Duplex and Super Duplex Steel

Duplex steel consists of approximately 50% ferrite and 50% austenite and has high corrosion resistance and stability.

The ratio of ferrite/austenite depends largely on the content of the respective alloying element like chromium, nickel, carbon, molybdenum and nitrogen along with the thermal treatment/cooling used.
The most commonly used Duplex Stainless Steel grade is 2205 (22% Chromium, 5% Nickel)

Duplex Steel comparison chart:


Equivalent Grade in other Standards

UNS S31803

ASTM A240, A276, A479, A789, A790, A815, A923, A928, A988

UNS S32205

ASTM A240, A240M, A276, A479, A480, A480M, A798, A7901, A815, A923, A928, A988

Super Duplex Steel Comparison chart:


Equivalent Grade in other Standards

UNS S32750

ASTM A182 F53, A240, A479, A789, A790, A815, A928, A949, A988

UNS S32760

ASTM A182 F55, A240, A276, A314, A473, A479, A789, A790, A815, A988