Hangbo Alloy Group supplies a variety of 15-5PH (UNS S15500) precipitation-hardening stainless steel products, including round bars, plates, strips, seamless tubes, forgings, and wires. Below is a comprehensive description of 15-5PH precipitation-hardening stainless steel.
1. Introduction to 15-5PH
Description: 15-5PH (UNS S15500) is a widely used martensitic precipitation-hardening stainless steel, named after its key component ratios (≈15% Cr, ≈5% Ni-Cu). It forms a martensitic matrix after solution treatment, and copper-rich (Ni-Cu-Nb) precipitates are generated during aging to achieve strengthening. It combines corrosion resistance close to 304 stainless steel with ultra-high mechanical properties (tensile strength 860-1275 MPa based on aging conditions) and maintains stable performance in the temperature range of -55°C to 315°C. These characteristics make it an ideal choice for scenarios requiring high strength, corrosion resistance, and precise dimensional control.
International Equivalent Grades:
USA: UNS S15500, ASTM A564 (Grade XM-12)
China: 05Cr15Ni5Cu4Nb (per GB/T 20878 standard)
Europe: EN 1.4545, DIN X5CrNiCuNb15-5
Japan: SUS631 (JIS G4303)
2. Standards for 15-5PH
Plates/Sheets: ASTM A693 (Grade S15500),AMS 5862, GB/T 4237
Round Bars: ASTM A564 (Grade S15500), AMS5659, GB/T 1220, EN 10088-3
Seamless Tubes: GB/T 14975, EN 10216-5
Forgings: ASTM A705/A705M (Grade S15500), EN 10222-5
3. Chemical Composition of 15-5PH
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.07 |
| Chromium (Cr) | 14.0-15.5 |
| Nickel (Ni) | 3.5-5.5 |
| Copper (Cu) | 2.5-4.5 |
| Niobium (Nb) | 0.15-0.45 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
4. Physical Properties of 15-5PH
| Property | Value |
|---|---|
| Density | 7.75 g/cm³ |
| Melting Range | 1420-1460 °C |
5. Material Characteristics of 15-5PH
Precipitation Hardening Mechanism: No quenching and tempering process (required for traditional martensitic steels) is needed. Strengthening is achieved through "solution treatment (1040°C) + aging treatment" (common conditions: H900, H1025, H1150, H1100M), enabling flexible adjustment of the strength-toughness balance.
Superior Strength-Corrosion Balance: The yield strength in H900 condition is ≥860 MPa, which is 2-3 times that of 304/316L. Its corrosion resistance is comparable to 304 (resistant to atmospheric, fresh water, and mild acid/alkali corrosion), and its stress corrosion cracking resistance is superior to 17-4PH.
Excellent Toughness & Dimensional Stability: It exhibits outstanding low-temperature toughness (impact energy ≥68 J at -55°C) and minimal deformation during heat treatment, meeting the requirements of high-precision components.
Good Processability: In the soft solution-annealed state, its machinability is better than that of austenitic stainless steels. It is compatible with TIG/MIG welding, and post-weld aging is recommended to restore strength.
Medium-Temperature Adaptability: It maintains stable performance at temperatures ≤315°C; above 315°C, precipitates coarsen, leading to a decrease in strength.
Optimized Toughness Performance: Compared with 17-4PH, 15-5PH has better fracture toughness and fatigue resistance at the same strength level.
6. Application Fields of 15-5PH
Aerospace & Defense: Used in aircraft landing gear structural components, missile casings, and satellite support parts, balancing high strength-to-weight ratio and corrosion resistance.
Oil & Gas Industry: Applied to downhole tools, wellhead valves, and offshore platform fasteners, withstanding high-pressure wellbore media and marine atmospheric corrosion.
Medical Equipment: Employed in surgical instruments, orthopedic implants (bone plates, screws), and medical device housings, meeting biocompatibility and high-strength requirements.
Valves & Pumps: Used in high-pressure valve cores, pump shafts, and impellers, resisting wear and corrosion in industrial fluid systems (e.g., chemical media, high-pressure water).
High-End Precision Machinery: Suitable for high-precision gears, bearings, and measuring instrument components, combining high strength and dimensional stability.
