Inconel718 alloy is a base high-temperature alloy strengthened by body-centered tetragonal Y" and face-centered cubic Y phase precipitation. It has good comprehensive properties in the temperature range of -253~700C, and its yield strength below 650°C ranks first among deformed high-temperature alloys. First, it has good fatigue resistance, radiation resistance, oxidation resistance, and corrosion resistance, as well as good processing performance, welding performance and long-term organizational stability. It can manufacture various parts with complex shapes and is widely used in 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 structure is particularly sensitive to the thermal processing process. By understanding 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 according to different use requirements. A variety of parts are available to meet different strength levels and usage requirements. The varieties supplied include forgings, forged bars, rolled bars, cold-rolled bars, round cakes, rings, plates, strips, wires, tubes, etc. It can be made into discs, rings, blades, shafts, fasteners and elastic elements, plate structural parts, machines and other parts for long-term use in aviation.

American brand: Inconel718/UNS NO7718

French brand: Nc19FeNb

German brand: WNr.2.4668/NiCr19Fe19Nb5

ISO grade: NiCr19Nb5Mo3

chemical composition

Chemical composition of Inconel718 The chemical composition of this alloy is divided into 3 categories: standard composition, high-quality composition and high-purity composition, see Table 1-1. The high-quality components reduce carbon and increase niobium on the basis of standard components, thereby reducing the amount of niobium carbide, reducing fatigue sources and increasing the amount of strengthening phases, thereby improving fatigue resistance and material strength. At the same time, harmful impurities and gas levels are reduced. High-purity ingredients are based on high-quality standards to reduce the content of sulfur and harmful impurities and improve material purity and comprehensive performance.

Inconel718 alloy used in nuclear energy needs to control the boron content (other elements remain unchanged), and the specific content is determined by negotiation between the supplier and the buyer. When w (B) s0.002%, to distinguish it from the Inconel718 alloy used in the aviation industry, the alloy grade is Inconel718A

Inconel718 heat treatment system

The alloy has different heat treatment systems to control the grain size, control the morphology, distribution and quantity of the 8 phases, so as to obtain different levels of mechanical properties. Alloy heat treatment systems are divided into three categories:

1. (1010~1065)C+10, 1h, oil cooling, air cooling or water cooling +720C+5, 8h, furnace cooling at 50/h to 620C+5, 8h, air cooling. The grains of materials treated by this system will be coarsened. , although there is no 8 phase in the boundary or within the grain, and there is notch sensitivity, it is beneficial to improve impact performance and resist low-temperature hydrogen embrittlement. 

2. (950~980)C+10°, 1h, oil cooling, air cooling or water cooling +720°C+5C, 8h, furnace cooling at 50/h to 620C+5C, 8h, air cooling. Materials processed by this system are: 8-phase, which helps eliminate notch sensitivity, is the most commonly used heat treatment system, also known as the standard heat treatment system.

3. 3720°C+5°C, 8h, furnace cooling at 50"C/h to 620°C+5C, 8h, air cooling. After being processed by this system, there will be less phase 8 in the material, which can improve the strength and strength of the material. Impact properties. This system is also called a direct aging heat treatment system. Inconel718 variety specifications and supply status

We can supply die forgings (discs, integral forgings), cakes, rings, bars (forged bars, rolled bars, cold drawn bars), plates, wires, strips, tubes, fasteners of different shapes and sizes, elastic components, etc., etc. The status of the goods is determined by the supply and demand parties. Wire is delivered in coils in the agreed delivery conditionInconel718 Melting and Casting Process

The alloy smelting process is divided into three categories: vacuum induction plus electroslag remelting, vacuum induction plus vacuum arc remelting, and vacuum induction plus electroslag remelting plus vacuum arc remelting. According to the use requirements of the parts, the required refining process can be selected to meet the application requirements.

Inconel718 application overview and special requirements

Manufacturing of various stationary and rotating parts in aviation and aerospace engines, such as disks, rings, casings, shafts, blades, fasteners, elastic elements, gas ducts, sealing elements, etc. and welded structural parts; manufacturing of nuclear energy industry applications Various elastic elements and grids; manufacturing parts and other parts for applications in the petroleum and chemical industries. In recent years, on the basis of the continuous deepening of research on this alloy and the continuous expansion of its applications, many new processes have been developed to improve quality and reduce costs: vacuum arc remelting uses an ammonia cooling process to effectively reduce segregation. The injection molding process is used to produce ring parts, which reduces production costs and shortens the production cycle. The superplastic molding process is used to expand the production range of the product.

Application scope

Due to its high temperature strength, excellent corrosion resistance and easy processability at 700°C, it can be widely used in various high-demand situations.

1. Steam turbine 2. Liquid fuel arrow 3. Cryogenic engineering 4. Acidic environment 5. Nuclear engineering