GH2136 Alloy

GH2136 is an advanced Fe-Ni-Cr-based precipitation-hardening wrought superalloy, further optimized on the basis of GH2135 to address higher-temperature service demands. It achieves strengthening primarily through the coherent precipitation of γ’ phase (Ni₃Ti, Al, Nb, V) and is supplemented by synergistic solid solution strengthening from chromium (Cr), molybdenum (Mo), and niobium (Nb). Compared to GH2135, this alloy exhibits enhanced high-temperature creep rupture strength (especially above 850℃), improved resistance to thermal corrosion from sulfur-containing media, and better microstructural stability under long-term high-temperature exposure, enabling reliable long-term operation in harsh medium-to-high temperature environments ranging from 750℃ to 900℃.

Notably, GH2136 maintains excellent mechanical properties even in environments with high-temperature sulfur-containing steam (e.g., flue gas in waste incineration power plants) or weak alkaline media. Its balanced hot workability and weldability make it a cost-effective alternative to high-nickel superalloys (e.g., Inconel 718, Hastelloy X) in high-temperature, high-corrosion scenarios. It is widely used in next-generation aerospace engines, advanced ultra-supercritical power generation, and heavy-duty petrochemical industries where material high-temperature load-bearing capacity and 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 8.12g/cm³ at room temperature (25℃), which is slightly higher than GH2135 (8.05g/cm³) due to increased niobium and vanadium content, but still 6-8% lower than nickel-based superalloys (e.g., GH3128: 8.70g/cm³). This low-density advantage is critical for weight-sensitive components such as large turbine disks and aerospace structural parts, reducing equipment overall weight by 3-8% compared to high-nickel alternatives.
• Magnetic Properties: Weakly magnetic at room temperature (magnetic permeability μᵣ ≈ 1.007-1.013); magnetic property gradually fades as temperature rises, becoming nearly non-magnetic (μᵣ ≈ 1.001-1.002) in the service temperature range (750-900℃). This makes it suitable for applications near general electromagnetic equipment, though caution is still needed for high-precision magnetic sensors (e.g., aerospace navigation systems, nuclear reactor magnetic measurement devices).
• Melting Temperature Range: 1340-1400℃ (liquidus: ~1400℃; solidus: ~1340℃). The narrow melting range ensures uniform solidification during casting and forging, reducing internal defects (e.g., shrinkage porosity, segregation) and improving component structural integrity—critical for high-pressure load-bearing parts such as boiler headers and turbine rotors.
• Thermal Expansion Coefficient (CTE):

2.2 Thermal Properties

◦ 20-100℃: ~12.4×10⁻⁶/℃

◦ 20-600℃: ~13.8×10⁻⁶/℃

◦ 20-800℃: ~15.0×10⁻⁶/℃

◦ 20-900℃: ~15.4×10⁻⁶/℃

The more gradual CTE increase (compared to GH2135) minimizes thermal stress during frequent temperature cycling (e.g., aero-engine start-stop, boiler load adjustment), reducing thermal fatigue cracking risk by 40-50% compared to conventional Fe-Cr-Ni alloys (e.g., 316H stainless steel).

• Thermal Conductivity (λ):

◦ 100℃: ~15.5W/(m·K)

◦ 500℃: ~19.0W/(m·K)

◦ 800℃: ~21.5W/(m·K)

◦ 900℃: ~22.2W/(m·K)

The temperature-dependent conductivity improvement promotes efficient heat dissipation in high-temperature components, avoiding localized overheating (a major cause of creep acceleration) and extending part service life by 25-30% compared to GH2135.

2.3 Mechanical Properties (After Standard Heat Treatment: 1020-1050℃ solid solution for 1h, water cooling + 740-770℃ aging for 10h, air cooling)

Key Notes:

• The higher room-temperature strength (σᵦ ≥1120MPa) compared to GH2135 meets the load-bearing requirements of high-pressure fasteners and advanced compressor disks in next-generation high-thrust aero-engines;
• At 800℃ (a typical service temperature for advanced industrial gas turbine components), the creep rupture strength (≥320MPa) is 14-18% higher than that of GH2135, ensuring long-term structural stability under high-temperature and high-pressure conditions;
• Even at 900℃ (near its upper service limit), the retained elongation (≥7%) and creep rupture strength (≥150MPa) prevent brittle fracture during emergency shutdowns or thermal shocks, expanding its application range to higher-temperature scenarios (e.g., waste incineration power plant heat exchangers).

3. Application Products & Industry Scenarios

3.1 Aerospace Field

GH2136 is a core material for high-performance medium-to-high temperature components in next-generation aero-engines and aerospace vehicles, with typical applications including:

• Advanced Aero-engine Components: High-pressure compressor disks (rotational speed up to 17,000 rpm) and low-pressure turbine blades in large bypass ratio turbofan engines (thrust ≥150kN). These parts operate in environments with 750-850℃ gas and cyclic thermal stress; the alloy’s creep resistance ensures a service life of up to 35,000 flight hours.
• Aerospace Propulsion System Parts: High-temperature fasteners (used in combustion chamber casings and turbine stators) and fluid pipeline connectors in rocket auxiliary propulsion systems (e.g., liquid oxygen/kerosene engines). The alloy’s enhanced thermal corrosion resistance (to rocket fuel combustion by-products such as CO₂ and H₂O) improves reliability during long-duration space missions (e.g., satellite launch vehicles).

3.2 Energy Field

3.2.1 Advanced Ultra-supercritical (A-USC) Thermal Power Generation

In A-USC power plants (steam parameters: 650-700℃, 35-40MPa), GH2136 is used for:

• High-temperature Steam Valves: Main control valves and stop valves in the main steam pipeline, resisting high-temperature steam erosion and ensuring seal integrity for over 150,000 hours.
• Boiler Final Superheater Headers: High-temperature headers (620-650℃) connecting final superheaters, where its excellent thermal fatigue resistance reduces leakage risks caused by frequent load changes (e.g., daily peak-shaving operations).
• High-pressure Turbine Rotor Blades: Blades in the first four stages of high-pressure turbines, where the alloy’s creep resistance (to high-temperature steam) extends maintenance intervals by 30-36 months.

3.2.2 Waste Incineration & Biomass Power Generation

For power plants using waste or biomass fuel (flue gas temperature: 800-850℃, containing sulfur and chlorine), the alloy is applied to:

• Flue Gas Heat Exchanger Tubes: Tubes in waste heat boilers, resisting corrosion from sulfur-containing flue gas and reducing tube replacement frequency by 50-60% compared to 310S stainless steel.
• Ash Handling System Components: High-temperature ash hoppers and conveyor parts, withstanding 750-800℃ ash erosion and chemical corrosion from acidic ash.

3.3 Petrochemical Field

In large-scale petrochemical plants (especially heavy oil hydrogenation and coal-to-olefins units), GH2136 is used for:

• High-temperature Centrifugal Compressor Disks: Disks in coal gasification syngas compressors (operating temperature: 750-800℃, medium: syngas with H₂ and trace sulfur), where its creep resistance prevents disk deformation under long-term high-speed rotation (up to 14,000 rpm).
• Hydrogenation Reactor Internals: High-pressure valve stems and catalyst support grids in heavy oil hydrogenation reactors (pressure: 20-25MPa, temperature: 780-830℃), resisting hydrogen embrittlement and sulfur corrosion.
• Cracking Furnace Tubes: High-temperature furnace tubes (850-900℃) in coal-to-olefins cracking furnaces, reducing maintenance costs by 40-45% compared to GH3128 due to improved creep resistance and thermal stability.
• Metallurgical Industry: High-temperature rolling mill work rolls for nickel-based alloy hot rolling (working temperature: 800-850℃) and vacuum heat treatment furnace baskets (used for annealing high-strength superalloys). The alloy’s wear resistance and oxidation resistance extend roll service life by 70% and reduce basket replacement frequency.
• Marine Engineering: High-temperature exhaust manifold components in large marine gas turbines (fuel: low-sulfur marine diesel), resisting combined corrosion from 750-800℃ exhaust gas and marine salt spray.
• High-temperature Test Equipment: Sample holders for ultra-high-temperature creep testing (750-900℃) and high-load fixture components in material performance testing machines, providing stable support for long-term tests (up to 10,000 hours) and ensuring accurate test data for next-generation superalloy research.
• Hot Working: Forging temperature range: 1140-1220℃; initial forging temperature should not exceed 1220℃ to avoid grain coarsening, and final forging temperature should not be lower than 1000℃ to prevent grain boundary cracking (higher than GH2135 due to increased niobium content);
• Cold Working: Cold rolling or stamping can be performed at room temperature, with intermediate annealing (940-980℃, 1h) recommended after 20-30% deformation to restore ductility—note that cold workability is slightly lower than GH2135, so deformation rate should be controlled to avoid cracking;
• Heat Treatment: The two-step process (solid solution + aging) must be strictly controlled—over-aging (above 800℃) will cause γ’ phase coarsening and significant strength degradation, while under-aging (below 720℃) will result in insufficient precipitation strengthening and reduced high-temperature creep resistance.

3.4 Metallurgical & Other High-end Fields

4. Processing & Heat Treatment Recommendations

This comprehensive performance and application profile makes GH2136 an advanced, cost-effective superalloy for next-generation medium-to-high temperature high-end manufacturing, perfectly balancing high-temperature strength, corrosion resistance, and processability for the most demanding industrial equipment scenarios.