Duplex Stainless 17-7PH Applications
Grade 17-7 stainless steel is mostly found in washers and springs.
It is used in applications which require high strength and corrosion resistance
It is also used in intricate parts due its low distortion on heat treatment.
Weldability
Grade 17-7 stainless steel can be welded using arc and resistance welding techniques. Inert gas shielding is preferred during fusion welding in order to reduce oxidation of aluminum. It is not necessary to perform pre-heating and post-weld annealing processes.
Annealing
Grade 17-7 stainless steel is annealed at 1066°C (1950°F) for 3 min for 0.1 in. (2.5 mm) of thickness followed by air cooling.
Aging
Aging of grade 17-7 stainless steel can be done at 1177°C (2150°F) for 4 h followed by cooling. This process is followed by heating at 1078°C (1975°F) for 4 h and cooling. It is again heated at 844°C (1550°F) for 24 h and cooled, and heated at 760°C (1400°F) for 16 h followed by cooling to complete precipitation hardening process.
Cold Working
Grade 17-7 stainless steel can be easily cold worked using common methods in the condition A.
Hot Working
Solution treated material is heavily cold worked which results in condition C material.
Condition C material is heated at 482°C (900°F) for 1 h in condition CH900 followed by cooling. Solution treated material is heated at 955°C (1750°F) for 10 min after fabrication in condition A1750 followed by rapidly cooling at room temperature.
Within 1 h of treating to condition A1750, it is cooled at -73°C (-100°F) for 8 h in condition R100. It is then heated at 510°C (950°F) for 90 min in condition RH 950 followed by cooling. After fabrication, it is heated at 760°C (1400°F) for 90 min in condition T.
Within 60 min of cooling, it is then cooled at 13°C (55°F) for 30 min. From condition T, it is heated at 565°C (1050°F) for 90 min in condition TH1050 followed by cooling.
17-7ph (631) Chemical Composition
| Element | Content (%) |
| Iron, Fe | 70 - 75% |
| Chromium, Cr | 16.0 - 18.0 |
| Nickel, Ni | 6.50 - 7.75 |
| Silicon, Si | 1.0 |
| Manganese, Mn | 1.0 |
| Aluminum, Al | 0.75 - 1.50 |
| Carbon, C | 0.090 |
| Sulfur, S | 0.040 |
| Phosphorous, P | 0.040 |
17-7PH Mechanical Properties
| Properties | Metric | Imperial |
| Tensile strength | 1275 MPa | 184900 psi |
| Yield strength | 1030 MPa | 149000 psi |
| Fracture toughness (longitudinal, 44 HRC) | 76 MPa-m½ | 69.2 ksi-in½ |
| Elastic modulus | 204 GPa | 29588 ksi |
| Poisson's ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break | 6% | 6% |
| Reduction of area | 10% | 10% |
| Hardness, Rockwell C | 41 | 41 |
Available Sizes And Specifications
| 17-7PH/631 stainless steel plate sizes and specifications |
| Grade | 17-7PH/631/UNS S17700/SUS631 |
| Cold rolled stainless steel coil | Thickness: 0.3mm- 3.0mm, Width: 1000mm - 2000mm,Surface: 2B/BA/SB/8K/HL/1D/2D etc |
| Hot rolled stainless steel coil | Thickness: 3.0mm - 16mm, Width: 1000mm - 2000mm
Surface: No.1/pickling |
| Standard | ASTM A240/A480, ASTM B688, ASTM B463/SB463, ASTM B168/SB168, ASTM B443/SB443/B424/SB424B625/SB625 B575/SB575, JIS G4303, BS 1449, DN17441, G4305 |
