Supplied in the annealed condition, it achieves yield strengths of 80ksi (550Mpa), greater than most austenitic and duplex stainless steel grades. It cannot be hardened by heat treatment but can be strengthened by cold working. It also exhibits a low coefficient of thermal expansion and higher heat conductivity than austenitic steels and is suitable for working temperatures up to 300°C.
| Zeon Grade | Alloy Name | UNS | EN / DIN / W Nr. | AISI / ASTM | Trademarks | Zeon53 | Alloy 2507 | UNS S32750 | 1.441 | F53 | SAF2507/URANUS47N |
|---|
| Elements | Min | Max |
|---|---|---|
| Cr | 24.50 | 26.00 |
| Ni | 6.00 | 8.00 |
| Mo | 3.00 | 5.00 |
| Cu | - | 0.50 |
| C | - | 0.03 |
| Mn | 0.50 | 1.20 |
| N | 0.24 | 0.32 |
| Si | 0.10 | 0.80 |
| P | - | 0.035 |
| S | - | 0.020 |
| Fe | - | Bal |
| Density (Kg/m3) | 7810 |
| Magnetic Permeability (20°C) | 33 |
| Young’s Modulus (kN/mm2) | 199 |
| 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 |
| 0.2% Proof Stress | 550 N/mm2 | 79.8 ksi |
| Tensile Strength | 800 N/mm2 | 116 ksi |
| Elongation, 5.65√S0 and 4D | 25% | - |
| Reduction of Area | 45% | - |
| Hardness (Brinell) | <270 | - |
| Impact Strength (Room Temp) | 80J | - |
| Impact Strength (-46degC) | Longitidinal 45J (35J min) | - |
| Transverse 45J (35J min) | - |
| Corrosion Resistance Properties of Alloy 255 |
|---|
| The duplex microstructure and the low carbon content gives UNS S32750 very good resistance to intercrystalline corrosion. UNS S32750 is also an approved material according to NACE MR0175 ``Standard Material Requirements - Metals for Sulfide Stress Cracking and Stress Corrosion Cracking Resistance in Sour Oilfield Environments”. It also provides resistance against pitting corrosion and crevice corrosion. |
| Hot Forming | UNS S32750 should be hot worked between 1875ºF and 2250ºF. This should be followed by a solution anneal at 1925ºF minimum and a rapid air or water quench. |
|---|---|
| Cold Forming | Most of the common stainless steel forming methods can be used for cold working UNS S32750. |
| Machining | UNS S32750 is generally more difficult to machine than conventional austenitic steels and have different machining properties than those of high-alloy austenitic steels. The main difference is that duplex steels are relatively easier to machine with high speed tools than with cemented carbide tools compared to austenitic stainless steels with similar alloy content. |
| Heat Treatment | 2507 should be solution annealed and quenched after either hot or cold forming. Solution annealing should be done at a minimum of 1925ºF Annealing should be followed immediately by a rapid air or water quench. To obtain maximum corrosion resistance, heat treated products should be pickled and rinsed. |
| Welding | UNS S32750 possesses good weldability and can be joined to itself or other materials by shielded metal arc welding, gas tungsten arc welding , plasma arc welding, flux cored wire, or submerged arc welding. |
| Surface finish | UNS S32750 is available with pickled or machined and peeled surfaces. |
| Applications Of Alloy 2507 / F53 | ||
|---|---|---|
| Oil & Gas industry pumps, valves, wellhead and subsea equipment | Pollution control scrubbers, precipitators, fans and pumps | Marine propellers, shafts, rudders, seals, pumps, valves |
| Bolts and fasteners | Process industry equipment in sulphuric acid, nitric acid, phosphoric acid, PP / PVC/TiOx production, agrochemicals | Grain and vegetable processing plant, sugar cane centrifuges |
| Pulp and paper digester blow vales, feed valves, washers, black liquor heater tubes, bleaching components | Copper smelting fans, tuyere bars, wet scrubbers, leaching area precipitators | Water and sewage treatment, desalination, swimming pools |