Duplex 2507 Overview:

Duplex 2507 is a super duplex stainless steel designed for applications which demand exceptional strength and corrosion resistance. Alloy 2507 has 25% chromium, 4% molybdenum, and 7% nickel. This high molybdenum, chromium and nitrogen content results in excellent resistance to chloride pitting and crevice corrosion attack and the duplex structure provides 2507 with exceptional resistance to chloride stress corrosion cracking.

Usage of Duplex 2507 should be limited to applications below 600 Fdegree (316 Centigrade degree). Extended elevated temperature exposure can reduce both the toughness and corrosion resistance of alloy 2507.

Duplex 2507 possesses excellent mechanical properties. Often a light gauge of 2507 material can be used to achieve the same design strength of a thicker nickel alloy. The resulting savings in weight can dramatically reduce the overall cost of fabrication.

Corrosion Resistance:

2507 Duplex is highly resistant to uniform corrosion by organic acids such as formic and acetic acid. It is alsohighly resistant to inorganic acids, especially if they contain chlorides. Alloy 2507 is highly resistant to carbide-related intergranular corrosion. Due to the ferritic portion of the duplex structure of the alloy it is very resistant to stress corrosion cracking in warm chloride containing environments. Through additions of chromium, molybdenum and nitrogen localized corrosion such as pitting and crevice attack are improved. Alloy 2507 has excellent localized pitting resistance.

The characteristics of Duplex 2507:
High resistance to chloride stress corrosion cracking
High Strength
Superior resistance to chloride pitting and crevice corrosion
Good general corrosion resistance
Suggested for applications up to 600 F degree
Low rate of thermal expansion
Combination of properties given by austenitic and ferritic structure
Good weldability and workability

Chemical Composition, (%):
Cr 24.0-26.0 Si 0.80 Max
Ni 6.0-8.0 Cu 0.50 Max
Mo 3.0-5.0 P 0.035 Max
C 0.030 Max S 0.020 Max
N .24-.32 Fe Bal
Mn 1.20 Max

Applications is Duplex 2507:

Desalination Equipment
Chemical process pressure vessels, piping and heat exchangers
Marine Applications
Flue Gas Scrubbing Equipment
Pulp & Paper Mill Equipment
Offshore Oil production/technology
Oil and gas industry equipment

ASTM Specifications:
Pipe Smls A790
Pipe Welded A790
Tube Smls A789
Tube Welded A789
Sheet/Plate A240
Bar A276
Flanges & Fittings A182