Inconel 718 material introduction and application
In 718
Alloy 718 is a precipitation-strengthened nickel-based high-temperature and high-strength alloy
It has good comprehensive properties in the temperature range of -253 to 700°C. The yield strength below 650°C ranks first among deformed superalloys. It also has good fatigue resistance, radiation resistance, oxidation resistance, corrosion resistance, and good processing performance. , welding performance and long-term structural stability, and can manufacture various parts with complex shapes. In the aerospace, nuclear energy, and petroleum industries, it has been widely used in the above temperature range.
Another feature of this alloy is that the alloy's structure is particularly sensitive to the thermal processing process. By mastering the phase precipitation and dissolution rules in the alloy and the relationship between the structure, process, and properties, reasonable and feasible process procedures can be formulated for different use requirements. A variety of parts are available to meet different strength levels and usage requirements.
Alloy 718 corrosion resistance
It has excellent resistance to stress corrosion cracking and pitting corrosion in both high and low temperature environments, and its oxidation resistance is particularly excellent at high temperatures.
Alloy 718 physical properties
Melting point: 1260-1340 ℃
Density: 8.2 g/cm3
Hardness: ≥331 (HBS)
Magnetism: None
Similar brands
China: GH4169
Germany: W.Nr.2.4668
France: Nc19FeNb
Implementation standards
Forgings ASTM B637 AMS 5662/5663
Rod ASTM B637 AMS 5662/5663/5664
Plate/Strip ASTM B670 AMS 5596/5597
Seamless pipe AMS 5589/5590
Alloy 718 processing
Thermal processing
The suitable thermal processing temperature is 1120-900°C. The cooling method can be water quenching or other rapid cooling methods. After thermal processing, it should be annealed in time to ensure the best performance. During thermal 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 reaches 20% should not be lower than 960°C.
Cold working
Cold working should be carried out after solid solution treatment. The work hardening rate is greater than that of austenitic stainless steel. Therefore, the processing equipment should be adjusted accordingly, and there should be an intermediate annealing process during the cold working process.
Alloy 718 welding process
The alloy has satisfactory welding performance and can be welded by argon arc welding, electron beam welding, seam welding, spot welding and other methods.
Alloy 718 parts heat treatment process
The heat treatment of aviation parts is usually carried out according to the standard heat treatment system and the direct aging heat treatment system.
Application areas
• Aero engine components
• Various elastic elements and grids for the nuclear energy industry
• Parts for petroleum field applications
• Chemical industry
• Nuclear engineering
