ASTM A472/A472M-07
(Test Method)Standard Specification for Heat Stability of Steam Turbine Shafts and Rotor Forgings
Standard Specification for Heat Stability of Steam Turbine Shafts and Rotor Forgings
ABSTRACT
This measurement method covers the procedures for the standard practice of determining the heat stability of steam turbine and rotor forgings to ensure stability at operating temperature. Surface and test band preparation, and heating and cooling procedures prior to stability measurements are detailed. Interpretation of the results of cold and hot measurements is also described.
SCOPE
1.1 This specification covers the determination of heat stability of steam turbine shafts and rotor forgings to ensure stability at operating temperature. This specification is not ordinarily applicable to generator rotor forgings.
1.2 This specification is expressed in both inch-pound unit 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. The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the specification, 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 nonconformance with the standard.
1.3 Supplementary requirements of an optional nature 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.
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: A472/A472M – 07
Standard Specification for
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Heat Stability of Steam Turbine Shafts and Rotor Forgings
This standard is issued under the fixed designationA472/A472M; 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* 3. Procedure
1.1 This specification covers the determination of heat 3.1 The heat stability test shall be conducted by the forging
stability of steam turbine shafts and rotor forgings to ensure supplierafterfinalheattreatmentandaftertheforginghasbeen
stability at operating temperature. This specification is not centered and machined with allowance to finish to the purchas-
ordinarily applicable to generator rotor forgings. er’s drawing. Material for mechanical tests may be removed
1.2 This specification is expressed in both inch-pound unit before or after the stability test at the manufacturer’s option,
and in SI units; however, unless the purchase order or contract unless check tests after the stability test are required by the
specifies the applicable M specification designation (SI units), purchaser.
the inch-pound units shall apply. The values stated in either 3.2 With prior approval from the purchaser, the forgings
inch-pound units or SI units are to be regarded separately as may be stress-relieved as part of the heat stability test. When
standard. Within the specification, the SI units are shown in this is done, the stress-relieving temperature shall be within 50
brackets. The values stated in each system may not be exact to 100°F [30 to 55°C] below final tempering temperature.
equivalents;therefore,eachsystemshallbeusedindependently Rotate the forgings at 2 to 4 r/min and hold at stress-relieving
of the other. Combining values from the two systems may temperature for at least 2 h/in. [2 h/25 mm] of maximum radial
result in nonconformance with the standard. thickness, after which the temperature may be decreased to the
1.3 Supplementary requirements of an optional nature are specified heat stability test temperature and the test performed.
provided for use at the option of the purchaser. The supple-
4. Heat Stability Test Bands
mentary requirements shall apply only when specified indi-
4.1 ThesuppliershallmarkpositionsA,B,C,andD,spaced
vidually by the purchaser in the purchase order or contract.
1.4 This standard does not purport to address all of the 90°apartcircumferentially,preferablyonanendoftheforging.
Markings shall be retained throughout all subsequent opera-
safety concerns, if any, associated with its use. It is the
tions.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 4.2 Preferably, there shall be a minimum of 5 test bands,
denoted as 1, 2, 3, 4, and 5, machined on the circumference of
bility of regulatory limitations prior to use.
the forging. Numbering shall start at the left side of the forging
2. Ordering Information
drawing. Bands 1 and 5 shall be located as close to the end of
2.1 It shall be the responsibility of the purchaser to specify the forging as practical. Band 3 shall be located as near to
all requirements necessary for testing under this specification. midlength as practical. Bands 2 and 4 shall be located
Requirements to be considered include, but are not limited to, approximately equidistant between 1 and 3, and 3 and 5,
the following: respectively.
2.1.1 ASTM designation and year date, 4.3 When the shipped length of the barrel portion of the
2.1.2 The minimum test temperature, forging is less than 8 ft [2.4 m], bands 2 and 4 may be omitted.
2.1.3 The portion of the forging to be subjected to the heat 4.4 The purchaser’s drawing may show the desired number
stability test temperature, and and location of bands and shall indicate that portion of the
2.1.4 Supplementary or other special requirements. forging that shall be located within the heating chamber. Bands
1 and 5 are to be located outside of the heating chamber.
Preferably, the gland areas/packing seal areas are inside the
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heating chamber.
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and RelatedAlloys and is the direct responsibility of Subcommittee
4.5 The test bands shall be machined with the forging
A01.06 on Steel Forgings and Billets.
running on centers except in the cases of forgings weighing
Current edition approved Sept. 1, 2007. Published September 2007. Originally
over 125 000 lb [56.7 metric tons] the machining shall be
approved in 1962. Last previous edition approved in 2005 as A472/A472M – 05.
DOI: 10.1520/A0472_A0472M-07. performed with the forgings
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