ASTM A288-91(2018)

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Designation: A288 − 91 (Reapproved 2013) A288 − 91 (Reapproved 2018)
Standard Specification for
Carbon and Alloy Steel Forgings for Magnetic Retaining
Rings for Turbine Generators
This standard is issued under the fixed designation A288; 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
1.1 This specification covers quenched and tempered carbon and alloy steel forgings for magnetic retaining rings for turbine
generators.
1.2 Supplementary requirements of an optional nature are provided. These shall apply only when specified by the purchaser.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
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.
2. Referenced Documents
2.1 ASTM Standards:
A275/A275M Practice for Magnetic Particle Examination of Steel Forgings
A531/A531M Practice for Ultrasonic Examination of Turbine-Generator Steel Retaining Rings
A788/A788M Specification for Steel Forgings, General Requirements
3. Ordering Information
3.1 In addition to the ordering information required by Specification A788/A788M, the purchaser shall include with the inquiry
and order a detailed drawing, sketch, or written description of the forging, including the number and location of mechanical test
specimens.
4. Manufacture
4.1 The melting processes of Specification A788/A788M shall be applicable except that the basic electric furnace process shall
be used if separate refining or remelting is not employed.
4.2 Vacuum Degassing—For Class 3 machined forgings over 2 ⁄2 in. (63.5 mm) wall thickness, and Classes 4 to 8, the molten
steel shall be vacuum treated immediately prior to or during the operation of pouring the ingot in order to remove objectionable
gases, especially hydrogen.
4.3 Discard—Sufficient discard shall be made from each ingot to secure freedom from piping and undue segregation.
4.4 Heat Treatment:
4.4.1 Heat Treatment for Mechanical Properties—Heat treatment for properties shall be by quenching and tempering.
4.4.2 Tempering Temperature—The final tempering temperature shall be not less than 1100°F (595°C).1100 °F (595 °C).
4.5 Machining:
4.5.1 Preliminary Machining—Forgings shall be machined all over prior to quenching and tempering for mechanical properties.
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.06
on Steel Forgings and Billets.
Current edition approved June 1, 2013March 1, 2018. Published June 2013March 2018. Originally approved in 1946. Last previous edition approved in 20082013 as
A288 – 91(2008).(2013). DOI: 10.1520/A0288-91R13.10.1520/A0288-91R18.
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A288 − 91 (2018)
4.5.2 Machine to Purchaser’s Requirements for Shipment—If required, forgings shall be machined to the dimensions shown on
the purchaser’s drawing prior to shipment.
5. Chemical Composition
5.1 The steel shall conform to the chemical composition prescribed in Table 1.
5.2 Heat Analysis—The heat analysis obtained from sampling in accordance with Specification A788/A788M shall comply with
Table 1.
5.3 Product Analysis—The purchaser may use the product analysis provision of Table 1 of Specification A788/A788M to obtain
a product analysis from a forging representing each heat or multiple heat.
6. Mechanical Properties
6.1 Tensile Requirements—The material shall conform to the requirements for tensile properties prescribed in Table 2.
6.2 Notch Toughness Requirements—The material shall conform to the requirements for notch toughness as prescribed in Table
2.
7. General Requirements
7.1 Material supplied to this specification shall conform to the requirements of Specific
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