The Ultimate Guide to UNS S45000 Steel
Dr. Robert Anderson
Senior Materials Scientist
Introduction to UNS S45000
UNS S45000 is a high-performance precipitation-hardenable stainless steel known for its exceptional corrosion resistance, high strength, and excellent mechanical properties. This premium alloy is widely used in aerospace, marine, and industrial applications where durability and reliability are critical.
In this guide, we’ll explore:
✔ Composition & Key Properties of UNS S45000
✔ Heat Treatment & Mechanical Performance
✔ Applications in Aerospace & Beyond
✔ Advantages Over Other Stainless Steels
Composition & Key Properties
UNS S45000 (also known as AMS 5773F steel) has a carefully balanced chemical composition for optimal performance:
| Element | Min (%) | Max (%) |
|---|---|---|
| Chromium (Cr) | 14.00 | 16.00 |
| Nickel (Ni) | 6.00 | 7.00 |
| Molybdenum (Mo) | 0.50 | 1.00 |
| Copper (Cu) | 1.25 | 1.75 |
| Carbon (C) | – | 0.05 |
Why This Matters:
Corrosion Resistance – Comparable to 18-8 stainless steels
High Strength – Tensile strength up to 180 ksi (1241 MPa) after precipitation hardening
Excellent Ductility – Maintains good elongation and toughness
Heat Treatment & Mechanical Performance
UNS S45000 is supplied in a solution heat-treated condition and can be further precipitation hardened for enhanced strength.
Solution Heat Treatment:
- Heated to 1900°F (1038°C)
- Rapidly cooled for optimal microstructure
Precipitation Hardening Options:
| Condition | Temperature | Tensile Strength (min) | Hardness (HB) |
|---|---|---|---|
| H900 | 900°F (482°C) | 180 ksi (1241 MPa) | 363 HB |
| H950 | 950°F (510°C) | 170 ksi (1172 MPa) | 341 HB |
| H1150 | 1150°F (621°C) | 125 ksi (862 MPa) | 262 HB |
Best for Aerospace: H900 offers the highest strength, while H1150 provides better ductility for forming.
Applications of UNS S45000
1. Aerospace Components
- Aircraft landing gear
- Engine mounts
- Structural fasteners
2. Marine & Chemical Industries
- Valve components
- Shafts & pump parts
3. High-Strength Industrial Parts
- Bolts, nuts, and washers
- Hydraulic system components
Advantages Over Other Stainless Steels
| Feature | UNS S45000 | 304 Stainless | 17-4PH Stainless |
|---|---|---|---|
| Corrosion Resistance | |||
| Strength (H900) | 180 ksi | 75 ksi | 160 ksi |
| Machinability | Good | Excellent | Fair |
✔ Superior Strength-to-Weight Ratio – Ideal for weight-sensitive aerospace applications.
✔ Stress-Corrosion Resistance – Performs well in harsh environments.
Conclusion: Why Choose UNS S45000?
UNS S45000 is a versatile, high-performance stainless steel that excels in:
Extreme environments (aerospace, marine)
High-stress applications (fasteners, structural parts)
Precision components requiring tight tolerances
For industries demanding reliability, strength, and corrosion resistance, UNS S45000 (AMS 5773F) is an outstanding choice.
Looking for UNS S45000 suppliers? Ensure they comply with AMS 5773F specifications for guaranteed quality!
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