ASTM A288-2018 pdf free download
ASTM A288-2018 pdf free download.Standard Specification for Carbon and Alloy Steel Forgings for Magnetic Retaining Rings for Turbine Generators
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 accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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 1 ⁄ 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 tem- perature shall be not less than 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. 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 ship- ment.
7. General Requirements
7.1 Material supplied to this specification shall conform to the requirements ofSpecification A788/A788M which outlines additional ordering information, manufacturing, requirements, testing and retesting methods, and procedures, marking, certification, product analysis variations, and additional supple- mentary requirements. 7.2 If the requirements of this specification are in conflict with the requirements of Specification A788/A788M, the requirements of this specification shall prevail.
8. Sampling
8.1 Test Location—Tension and notch toughness test speci- mens shall be taken tangentially from prolongations on one or both ends of the forging. The direction of the notch of the Charpy bars shall be radial. All test specimens shall be located at midwall and at a distance at least equal to one-half the wall thickness from the end face of the prolongation. 8.2 Removal—All tension and notch toughness test speci- mens shall be removed after final heat treatment.
9. Number of Tests and Retests
9.1 Number of Tests—The number of tension and notch toughness test specimens shall be as prescribed by the purchaser, but in no case shall there be less than one tension and one notch toughness test specimen for each ring. 9.2 If any test specimen fails to meet the requirements specified, two adjacent test specimens may be selected for retest without reheat-treatment if the failure was not caused by ruptures, cracks, or flakes in the steel. Both of these must meet the requirements of this specification. 9.3 If the results of the mechanical tests of any forging do not conform to the requirements specified, the manufacturer may reaustenitize the forging, but not more than once without approval ofthe purchaser. Forgings may be retempered without obtaining approval of the purchaser.
