GH2036 Alloy

GH2036 is a high-performance Fe-Ni-Cr-based solid solution strengthened wrought superalloy, designed for medium-temperature service scenarios requiring excellent oxidation resistance and thermal stability. It achieves strengthening primarily through the synergistic solid solution effect of chromium (Cr), nickel (Ni), and molybdenum (Mo), without relying on precipitation phases (unlike precipitation-hardening alloys such as GH2136). This alloy exhibits outstanding high-temperature oxidation resistance, good thermal fatigue resistance, and stable mechanical properties at medium temperatures, enabling reliable long-term operation in harsh environments ranging from 650℃ to 850℃.

Notably, GH2036 maintains stable performance even in environments with high-temperature air, low-sulfur steam, or weak acidic media. Its excellent hot workability and weldability make it a cost-effective choice for manufacturing large-scale thin-walled or complex-shaped components, widely used in thermal power generation, petrochemical, and metallurgical industries where material processability and medium-temperature corrosion resistance 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 8.25g/cm³ at room temperature (25℃), which is lower than precipitation-hardening alloys such as GH2136 (8.12g/cm³ is incorrect, GH2136 is ~8.12g/cm³, GH2036 is slightly higher due to higher Ni content) — specifically, 3-5% lower than nickel-based superalloys (e.g., GH3128: 8.70g/cm³). This low-density advantage is critical for weight-sensitive components such as thin-walled furnace tubes and heat exchanger panels, reducing equipment overall weight by 4-9% compared to high-nickel alternatives.
• Magnetic Properties: Non-magnetic across the entire service temperature range (room temperature to 850℃) (magnetic permeability μᵣ ≈ 1.000-1.002). This makes it highly suitable for applications near electromagnetic equipment or precision magnetic sensors (e.g., power plant electromagnetic flowmeters, aerospace navigation systems), as it does not interfere with magnetic field distribution.
• Melting Temperature Range: 1420-1480℃ (liquidus: ~1480℃; solidus: ~1420℃). The wide and stable melting range ensures good fluidity during casting and uniform deformation during forging, reducing internal defects (e.g., shrinkage, cracking) and improving component structural integrity—critical for large-scale welded components such as boiler headers.
• Thermal Expansion Coefficient (CTE):

2.2 Thermal Properties

◦ 20-100℃: ~12.6×10⁻⁶/℃

◦ 20-600℃: ~14.1×10⁻⁶/℃

◦ 20-800℃: ~15.3×10⁻⁶/℃

◦ 20-850℃: ~15.7×10⁻⁶/℃

The gradual CTE increase minimizes thermal stress during frequent temperature cycling (e.g., boiler start-stop, heat exchanger load adjustment), reducing thermal fatigue cracking risk by 35-45% compared to conventional Fe-Cr alloys (e.g., 304 stainless steel).

• Thermal Conductivity (λ):

◦ 100℃: ~15.8W/(m·K)

◦ 500℃: ~19.3W/(m·K)

◦ 800℃: ~22.1W/(m·K)

◦ 850℃: ~22.8W/(m·K)

The temperature-dependent conductivity improvement promotes efficient heat transfer in medium-temperature components, avoiding localized overheating (a major cause of material softening) and extending part service life by 20-25% compared to similar solid solution alloys (e.g., GH3030).

2.3 Mechanical Properties (After Standard Heat Treatment: 1100-1150℃ solid solution for 1h, air cooling)

Key Notes:

• The high room-temperature elongation (≥30%) ensures excellent formability, allowing the alloy to be processed into thin-walled tubes (minimum wall thickness ≥1mm) or complex sheet metal parts via rolling, bending, or stamping;
• At 700℃ (a typical service temperature for thermal power plant superheaters), the creep rupture strength (≥250MPa) is 18-22% higher than that of GH3030, ensuring long-term structural stability under medium-temperature load;
• Even at 850℃ (near its upper service limit), the retained elongation (≥16%) prevents brittle fracture during emergency shutdowns, making it suitable for components with frequent thermal cycling (e.g., petrochemical heat exchanger tubes).

3. Application Products & Industry Scenarios

3.1 Energy Field

3.1.1 Thermal Power Generation

In subcritical and supercritical thermal power plants (steam parameters: 540-600℃, 16-25MPa), GH2036 is used for:

• Superheater & Reheater Tubes: Medium-temperature superheater tubes (540-580℃) and reheater tubes, resisting high-temperature steam oxidation and reducing tube replacement frequency by 30-40% compared to 12Cr1MoV steel;
• Boiler Headers: Medium-pressure headers (500-550℃) connecting superheaters, where its excellent weldability allows for large-diameter header manufacturing (maximum diameter ≥1000mm) without welding defects;
• Heat Exchanger Tubes: Tubes in feedwater heaters, withstanding 300-400℃ high-pressure water corrosion and ensuring heat exchange efficiency.

3.1.2 Solar Thermal Power Generation

For parabolic trough solar thermal power plants (heat transfer fluid temperature: 390-420℃), the alloy is applied to:

• Heat Absorber Tubes: Stainless steel-lined heat absorber tubes (outer layer: GH2036, inner layer: corrosion-resistant alloy), resisting outdoor UV radiation and high-temperature heat transfer fluid erosion;
• Heat Exchanger Plates: Plates in steam generators, where its good thermal conductivity ensures efficient heat transfer from heat transfer fluid to water.

3.2 Petrochemical Field

In medium-scale petrochemical plants (especially oil refining and ethylene production units), GH2036 is used for:

• Heating Furnace Tubes: Medium-temperature furnace tubes (650-750℃) in oil refining heating furnaces, resisting hydrocarbon gas corrosion and reducing maintenance costs by 25-30% compared to 316 stainless steel;
• Chemical Medium Pipes: Pipes for transporting high-temperature organic media (e.g., ethylene, propylene) at 500-600℃, where its non-magnetic property avoids medium flow disturbance caused by magnetic adsorption;
• Tower Internals: Trays and packing supports in distillation towers (operating temperature: 400-500℃), withstanding medium corrosion and cyclic thermal stress.
• Metallurgical Industry: Continuous annealing furnace belts (working temperature: 650-750℃) for stainless steel sheets, where its excellent oxidation resistance extends belt service life by 50-60% compared to 309 stainless steel;
• Industrial Kilns: Liner plates and door seals for ceramic sintering kilns (operating temperature: 700-800℃), resisting high-temperature air oxidation and thermal shock;
• High-temperature Conveyors: Conveyor rollers for high-temperature heat treatment of aluminum alloys (working temperature: 550-650℃), withstanding alloy melt splashing and mechanical wear.
• Aerospace Auxiliary Systems: High-temperature air ducts and oil pipes in aircraft auxiliary power units (APUs) (operating temperature: 500-600℃), where its light weight and non-magnetic property meet system design requirements;
• Automotive Industry: Exhaust manifolds for high-performance racing cars (operating temperature: 600-700℃), resisting high-temperature exhaust gas corrosion and reducing manifold weight by 15-20% compared to cast iron;
• High-temperature Test Equipment: Sample frames for material medium-temperature oxidation testing (650-850℃) and low-load fixture components, providing stable support for long-term tests (up to 5,000 hours).
• 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 950℃ to prevent work hardening;
• Cold Working: Cold rolling, stamping, or bending can be performed at room temperature, with intermediate annealing (950-1000℃, 1h) recommended after 30-40% deformation to restore ductility—cold workability is significantly better than precipitation-hardening alloys (e.g., GH2136);
• Welding: Suitable for various welding methods, including TIG welding, MIG welding, and resistance welding. Welding filler metal recommended: ERNiCrMo-3; preheating temperature: 150-200℃; post-weld heat treatment: 1050-1100℃ solid solution for 1h, air cooling, to eliminate welding stress and restore corrosion resistance.

3.3 Metallurgical & Industrial Heating Fields

3.4 Aerospace Auxiliary & Other Fields

4. Processing & Welding Recommendations

This comprehensive performance and application profile makes GH2036 a cost-effective, versatile solid solution superalloy for medium-temperature industrial manufacturing, perfectly balancing processability, corrosion resistance, and medium-temperature strength for large-scale, complex-shaped components.