ASTM A890/A890M REV A: Standard Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion- Resistant, Duplex (Austenitic/Ferritic) for General Application

This specification covers a group of cast duplex stainless steels (austenitic/ferritic).

The duplex stainless steel alloys offer a combination of enhanced mechanical properties and corrosion resistance when properly balanced in composition and properly heat treated. Ferrite levels are not specified, but these alloys will develop a range of approximately 30 to 60 % ferrite with the balance austenite. It is the responsibility of the purchaser to determine which grade shall be furnished depending on design and service conditions, mechanical properties, and corrosionresistant characteristics.

NOTE 1—Because of the possibility of precipitation of embrittling phases, the grades included in this specification are not recommended for service at temperatures above 600ºF [315ºC].

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.

Within the text, the SI units are shown in brackets.

*A Summary of Changes section appears at the end of this standard

austenite

duplex stainless steel

ferrite

stainless steel

steel castings