| The Super Alloys management team are amongst the most experienced professionals in the market. Supported by professional metallurgists and technicians, Super Alloys not only provide access to the largest range of high-tec metals in Europe, but also access to the broadest range of expertise. The unique combination of access to stock, expertise and rapid delivery reduces lead times and can eliminate costly production delays. The Super Alloys range of materials includes: · Titanium Alloys · Nickel Alloys · Steels 17-4 Age-Hardening Martensitic Stainless Steel 17-4 stainless steel is an age-hardening martensitic alloy combining high strength with the corrosion resistance of stainless steel. Hardening is achieved by a short-time, simple low-temperature treatment. Unlike conventional martensitic stainless steels, such as type 410, 17-4 stainless steel is quite weldable. The strength, corrosion resistance and simplified fabrication can make 17-4 stainless steel a cost-effective replacement for high strength carbon steels as well as other stainless grades. Applications of 17-4 Stainless Steel Typical Applications for the 17-4 stainless steel age-hardening martensitic alloy include: · Gate valves · Aircraft structures, accessories, engine parts · Chemical processing equipment · Food processing machinery · Pump shafts, gears, plungers · Valve stems, balls, bushings, seats · Pulp & paper mill equipment · Fasteners Composition of 17-4 Stainless Steel The composition range for 17-4 stainless steel is provided in table 1. Table 1. Composition of 17-4 Age-Hardening Martensitic stainless steel. | | | | | Chromium | 15.00 | 17.50 | | Nickel | 3.00 | 5.00 | | Copper | 3.00 | 4.00 | | Manganese | - | 1.00 | | Silicon | - | 1.00 | | Columbium + Tantalum | 5 x C | 0.45 | | Carbon | - | 0.07 | | Phosphorus | - | 0.04* | | Sulfur | - | 0.03* | | Molybdenum | - | 0.05 | | Iron | remainder | Specifications The various forms of 17-4 stainless steel are covered by the following standards: · UNS S17400 (Sheet, Plate, bar) · UNS S17480 (MIG, TIG & Coil Weld Wire) · UNS W37410 (Covered Electrodes) · DIN 1.4548 Table 3. Specifications relating to 17-4 stainless steel. | | | | | | | Sheet Plate | 5604 | SA-693 | A 693 | | | Bar | 5643 | SA-564 | A 564 | | | Forgings | | SA-705 Type 630 | A 705 Type 630 | | | Weld Wire (S17480) | 5803 | | | A5.9 ER 630 | | Weld Wire (W37410) | 5827 | | | A5.4 E630 | Heat Treatments for 17-4 Stainless Steel 17-4 stainless steel is a martensitic, precipitation-hardening stainless steel. At the solution treating temperature, 1900°F (1040°C), the metal is austenitic but undergoes transformation to a low-carbon martensitic structure on cooling to room temperature. This transformation is not complete until the temperature drops to 90°F (32°C). Subsequent heating to temperatures of 900 to 1150°F (480 to 620°C) for one to four hours precipitation strengthens the alloy. This hardening treatment also tempers the martensitic structure, increasing ductility and toughness. Physical Properties of 17-4 Stainless Steel Table 4. Physical properties of 17-4 stainless steel. | | | | Melting Range | 2560-2625°F (1404-1440°C) | | For Condition H 900 Density lb/in3 | 0.282 | | Electrical resistivity Ohm · circular mil/ft | 463 | | Specific Heat Btu/lb°F | 0.11 | | Poisson’s Ratio 70°F | 0.272 | | Modulus of Elasticity psi x 106 | | | Tension 70°F | 28.5 | | 200°F | 28.0 | | 400°F | 27.0 | | 600°F | 26.0 | | Torsion 70°F | 11.2 | Magnetic Permeability of 17-4 Stainless Steel | H=100 Oersted | H=200 Oersted | Max | | 90 | 56 | 135 | Thermal Properties of 17-4 Stainless Steel The thermal properties of 17-4 stainless steel are summarised in table 5. Table 5. Mean Coefficient of Thermal Expansion inch/inch°F x 10-6. | | | | -100 to 70°F | 5.8 | | 70 to 200°F | 6.0 | | 70 to 400°F | 6.1 | | 70 to 600°F | 6.3 | | 70 to 800°F | 6.5 | Thermal Conductivity of 17-4 Stainless Steel The thermal conductivity of 17-4 stainless steel are summarised in table 3. Table 6. Thermal Conductivity of 17-4 stainless steel in Btu×ft/ft²·hr·°F. | At 300°F | 10.3 | | 500°F | 11.3 | | 860°F | 13.0 | | 900°F | 13.1 | Typical Mechanical Properties of 17-4 Stainless Steel Table 7. Typical mechanical properties of 17-4 stainless steel. | | | | | | | | | | | | | | | | | | | H 900** | 200 | 185 | 14 | 50 | 420 | C 44 | 15 | | H 925 | 190 | 175 | 14 | 54 | 409 | C 42 | 25 | | H 1025 | 170 | 165 | 15 | 56 | 352 | C 38 | 35 | | H 1075 | 165 | 150 | 16 | 58 | 341 | C 36 | 40 | | H 1100 | 150 | 135 | 17 | 58 | 332 | C 35 | 25 | | H 1150 | 145 | 125 | 19 | 60 | 311 | C 33 | 30 | | H 1150-M | 125 | 85 | 22 | 68 | 277 | C 27 | 100 |
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Super Alloys - Titanium, Nickel and Steel Alloys
