High-performance alloy material for industrial engineering and critical application conditions.
Scope of supply for Aviation Group
Forgings, round rods, steel plates, rings, seamless pipes, steel plates/steel belts, wire welding materials, welcome to inquire!
1. Introduction to GH4738 Materials
GH4738 is a γ’ phase precipitation-strengthened nickel-based superalloy, featuring excellent gas corrosion resistance, high yield strength, superior fatigue performance, good hot/cold workability and stable microstructure. It is widely applied to aero-engine rotating components with maximum service temperature ≤815℃. Available product forms include hot rolled & cold rolled sheets, tubes, strips, wires, forgings, castings and fasteners.
GJB 1953-1994 Specifications on Hot Rolled Rods for High Temperature Alloys for Rotating Parts of Aero Engines
GJB 2611-1996 Specifications for Cold Drawn Rods for Aviation High Temperature Alloys
GJB 2612-1996 Specifications for Cold Drawn Welding Wires of High Temperature Alloys for Aviation
GJB 3020-1997 Specifications for Aviation High Temperature Alloy Ring Blanks
GJB 3165-1998 Specifications on Hot Rolled & Forged Rods for Aviation Load-Bearing Components
GJB 3782-1999 Specifications for Aviation High Temperature Alloy Rods
HB 5198-1982 Wrought High-Temperature Alloy Rods for Aviation Blades
2. Chemical composition of GH4738
| Alloy | Limit | C | Cr | Ni | Co | Mo | Al | Ti | B | Zr | Fe | Mn | Si | P | S | Cu |
| GH4738 | Minimum | 0.03 | 18 | Bal | 12 | 3.5 | 1.2 | 2.75 | 0.003 | 0.02 | – | – | – | – | – | – |
| Maximum | 0.10 | 21 | 15 | 5.0 | 1.6 | 3.25 | 0.010 | 0.08 | 2.0 | 0.10 | 0.15 | 0.015 | 0.015 | 0.10 |
Note: Trace impurity limits: ω(Pb)≤0.001%, ω(As)≤0.0025%, ω(Sn)≤0.0012%, ω(Sb)≤0.0025%, ω(Bi)≤0.0001%.
3. GH4738 physical properties
| Density | 8.22g/cm³ |
| Melting point | 1330-1360℃ |
| Magnetic property | Non-magnetic |
Thermal conductivity
| Temperature/℃ | 360 | 460 | 545 | 640 | 770 | 855 | 985 |
| Thermal conductivity λ/(W/(m·℃)) | 16.8 | 18.3 | 20.2 | 22.4 | 24.1 | 25.3 | 28.0 |
Specific heat capacity
| Temperature/℃ | 360 | 460 | 545 | 640 | 770 | 855 | 985 |
| Specific heat c/(J/(kg·℃)) | 515 | 540 | 573 | 603 | 640 | 665 | 707 |
Coefficient of linear expansion
| Temperature range/℃ | 20～100 | 20～200 | 20～300 | 20～400 | 20～500 | 20～600 | 20～700 | 20～800 | 20～900 |
| Linear expansion coefficient/(10⁻⁶/℃) | 12.47 | 12.73 | 13.04 | 13.53 | 13.97 | 14.47 | 15.05 | 15.68 | 15.95 |
4. Chemical properties of GH4738
Oxidation rate after 100h air oxidation test
| Test temperature/℃ | 900 | 1000 |
| Oxidation rate/(g/(m²·h)) | 0.083 | 0.226 |
Corrosion resistance: The alloy possesses excellent salt spray corrosion resistance.
5. GH4738 processing performance & technical requirements
1) Ideal forging forming temperature range: 1220℃~950℃. Solid solution treatment shall be carried out after heavy forming processes.
2) The average grain size is closely related to forging deformation amount and finish forging temperature.
3) Excellent weldability, compatible with multiple welding processes. Post-weld aging treatment can recover strength close to full heat-treated state.
4) Parts heat treatment must be performed under neutral or sulfur-free reducing atmosphere to prevent sulfidation.
6. GH4738 application fields
This alloy is widely used for domestic aero-engine gas turbine rotating components including turbine blades and turbine disks, with mature service application experience.
