Overview
Alloy 32750 is a super duplex stainless steel supplied in the solution annealed condition. As a super duplex stainless steel, it combines the desirable aspects of both austenitic and ferritic grades. The higher chromium, molybdenum and nitrogen contents result in a Pitting Resistance Equivalent number (PREN) of >41, providing pitting and crevice corrosion resistance superior to austenitic and duplex stainless steels in almost all corrosive media, and a Critical Pitting Temperature exceeding 50°C.
Supplied in the annealed condition, it achieves yield strengths of 80ksi (550Mpa), greater than most austenitic and duplex stainless steel grades. It cannot be hardened by heat treatment but can be strengthened by cold working. It also exhibits a low coefficient of thermal expansion and higher heat conductivity than austenitic steels and is suitable for working temperatures up to 300°C. Alloy 32750 is listed in NACE MR 0175 for sour service and having gained ASME Approval for Pressure Vessel applications it can be used in a wide variety of applications.
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. Petrochemical
2. Nuclear power
3. Mechanical
4. Fertilizer
5. Shipbuilding
6. Pipeline
7. Plumbing
8. Solar water heaters
