US Grade: InconelX-750 Nickel-based High Temperature Alloy
Chinese grade: GH145/GH4145
German grade: NiCr15Fe7TiAl
French grade: NC15FeTNbA
Japanese brand: NCF750
Summary of inconelx-750 Nickel-based High-temperature Alloy
The inconelx-750 alloy is mainly a nickel-based high-temperature alloy with aging through γ'[Ni3(al, Ti, Nb)] phase. It has good corrosion resistance and oxidation resistance below 980°C, high strength below 800°C, and good slack resistance below 540°C, and good formability and welding properties. This alloy is mainly used to manufacture high-strength, corrosion-resistant annular parts, structural parts and bolts, medium and low stress, slack-resistant flat springs and coil springs that work below 540°C. It can also be used to manufacture turbine blades and other parts. Products include boards, strips, bars, forgings, rings, wires, pipes, etc.
Inconelx-750 Material Grade: Inconelx-750.
Similar brands of inconelx-750: gh145/GH4145 (China), nicr15fe7tial (Germany), nc15fetnba (France).
inconelx-750 Material Technical Standard
●Chemical composition of inconelx-750
| C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≥ | Ni≥ | Mo≥ | Cu≤ |
| 0.08 | 0.50 | 1.00 | 0.015 | 0.010 | 14.0-17.0 | 70.0 | - | 0.50 |
| other | N≤ | Al≤ | Ti≤ | Fe≤ | Co≤ | V≤ | W≤ | Nb+Ta |
| 0.40-1.00 | 2.25-2.75 | 5.0-9.0 | 1.00 |
|
| 0.70-1.20 |
Note: Mn and Si in the table refer to the content of rods, forgings, rings, and wires. The content of plates, strips and pipes is: ω (Mn) ≤0.35%, ω (Si) ≤0.35%.
Inconelx-750 heat treatment system
The solid solution heat treatment system with plate and tube under supply is 980℃±15℃, air-cooled. Intermediate materials and heat treatment systems are available for the following heat treatments.
(1) Annealing: 955-1010℃, water-cooled.
(2) Annealing before welding: 980℃, 1H.
(3) Stress elimination annealing: 900℃ for 2h.
(4) Stress elimination annealing: 885℃±15℃, 24 hours, air-cooled.
Inconelx-750 variety specifications and supply status
It can supply bars, forgings, rings, hot-rolled plates, cold-rolled plates, strips, pipes, and wires of various specifications.
(1) The sheets and strips are generally supplied after hot rolling or cold rolling, annealing or solid solution, pickling and polishing.
(2) Bars, forgings, and rings can be supplied in the form of forging or hot rolling; they can also be supplied in the form of forging and solution treatment; the bars can be supplied in the form of solution polishing or turning, and can be placed in the position in the cold drawing state when ordering.
(3) The pipeline is supplied after solid solution treatment and descaling.
(4) Wires can be supplied in solid solution state; wires with nominal diameter or thickness less than 6.35mm can undergo cold drawing deformation of 50%-65% after solid solution treatment; wires with nominal diameter or side length greater than 6.35mm can undergo cold drawing deformation of nominal diameter or side length greater than 6.35mm after solid solution treatment. For wires with nominal diameter or side length not greater than 0.65mm, cold drawing deformation is required to be no less than 15% after solid solution treatment.
inconelx-750 melting and casting process: adopts arc furnace + vacuum self-consumption remelting, vacuum induction + electroslag, electroslag + vacuum self-consumption remelting or vacuum induction + vacuum self-consumption remelting.
Application situation and special requirements of inconelx-750: This alloy is mainly used to manufacture corrosion-resistant plane wave springs, circumferential coil springs, spiral pressure springs, spring snap rings and sealing rings with operating temperatures below 540℃.
Physical and Chemical Properties of Inconelx-750
●Thermal performance of inconelx-750
(1) The melting temperature range of inconelx-750 is 1395-1425℃
(2) Thermal conductivity of inconelx-750
| θ/℃ | 50 | 100 | 300 | 500 | 900 |
| λ/(W/(m·℃)) | 14.7 | 15.9 | 20.1 | 25.1 | 37.3 |
●InconelX-750 linear expansion coefficient
| θ/℃ | 20~200 | 20~300 | 20~400 | 20~500 | 20~600 | 20~700 | 20~800 |
| α/10-6℃-1 | 13.1 | 13.5 | 14.1 | 14.4 | 15.0 | 15.6 | 16.2 |
Inconelx-750 density: ρ=8.25g/cm3[7].
The electrical properties of inconelx-750: resistivity ρ=1.22×10-6Ω. at 50°C.
Mechanical properties of inconelx-750
●The room temperature mechanical properties of strips, plates and pipes specified by the Inconel X-750 technical standard
| variety | Specification δ/mm | Heat treatment system | σb/MPa | σP0.2/MPa | δ4D/% | φ/% | HRC |
| Band material |
| Delivery status | ≤930 | - | ≥18 | - | - |
| Delivery status +730℃±10℃, 8h, furnace cooling 55℃/h or air cooling to 620℃±10℃, 8h, air cooling, total aging time shall not be less than 18h | ≥1105 | - | ≥12 | - | ≥30 |
| Plate | ≤0.60 | Delivery status | ≤930 | ≤515 | ≥30 | - | - |
| >0.60 | ≤930 | ≤515 | ≥35 | - | - |
| Plate |
| Delivery status +730℃±10℃, 8h, furnace cooling 55℃/h or air cooling to 620℃±10℃, 8h, air cooling, total aging time shall not be less than 18h | ≥1170 | ≥795 | ≥18 | - | ≥32 |
| Pipe |
| Delivery status | ≤965 | ≤550 | ≥35 | - | - |
| Delivery status +730℃±10℃, 8h, furnace cooling 55℃/h or air cooling to 620℃±10℃, 8h, air cooling, total aging time shall not be less than 18h | ≥1170 | ≥790 | ≥15 | - | - |
Note: The conveying state is solid solution 980℃±15℃, keep it for appropriate time, air-cooled or fast-cooled, and remove the scale.
●The room temperature mechanical properties of wire materials specified in inconelx-750 technical standards
| variety | Specifications/mm | Heat treatment system | Round wire | Square or flat wire |
| σb/MPa | σb/MPa |
| Silk material | ≤6.35 | Class A, delivery status | ≥1310 | ≥1210 |
| >6.35～15.88 | ≥1110 | ≥1110 |
| ≤0.65 | Class B, delivery status | ≤1030 |
|
| >0.65～12.70 | 895～1140 |
|
| ≥0.30～6.35 | Class A, delivery status +650℃±10℃, 4h, air-cooled | ≥1520 |
|
| >6.35～10.60 | ≥1380 |
|
| >10.60～15.90 | ≥1240 |
|
| ≥0.30～6.35 | Class A, delivery status +1150℃±10℃, 2h, air-cooled, +840℃±10℃, 24h, air-cooled, +650℃±10℃, 20h, air-cooled | ≥1030 |
|
| >6.35～15.90 | ≥1000 |
|
| ≤0.65 | Class B +730℃±10℃, 16h, air-cooled | ≥1070 |
|
| >0.65～12.70 | ≥1140 |
|
| variety | Specifications/mm | Heat treatment system | Round wire | Square or flat wire |
| σb/MPa | σb/MPa |
| Silk material | ≤6.35 | Class A, delivery status | ≥1310 | ≥1210 |
| >6.35～15.88 | ≥1110 | ≥1110 |
| ≤0.65 | Class B, delivery status | ≤1030 |
|
| >0.65～12.70 | 895～1140 |
|
| ≥0.30～6.35 | Class A, delivery status +650℃±10℃, 4h, air-cooled | ≥1520 |
|
| >6.35～10.60 | ≥1380 |
|
| >10.60～15.90 | ≥1240 |
|
| ≥0.30～6.35 | Class A, delivery status +1150℃±10℃, 2h, air-cooled, +840℃±10℃, 24h, air-cooled, +650℃±10℃, 20h, air-cooled | ≥1030 |
|
| >6.35～15.90 | ≥1000 |
|
| ≤0.65 | Class B +730℃±10℃, 16h, air-cooled | ≥1070 |
|
| >0.65～12.70 | ≥1140 |
|
Note: In the delivery state, before cold-drawing to the finished product, the wire should be solid solution treatment at a certain temperature of 1090-1200℃, and then cold-drawing is carried out according to the following regulations;
Grade A: The cold-drawing deformation of steel wire with nominal diameter or side length less than 6.35mm is 50% to 65%, and the cold-drawing deformation of steel wire with nominal diameter or side length greater than 6.35mm is greater than 30%.
Category B: For steel wires with nominal diameter or side length not greater than 0.65mm, the cold-drawing deformation is about 15%.
●Inconelx-750 Stress fracture performance of bars, forgings and rings
| θ/℃ | σ/MPa | t/h | δ4D/% |
| 730℃±3℃ | 362 | ≥23 | ≥5 |
Organizational structure of inconelx-750
The phase transition temperature of inconelx-750: The precipitation temperature of the γ′ phase is about 600°C, and the precipitation peak is about 800°C. Dissolution begins at 900°C, and almost all dissolves at 970°C.
Time-temperature structure transition curve of inconelx-750 alloy.
Microstructure of inconelx-750 alloy: After standard heat treatment, the inconelx-750 alloy structure consists of γ matrix, Ti(C,n), Nb(C,n), M23C6 carbide and γ′[Ni3(al, Ti,Nb)] phase. The γ′ content is about 14.5%, which is the main reinforced phase of the alloy.
Process performance and requirements of inconelx-750
Forming properties of inconelx-750 alloy: The forging temperature of the alloy is between 1220 and 950℃. In order to obtain good final forging or rod structure and properties, subsequent forging heating temperatures should be performed at corresponding lower temperatures. The final forging temperature should not be lower than 950℃. The alloy should undergo solid solution treatment after vigorous formation.
Inconelx-750 welding performance: This alloy has good welding properties and can be used for various welding, but is difficult to weld for large section parts and better for small section parts and thin plates. Welding must be carried out after annealing or solid solution treatment. After welding, stress removal treatment should be carried out, and humidity should be maintained at 980℃ for 0.5h or 900℃ for 2h. After aging treatment, the strength of the welded components can be obtained in a state of close to complete heat treatment.
inconelx-750 Parts Heat Treatment Process: Parts Heat Treatment should be carried out in a neutral or sulfur-free reducing atmosphere to avoid vulcanization. Parts should be avoided from "hot and cold" treatment between 870°C and 650°C. For large section parts, to prevent cracks, they should be cooled in the air after solid solution treatment. The final heat treatment of finished parts is as follows:
(1) For parts that work above 600℃ and require maximum creep resistance:
Solid solution: 1150℃±15℃, insulation for 2-4h, air-cooled;
Aging: 845℃±15℃, insulation for 24 hours, air-cooled +705℃±15℃, insulation for 24 hours, air-cooled.
(2) For parts that work below 600℃ and require *** room temperature and high temperature tensile properties:
Solid solution: 980℃±15℃, insulation for 1h, air-cooled;
Aging: 730℃±15℃, insulation for 8h, furnace cooling for 50℃/h to 620℃±10℃, insulation for 8h, air cooling.
(3) The following heat treatment systems are usually used for ring parts:
Solid solution: 1095℃±15℃, insulation for 2-4h, air-cooled;
Aging: 845℃±15℃, insulation for 24 hours, air-cooled or furnace cooled to +705℃±15℃, insulation for 20 hours, air-cooled.
(4) The following systems are used for heat treatment of rods and forgings at temperatures below 600°C
Homogenization: 885℃±15℃, insulation for 24 hours, air-cooled;
Aging: 705℃±15℃, insulation 20±1H, air-cooled.
(5) The plates, belts and wires for plates and springs in annealed state can be heat treated using the following systems:
Aging: 1) 705℃±15℃, insulation for 22 hours, air-cooled;
(6) Leave it at 760°C for 1 h.
Solid solution: 980℃±15℃, insulation for 1h, air-cooled;
Aging: 730℃±10℃, insulation for 8h, furnace cooling for 50℃/h to +620℃±10℃, insulation for 8h, air cooling.
Processing and grinding properties of inconelx-750 alloy: This alloy can be processed under various conditions, with good processing performance under annealing or solid solution state.
Inconelx-750 specifications and supply status
Category: Danyang Xinmao Alloy can produce inconelx-750 seamless pipes, inconelx-750 steel plates, inconelx-750 round steel, inconelx-750 forgings, inconelx-750 flanges, inconelx-750 rings, inconelx-750 welded pipes, inconelx-750 steel strips, inconelx-750 wires and supporting welding materials.
Delivery status: Seamless steel pipe: solution + acidic white, length can be fixed; plate: solid solution, pickling, trimming; welded pipe: solid solution acidic white + RT% flaw detection, forging: annealing + turning; bar forging, surface polishing or turning polishing; strip steel cold rolling, solution softening, descaling; wire solution delivery pickling board or straight strip, solid solution straight strip polishing state.