What are characteristics of GH4049 Superalloy

1. What are the characteristics of GH4049 Superalloy

GH4049 is a nickel-based precipitation-hardening superalloy primarily developed for ultra-high-temperature service, making it a critical material in advanced high-performance engineering. Its key characteristics are tailored to withstand extreme thermal and mechanical stress, including:

Exceptional High-Temperature Strength: Enabled by a precipitation-hardening mechanism-where fine intermetallic phases (primarily γ' phase, composed of Ni₃(Al, Ti)) form within the nickel matrix during heat treatment. This structure grants the alloy outstanding strength and creep resistance (resistance to slow permanent deformation) at temperatures up to 1100°C (2012°F), far exceeding mid-temperature nickel alloys like GH3030.

Superior Thermal Stability: It maintains its microstructural integrity and mechanical properties even after prolonged exposure to ultra-high temperatures (e.g., 1000–1100°C) and cyclic thermal loading. This stability prevents premature softening or cracking, ensuring long service life for components in high-heat environments.

Good Oxidation and Hot Corrosion Resistance: The alloy contains chromium (Cr) and small additions of elements like cobalt (Co) and molybdenum (Mo), which form a continuous, dense oxide layer on the surface. This layer acts as a barrier against oxidative attack and corrosion from high-temperature gases (e.g., turbine exhaust) or molten salts, critical for aerospace and energy applications.

Controlled Microstructure for Processability: Despite its high strength, GH4049 can be fabricated via standard methods such as forging, extrusion, and welding (with proper pre- and post-weld heat treatments to avoid microstructural defects). It is often processed into complex shapes like turbine blades or vanes, though its high strength requires more rigorous manufacturing controls compared to lower-strength alloys.

Targeted for High-Stress, High-Temp Components: Unlike alloys designed for general corrosion resistance, GH4049 is optimized for mechanical performance at extreme temperatures, making it ideal for load-bearing parts in demanding systems.

2. What is the yield strength of GH4049

The yield strength of GH4049 (the stress at which the alloy begins to deform permanently) is highly dependent on its heat treatment state (critical for precipitation hardening) and test temperature, as high temperatures typically reduce yield strength. Below are typical values based on industry standards (e.g., GB/T 14992, AMS specifications) and common heat treatment cycles (e.g., solution annealing + aging):

Test Temperature	Typical Yield Strength (0.2% offset, MPa)	Typical Yield Strength (0.2% offset, ksi)
Room Temperature (25°C/77°F)	≥ 800 MPa	≥ 116 ksi
700°C (1292°F)	≥ 650 MPa	≥ 94 ksi
900°C (1652°F)	≥ 350 MPa	≥ 51 ksi
1000°C (1832°F)	≥ 200 MPa	≥ 29 ksi

3. What is the tensile strength of GH4049

The tensile strength of GH4049 (the maximum stress the alloy can withstand before breaking) also varies with heat treatment and test temperature, following a similar trend to yield strength (decreasing with rising temperature). Typical tensile strength values (based on standard heat treatments and industry data) are:

Test Temperature	Typical Tensile Strength (MPa)	Typical Tensile Strength (ksi)
Room Temperature (25°C/77°F)	≥ 1200 MPa	≥ 174 ksi
700°C (1292°F)	≥ 950 MPa	≥ 138 ksi
900°C (1652°F)	≥ 550 MPa	≥ 80 ksi
1000°C (1832°F)	≥ 300 MPa	≥ 44 ksi