Haynes282 Alloy

Haynes282 (UNS N07282) is a state-of-the-art age-hardenable nickel-chromium-cobalt-tungsten (Ni-Cr-Co-W) based superalloy, engineered for wide-temperature-range applications (650-815℃) demanding exceptional creep resistance, thermal stability, and compatibility with aggressive high-temperature environments. Unlike Haynes263 (optimized for 550-650℃ via γ’ phase strengthening) and Haynes242 (relying on long-range ordering), Haynes282 achieves its breakthrough performance through multi-element modulated γ’ phase (Ni₃(Al,Ti,Ta)) precipitation—a refined strengthening mechanism that balances high-temperature strength (up to 815℃) with outstanding fabricability. This makes it the material of choice for critical hot-section components in advanced gas turbines (aerospace and industrial) and ultra-supercritical (USC) power plants, where service conditions span medium to high temperatures with cyclic thermal stress.

1. Chemical Composition (Mass Fraction, %)

Haynes282’s composition is a sophisticated balance of γ’ phase formers, solid-solution strengtheners, and grain boundary modifiers—tailored to maximize high-temperature performance while retaining processability for complex components (e.g., turbine rotors, blades).

2. Physical Properties

Haynes282’s physical properties are optimized for compatibility with adjacent high-temperature components (e.g., turbine casings, heat exchanger tubes) and efficient heat management in wide-temperature-range operation.

2.1 Core Physical Parameters

• Density: 8.70 g/cm³ (room temperature, 25℃)

Higher than Haynes263 (8.47 g/cm³) due to W/Ta addition, but offset by superior high-temperature strength—enabling thinner-walled components (e.g., turbine blades) that reduce overall weight.

• Melting Temperature Range: 1320-1380℃ (liquidus: 1380℃; solidus: 1320℃)

Narrow range ensures uniform casting and welding; compatible with investment casting for complex turbine blade geometries.

• Thermal Expansion Coefficient (CTE):

◦ 25-538℃: 12.8×10⁻⁶/℃

◦ 25-815℃: 13.5×10⁻⁶/℃

Matched to ceramic thermal barrier coatings (TBCs, e.g., YSZ: 10.5×10⁻⁶/℃) with minimal thermal mismatch—reducing TBC spallation in cyclic operation.

• Thermal Conductivity (λ):

◦ 100℃: 14.5 W/(m·K)

◦ 650℃: 18.2 W/(m·K)

◦ 815℃: 21.0 W/(m·K)

Gradual increase with temperature facilitates heat dissipation in high-temperature zones (e.g., turbine rotor hubs) while maintaining thermal stability in medium-temperature sections.

• Electrical Resistivity (ρ):

◦ Room temperature: 130 μΩ·cm

◦ 815℃: 155 μΩ·cm

Moderate resistivity reduces eddy current losses in high-speed turbine rotors (up to 15,000 RPM).

2.2 Magnetic Properties

• Magnetic Permeability (μ): ~1.002-1.005μ₀ (room temperature, H=800A/m)

Essentially non-magnetic, avoiding interference with aircraft radar systems and turbine magnetic bearing controls.

• Curie Temperature (Tc): ~400℃

Remains non-magnetic above 400℃—critical for maintaining performance in hot-section components (operating ≥650℃).

3. Mechanical Properties (After Standard Heat Treatment)

Haynes282’s mechanical performance is defined by its refined γ’ phase strengthening, with properties tailored for wide-temperature-range service (650-815℃). The standard heat treatment cycle is:

Solution Annealing: 1150℃ (2102℉) for 1 hour, air cooling → Aging: 760℃ (1400℉) for 16 hours + 650℃ (1202℉) for 8 hours, air cooling.

Key Mechanical Performance Notes

• Exceptional Wide-Temperature Creep Resistance: At 815℃, 1000-hour creep rupture strength (≥160MPa) is 60% higher than Haynes263 (≤100MPa), enabling service in high 涡 turbine components (e.g., high-pressure turbine blades) that operate at 750-815℃.
• Superior Thermal Fatigue Resistance: At 650-815℃ cyclic temperature (1h heating/1h cooling), fatigue life (10⁴ cycles) is ≥1000 cycles—outperforming Inconel 718 (700 cycles) and making it ideal for USC power plant heat exchanger tubes.
• Ductility Retention at High Temperatures: Even at 815℃, elongation (≥15%) and reduction of area (≥30%) prevent brittle failure during emergency shutdowns—critical for safety-critical components (e.g., turbine rotors).

4. Environmental Resistance (Core Application Advantage)

Haynes282 is engineered for aggressive high-temperature environments, with targeted resistance to oxidation, thermal corrosion, and molten salt erosion—key for long service life in advanced gas turbines and USC power plants.

5. Application Products & Industry Scenarios

Haynes282’s unique blend of wide-temperature strength, creep resistance, and fabricability makes it irreplaceable in next-generation high-temperature components across industries.

5.1 Aerospace Gas Turbine Industry

• High-Pressure Turbine (HPT) Blades & Rotors: Operate at 750-815℃, withstanding centrifugal stress (up to 200MPa) and hot gas erosion. Haynes282’s 10,000-hour creep strength (≥120MPa at 815℃) extends service life to 8,000+ flight cycles (vs. 5,000 cycles for Inconel 718).
• Turbine Nozzles & Shrouds: In commercial airliner engines (e.g., Boeing 787’s GEnx), resist cyclic thermal stress (650-815℃) and TBC compatibility. Thin-walled (1-3mm) structures reduce engine weight by 5-8%.
• Afterburner Liners (Military Jets): Endure intermittent high temperatures (750-815℃) and fuel-rich combustion; thermal fatigue resistance ensures 3,000+ flight hours (vs. 2,000 hours for Haynes214).
• Steam Turbine Rotors & Blades: In 700℃ USC power plants, operate at high steam pressure (35MPa) and temperature. Haynes282’s creep resistance reduces rotor deformation by 40% vs. ferritic-martensitic steels, improving power generation efficiency by 5-7%.
• Heat Exchanger Tubes: For molten salt energy storage (600-700℃) and USC boiler superheaters, resist thermal corrosion and cyclic fatigue. Service life extended to 15+ years (vs. 8-10 years for Inconel 625).
• Industrial Gas Turbine (IGT) Hot Sections: In 150-300MW IGTs (e.g., Siemens SGT5-8000H), transition pieces and vane platforms operate at 700-780℃. Haynes282’s thermal stability reduces maintenance intervals to 18,000 hours (vs. 12,000 hours for Haynes230).
• Marine Gas Turbine Components: In naval frigates’ gas turbines, resist salt-laden combustion gas (high Cl⁻ content) and cyclic operation. Corrosion resistance ensures 10,000+ operating hours (vs. 6,000 hours for 310S stainless steel).

5.2 Ultra-Supercritical (USC) Power Generation

5.3 Industrial & Marine Turbomachinery

6. Processing & Heat Treatment Guidelines

Haynes282’s processability is a key advantage for manufacturing complex high-temperature components, requiring precise control to optimize γ’ phase distribution and avoid microstructural defects.

6.1 Hot Working

• Forging Temperature Range: 1080-1180℃ (1976-2156℉)

◦ Initial forging: ≥1150℃ (to dissolve coarse γ’ phases and ensure full recrystallization).

◦ Final forging: ≥1080℃ (to avoid work hardening and premature γ’ precipitation).

• Hot Rolling: Reduction ratio per pass: 30-40%; intermediate annealing (1120℃, 30min, air cooling) after 60-70% total deformation to restore ductility. Ideal for producing turbine rotor forging blanks (diameter up to 1.5m).
• Casting Temperature: 1400-1450℃ (2552-2642℉)

6.2 Investment Casting

◦ Mold preheating: 1000-1050℃ to reduce thermal gradient and avoid casting defects (e.g., shrinkage porosity).

◦ Post-casting Heat Treatment: 1150℃ solution anneal (2h, air cool) + standard aging—critical for homogenizing γ’ phase in complex blade geometries.

6.3 Welding

• Recommended Methods: Gas Tungsten Arc Welding (GTAW), Electron Beam Welding (EBW); avoid oxyfuel welding (risk of carbon pickup).
• **Filler Metal

（注：文档部分内容可能由 AI 生成）