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.

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.