Abstract

This specification covers precipitation hardened iron base superalloy forgings which are primarily intended for use as turbine rotor disks and wheels. Two heat treatments are covered and selection will depend upon design, service conditions, mechanical properties, and elevated temperature characteristics. The material shall be made by vacuum melting followed by consumable electrode vacuum arc or electroslag remelting. The forgings shall undergo the following tests: tension test, hardness test, stress rupture test, and creep test. Also, the forgings shall be subjected to non-destructive examinations like ultrasonic examination and liquid penetrant examination. The forgings shall be uniform in quality and condition, clean, sound, and free of cracks, seams, laps, shrinkage, and other injurious imperfections.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This specification covers precipitation hardening iron base superalloy forgings which are primarily intended for use as turbine rotor disks and wheels.

1.2 Two heat treatments are covered. Selection will depend upon design, service conditions, mechanical properties, and elevated temperature characteristics.

1.3 All of the provisions of Specification A788/A788M , apply, except as amended herein.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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 non-conformance with the standard.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

A788/A788M Specification for Steel Forgings, General Requirements

E112 Test Methods for Determining Average Grain Size

E139 Test Methods for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of Metallic Materials

E165 Practice for Liquid Penetrant Examination for General Industry

E292 Test Methods for Conducting Time-for-Rupture Notch Tension Tests of Materials

Keywords

age hardened; alloy steel turbine disk; alloy steel turbine wheel; creep; elevated temperature service; forging; precipitation hardened; stress rupture; superalloy; Forgings--specifications; Forgings (turbine rotors/disks/shafts); Generator materials--turbine; Alloy steel forgings--specifications; Iron alloys--specifications; Iron-base superalloy forgings; Precipitation-hardening metals/alloys--specifications; Superalloy steels--specifications; Turbine rotors/shafts ;

ICS Code

ICS Number Code 77.140.85 (Iron and steel forgings)

DOI: 10.1520/A0891_A0891M-10

ASTM International is a member of CrossRef.

ASTM A891 / A891M