ASTM A890 / A890M

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.

Chemical Properties

Type Grade UNS
25Cr - 5Ni - M0 - Cu - N 1BA J93372
25Cr - 6Ni - Mo - Cu - N 1CB J93373
24Cr - 10Ni - Mo - N 2A J93345
25Cr - 5Ni - Mo - N 3A J93371
22Cr - 5Ni - Mo - N 4A J92205
25Cr - 7Ni - Mo - N 5AB J93404
25Cr - 7Ni - Mo - N 6AB J93380
27Cr - 7Ni - Mo - W - N 7AC J93379