Specifications

  • Alloy 255
  • Super Duplex 255
  • 1.4507
  • X2 CrNiMoCuN 25-6-3
  • Z3 CNDU 25-07 Az
  • Norsok MDS D57
  • ASTM A276/A476 F61
  • UNS S32550
  • ASME A182 F61
View Data Tables For This Product

Ferralium 255 – SD50 HS110 (UNS S32550 110ksi)

Ferralium® 255 – SD50 HS110 is a higher strength super duplex stainless steel supplied in the strain hardened condition (Condition S). By precise further processing, it achieves significantly raised yield and tensile strengths whilst still retaining good levels of impact strength. Typically offered in tubular form, the machined bar will serve as coupling material, suitable for subsequent processing to coupling stock, couplings and other tubular goods as outlined in API 5CRA / 5CT. It therefore provides a cost-effective alternative for applications that previously used higher cost alloys. The production route allows smaller quantities to be economically manufactured against competitive lead times.

As a 25% Cr alloy, with significant additions of copper, it offers excellent corrosion resistance in a wide variety of corrosive chemicals including sulphuric, nitric and phosphoric acid. In seawater and other chloride containing environments it also provides outstanding resistance to pitting and crevice corrosion, with Critical Pitting Temperature exceeding 50°C. Excellent ductility and impact strength at both ambient and sub-zero temperatures combine with a high resistance to abrasion, erosion and cavitation erosion.

Ferralium® 255 – SD50 HS110 builds upon the Ferralium® 255 – SD50 product which is listed in NACE MR 01 75 for sour service and has gained ASME Approval for Pressure Vessel applications. It is tested to the highest degree using tests designed to guarantee that our trade-marked product possesses high integrity, correct phase balance and the absence of sigma and other deleterious phases.

Saw Alloy

Specifications

  • Alloy 255
  • Super Duplex 255
  • 1.4507
  • X2 CrNiMoCuN 25-6-3
  • Z3 CNDU 25-07 Az
  • Norsok MDS D57
  • ASTM A276/A476 F61
  • UNS S32550
  • ASME A182 F61
View Data Tables For This Product

Data Tables

Chemical Composition:

CrNiMoCoNb (+Ta)TiVWCuCMnNSiPSFeAl
Min24.505.503.101.500.800.20
Max26.506.503.802.000.0251.200.250.700.0250.005Balance

Mechanical Properties:

Bars up to and including 6.5” diameter or section
0.2% Proof Stress758 - 965 N/mm2110-140 ksi
Tensile Strength862 N/mm2125 ksi
Elongation, 5.65√S0 and 4D16%
Hardness (Rockwell C)< 35
Impact Strength (-10degC), Transverse40J av (27J min)30 ft.lb av (20 ft.lb min)

Notes:

  1. Testing shall be carried out in accordance with ASTM A370 or EN ISO 6892-1 (tensile), EN ISO 6506-1 (hardness)
  2. Minimum properties quoted (tested at room temperature in a longitudinal direction unless stated)
  3. Testing performed on each melt of material per heat treatment batch
  4. ASTM G48A corrosion test (at 50°C)  no pitting and < 0.8g/m2 weight loss
  5. Ferrite content   35-55%
  6. Microstructure certified free from grain boundary carbides, sigma, chi and laves phases
  7. Specification only applicable for nominal critical wall thickness ≤1” (25.4mm) after conversion of bar to tubular form

 

 

 

Physical Properties:

Density (Kg/m3)7810
Magnetic Permeability (20°C)33
Young’s Modulus (kN/mm2)220
Specific Electrical Resistance, 20°C (Ω-m)0.80 x 10-6
Mean coefficient of thermal expansion, 20-100°C (m/m/degC)11.1 x 10-6
Specific Heat, 20°C (J/kg.K)475
Thermal conductivity, 20°C (W/m.K)14.2
Fracture Toughness, KQ (MPa/m2)98

Product Features

Key Features:

  • Ferralium® was originally developed in 1960’s, pioneering the addition of nitrogen, to create the first super duplex stainless steel
  • Ferralium® was then continually developed through 1990’s to extend PREN > 40, and more recently to increase mechanical properties
  • Pitting Resistance Equivalent (PREN) >40, indicating outstanding resistance to pitting and crevice corrosion
  • Very low levels of sulphur minimise the likelihood of inclusions as sites for potential pitting corrosion
  • Higher copper content provides self-healing effect at sites of pitting to inhibit further growth
  • Now available in a high strength variant, achieving proof stress exceeding 110ksi (758N/mm2) in diameters up to 6 ½“

Applications:

  • Ferralium® 255 – SD50 is widely specified in the Oil & Gas industry for pumps, valves, wellhead and subsea equipment
  • Ferralium® 255 – SD50 HS110 has been developed for applications currently only able to be supplied from tubular goods in more costly nickel alloys
  • Coupling material for conversion to coupling stock, couplings, collars and associated components
Datasheet SD Ferralium 255 SD50 HS110 Brochure Ferralium 255 SD50 detailed product information (rev2)
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