1. Scope

1.1 This specification covers ductile iron castings that are subsequently heat treated by an austempering process as defined in .

1.2 The application of the austempering heat treatment extends the range of properties achievable in ductile iron castings.

1.3 No precise quantitative relationship can be stated between the properties of the iron in various locations of the same casting or between the properties of castings and those of a test specimen cast from the same iron (see ). However, austempering heat treatment will tend to diminish any differences in mechanical properties.

1.4 The production of castings, machining (if required), and the austempering heat treatments may be performed by different manufacturers, as covered in Section . The purchaser should establish by contract agreement, at the time of ordering, the responsibility of the various parties for meeting the specification requirements.

1.5 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets [ ]. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.

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

A247 Test Method for Evaluating the Microstructure of Graphite in Iron Castings

A370 Test Methods and Definitions for Mechanical Testing of Steel Products

A732/A732M Specification for Castings, Investment, Carbon and Low Alloy Steel for General Application, and Cobalt Alloy for High Strength at Elevated Temperatures

A834 Specification for Common Requirements for Iron Castings for General Industrial Use

E8 Test Methods for Tension Testing of Metallic Materials

E10 Test Method for Brinell Hardness of Metallic Materials

E23 Test Methods for Notched Bar Impact Testing of Metallic Materials

Military Standard

Keywords

Ausferrite; Austempering; Ductile Cast Iron; Hardenability; Heat Treatment; Proeutectoid Ferrite; Austempered ductile iron castings--specifications; Ductile iron castings--specifications

ICS Code

ICS Number Code 77.140.80 (Iron and steel castings)

DOI: 10.1520/A0897_A0897M-06

ASTM International is a member of CrossRef.