GRADE S32760 – F55
Stainless, Duplex, Super Duplex
UNS S32760 – F55 : SUPER DUPLEX : ASTM A182, A276, A479, BS EN 10088
GENERAL SCOPE
The characteristic features of high strength and corrosion resistance exhibited by the dual microstructure (50% Austenite, 50% Ferrite) associated with Duplex Stainless Steels, are enhanced by a further addition of Chromium (to 25%), and also Tungsten and Copper.
The alloy’s pitting and Crevice Corrosion resistance is better than Standard F51 duplex, The pitting index (PREN) is increased to 40 min from standard F51 Duplex value of 33 min.
Thin sections (Tubulars) are capable of being cold worked to give yield strength of 105 KSI min.
To optimise mechanical properties, avoid clinking, and to avoid deleterious intermetallics within the microstructure; special high temp forming and heat treatment control practices must be followed during processing.
CHEMICAL COMPOSITION
| C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N | W | PREN | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | . | . | . | . | . | 24.00 | 6.00 | 3.00 | 0.50 | 0.20 | 0.50 | 40.00 | 0.00 |
| Max | 0.03 | 1.00 | 1.00 | 0.030 | 0.010 | 26.00 | 8.00 | 4.00 | 1.00 | 0.30 | 1.00 | . | 0.00 |
MECHANICAL PROPERTIES
| U.T.S | 109 KSI Min | (750 N/mm2) |
| 0.2% Proof Stress | 80 KSI Min | (550 N/mm2) |
| Elongation | 25 % | |
| Red of Area | 45 % | |
| CVN Impacts @ -46°C (-50°F) | 45 Joules | (33 ft-lbf) |