GH4738
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Description
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 nickel-based high-temperature alloy strengthened by γ’ phase precipitation. It has good gas corrosion resistance, high yield strength and fatigue properties, good process plasticity and stable structure. It is widely used in rotating parts of aircraft engines, and the operating temperature is not higher than 815℃. Cold-rolled and hot-rolled sheets, pipes, strips, wires and forgings, castings, and fasteners can be produced.
GH4738 standard implementation
GJB 1953-1994 “Specifications on Hot Rolled Rods for High Temperature Alloys for Rotating Parts of Aero Engines”
GJB 2611-1996 “Specifications for Cold Pulling Rods for High Temperature Alloys for Aviation”
GJB 2612-1996 “Specifications for Cold Drawing of High Temperature Alloys for Welding”
GJB 3020-1997 “Specifications for High Temperature Alloy Ring Bills for Aviation”
GJB 3165-1998 “Specifications on Hot Rolling and Forged Rods for Aviation Loading Parts”
GJB 3782-1999 “Specifications for High Temperature Alloy Rods for Aviation”
HB 5198-1982 “Deformed high-temperature alloy rods for aviation blades”
2. Chemical composition of GH4738
| alloy | % | C | Cr | In | Co | Mo | Al | Of | B | Zr | Fe | Mn | And | P | S | Cu |
| Gh4738 | Minimum value | 0.03 | 18 | Remain
quantity |
12 | 3.5 | 1.2 | 2.75 | 0.003 | 0.02 | – | – | – | – | – | – |
| Maximum value | 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: The trace impurities are ω(Pb)≤0.001%, ω(As)≤0.0025%, ω(Sn)≤0.0012%, ω(Sb)≤0.0025%, and ω(Bi)≤0.0001%.
3. GH4738 physical properties
| density | 8.22g/cm3 |
| Melting point | 1330-1360 ℃ |
| magnetic | Non-magnetic |
Thermal conductivity
| I/℃ | 360 | 460 | 545 | 640 | 770 | 855 | 985 |
| λ/（W/（m·C）） | 16.8 | 18.3 | 20.2 | 22.4 | 24.1 | 25.3 | 28.0 |
Specific heat capacity
| I/℃ | 360 | 460 | 545 | 640 | 770 | 855 | 985 |
| c/（J/（kg·C）） | 515 | 540 | 573 | 603 | 640 | 665 | 707 |
Coefficient of linear expansion
| I/℃ | 20～100 | 20～200 | 20～300 | 20～400 | 20～500 | 20～600 | 20～700 | 20～800 | 20～900 |
| A/10-6C-1 | 12.47 | 12.73 | 13.04 | 13.53 | 13.97 | 14.47 | 15.05 | 15.68 | 15.95 |
IV. Chemical properties of GH4738
Oxidation rate of antioxidant alloy after 100 hours of test in air medium
| Test time/h | 900 | 1000 |
| Oxidation rate/(g/(m2.h)) | 0.083 | 0.226 |
Corrosion resistance alloy has good corrosion resistance against salt spray.
V. GH4738 process performance and requirements
1) The forging temperature of the alloy is easy to form between 1220 and 950℃. The alloy is subjected to solid solution treatment after the vigorous forming process.
2) The average grain size of the alloy is closely related to the degree of deformation of the forging and the final forging temperature.
3) The alloy has good welding properties and can be carried out in various welding. Aging treatment after welding can obtain strength approximately in a complete heat treatment state.
4) The heat treatment of parts is carried out in a neutral or reducing atmosphere without sulfur to avoid vulcanization.
6. GH4738 application fields
This alloy is widely used in aircraft engine gas turbines in China, mainly used as rotating parts such as turbine blades and turbine discs, and has mature experience in using it.
