GH1140 Alloy

GH1140 is a nickel-based precipitation-hardening wrought superalloy, primarily strengthened by the precipitation of γ’ phase (Ni₃Al, Ti, Nb) and supplemented by solid solution strengthening of chromium and molybdenum. It possesses excellent high-temperature creep resistance, outstanding thermal stability, and strong resistance to high-temperature oxidation and corrosion, enabling long-term stable operation in harsh high-temperature environments ranging from 850℃ to 1050℃. This alloy is widely applied in high-end manufacturing industries with strict requirements for material high-temperature performance, especially in scenarios involving long-term high-temperature load-bearing, cyclic thermal stress, and corrosive media. The following is a detailed breakdown of its chemical composition, physical properties, and application products.

1. Chemical Composition (Mass Fraction, %)

2. Physical Properties

1. Density: At room temperature, the density of GH1140 is approximately 8.25g/cm³, which falls within the conventional density range of nickel-based precipitation-hardening superalloys. This characteristic facilitates accurate weight calculation during the structural design of high-temperature components, helping to balance the requirements of equipment lightweight design and load-bearing capacity, especially for rotating parts such as turbine disks.
2. Thermal Properties:

◦ Melting temperature range: 1370-1430℃. The moderate and stable melting temperature range ensures the alloy maintains structural integrity without melting or severe softening under long-term high-temperature working conditions, providing a reliable material foundation for high-temperature load-bearing applications such as aero-engine hot-end components.

◦ Thermal expansion coefficient: It measures about 11.8×10⁻⁶/℃ in the 20-100℃ range, and increases moderately to approximately 13.5×10⁻⁶/℃ when heated to 20-950℃. The gradual and stable change in thermal expansion coefficient minimizes thermal stress caused by rapid temperature fluctuations, significantly enhancing the alloy’s resistance to thermal fatigue cracking, which is crucial for components undergoing cyclic heating and cooling.

◦ Thermal conductivity: At 100℃, the thermal conductivity is around 15.2W/(m・K); at 950℃, it rises to roughly 23.8W/(m・K). The temperature-dependent increase in thermal conductivity promotes efficient dissipation of local heat in high-temperature components, avoiding excessive localized heating and subsequent degradation of material mechanical properties, thus extending the service life of parts.

1. Mechanical Properties (After standard heat treatment: 1080-1120℃ solid solution + 800-840℃ aging for 16h, air cooling):

◦ Yield strength (σ₀.₂, room temperature): ≥780MPa. This high yield strength enables the alloy to effectively resist plastic deformation under normal-temperature static loads, ensuring long-term structural stability of components such as high-temperature fasteners and compressor disks.

◦ Tensile strength (σᵦ, room temperature): ≥930MPa. The excellent tensile strength allows the alloy to withstand complex external forces (e.g., tension, bending, and shear) in engineering applications, meeting the load-bearing requirements of critical high-temperature parts in aero-engines and gas turbines.

◦ Elongation (δ₅, room temperature): ≥16%. The moderate plastic deformation capacity ensures the alloy can be processed into complex-shaped components via forging, rolling, and machining processes, while reducing the risk of cracking during manufacturing and assembly.

◦ High-temperature mechanical properties (at 950℃): The yield strength is ≥420MPa, the tensile strength is ≥520MPa, and the elongation is ≥12%. More importantly, its creep rupture strength reaches ≥220MPa at 950℃ for 1000h, which fully satisfies the long-term high-temperature load-bearing demands of structural parts such as turbine blades (low-pressure stages) and combustion chamber supports.

1. Magnetic Properties: GH1140 exhibits weakly magnetic characteristics at room temperature; as the temperature rises to its service temperature range (850-1050℃), the magnetic property gradually fades to near non-magnetic. This feature makes it suitable for most industrial environments, and only when used near high-precision magnetic instruments (e.g., aerospace navigation sensors) does its weak magnetic influence need to be considered.

3. Application Products

Relying on its excellent comprehensive high-temperature performance, GH1140 alloy has become a key material in advanced high-temperature equipment manufacturing, with core application products including:

• Aerospace Field: As a critical material for advanced aero-engines and gas turbines, it is mainly used to manufacture high-temperature load-bearing and rotating components such as turbine disks (medium-pressure stages), compressor disks (high-pressure stages), high-temperature fasteners, and combustion chamber liners. These parts operate in harsh environments with high-temperature (above 900℃), high rotational speed, and gas erosion; GH1140’s high-temperature creep resistance and oxidation resistance ensure safe and stable operation of the engine. It is also applied in the thermal protection system of hypersonic aircraft, such as high-temperature structural brackets in the propulsion system.
• Energy Field: In gas turbine power generation, it is used to produce turbine rotor disks, combustion chamber support rings, and high-temperature heat exchanger tubes, which withstand long-term erosion by high-temperature (above 850℃) and high-pressure gas. The alloy’s thermal stability and creep resistance improve the efficiency of gas turbines (up to 55% for combined cycle power generation) while extending the equipment’s service life to over 100,000 hours. In the nuclear energy field, it is utilized for manufacturing high-temperature structural parts in nuclear reactor secondary loop systems, resisting corrosion by high-temperature steam and weak radiation.
• Petrochemical Field: It is ideal for manufacturing high-temperature centrifugal compressor impellers, high-temperature valve stems, and reactor inner liners in petrochemical plants. These components operate at 800-1000℃ in the presence of corrosive media (e.g., hydrocarbons, hydrogen sulfide, and high-temperature organic acids); GH1140’s resistance to high-temperature corrosion and creep ensures continuous, stable operation of the equipment, reducing maintenance costs by 30% and minimizing production downtime.
• Other High-Temperature Fields: In the metallurgical industry, it is used to make high-temperature rolling mill work rolls and vacuum heat treatment furnace baskets, withstanding long-term high-temperature oxidation (up to 1000℃) and mechanical load. In the marine engineering field, it is applied to high-temperature exhaust manifold components of marine gas turbines, resisting the combined corrosion of high-temperature exhaust gas and marine salt spray. It also finds use in high-temperature test equipment, such as high-temperature creep test fixtures and thermal fatigue test specimens for material performance testing machines.