The difference between Inconel 625 and Inconel 718 is the material composition and use.

inconel 718 is a precipitation-strengthened nickel-based high-temperature alloy material.

Similar brands: GH4169, GH169 (China), NC19FeNb (France), NiCr19Fe19Nb5Mo3 (Germany), NA 51 (UK) Inconel718, UNS NO7718 (USA)? NiCr19Nb5Mo3 (ISO) Inconel718 (N07718) Nickel-based alloy Inconel718 alloy contains niobium,

Molybdenum's precipitation hardening nickel-chromium iron alloy has high strength, good toughness below 650°C, and corrosion resistance in both high and low temperature environments.

Available in solution treated or precipitation hardened condition.

Overview It has the following characteristics ● Easy processability ● High tensile strength, fatigue strength, creep strength and rupture strength at 700℃ ● High oxidation resistance at 1000℃ ● Stable chemical properties at low temperatures ●

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

●Steam turbine ●Liquid fuel rocket ●Cryogenic engineering ●Acidic environment ●Nuclear engineering Physical properties Density Density ρ=8.24g/cm3 Melting temperature range Melting temperature range 1260~1320℃ Processing and heat treatment Inconel718 alloy is a difficult-to-process material in the field of mechanical processing.

The surface of the preheated workpiece must be cleaned before and during the heating process 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 come from marking paint, chalk, lubricating oil, water, fuel, etc.

The sulfur content of the fuel should be low. For example, the impurity content of liquefied petroleum 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 electric furnace for heating should preferably have a more precise temperature control capability. The furnace gas must be neutral or weakly alkaline, and the furnace gas composition should be prevented from fluctuating in oxidizing and reducing properties.

The suitable hot processing temperature for hot processing Inconel718 alloy is 1120-900°C. The cooling method can be water quenching or other rapid cooling methods. After hot 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 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 the cold working process.

Different solution treatment and aging treatment processes of heat treatment will produce different material properties.

Due to the low diffusion rate of the γ" phase, Inconel718 alloy can obtain the best mechanical properties through long-term aging treatment. The oxide polished near the weld of Inconel718 workpiece is more difficult to remove than that of stainless steel, and fine sand is required.

Belt grinding, before pickling in a mixed acid of nitric acid and hydrofluoric acid, also use sandpaper to remove oxides or carry out salt bath pretreatment. Machining of Inconel718 needs to be carried out after solid solution treatment, taking into account the material's properties.

Work hardening, unlike austenitic stainless steel, Inconel718 is suitable for low surface cutting speeds. The welding precipitation hardening Inconel718 alloy is very suitable for welding and has no tendency to crack after welding. It has good weldability, easy processability, and high strength.

These are the major advantages of this material. Inconel718 is suitable for arc welding, plasma welding, etc. Before welding, the surface of the material must be clean, free of oil stains, chalk marks, etc., and the 25mm area around the weld must be polished to expose bright metal.

Overview of Inconel625 nickel-based alloy Inconel625 characteristics and application areas: This alloy is a solid solution-strengthened nickel-based deformed high-temperature alloy with molybdenum and niobium as the main strengthening elements. It has excellent corrosion resistance and high oxidation properties, and has good performance from low temperature to 980°C.

It has excellent tensile properties and fatigue properties and is resistant to stress corrosion in salt spray atmosphere. Therefore, it can be widely used in manufacturing aerospace engine parts, aerospace structural components and chemical equipment.