Overview
| Product characteristics | corrosion | Product name | Nickel chromium alloy |
| Grade | GH4145 | producing area | Changzhou |
| Nickel content | Margin% | Impurity content | 0.01% |
Product Details
Changzhou Brilliance Special Steel Co.,Ltd
Material grade
UNS N07750
Similar brands
Inconel X-750 (USA), NiCr15Fe7TiAl (Germany), NC15FeTNbA (France), NCF750 (Japan)Technical standards for materials:
Q/3B 4088-1994 "GH4145 Alloy Capillary Materials"
Q/3B 4098-1995 "GH4145 Alloy Wire"
Q/3B 4198-1993 "GH4145 Alloy Cold Rolled Sheet and Strip"
chemical composition
Table 1-1
Note: Mn and Si in the table refer to the content of rods, forgings, rings, and wires. For plates, strips, and pipes, Mn ≤ 0.35%, Si ≤ 0.35%.
Physical and chemical properties
Thermal performance
It has good oxidation resistance below 980 ℃, high strength below 800 ℃, good relaxation resistance below 540 ℃, as well as good formability and welding performance. This alloy is mainly used for manufacturing plane and spiral springs with high strength and resistance to relaxation that work in aviation engines below 800 ℃. [1]
melting range :1395-1425 ℃
Thermal conductivity
See Table 2-1
2.1.3. The linear expansion coefficient of GH4145 (GH145) is shown in Table 2-2
density:ρ= 8.25g/cm3
Electrical performance:Resistivity at 50 ℃ ρ= 1.22 * 10-6 Ω. m
Metallographic structure
The microstructure of alloy in standard heat treatment state is determined by γ Matrix, Ti (C, N), Nb (C, N), M23C6 carbide, and γ&＃ 39; [Ni3 (Al, Ti, Nb)] phase composition, γ&＃ 39; The content is approximately 14.5%, which is the main strengthening phase of the alloy.
Process performance and requirements
1. The forging temperature of the alloy is easy to form between 1220 and 950 ℃. The alloy undergoes solution treatment after intense forming process.
2. The average grain size of this alloy is closely related to the degree of deformation of the forging and the final forging temperature.
3. The alloy has good welding performance and can be used for various welding. Aging treatment after welding can obtain strength that is approximately in a fully heat treated state.
4. The heat treatment of the parts is carried out in a neutral or reducing atmosphere without sulfur to avoid vulcanization.
Heat treatment system
The solid solution heat treatment system for the supply status of plates, strips, and pipes is 980 ℃± 15 ℃, air-cooled. The intermediate heat treatment system for materials and parts can be selected from the following processes for heat treatment.
Annealing: 955-1010 ℃, water cooled.
Annealing before welding of welded parts: 980 ℃, 1 hour.
Welding stress relief annealing: 900 ℃, moisturizing for 2 hours.
Stress relief annealing: 885 ℃± 15 ℃, 24 hours, air cooled.
Variety specifications and supply status
We can supply various specifications of bars, forgings, rings, hot-rolled plates, cold-rolled plates, strips, pipes, and wires.
Plate and strip are generally supplied after hot rolling or cold rolling, annealing or solid solution, pickling and polishing.
Bars, forgings, and rings can be supplied in either the forged or hot-rolled state; It can also be supplied after solid solution treatment after forging; Bars can be supplied by grinding or turning after solid solution, and can be placed in the cold drawn state when required by the order.
Silk can be supplied in a solid solution state; For wires with a nominal diameter or thickness below 6.35mm, they can be dissolved and supplied with cold drawn deformation of 50% to 65%; Wire with a nominal diameter or side length greater than 6.35mm shall be supplied with a cold drawn deformation of not less than 30% after solution treatment. For wires with a nominal diameter or side length not exceeding 0.65mm, they shall be supplied with a cold drawn deformation of not less than 15% after solution treatment as required. [1]
Melting and Casting Processes
The alloy adopts electric arc furnace plus vacuum consumable remelting, vacuum induction plus electroslag, electroslag plus vacuum consumable remelting, or vacuum induction plus vacuum consumable remelting.
Application Overview and Special Requirements
This alloy is mainly used for manufacturing parts such as planar waveform springs, circumferential spiral springs, spiral compression springs, spring clips, and sealing rings for aircraft engines with operating temperatures below 540 ℃.