Standard Test Method for Heat Stability of Steam Turbine Shafts and Rotor Forgings

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1.1 This test method covers the determination of heat stability of steam turbine shafts and rotor forgings to ensure stability at operating temperature. This test method is not ordinarily applicable to generator rotor forgings.
1.2 The values stated in inch-pound units are to be regarded as the standard.
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 and health practices and determine the applicability of regulatory limitations prior to use.

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Publication Date
09-Apr-2003
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ASTM A472-98(2003) - Standard Test Method for Heat Stability of Steam Turbine Shafts and Rotor Forgings
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
Designation:A 472–98 (Reapproved 2003)
Standard Test Method for
Heat Stability of Steam Turbine Shafts and Rotor Forgings
This standard is issued under the fixed designation A 472; 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.
1. Scope radial thickness, after which the temperature may be decreased
to the specified heat stability test temperature and the test
1.1 This test method covers the determination of heat
performed.
stability of steam turbine shafts and rotor forgings to ensure
stability at operating temperature. This test method is not
4. Heat Stability Test Bands
ordinarily applicable to generator rotor forgings.
4.1 ThesuppliershallmarkpositionsA,B,C,andD,spaced
1.2 The values stated in inch-pound units are to be regarded
90°apartcircumferentially,preferablyonanendoftheforging.
as the standard.
Markings shall be retained throughout all subsequent opera-
1.3 This standard does not purport to address all of the
tions.
safety concerns, if any, associated with its use. It is the
4.2 Preferably there shall be a minimum of 5 test bands,
responsibility of the user of this standard to establish appro-
denoted as 1, 2, 3, 4, and 5, machined on the circumference of
priate safety and health practices and determine the applica-
the forging. Numbering shall start at the left side of the forging
bility of regulatory limitations prior to use.
drawing. Bands 1 and 5 shall be located as close to the end of
2. Ordering Information the forging as practical. Band 3 shall be located as near to
midlength as practical. Bands 2 and 4 shall be located
2.1 The purchase order or forging drawing shall specify the
approximately equidistant between 1 and 3, and 3 and 5
minimum temperature for the heat stability test. The forging
respectively.
drawing shall show the portion of the forging to be subjected to
4.3 When the shipped length of the barrel portion of the
the heat stability test temperature.
forging is less than 8 ft (2.4 m), bands 2 and 4 may be omitted.
3. Procedure
4.4 The purchaser’s drawing may show the desired number
and location of bands and shall indicate that portion of the
3.1 The heat stability test shall be conducted by the forging
forging that shall be located within the heating chamber. Bands
supplierafterfinalheattreatmentandaftertheforginghasbeen
1 and 5 are to be located outside of the heating chamber.
centered and machined with allowance to finish to the purchas-
Preferably, the gland areas/packing seal areas are inside the
er’s drawing. Material for mechanical tests may be removed
heating chamber.
before or after the stability test at the manufacturer’s option,
4.5 The test bands shall be machined with the forging
unless check tests after the stability test are required by the
running on centers except in the cases of forgings weighing
purchaser.
over 125 000 lb (56.7 metric tons) the machining shall be
3.2 With prior approval from the purchaser, the forgings
performed with the forgings running on steady rests. Readings
may be stress relieved as part of the heat stability test. When
shall be taken with the forging running on centers except in the
this is done, the stress-relieving temperature shall be within 50
cases of forgings weighing over 125 000 lb where readings
to 100°F (28 to 55.5°C) below final tempering temperature.
may be taken with the forgings running on steady rests.
Rotate the forgings at 2 to 4 r/min and hold at stress-relieving
Between readings, the forgings may be rotated on steady rests.
temperature for at least 2 h/in. (2 h/25.4 mm) of maximum
5. Surface Preparation
This test method is under the jurisdiction of ASTM Committee A01 on Steel,
5.1 Removeoil,grease,dirt,andotherforeignmaterialfrom
Stainless Steel, and RelatedAlloys and is the direct responsibility of Subcommittee
the surface of the forging prior to the heat stability test. A
A01.06 on Steel Forgings and Billets.
suitable coating may be applied to provide uniform emissivity.
Current edition approved April 10, 2003. Published July 2003. Originally
approved in 1962. Last previous edition approved in 1998 as A 472 –98.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
A 472–98 (2003)
6. Heating and Cooling 7.3 Hot Measurements—Take measurements on all bands
hourly during the heating cycle until the forging has been
6.1 Place the forging in the heating chamber and rotate the
heated to the specified temperature. When three consecutive
forging at a speed of 2 to 4 r/min.
hourly deflection measurements at the specified temperature
6.2 Place thermocouples in contact with the forging at each
check within 0.0005 i
...

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