• 2015-08-29

    What is duplex stainless steel?

Duplex stainless steel is the SUPERSTAR in the material field. This alloy combines the benefits of both ferrite and austenite and we are able to see the balanced microstructure mixture of this two phases in the solution annealed condition.

Duplex stainless steel is immune to intergranular corrosion because of LOW carbon and HIGH chromium contents.
This is why duplex stainless steel has been used in the harsh environment instead of 316L or other alloys nowadays.
The benefits of Duplex Stainless Steel are as follows.
•Very high degree of resistance to pitting and crevice corrosion 
•High wear-resistance
•High tensile strength 
•High yield strength
The applications of Duplex Stainless Steel 
•Desalination systems
•Bridges / Architectural structures
•Chemicals transportation and tubing 
•Oil refining industry 
•Pulp and paper industry
•Chemical industry
The mechanical properties of Duplex Stainless Steel – 2205 and 2507
Material Cr Ni Mo N HB Yield Strength Mpa Tensile Strength MPa Elongation% PRE
2205 22.5 5.5 3 0.2 250 450 655 25 34
2507 25.5 7 4.5 0.25 255 550 795 15 43

PRE (pitting resistance equivalent)=Cr%+3.3 x Mo% +1.6 x N%
The percentage of above chemical elements could be adjusted at LAWAI
The above values are the approximation