Ferralium 255

Ferralium 255

Nickel (Ni) - 5.5 Median
(4.5 Min - 6.5 Max)
Copper (Cu) - 2.00 Median
(1.5 Min - 2.5 Max)
Chromium (Cr) - 25.5 Median
(24.0 Min - 27.0 Max)
Molybdenum (Mo) - 2.95 Median
(2.0 Min - 3.9 Max)
Manganese (Mn) - 1.5 Max
Silicon (Si) - 1.0 Max
Other

Key

Nickel
Copper
Chromium
Aluminum
Molybdenum
Iron
Titanium
Manganese
Cobalt
Other
  • Nickel (Ni) 5.5 Median
    (4.5 Min - 6.5 Max)
  • Copper (Cu) 2.00 Median
    (1.5 Min - 2.5 Max)
  • Chromium (Cr) 25.5 Median
    (24.0 Min - 27.0 Max)
  • Molybdenum (Mo) 2.95 Median
    (2.0 Min - 3.9 Max)
  • Manganese (Mn) 1.5 Max
  • Carbon (C) .04 Max
  • Silicon (Si) 1.0 Max
  • Nitrogen ( N ) 0.1750 Median
    (0.10 Min - 0.25 Max)
  • Phosphorus ( P ) 0.04 Max
  • Sulfur (S) 0.03

UNS S32550

Ferralium 255 is a super duplex stainless which has a pitting resistance number greater than 40. Due to its copper content, it resists corrosion better than the other super duplexes, particularly in seawater applications.

Request a Quote

Summary

  • Environment:
    Oxidation Resistant
  • Temperature Limit:
    122 °F / 50 °C
  • Ultimate Tensile (Typical):
    125 ksi / 862 mpa

Specifications & Technical Data

If your question isn’t answered below, download the technical data sheet here.

Specifications

  • Plate, Sheet & Strip: ASTM A240
  • Rod & Bar: ASTM A479

Physical Properties

Density at 20°C 7.81 g/cc
Mean Coefficient of Thermal Expansion (m/m/°C) 20 – 100°C 11.1 x 10-6
20 – 200°C 11.5 x 10-6
20 – 300°C 12.0 x 10-6
Thermal Conductivity (W/m•K) 20°C 14.2
100°C 16.3
200°C 18.4
Specific Electrical Resistance (Ω-m) 20°C 0.80
100°C 0.88
200°C 0.93
Specific Heat (J/kg•K) 20°C 475
100°C 500
200°C 532
Magnetic Permeability 33
Young’s Modulus (kN/mm2) 199 x 103
Compression Modulus (N/mm2) 150 x 103
Torsional Modulus (N/mm2) 75 x 103
Fracture Toughness, KQ (N/mm2 – m1⁄2) 98
Poisson’s Ratio 0.32

Mechanical Properties

Bars up to and including 4.0” (100mm) diameter or section Bars greater than 4.0”
(100mm) and up to 12.0” (300mm) diameter or section
Bars greater than 12.0”
(300mm) diameter or section
0.2% Proof Stress 586 N/mm2 85ksi 586 N/mm2 85ksi 570 N/mm2 83ksi
Tensile Strength 790 N/mm2 114.5ksi 790 N/mm2 114.5ksi 760 N/mm2 110ksi
Elongation,
5.65√S0 and 4D
25% 25% 25%
Reduction of Area 50% 50% 50%
Hardness (Brinell) 220-270 220-270 220-270
Impact Strength
(Room Temp)
80J 59 ft.lb 80J 59 ft.lb 80J 59 ft.lb
Impact Strength
(-46°C)
45J av
(35J min)
33 ft.lb av
(25.8 ft.lb min)
45J av
(35J min)
33 ft.lb av
(25.8 ft.lb min)
45J av
(35J min)
33 ft.lb av
(25.8 ft.lb min)

 

Typical Mechanical Properties of FERRALIUM 255-SD50 at Elevated Temperatures

Typical Mechanical Properties of FERRALIUM 255-SD50 at Elevated Temperatures

Typical Impact Properties of FERRALIUM 255-SD50 at Ambient and Subzero Temperatures

Typical Impact Properties of FERRALIUM 255-SD50 at Ambient and Subzero Temperatures

Corrosion Resistance

Material Comparisons
Ferralium® 255-SD50 S17400
(17- 4PH)
S32205 N07718 S31254
Pitting Resistance Equivalent number >40 16 34 31 43
0.2% Proof Strength (N/mm2) 586 1100 510 500 325
Corrosion Rate (mm/year) – Seawater <0.01 ~1 <0.01 <0.01 <0.01
Corrosion Rate (mm/year) – 10% sulphuric acid at 80°C B <0.15 10 0.4 <0.15 1.5
Corrosion Rate (mm/year) – Boiling 50% nitric acid <0.15 <0.15 <0.15 <0.15 0.4
Wear Properties related to Hardness (HRC), maximum 28 38 25 20 20

Machinability

Recommended Machining for Ferralium® 255 – SD50
Operation Cutting Speed m/min
(ft/min)
Feed Rate
mm/rev (in/rev)
Depth of cut
mm (in)
Milling 40 (130) 0.05 – 0.13 mm/tooth
0.02 – 0.005 in/tooth
0.5 – 6.0 (0.02 – 0.25)
Drilling 6.4mm (1/4″) dia 250 rpm 0.075 (0.003)
Drilling 25.4mm (1″) dia 150 rpm 0.28 (0.011)
Turning – Roughing 30 – 45 (100 – 150) 0.2-0.38 (0.008 – 0.015) 3 (0.125)
Turning – Finishing 50 – 60 (165 – 200) 0.13-0.20 (0.005 – 0.008) 0.5 (0.02)
Tooling Milling/Turning: Carbide (SANDVIK GC 235, SECOT25M)
Drilling: HSS, point angle 118°, chisel angle 120°
Three Blue Hexagons Are Lined Up On A White Background Three Blue Hexagons Are Lined Up On A White Background

Industries We Serve

Nickel Systems provides high quality exotic grade materials that hold up in the toughest, most severe heat and corrosive environments. With our large inventory of specialty fasteners in stock, we are always ready to answer the call to serve the most challenging applications.

A Bunch Of Nuts And Bolts On A White Surface
Contact Us Today

Contact Experts for Your High Nickel Alloy Fasteners

Contact Us