UNS S17400 / EN 1.4542 / AISI 630
Except for the presence of small amounts of alloying elements such as copper, aluminium, phosphorus, or titanium, precipitation-hardening (PH) alloys are similar to other stainless steels and nickel-based alloys. After a component is formed from a PH alloy, it undergoes an age-hardening heat treatment. During this process, these alloying elements precipitate as hard intermetallic compounds, resulting in a significant increase in hardness, strength, and overall mechanical performance
17-4 PH stainless steel is a martensitic precipitation-hardening alloy that offers an excellent combination of high strength, corrosion resistance, and toughness. It maintains good mechanical properties at temperatures up to 600°F (316°C) and provides reliable performance in both base metal and welded conditions. Additionally, its low-temperature, rapid heat treatment minimizes warpage and scaling, making it ideal for precision components.
SPECIFICATIONS
Material Grade: 17-4 PH (Grade 630)
UNS No.: S17400
Type: Martensitic Precipitation-Hardening Stainless Steel
Standards: ASTM A564 / ASTM A705 / AMS 5604 / AMS 5643
Form Availability: Sheets, Plates, Bars, Rods, Pipes, Tubes, Forgings
Heat Treatment Conditions: Solution Annealed (Condition A), H900, H1025, H1075, H1100, H1150
Maximum Service Temperature: Up to 600°F (316°C)
Corrosion Resistance: Comparable to SS 304
Machinability: Good in solution-annealed condition
Weldability: Good with proper procedures
| Element | Composition |
|---|---|
| Carbon (C) | 0.07 max |
| Manganese (Mn) | 1.00 max |
| Silicon (Si) | 1.00 max |
| Phosphorus (P) | 0.040 max |
| Sulphur (S) | 0.030 max |
| Chromium (Cr) | 15.0 – 17.5 |
| Nickel (Ni) | 3.0 – 5.0 |
| Copper (Cu) | 3.0 – 5.0 |
| Niobium + Tantalum (Nb + Ta) | 0.15 – 0.45 |
| Iron (Fe) | Balance |
| Property | Value |
|---|---|
| Tensile Strength | ≥ 1310 MPa |
| Yield Strength | ≥ 1170 MPa |
| Elongation | ≥ 10 % |
| Hardness | 38 – 44 HRC |
| Properties | Condition A | H900 | H1025 | H1075 | H1100 | H1150 | H1150M |
|---|---|---|---|---|---|---|---|
| UTS, ksi (MPa) | 185 max (1276) | 190 min (1310) | 170 min (1172) | 155 min (1069) | 145 min (1000) | 140 min (965) | 135 min (931) |
| 0.2% YS, ksi (MPa) | 160 max (1103) | 170 min (1172) | 155 min (1069) | 145 min (1000) | 125 min (862) | 115 min (790) | 105 min (724) |
| Elongation % in 2” (50.8 mm) | 3 min | 5 min | 5 min | 5 min | 5 min | 5 min | 8 min |
| Rockwell Hardness (HRC) | 38 max | 40 – 48 | 38 – 46 | 35 – 43 | 31 – 40 | 31 – 40 | 28 – 38 |
Applications
- Oil & Gas Industry – Valves, pump components, shafts, fittings
- Aerospace Industry – Aircraft structural parts, fasteners, landing gear components
- Power Plants – Turbine components, shafts, couplings
- Chemical Processing – Corrosion-resistant equipment & pressure components
- Marine & Offshore – Seawater-resistant mechanical parts
- Defense & Heavy Engineering – High-strength precision components
- Pumps & Valves Manufacturing – Valve bodies, stems, seats, impellers
- Industrial Machinery – Gears, bushings, high-load mechanical parts