17-4PH Stainless Steel
17-4PH is a martensitic precipitation hardening stainless steel containing 15.0% to 17.5% chromium, 3.0% to 5.0% nickel, 3.0% to 5.0% copper, and 0.15% to 0.45% niobium. Martensitic transformation and aging form the hardening precipitates, producing high strength and hardness up to 40HRC. The source describes corrosion resistance close to 304 stainless steel, adjustable properties through heat treatment, stable mechanical performance below 300℃, good weldability, and resistance to corrosion fatigue.
Product details
Chemical composition
| 17-4PH | C | Si | Mn | P | S | Ni | Cr | Cu | Nb |
|---|---|---|---|---|---|---|---|---|---|
| min | – | – | – | – | – | 3.0 | 15.0 | 3.0 | 0.15 |
| max | 0.07 | 1.0 | 1.0 | 0.04 | 0.03 | 5.0 | 17.0 | 5.0 | 0.45 |
Grade equivalents
| English Item | UNS | W.Nr. | JIS | GB/T | Other Grades |
|---|---|---|---|---|---|
| 17-4PH | S17400 | 1.4542 | SUS630 | S51740 05Cr17Ni4Cu4Nb 0Cr17Ni4Cu4Nb | X5CrNiCuNb16-4 X5CrNiCuNb17-4 Z6CNU17-04 STS630 |
Physical properties
| Density g/cm³ | 7.78 |
|---|---|
| Melting range ℃ | 1350-1420 |
| Thermal conductivity (100℃) λ/(W/m•℃) | 18.3 |
| Specific heat J/kg•℃ | 502 |
| Elastic modulus GPa | 196 |
| Electrical resistivity μΩ•m | 0.98 |
| Linear expansion coefficient a/10-6℃-1 | 10.8 |
Mechanical properties
| Tensile strength Rm N/mm | ≥1310 |
|---|---|
| Yield strength RP0.2 N/mm | ≥1180 |
| Elongation % | ≥10 |
| Hardness HB | ≥375 |
| *After aging heat treatment | |
Available product forms
- Round Bar
- Plate
- Pipe & Tube
- Welding Consumables
- Flanges
- Hex Bolts
- Threaded Rod
- Nuts & Washers
Technical values are transcribed and translated from the supplied Milike Chinese catalogue. Confirm the applicable purchase specification, heat treatment condition, and inspection requirements before final material selection.
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