Product Features
- Ease of processing
- High tensile strength , fatigue strength , creep strength and rupture strength at 700℃
- High oxidation resistance at 1000℃
- Stable chemical properties at low temperature
- Good welding performance
Application field
Due to its high temperature strength at 700°C, excellent corrosion resistance and easy processability, it can be widely used in various high-demand occasions. ● Steam turbine ●Liquid fuel rocket
- Cryogenic engineering
- Acid environment
- Nuclear Engineering
Inconel 718 Chemical composition
Alloy | % | Ni | Cr | Fe | Mo | Nb | Co | C | Mn | Si | S | Cu | Al | Ti |
Min. | 50 | 17 | Balance | 2.8 | 4.75 | 0.2 | 0.7 | |||||||
Max. | 55 | 21 | 3.3 | 5.5 | 1 | 0.08 | 0.35 | 0.35 | 0.01 | 0.3 | 0.8 | 1.15 |
Inconel 718 Physical properties
Density | 8.2 g/cm³ |
Melting point | 1260-1340 ℃ |
Inconel 718 Alloy minimum mechanical properties in the roomtemperature
Alloy | Tensile strength | Yield strength | Elongation | Brinell hardness HB |
Solution treatment | 965 | 550 | 30 | ≤363 |
718 Alloy Characteristic as below：
4.Steady mechanical performance in the low temperature.
Inconel 718 Metallurgical structure
Inconel 718 Corrosion resistance
718 alloy with extremely resistance to stress corrosion cracking and pitting ability in high temperature or low temperature environments, especially the inoxidability in the high temperature.
Inconel 718 Application field：
The elevated temperature strength, excellent corrosion resistance and workability at 700℃ properties made it use in a wide range of high requirement environments.
1.Steam turbine
2.Liquid-fuel rocket
3.Cryogenic engineering
4.Acid environment
Machining and Heat Treatingedit broadcast
Inconel 718 alloy is a difficult-to-machine material in the field of machining .
Warm up
The workpiece must be surface cleaned before and during heating to keep the surface clean. If the heating environment contains sulfur, phosphorus, lead or other low melting point metals, Inconel718 alloy will become brittle. Impurities originate from marked paint, chalk, lubricating oil, water, fuel, etc. The sulfur content of fuel should be low. For example, the impurity content of liquefied gas and natural gas should be less than 0.1%, the sulfur content of city gas should be less than 0.25g/m3, and the sulfur content of petroleum gas should be less than 0.5%.
The heated electric furnace should preferably have a relatively accurate temperature control ability, the furnace gas must be neutral or weakly alkaline, and the fluctuation of the furnace gas composition in oxidizing and reducing properties should be avoided.
Thermal processing
The suitable hot working temperature of Inconel718 alloy is 1120-900℃. The cooling method can be water quenching or other rapid cooling methods. After hot working, it should be annealed in time to ensure the best performance. During hot processing, the material should be heated to the upper limit of the processing temperature. In order to ensure the plasticity during processing, the final processing temperature when the deformation amount reaches 20% should not be lower than 960 °C.
Cold working
Cold working should be carried out after solution treatment . The work hardening rate of Inconel718 is greater than that of austenitic stainless steel , so the processing equipment should be adjusted accordingly, and there should be an intermediate annealing process during cold working.
Heat treatment
Different solution treatment and aging treatment processes will result in different material properties. Due to the low diffusion rate of the γ” phase, the best mechanical properties of Inconel718 alloy can be obtained by long-term aging treatment.
Polished
The oxides near the welds of Inconel718 workpieces are more difficult to remove than those of stainless steel. They need to be polished with a fine abrasive belt. Before pickling in a mixed acid of nitric acid and hydrofluoric acid , sandpaper should also be used to remove oxides or salt bath pretreatment. deal with.
Machining
Machining of Inconel718 needs to be carried out after solution treatment , taking into account the work hardening . Unlike austenitic stainless steel, Inconel718 is suitable for low surface cutting speeds .
Welding
The precipitation hardening Inconel 718 alloy is very suitable for welding and has no tendency to crack after welding. Weldability, ease of processing, and high strength are several advantages of this material.
Inconel718 is suitable for arc welding , plasma welding, etc. Before welding, the surface of the material should be clean, free of oil stains, chalk marks, etc., and the bright metal should be polished within 25mm around the weld .
