AMS 5520 is a critical aerospace and industrial specification governing high-performance 15-7 PH (UNS S15700 / 1.4574) semi-austenitic precipitation-hardening stainless steel. This standard covers ultra-thin to medium-thickness sheets, strips, foils and plates with a minimum nominal thickness of 0.0015 inch (0.038 mm), widely used for precision aerospace components and high-strength elastic parts. As a reliable China premium precipitation hardening stainless steel supplier,ZYTC Alloy provides fully AMS 5520 and ASTM A693 compliant 15-7 PH stainless steel sheets and strips with stable batch consistency, precise dimensional tolerance and strictly controlled mechanical properties. 15-7 PH is a chromium-nickel-molybdenum-aluminum reinforced superalloy, featuring unique heat-tunable strength, moderate corrosion resistance and excellent high-temperature stability. It stands out from conventional PH stainless steels due to its minimum distortion after heat treatment, making it the preferred material for high-precision structural components requiring tight tolerance control.
Specifications – 15-7PH| Specification | Description |
|---|
| AMS 5520 | Sheet, strip, foil, and plate | | AMS 5657 | Wire and bar | | ASTM A693 | Sheet and strip | | ASTM A564 | Bar | | UNS S15700 | Unified numbering system | | AISI 632 | AISI designation | | DIN 1.4574 | German standard | | EN X7CrNiMoAl15-7 | European standard |
|  |
Chemical Composition| Chemical Composition (Weight %) | 15-7PH |
|---|
| Chromium (Cr) | 14.0 – 16.0 | | Nickel (Ni) | 6.5 – 7.75 | | Molybdenum (Mo) | 2.0 – 3.0 | | Aluminum (Al) | 0.75 – 1.50 | | Carbon (C) | 0.09 max. | | Manganese (Mn) | 1.00 max. | | Silicon (Si) | 1.00 max. | | Iron (Fe) | Balance |
| Physical Properties | Metric | Imperial |
|---|
| Density | 7.81 g/cm³ | 0.282 lb/in³ | | Electrical Resistivity | 80 µΩ·cm | 80 µΩ·cm | | Coefficient of Expansion (20-90°C) | 14.4 µm/m·°C | 8.0 µin/in·°F |
Mechanical Properties| Material | Condition | Thickness (in) | Tensile Strength (ksi) | Yield Strength (ksi) | Elongation % | Hardness | | 15-7PH | Solution Treated | <0.005 | 150 (max) | 65 (max) | 25 | 100 HB (max) | | 15-7PH | TH1050 (AMS 5520) | 0.010-0.020 | 190 | 170 | 4 | 40 HRC | | 15-7PH | TH1050 (AMS 5520) | 0.020-0.1875 | 190 | 170 | 5 | 40 HRC | | 15-7PH | TH1050 (AMS 5520) | 0.1875-0.500 | 190 | 170 | 6 | 40 HRC | | 15-7PH | RH950 (AMS 5520) | 0.010-0.020 | 225 | 220 | 3 | 45 HRC | | 15-7PH | RH950 (AMS 5520) | 0.020-0.1875 | 225 | 220 | 4 | 45 HRC | | 15-7PH | RH950 (AMS 5520) | 0.1875-0.500 | 225 | 220 | 5 | 45 HRC | | 15-7PH | Condition C | - | 200 | 175 | 1 | 41 HRC | | 15-7PH | Condition CH900 | - | 240 | 230 | 1 | 46 HRC |
Heat Treatment & Operating Conditions15-7PH is supplied in the annealed condition and can be hardened through the following heat treatment sequences: | Condition | Heat Treatment Schedule | Key Properties |
|---|
| TH1050 | Solution treat at 1065°C (1950°F), air cool; austenite condition at 760°C (1400°F) × 90 min; precipitation harden at 566°C (1050°F) × 90 min | High strength, good ductility | | RH950 | Solution treat at 1065°C (1950°F), air cool; austenite condition at 954°C (1750°F) × 10 min; cool to -73°C (-100°F) × 8 hours; precipitation harden at 510°C (950°F) × 90 min | Maximum strength | | CH900 | Cold reduction (Condition C) + age at 482°C (900°F) × 60 min | Highest strength, limited ductility |
Key Advantages: High Strength: Achieves tensile strengths up to 265 ksi in CH900 condition Corrosion Resistance: Superior to standard hardenable martensitic grades; approaches austenitic chromium-nickel stainless steels in many environments Minimum Distortion: Heat treatment causes minimal dimensional change Formability: Easily formed in annealed condition
Weldability Considerations: 15-7PH is weldable by conventional methods, although it has less superior weldability than other PH steels such as 17-4PH due to aluminum content, which degrades penetration and enhances weld slag formation during arc welding
ApplicationsAerospace: Bulkheads, aircraft structural components, welded and brazed honeycomb paneling, actuator components Springs: Retaining rings, flat springs, diaphragms Precision Instrumentation: Sensor diaphragms, pressure sensor components, rotational parts Heat-Treatable Components: Parts requiring tailored mechanical properties through heat treatment
|
