensile strength, yield strength, elongation, impact value, Brinell hardness number, and Rockwell hardness number. All bars or forged blanks of starting material shall be subjected to nondestructive inspection using any of the following methods: Eddy current, Magnetic particle inspection (wet or dry), Liquid penetrant inspection, Ultrasonic testing, or Visual testing.
SCOPE
1.1 This specification2 covers stainless and alloy-steel bolting material and bolting components specially heat treated for high-temperature service, such as steam turbine, gas turbine, and similar uses. See Specification A962/A962M for the definition of bolting. This material requires special processing and should not be used in general-purpose applications. Bolting furnished as bars shall be hot wrought and may be further processed by centerless grinding or by cold drawing.
1.2 The high-temperature properties of the bolting materials and components covered by this specification are dependent upon special heat treatment, which is required. Although the high-temperature properties are not specified, they are implied by control of the chemistry, heat treatment, and room-temperature properties of the bolting material.
1.3 Three levels of bolting strength are covered, designated Grades B4B, B4C, and B4D.
1.4 The following referenced general requirements are indispensable for application of this specification: Specification A962/A962M.
1.5 Supplementary requirements are provided for use at the option of the purchaser. The supplementary requirements shall apply only when specified individually by the purchaser in the purchase order or contract.
1.6 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M specification designation (SI units), the inch-pound units shall apply.
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.8 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
Relations
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:A437/A437M −15 (Reapproved 2021)
Standard Specification for
Stainless and Alloy-Steel Turbine-Type Bolting Specially
Heat Treated for High-Temperature Service
This standard is issued under the fixed designationA437/A437M; 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* system may not be exact equivalents; therefore, each system
2 shall be used independently of the other. Combining values
1.1 This specification covers stainless and alloy-steel bolt-
from the two systems may result in non-conformance with the
ing material and bolting components specially heat treated for
standard.
high-temperature service, such as steam turbine, gas turbine,
1.8 This international standard was developed in accor-
and similar uses. See Specification A962/A962M for the
dance with internationally recognized principles on standard-
definition of bolting. This material requires special processing
ization established in the Decision on Principles for the
and should not be used in general-purpose applications. Bolt-
Development of International Standards, Guides and Recom-
ing furnished as bars shall be hot wrought and may be further
mendations issued by the World Trade Organization Technical
processed by centerless grinding or by cold drawing.
Barriers to Trade (TBT) Committee.
1.2 The high-temperature properties of the bolting materials
and components covered by this specification are dependent
2. Referenced Documents
upon special heat treatment, which is required. Although the
2.1 ASTM Standards:
high-temperature properties are not specified, they are implied
A962/A962M Specification for Common Requirements for
by control of the chemistry, heat treatment, and room-
Bolting Intended for Use at Any Temperature from Cryo-
temperature properties of the bolting material.
genic to the Creep Range
1.3 Three levels of bolting strength are covered, designated
E292 Test Methods for Conducting Time-for-Rupture Notch
Grades B4B, B4C, and B4D.
Tension Tests of Materials
1.4 The following referenced general requirements are in-
E112 Test Methods for Determining Average Grain Size
dispensable for application of this specification: Specification
3. Ordering Information
A962/A962M.
3.1 It shall be the responsibility of the purchaser to specify
1.5 Supplementary requirements are provided for use at the
all requirements necessary for product under this specification.
option of the purchaser. The supplementary requirements shall
Such requirements to be considered include, but are not limited
apply only when specified individually by the purchaser in the
to, the following:
purchase order or contract.
3.1.1 Specification designation, grade, issue date, and revi-
1.6 This specification is expressed in both inch-pound units
sion letter,
and in SI units; however, unless the purchase order or contract
3.1.2 Quantity (weight or number of pieces),
specifies the applicable M specification designation (SI units),
3.1.3 Description (bars, bolts, nuts, etc.),
the inch-pound units shall apply.
3.1.4 Dimensions,
1.7 The values stated in either SI units or inch-pound units
3.1.5 Finish, and
are to be regarded separately as standard. Within the text, the
3.1.6 Impact testing of nuts, if required (see Section 8).
SI units are shown in brackets. The values stated in each
4. Common Requirements
4.1 Bolting materials and bolting components supplied to
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
this specification shall conform to the requirements of Speci-
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
fication A962/A962M. These requirements include test
A01.22 on Steel Forgings and Wrought Fittings for PipingApplications and Bolting
Materials for Piping and Special Purpose Applications.
Current edition approved Sept. 1, 2021. Published October 2021. Originally
approved in 1959. Last previous edition approved in 2015 as A437/A437M – 15. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/A0437_A0437M-15R21. contact ASTM Customer Service at service@astm.org. 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-437 in Section II of that code. 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
A437/A437M−15 (2021)
methods, finish, thread dimensions, macroetch (Grade B4D 7. Tensile Requirements
only), marking, certification, optional supplementary
7.1 Bolting material shall conform to the requirements as to
requirements, and others. Failure to comply with the require-
tensile properties prescribed in Table 2 at room temperature
ments of Specification A962/A962M constitutes nonconfor-
after heat treatment.
mance with this specification. In case of conflict between this
7.2 The longitudinal axis of the test specimen shall be
specificationandSpecificationA962/A962M,thisspecification
parallel to the direction of rolling.
shall prevail.
8. Impact Requirements
5. Heat Treatment
8.1 Grades B4B, B4C, and B4D shall conform to the
5.1 Grades B4B and B4C shall be heated to a temperature
requirements as to impact properties prescribed in Table 3 at
range of 1875 to 1925 °F [1025 to 1050 °C] and liquid
room temperature after heat treatment.
quenched to below 600 °F [316 °C]. The material Grades B4B
and B4C shall then be uniformly reheated for tempering at a
9. Hardness Tests
tempering temperature at least 100 °F [55 °C] higher than the
9.1 Grades B4B, B4C, and B4D shall conform to the
proposed operating temperature but not less than 1150 °F [620
requirements as to hardness as prescribed in Table 4 and Table
°C], then air or furnace cooled to room temperature. The
5 at room temperature after heat treatment.
material shall be at the tempering temperature for a minimum
of 2 h. Double tempering may be used to enhance properties.
10. Nuts
5.2 Grade B4D shall be heated to a temperature range of
10.1 When specified by the purchaser, nuts shall be subject
1700 to 1750 °F [925 to 954 °C] and oil quenched. The
to the impact and tension requirements of this specification.
material shall then be uniformly reheated or tempered at a
The tests shall be made on test specimens taken from the ba
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