UNS S17700 | AMS 5528 | ASTM A 693 | ASME SA 564 | DIN 1.4568 | Alloy 631 | MIL-S- 25043
Stainless Steel 17-7PH (AMS 5528 / AMS 5529/ AMS 5644)
Introduction
The two main properties of precipitation-hardened stainless steels are high corrosion resistance and high strength. Stainless steel grade 17-7 PH is a precipitation hardened stainless steel that possesses high strength and hardness, excellent fatigue properties, good formability, good corrosion resistance, and minimal distortion upon heat treatment. The properties of this alloy are well suited for aerospace applications.
Stainless steel grade 17-7 PH is suitable for use in fresh water and industrial atmospheres, and mild chemical and oxidizing environments. It is recommended that 17-7 PH should not be used in salt water or reducing environments.
Chemical Composition
The chemical composition of stainless steel grade 17-7 PH is outlined in the following table.
| Element | Content (%) |
| Chromium, Cr | 16-18 |
| Nickel, Ni | 6.50 – 7.75 |
| Manganese, Mn | 1 max |
| Silicon, Si | 1 max |
| Aluminum, Al | 0.75 – 1.50 |
| Carbon, C | 0.09 max |
| Phosphorous, P | 0.040 max |
| Sulfur, S | 0.030 max |
| Iron, Fe | Balance |
Technical Data Sheet
| Chemical Composition Limits | ||||||||
| Weight% | C | Mn | Si | P | S | Cr | Ni | Al |
| 17-7PH | 0.09 max | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 16.00-18.00 | 6.50-7.75 | 0.75-1.50 |
Alloy 17-7 PH a precipitation hardening stainless steel that provides high strength and hardness, excellent fatigue properties, good corrosion resistance, good formability, and minimum distortion upon heat treatment.
Alloy 17-7 PH provides valuable property combinations particularly well suited for aerospace applications. This special alloy also provides benefits for other applications requiring high strength and good corrosion resistance, as well as excellent properties for flat springs at temperatures up to 315°C (600°F ).
Corrosion Resistance
17-7 PH stainless steel provides corrosion resistance in conditions TH 1050 and RH 950 is generally superior to that of the standard hardenable chromium types of stainless steels such as Types 410, 420 and 431, but is not quite as good as chromium-nickel Type 304. Corrosion resistance in Condition CH 900 approaches that of Type 304 in most environments.
Formability
In Condition A, Alloy 17-7 PH can be formed comparably to Type 301. It work hardens rapidly and may require intermediate annealing in deep drawing or in forming intricate parts. Spring-back is similar to that of Type 301. Alloy 17-7 PH is extremely hard and strong in Condition C. Therefore, fabrication techniques for such materials must be used.
Typical Mechanical Properties
| Material | Condition | Ultimate Tensile Strength (ksi) | 0.2 % Yield Strength (ksi) | Elongation % in 2D | % Reduction of Area | Rockwell C Hardness |
| 17-7 Sheet / Strip AMS 5528 |
Cond A | 105 max | 65 | 20 | – | 92 HRB max |
| 17-7 Sheet / Strip AMS 5528 |
TH1050 | 180-120 | 150 | 4-6 | – | 38-46 |
| 17-7 Sheet / Strip | RH950 | 220 | 200 | 9 | – | 46 |
| 17-7 Sheet / Strip AMS 5529 |
Cond C | 200 min | 175 min | 1 | – | 41 min |
| 17-7 Sheet / Strip AMS 5529 |
CH 900 | 240 min | 230 min | 1 | – | 46 min |
| 17-7 Bar AMS 5644 |
Cond A | 170 min | 140 min | 6 | 25 | 363 HB min |
Alloy 17-7PH is available in Sheet, Strip, Plate, Bars (Round Bars), Tube, Forgings and Welding Wire. 17-7PH Foil (Shim) is available in various thicknesses.Availability
Applications
Stainless steel grade 17-7 PH is primarily used for applications requiring corrosion resistance, good strength, and mechanical properties up to 427°C (800°F) in operation. It is also commonly used for intricate parts due to its low distortion in heat treatment.
Stainless steel grade 17-7 PH finds uses in the following:
- Variety of springs and washers
- Chemical processing equipment
- Heat exchangers
- Power boilers
- Superheater tubes
- Components used in high-strength/high-temperature conditions
Services
At Fountain Head Alloys, we specialise in the rapid turn-around of orders, with most stock items ready for shipping out the same day to anywhere in the world. For time-critical orders, such as AOGs use our AOG service desk (sales@fountainheadalloys.com), the team are dedicated to processing and dispatching orders on the same day, even for cutting orders on bar and sheet products.
Disclaimer
Every effort is made to ensure that technical specifications are accurate. However, technical specifications included herein should be used as a guideline only. All specifications are subject to change without notice.
Specifications
ASME SA 564, SA 693 and SA 705
W.NR 1.4541
PWA-LCS
GE-S400/1000
UNS S17700
AMS 5528 Sheet, Strip and Plate
AMS 5529 Sheet, Strip Cold Rolled
AMS 5568 Welded Tubing
AMS 5644 Bars and Forgings (Cap. ASTM A 564 Type 631)
AMS 5678 Wire
AMS 5824 Welding Wire
MIL-S-25043 Cond. C, Sheet, Strip and Plate
ASTM A 693, ASTM A 313, ASTM A 564, ASTM A 579 and ASTM A 705
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