Hitachi Metal & Alloy. are a stockholder of the 32750 duplex alloys in sheet, plate, and round bar with the added capability of cutting processes to meet requirements across a number of industries.

The following are the properties of 32750 super duplex:

  • Ferritic-Austenitic stainless steel.
  • Excellent corrosion resistance against general corrosion, stress corrosion cracking, corrosion fatigue, pitting, crevice and erosion corrosion and possessing very high mechanical strength properties.
  • Good weldability, post weld heat treatment not necessary.
  • Max. Temperature for long periods of service: 280°C (536°F) / (300°C/572°F possible for short periods).
  • Surface condition for optimum corrosion resistance: pickled or machined.
Inconel-625[1]

Application

Components in offshore, waste water, sea water desalination and chemical plants with aggressive chloride-containing media e.g. heat exchangers, compressor and pump components.

Technical Info

Chemical Composition (average %)

CSiMnCrMoNiCuNPREN
0.0200.250.5525.803.407.00max. 0.500.30Min. 40

Standards

UNS S32750

Hot Forming

Forging

1200 to 950°C / Air cooling

Heat Treatment

Solution annealing:

1150 to 1000°C (2102-1832°F)
Air cooling

Heat Treatment

Solution annealing / quenching:

1100°C (2012°F)
Water , air (thickness below 2mm)

Structure as quenched:

Ferrite + Austenite

Welding

Weldability of super duplex 32750 is good. The welding procedures are similar to those applied for conventional duplex grades. Welding consumables for different welding methods are available.

Mechanical Properties

Condition: solution annealed

ProductDimension
Size
mm
0.2% proof stress
N/mm2
min.
Tensile strength
N/mm2
min.
Elongation A5
% min.
L    Q     T
Impact strength
(ISO-V)
J min.
L    Q     T
St, Sch≤ 16050079525   - –    - -100   - –    - -
P≤ 75252)  252)  - -100   60    - -

St = Bar ,
Sch = Forging,
P = Sheet or plate
L = Longitudinal, Q = Transverse, T = Tangential
1) < 3mm = A80mm specimen
The values for other products and dimensions shall be established by agreement.

Hight Temperature Properties

Condition: solution annealed/quenched

0.2% yield strength
N/mm² min.
Temperature
100°C (212°F)150°C (302°F)200°C (392°F)250°C (482°F)
450420400380

Physical Properties

Thermal conductivity at …………….. 20°C (68°F) …………..15.0 …………W/(m.K)
Specific heat at ………………………..20°C (68°F) …………..500 ………….J/(kg.K)
Electrical resistivity at ………………. 20°C (68°F) …………..0.80 …..Ohm.mm2/m
Modulus of elasticity at …………….. 20°C (68°F) …………..200 x 103 …N/mm2
Magnetic properties …………………………………………………magnetic