2507

Super duplex stainless steel pipes, plates, fittings, and forgings have a microstructure composed of approximately 50% austenite and 50% ferrite matrix. This combination, along with the alloy composition, offers several key benefits: - high strength compared to standard austenitic steels like type 316L; - excellent overall corrosion resistance in a wide range of environments; - high resistance to chloride-induced stress corrosion cracking (CSCC); - remarkable resistance to pitting attack in environments containing chlorides, such as seawater. These characteristics make super duplex alloys ideal for continuously evolving applications in the
offshore oil/gas, chemical, and petrochemical industry. They are frequently used in piping systems, flow lines, risers, manifolds, and more.

25%Cr ferritic-austenitic superduplex stainless steels.

Austenite-ferrite duplex microstructure in AW or solution annealed condition with an approximate 30- 60% ferrite level, depending on heat cycle conditions.

• EN W.Nr.: 1.4410 (X2CrNiMoN25-7-4)
• ASTM: A182 F53, A182 F55, A890 Gr5A, A890 Gr6A
• UNS: S32750, S32760, J93404
• PROPRIETARY: SAF 2507 (Sandvik), Uranus® 47N (Industeel)

Generally, preheating is not required. The interpass temperature is set to a maximum of 150 °C. A heat input range of 1.0–2.0 kJ/mm, depending on the thickness of the material, is acceptable, with many codes specifying a maximum limit of 1.5 or 1.75 kJ/mm. Although welds on duplex stainless steels are almost always left as-welded, major repairs on castings are generally carried out in a solution-treated condition. Industry practices suggest that excellent mechanical properties can be obtained through water quenching at 1120 °C, held for 3-6 hours.