- Description
17-4PH Stainless Steel Plate Complete Guide: Heat Treatment, Mechanical Properties & Industrial Applications
17-4PH stainless steel plate (also known as UNS S17400 / 630 stainless steel) is a precipitation-hardening martensitic stainless steel widely used in applications requiring a combination of high strength, good corrosion resistance, and dimensional stability.
It is commonly used in defense systems, nuclear components, aerospace structures, chemical equipment, and high-load mechanical parts.
1. What is 17-4PH Stainless Steel?
| Property | Description |
|---|---|
| Steel type | Precipitation-hardening stainless steel |
| UNS designation | S17400 |
| Equivalent grade | 630 stainless steel |
| Main alloying elements | Cr, Ni, Cu |
The strengthening mechanism is based on precipitation hardening (aging process), which allows very high mechanical strength after heat treatment.
2. Solution Treatment + Aging Process
17-4PH performance is controlled by two key steps: solution treatment and aging.
- Solution treatment: dissolves alloying elements into a uniform structure
- Aging treatment: precipitates strengthening phases to increase strength
| Condition | Mechanical Behavior |
|---|---|
| Solution treated | Soft, good machinability |
| H900 | Maximum strength condition |
| H1025 | Balanced strength and toughness |
| H1150 | Higher toughness, reduced hardness |
3. Mechanical Properties Overview
- Very high tensile strength after aging
- Good corrosion resistance in moderate environments
- Excellent dimensional stability after heat treatment
- Good fatigue resistance for cyclic loading
| Condition | Strength Level |
|---|---|
| Solution treated | Low |
| H900 | Very high |
| H1025 | High (balanced) |
| H1150 | Moderate (toughness optimized) |
4. 17-4PH vs 630 Stainless Steel
17-4PH and 630 stainless steel refer to the same material system, with different naming conventions used across industries.
| Designation | Usage Context |
|---|---|
| 17-4PH | Common industrial / aerospace naming |
| 630 (UNS S17400) | Standardized metallurgical designation |
5. Typical Applications
| Industry | Application Examples |
|---|---|
| Aerospace | Structural components, support brackets |
| Defense | High-strength mechanical assemblies |
| Nuclear industry | Critical load-bearing components |
| Industrial machinery | Shafts, gears, high-load parts |
6. Processing Considerations
- Machining is easier in solution-treated condition
- Aging should be performed after final shaping
- Heat treatment must be tightly controlled for consistency
- Welding requires careful procedure control
7. Teda Ganghua Stainless Steel Supply Capability
At Teda Ganghua, we supply high-quality 17-4PH stainless steel plates (630 grade) with stable precipitation-hardening performance. Our materials are widely used in aerospace, nuclear engineering, and high-strength industrial systems.
We provide precision cutting, heat-treatment coordination, and customized fabrication services to meet strict engineering requirements for global customers.
Explore our stainless steel products here:
Stainless Steel Plate Products
Conclusion
17-4PH stainless steel plate is one of the most important precipitation-hardening alloys in modern engineering. With excellent strength, good corrosion resistance, and controllable heat treatment states, it is widely used in aerospace, nuclear, and high-performance industrial applications.
