Grade S32550

UNS S32550 : Super Duplex : A276 (VO1.03), A479 (VO1.03)
Trade Name Ferralium Alloy 255 (5)

General scope

The characteristic features of high strength and corrosion resistance exhibited by the dual microstructure (austenite, ferrite) associated with duplex stainless steels are found in UNS S32550. It is similar in composition to the more widely used super duplex grade UNS S32760. UNS S32550 has a slightly higher copper level, lower nickel and no deliberate tungsten additions, and is normally supplied to achieve the UNS S32760 PREN requirement of 40.

Chemical composition

(PREN = % Cr + 3.3% Mo + 16% N)
C Si Mn P S Cr Ni Mo Cu N PREN Fe
Min 24.00 4.50 2.90 1.50 0.10 40.00 0.00
Max 0.04 1.00 1.50 0.040 0.030 27.00 6.50 3.90 2.50 0.25 0.00

Mechanical properties

Condition: Solution Annealed and Water Quenched.

NACE MR0175 limits the supply hardness to 28 HRC max.
U.T.S 110 KSI Min (760 N/mm2)
0.2% Proof Stress 80 KSI Min (550 N/mm2)
Elongation 15 %
CVN Impacts @ -46°C (-50°F) 45 Joules (33 ft-lbf)
Size range: 1”∅ - 12”∅

Primarily manufactured in:

  • Dubai, UAE
  • Edmonton, Canada
  • Houston, Texas
  • Sheffield, England
  • Singapore