Alloy 17-7 PH is a precipitation hardening stainless steel that offers a unique combination of high strength, corrosion resistance, and excellent formability. It derives its name from its chemical
composition and the process used for its heat treatment.
The "17” in 17-7 PH represents the approximate percentage of chromium present in the alloy, while the "7” refers to the approximate percentage of nickel. The “PH” stands for precipitation hardening, which is the heat treatment process used to achieve its remarkable strength.
One of the key characteristics of Alloy 17-7 PH is its high tensile strength. It has a significantly higher strength compared to standard austenitic stainless steels, making it suitable for applications that require robust mechanical properties. It exhibits a combination of high strength and good ductility, allowing it to withstand heavy loads and resist deformation.
Alloy 17-7 PH also offers excellent corrosion resistance. It demonstrates good resistance to atmospheric corrosion and is resistant to attack by fresh water and mild chemical environments.
Available tube product forms
Typical Applications
- Aircraft Structural Parts
- Torsion Bars
- Fasteners And Springs
- Surgical Instruments
- Medical Devices
Typical Manufacturing Specifications
- ASTM B444
- BS 3074
- AMS 5581
- Also individual customer specifications
Industries predominantly using this grade
Technical Data
Mechanical Properties
| Tensile Strength |
1100 MPa (160,000 psi) minimum |
| Yield Strength |
1035 MPa (150,000 psi) minimum |
| Elongation |
20% minimum |
| Hardness |
HRC 40-47 (in Condition TH1050) |
Physical Properties
| Density |
7.8 g/cm³ |
| Melting Range |
1370-1400°C (2500-2550°F) |
| Thermal Conductivity |
17.9 W/m·K (at 20°C) |
| Electrical Resistivity |
0.83 μΩ·m (at 20°C) |
| Modulus of Elasticity |
203 GPa (29.5 x 10^6 psi) |
Chemical Composition (% by weight)
|
Element |
Min |
Max |
|
Cr |
16 |
18 |
|
Ni |
6.5 |
7.75 |
|
Al |
0.75 |
1.5 |
|
Mn |
-
|
1 |
|
Si |
-
|
1 |
|
C |
- |
0.09 |
|
P |
- |
0.04 |
|
S |
- |
0.03 |
| Fe |
Balance |