Inconel 718 (a nickel chromium alloy with high strength and corrosion resistance)
Inconel 718 is a nickel chromium alloy with high strength and corrosion resistance. It is used in the temperature range of -423 ° to 1300 ° F (-253 ° to 705 ° C). As an age hardening alloy, nickel Inconel 718 can easily manufacture very complex parts, and its welding characteristics are also outstanding. It also has good tensile, fatigue, creep, and fracture strength, combined with ease of manufacturing and corrosion resistance.
Due to its comprehensive performance, Inconel 718 can be used in a wide range of applications, such as liquid fuel rockets, rings and casings, various formed metal plate parts for aircraft and land-based gas turbine engines, low-temperature storage tanks, as well as fasteners and instrument inconel cnc machining parts.
Corresponding brand:Alloy 718 ; GH4169 ; Inconel 718 ; Nickel 718 ; UNS: N07718 ; W. Nr: 2.4668
Material standards:ASTM: B 637, B 670 ; ASME: CASE 2222-1, SFA 5.14 ; AMS: 5596, 5662, 5663, 5832 ; GE: B50TF14, B50TF15
Material characteristics:
- Easy to process
- High tensile strength, fatigue strength, creep strength, and fracture strength at 700 ℃
- High antioxidant activity at 1000 ℃
- Stable chemical properties at low temperatures
- Good welding performance
Inconel 718 welding process:
This alloy has good welding performance and can be welded using methods such as argon arc welding, electron beam welding, seam welding, spot welding, etc.
Inconel 718 parts heat treatment process:
The heat treatment of aviation parts is usually carried out according to standard heat treatment systems and direct aging heat treatment systems.
Inconel 718 welding mode
Inconel 718 alloy can be easily welded using gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), manual arc welding (SMAW), electron beam (EB), and resistance welding techniques. Its welding inconel characteristics are similar to HASTELLOY X alloy. It is not recommended to use submerged arc welding (SAW) and oxyacetylene welding, as these processes are characterized by high heat input to the base material and slow weld cooling. These factors will increase welding constraints and promote cracking.
Preparation of base material
Before performing any welding operation, the welding surface and adjacent areas should be thoroughly cleaned with an appropriate solvent. All grease, oil, cutting oil, crayon marks, processing solutions, corrosion products, paint, scale, dye penetrant solutions, and other foreign objects should be completely removed.
Selection of filler metal
Matching filler metals (AWS A5.14 ERNiFCr-2, AMS5832) should be used to connect Inconel 718 alloy. For welding 718 alloy onto other alloys, it is recommended to use HASTELLOY ® S (AMS 5838) or W (AWS A5.14 ErnIM-3, AMS 5786) filler wire.
Preheating and interlayer temperature
No preheating required. Preheating is usually carried out at room temperature (typical workshop conditions). The interlayer temperature should be maintained below 200 ° F (93 ° C). If necessary, auxiliary cooling methods can be used between weld beads, provided that these methods do not introduce contaminants.
Post weld heat treatment
Inconel 718 alloy is typically used under fully aged conditions. After forming and welding, full solution annealing is usually performed before aging to achieve optimal joint and overall cnc manufacturing performance. The best practice depends on the specific manufacturing conditions before aging.
