ASTM A470/A470M-05(2020)
(Specification)Standard Specification for Vacuum-Treated Carbon and Alloy Steel Forgings for Turbine Rotors and Shafts
Standard Specification for Vacuum-Treated Carbon and Alloy Steel Forgings for Turbine Rotors and Shafts
ABSTRACT
This specification covers vacuum-treated carbon and alloy steel forgings for turbine rotors and shafts. Materials shall be manufactured and treated by: melting process via basic electric-furnace; secondary melting process via electrode-electroslag or vacuum-arc remelting; vacuum degassing; forging process via hot mechanical working; heat treatment via double-normalizing and tempering, or normalizing, quenching and tempering; and rough machining and axial boring. Tension and impact tests shall be done to evaluate the conformance of steel forgings with the following mechanical properties: tensile strength and toughness, notch toughness, yield strength, elongation, and reduction of area. Chemical composition conformances shall also be assessed by heat and product analyses. Nondestructive tests, such as ultrasonic and internal examination, and stability tests shall also be performed. Retreatments may be executed one or more times, but not more than three additional times, if results of the mechanical tests do not conform to specified requirements.
SCOPE
1.1 This specification covers vacuum-treated carbon and alloy steel forgings for turbine rotors and shafts.
1.2 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.
1.3 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.
1.4 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:A470/A470M −05 (Reapproved 2020)
Standard Specification for
Vacuum-Treated Carbon and Alloy Steel Forgings for
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Turbine Rotors and Shafts
This standard is issued under the fixed designationA470/A470M; 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.
1. Scope A418/A418M Practice for Ultrasonic Examination of Tur-
bine and Generator Steel Rotor Forgings
1.1 This specification covers vacuum-treated carbon and
A472/A472M Specification for Heat Stability of Steam Tur-
alloy steel forgings for turbine rotors and shafts.
bine Shafts and Rotor Forgings
1.2 The values stated in either SI units or inch-pound units
A788/A788M Specification for Steel Forgings, General Re-
are to be regarded separately as standard. The values stated in
quirements
each system are not necessarily exact equivalents; therefore, to
E139 Test Methods for Conducting Creep, Creep-Rupture,
ensure conformance with the standard, each system shall be
and Stress-Rupture Tests of Metallic Materials
used independently of the other, and values from the two
systems shall not be combined.
3. Ordering Information and General Requirements
1.3 This standard does not purport to address all of the
3.1 Material supplied to this specification shall conform to
safety concerns, if any, associated with its use. It is the
the requirements of Specification A788/A788M, which out-
responsibility of the user of this standard to establish appro-
lines additional ordering information, manufacturing methods
priate safety, health, and environmental practices and deter-
and procedures, marking, certification, production analysis
mine the applicability of regulatory limitations prior to use.
variations, and additional supplementary requirements.
1.4 This international standard was developed in accor-
3.2 In addition to the ordering information required by
dance with internationally recognized principles on standard-
Specification A788/A788M, the purchaser shall include with
ization established in the Decision on Principles for the
the inquiry and order, the grade and class of steel, alternative
Development of International Standards, Guides and Recom-
maximum for silicon content (see Table 1), the choice of yield
mendations issued by the World Trade Organization Technical
strength offset (0.2 % or 0.02 %), and any tests, supplementary
Barriers to Trade (TBT) Committee.
requirements, and purchase options desired.
2. Referenced Documents
3.3 Forging Drawing—Each forging shall be manufactured
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in accordance with a drawing furnished by the purchaser
2.1 ASTM Standards:
showing the dimensions of the forging and bore hole, if any,
A275/A275M Practice for Magnetic Particle Examination of
and the location of mechanical test specimens.
Steel Forgings
A293 SpecificationforSteelForgings,CarbonandAlloy,for
3.4 Supplementary Requirements—Supplementary require-
Turbine Generator Rotors and Shafts; Replaced by A 470
ments are provided. These requirements shall apply only when
3
(Withdrawn 1984)
specified in the purchase order.
A370 Test Methods and Definitions for Mechanical Testing
3.5 If the requirements of this specification are in conflict
of Steel Products
with the requirements of Specification A788/A788M, the
requirements of this specification shall prevail.
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This specification is under the jurisdiction ofASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
4. Manufacture
A01.06 on Steel Forgings and Billets.
Current edition approved March 1, 2020. Published March 2020. Originally
4.1 Melting Process:
approved in 1962. Last previous edition approved in 2015 as A470/A470M – 05
4.1.1 The steel shall be made by the basic electric-furnace
(2015). DOI: 10.1520/A0470_A0470M–05R20.
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process.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4.1.2 Provisions for subsequent secondary melting of the
Standards volume information, refer to the standard’s Document Summary page on
steel by the consumable electrode-electroslag or vacuum-arc
the ASTM website.
3 remelting processes are included in Supplementary Require-
The last approved version of this historical standard is referenced on
www.astm.org. ment S7.
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