Overview
Duplex 2507 is a super duplex stainless steel developed for applications that demand high strength and corrosion resistance. Alloy 2507 has 25% chromium, 4% molybdenum, and 7% nickel. This high molybdenum, chromium and nitrogen content causes high resistance to chloride pitting and crevice corrosion attack and the duplex structure provides 2507 with exceptional resistance to chloride stress corrosion cracking.
Using Super Duplex UNS S32750 must be restricted to applications below 600° F (316° C). Extended elevated temperature exposure can reduce both the toughness and corrosion resistance of alloy 2507.
The steel combines high mechanical strength (typically up to 570 MPa yield strength) and good ductility with outstanding corrosion resistance in marine environments. The alloy is supplied with a PREN (Pitting Resistance Equivalent) at >= 40.0 which guarantees high resistance to pitting corrosion. In addition, the steel offers high resistance to crevice corrosion and stress corrosion cracking. Ambient and sub-zero (down to minus 50°C) notch ductility is good.
These attributes mean that this super duplex steel can be used successfully as an alternative to 300 series stainless steel (such as type 316), standard 22% Cr duplex steel (such as UNS S31803 / 1.4462 with PREN 33-34) and precipitation hardening stainless steels (typically 17/4PH).
Specification
ASTM A815/A815M-20 Standard Specification for Wrought Ferritic, Ferritic/Austenitic, and Martensitic Stainless Steel Piping Fittings.
Specifications | ASTM A815 / ASME SA815 |
Size | Seamless Butt Weld Fittings: 1/2″ – 24″, Welded Butt Weld Fittings: 1/2″ – 48″ |
Standards | ASME/ANSI B16.9, ASME B16.28, MSS-SP-43 |
Thickness | 5s, 10s, 40s, 80s, 10, 20, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS available with NACE MR 01-75 |
Type | Seamless / Welded / Fabricated |
Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Fe |
| S32750 | 0.030 max | 1.20 max | 0.80 max | 0.035 max | 0.020 max | 24.00 – 26.00 | 3.00 – 5.00 | 6.00 – 8.00 | 0.24 – 0.32 | 58.095 min |
Mechanical Properties
| Grades | Density (g/cm 3) | Density (lb/in 3) | Melting Point (°C) | Melting Point (°F) |
| S32750 | 7.8 | 0.281 | 1350 | 2460 |
Applications
- 1. Chemical processing, transport and storage
- 2. Oil and gas exploration and offshore rigs
- 3. Oil and gas refining
- 4. Marine environments
- 5. Pollution control equipment
- 6. Pulp & paper manufacturing
- 7. Chemical process plant
