GH3034 Alloy

GH3034 is a high-performance Ni-Cr-based solid solution strengthened wrought superalloy, developed for high-temperature service scenarios requiring exceptional oxidation resistance and thermal stability. It achieves strengthening primarily through the synergistic solid solution effect of chromium (Cr), nickel (Ni), and trace elements (titanium, aluminum), without relying on precipitation phases—differentiating it from precipitation-hardening alloys such as GH2136. This alloy exhibits outstanding high-temperature oxidation resistance (up to 1100℃ in air), excellent thermal fatigue resistance, and stable mechanical properties at elevated temperatures, enabling reliable long-term operation in harsh environments ranging from 800℃ to 1000℃.

Notably, GH3034 maintains stable performance even in environments with high-temperature sulfur-containing flue gas, molten salt, or weak alkaline media. Its excellent hot workability and weldability make it a cost-effective choice for manufacturing large-scale thin-walled or complex-shaped high-temperature components, widely used in aerospace auxiliary systems, advanced energy, and high-end petrochemical industries where material high-temperature corrosion resistance and processability are critical. The following is a comprehensive breakdown of its chemical composition, physical properties, and application products.

1. Chemical Composition (Mass Fraction, %)

2. Physical Properties

2.1 Basic Physical Parameters

• Density: Approximately 8.10g/cm³ at room temperature (25℃), which is lower than Ni-Cr-W-based superalloys such as GH3128 (8.70g/cm³) and slightly lower than Fe-Ni-Cr-based GH2036 (8.25g/cm³). This low-density advantage is critical for weight-sensitive high-temperature components such as thin-walled furnace tubes and aerospace auxiliary structural parts, reducing equipment overall weight by 5-10% compared to high-nickel superalloys with similar performance.
• Magnetic Properties: Non-magnetic across the entire service temperature range (room temperature to 1000℃) (magnetic permeability μᵣ ≈ 1.000-1.001). This makes it highly suitable for applications near electromagnetic equipment or precision magnetic sensors (e.g., aerospace navigation systems, nuclear reactor magnetic measurement devices), as it does not interfere with magnetic field distribution or sensor accuracy.
• Melting Temperature Range: 1370-1430℃ (liquidus: ~1430℃; solidus: ~1370℃). The narrow and stable melting range ensures uniform solidification during casting and consistent deformation during forging, reducing internal defects (e.g., shrinkage porosity, segregation) and improving component structural integrity—critical for large-scale welded components such as high-temperature headers and heat exchanger shells.
• Thermal Expansion Coefficient (CTE):

2.2 Thermal Properties

◦ 20-100℃: ~13.0×10⁻⁶/℃

◦ 20-600℃: ~14.5×10⁻⁶/℃

◦ 20-800℃: ~15.8×10⁻⁶/℃

◦ 20-1000℃: ~16.5×10⁻⁶/℃

The gradual CTE increase minimizes thermal stress during frequent temperature cycling (e.g., aero-engine auxiliary system start-stop, heat exchanger load adjustment), reducing thermal fatigue cracking risk by 40-50% compared to conventional Ni-Cr alloys (e.g., 600 alloy).

• Thermal Conductivity (λ):

◦ 100℃: ~15.5W/(m·K)

◦ 500℃: ~19.0W/(m·K)

◦ 800℃: ~22.5W/(m·K)

◦ 1000℃: ~24.0W/(m·K)

The temperature-dependent conductivity improvement promotes efficient heat transfer and dissipation in high-temperature components, avoiding localized overheating (a major cause of material softening and creep acceleration) and extending part service life by 25-30% compared to similar solid solution alloys (e.g., GH3030).

2.3 Mechanical Properties (After Standard Heat Treatment: 1050-1100℃ solid solution for 1h, water cooling or air cooling)

Key Notes:

• The exceptional room-temperature elongation (≥35%) ensures excellent formability, allowing the alloy to be processed into ultra-thin-walled tubes (minimum wall thickness ≥0.5mm) or complex sheet metal parts (e.g., curved heat exchanger panels) via rolling, bending, or stamping;
• At 800℃ (a typical service temperature for petrochemical cracking furnace tubes), the creep rupture strength (≥200MPa) is 22-28% higher than that of GH3030, ensuring long-term structural stability under high-temperature load;
• Even at 1000℃ (near its upper service limit), the retained elongation (≥18%) prevents brittle fracture during emergency shutdowns, making it suitable for components with frequent thermal cycling (e.g., aerospace auxiliary system exhaust pipes).

3. Application Products & Industry Scenarios

3.1 Aerospace Auxiliary Field

In advanced aerospace vehicles and aero-engine auxiliary systems, GH3034 is used for:

• Aero-engine Auxiliary Components: High-temperature air ducts and oil pipes in environmental control systems (ECS) (operating temperature: 800-900℃), where its non-magnetic property avoids interfering with navigation system sensors and its light weight reduces engine auxiliary system weight;
• Aerospace Thermal Protection Parts: Thin-walled heat shields and exhaust nozzles in auxiliary propulsion systems (e.g., satellite attitude control engines), resisting 900-1000℃ high-temperature gas erosion and ensuring service life during long-duration space missions;
• Aerospace Fasteners: High-temperature bolts and nuts used in engine accessory casings (operating temperature: 700-800℃), withstanding cyclic thermal stress and ensuring connection reliability.

3.2 Energy Field

3.2.1 Advanced Thermal Power Generation

In supercritical and ultra-supercritical thermal power plants (steam parameters: 600-620℃, 25-30MPa), GH3034 is used for:

• High-temperature Heat Exchanger Tubes: Tubes in secondary superheaters and reheaters, resisting high-temperature steam oxidation and reducing tube replacement frequency by 35-45% compared to 316H stainless steel;
• Boiler Header Liners: Inner liners of large-diameter high-pressure headers (operating temperature: 580-600℃), where its excellent corrosion resistance prevents header inner wall erosion by high-temperature steam impurities;
• Flue Gas Heat Recovery Components: Tubes in flue gas heat exchangers (FGRH) (operating temperature: 800-850℃), resisting sulfur-containing flue gas corrosion and improving thermal power plant energy efficiency.

3.2.2 Solar Thermal & Waste-to-Energy Power Generation

For tower-type solar thermal power plants (heat transfer fluid temperature: 550-600℃) and waste incineration power plants (flue gas temperature: 800-900℃), the alloy is applied to:

• Solar Receiver Tubes: High-temperature receiver tubes in solar towers, resisting outdoor UV radiation and high-temperature molten salt (e.g., nitrate salt) corrosion;
• Waste Heat Boiler Tubes: Tubes in waste incineration waste heat boilers, resisting chlorine-containing flue gas corrosion and extending tube service life by 50-60% compared to 310S stainless steel.

3.3 Petrochemical Field

In large-scale petrochemical plants (especially ethylene cracking and coal-to-olefins units), GH3034 is used for:

• Cracking Furnace Tubes: Medium-to-high temperature furnace tubes (850-950℃) in ethylene cracking furnaces, resisting hydrocarbon gas pyrolysis corrosion and reducing maintenance costs by 30-35% compared to GH3030;
• High-temperature Reactor Liners: Inner liners of coal gasification reactors (operating temperature: 900-950℃), where its excellent thermal stability prevents liner deformation under high-temperature and high-pressure syngas;
• Chemical Medium Pipes: Pipes for transporting high-temperature organic media (e.g., propylene, butadiene) at 600-700℃, where its non-magnetic property avoids medium flow disturbance caused by magnetic adsorption of impurities.
• Metallurgical Industry: Continuous annealing furnace belts (working temperature: 800-900℃) for high-strength stainless steel and titanium alloy sheets, where its excellent oxidation resistance extends belt service life by 60-70% compared to 309S stainless steel;
• Industrial Kilns: Liner plates and door seals for ceramic and glass sintering kilns (operating temperature: 900-1000℃), resisting high-temperature air oxidation and thermal shock;
• High-temperature Conveyors: Conveyor rollers for high-temperature heat treatment of superalloys (working temperature: 850-900℃), withstanding alloy melt splashing and mechanical wear.
• Hot Working: Forging temperature range: 1150-1200℃; initial forging temperature should not exceed 1200℃ to avoid grain coarsening, and final forging temperature should not be lower than 980℃ to prevent work hardening and cracking;
• Cold Working: Cold rolling, stamping, or bending can be performed at room temperature, with intermediate annealing (1000-1050℃, 1h) recommended after 25-35% deformation to restore ductility—cold workability is significantly better than precipitation-hardening alloys (e.g., GH2136) due to its solid solution structure;
• Welding: Suitable for various welding methods, including TIG welding, MIG welding, and electron beam welding. Welding filler metal recommended: ERNiCr-3; preheating temperature: 150-200℃ (no preheating required for thin-walled parts ≤3mm); post-weld heat treatment: 1050-1100℃ solid solution for 1h, air cooling, to eliminate welding stress and restore corrosion resistance and mechanical properties.

3.4 Metallurgical & High-temperature Industrial Fields

4. Processing & Welding Recommendations

This comprehensive performance and application profile makes GH3034 a cost-effective, high-performance solid solution superalloy for high-temperature industrial manufacturing, perfectly balancing processability, high-temperature oxidation resistance, and thermal stability for large-scale, complex-shaped high-temperature components.