Specifications
- Plate, Sheet & Strip: ASTM A240
- Rod & Bar: ASTM A479
Ferralium® 255 is a super duplex stainless steel known for its exceptional strength, corrosion resistance, and durability in harsh environments. With a chemical composition that includes high levels of chromium, molybdenum, and nitrogen, it offers superior resistance to pitting, crevice corrosion, and stress corrosion cracking, making it ideal for demanding applications. Commonly used in marine, chemical processing, and oil and gas industries, Ferralium 255 provides an excellent balance of mechanical performance and cost-effectiveness. Nickel Systems Inc. stocks a wide variety of fasteners made with this exotic alloy. Scroll down to get more information about Ferralium® 255 or request a quote today!
If your question isn’t answered below, download the technical data sheet here.
| 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 | |
| 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 |
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| 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) |
| 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 |
| 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° | |||
Ferralium® 255 is a super duplex stainless steel alloy with the primary chemical composition of chromium, molybdenum, & nitrogen. It’s name is derived from “Ferrum” (Latin for iron), indicating its base metal, and “Alloy”, emphasizing its composition as a high-performance stainless steel alloy. “255” refers to its minimum yield strength of 255 MPa (37 ksi), which highlights its superior mechanical strength compared to standard stainless steels. It is known for its resistance to pitting, crevice corrosion, & stress corrosion cracking.
Other Names for Ferralium® 255
