ASTM A439-83(2004)

1.1 This specification covers austenitic ductile iron castings, which are used primarily for their resistance to heat, corrosion, and wear, and for other special purposes.

1.2 Austenitic ductile iron, also known as austenitic nodular iron or austenitic spheroidal iron, is characterized by having its graphite substantially in a spheroidal form and substantially free of flake graphite. It contains some carbides and sufficient alloy content to produce an austenitic structure.

1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.