Superduplex stainless steels have a very high resistance to localized corrosion in chloride media, combined with a high mechanical strength.
UR™ 2507W (1.4501), with tungsten additions, is specially designed for enhanced localized corrosion resistance. The corrosion resistance of these grades is better than UR™ 904 and comparable to 6 Mo austenitics.
This Superduplex grade has a pitting resistance equivalent number, PREN, above 40, and a minimum guaranteed yield strength of 550 MPa, allowing for leaner design in load bearing applications.
The alloy composition, including molybdenum and nitrogen additions, has been optimized to obtain a 50/50 austenoferritic microstructure with outstanding corrosion resistance even for heavy plates.
The UR™ 2507W superduplex grade provides cost - efficient alternatives for a wide range of applications, including offshore, phosphoric and sulfuric acid production as well as flue gas cleaning.

2507 Stainless Steel strip Characteristic machining technology

CORROSION RESISTANCE :

The UR™ 2507W grade performs particularly well in highly corrosive conditions, including sulphuric and phosphoric acid solutions, even in presence of chlorides.

The duplex microstructure which provides high mechanical strength explains why the alloy behaves particularly well in abrasion - corrosion conditions (agitators, screws, rakes...). Superduplex grades are frequently used in mixed acids containing chlorides.

The minimum PREN value of 40 also explains why the alloys are highly resistant to pitting corrosion and crevice corrosion. The alloy behave much better than 904L and is, for pitting corrosion resistance, nearly equivalent to 6 Mo super austenitic grades.

In some cases, the crevice corrosion resistance is slightly higher than 6 Mo alloys due to the 25% Cr additions.

The stress corrosion resistance properties of superduplex stainless steels are excellent in high temperature chloride containing solutions as well as in sour gas applications. 

Application

Construction/Indutry/Building/Chemical/Auto

Seawater systems and desalination

Oil and gas Industry including sour gas applications

Petrochemical industry including PVC strippers

Pulp and paper industry (bleaching...)

Chemical industry including organic acids

Sulphuric acid plants

Phosphoric acid plants

Trucks multipurpose containers

Pollution control equipments (scrubbers)

Geothermal tubes

Hydrometallurgy