company news about Inconel 625

Inconel 625 was developed in the 1960s with the purpose of creating a material that could be used for steam-line piping. Some modifications were made to its original composition that have enabled it to be even more creep-resistant and weldable. Thanks to these enhancements, the applications of Inconel 625 have expanded far beyond its initial use, spanning a wide range of industries such as the chemical processing industry, and marine and nuclear sectors, where it is employed to manufacture pumps, valves, and other high-pressure equipment. Given its remarkable evolution and extensive practical applications, as a nickel-based alloy with a variety of excellent properties, it is widely used in multiple fields.

The following is a detailed introduction to it:

Chemical Composition

The main alloying elements of Inconel 625 include nickel (Ni), chromium (Cr), molybdenum (Mo), niobium (Nb), etc. Its typical chemical composition (mass fraction) is: nickel (Ni) ≥ 58%, chromium (Cr) 20% - 23%, molybdenum (Mo) 8% - 10%, niobium (Nb) + tantalum (Ta) 3.15% - 4.15%, iron (Fe) ≤ 5%, carbon (C) ≤ 0.1%, manganese (Mn) ≤ 0.5%, silicon (Si) ≤ 0.5%, phosphorus (P) ≤ 0.015%, sulfur (S) ≤ 0.015%.

Physical Properties

•Density: Approximately 8.44 g/cm³.

•Melting Point: 1290 - 1350°C.

•Coefficient of Thermal Expansion: In the range from room temperature to 1000°C, the average coefficient of thermal expansion is approximately 13.1×10⁻⁶/°C.

•Thermal Conductivity: At room temperature, the thermal conductivity is approximately 11.1 W/(m·K), and it will increase with the rise of temperature.

•Resistivity: The resistivity at room temperature is approximately 1.29 μΩ·m.

Mechanical Properties

Inconel 625 has excellent mechanical properties, including high strength, high toughness, and good fatigue resistance.

At room temperature, its tensile strength is usually ≥ 760 MPa, yield strength ≥ 345 MPa, and elongation ≥ 30%.

Even in a high-temperature environment, it can maintain high strength and toughness. For example, at 650°C, its tensile strength can still reach above 550 MPa.

•Corrosion Resistance: Uniform Corrosion Resistance: Inconel 625 has excellent resistance to a variety of corrosive media. It has good corrosion resistance in both oxidizing acids (such as nitric acid) and reducing acids (such as sulfuric acid and hydrochloric acid).

•Pitting and Crevice Corrosion Resistance: Due to the presence of elements such as chromium and molybdenum in its alloy composition, Inconel 625 has good resistance to pitting and crevice corrosion. In an environment containing chlorides, it can effectively resist the occurrence of pitting and crevice corrosion.

•Stress Corrosion Cracking Resistance: This alloy has a high resistance to chloride-induced stress corrosion cracking and is suitable for use in harsh corrosive environments.

Machining Properties

•Hot Working: Inconel 625 has good hot working properties, but it needs to be carried out within an appropriate temperature range. The hot working temperature is generally between 1050 - 1200°C. Within this temperature range, the alloy has good plasticity and workability.

•Cold Working: It can be cold worked, but as the cold working deformation amount increases, the hardness and strength of the material will increase, and the plasticity and toughness will decrease. Therefore, during cold working, appropriate intermediate annealing treatment is required to restore the machining properties of the material.

•Welding: Inconel 625 can be welded using a variety of welding methods, such as tungsten inert gas welding (TIG), metal inert gas welding (MIG), shielded metal arc welding, etc. When welding, appropriate welding materials and welding process parameters need to be selected to ensure the quality of the welded joint.

Application Fields

•Aerospace: It is used to manufacture components such as combustion chambers, turbine blades, and afterburners of aircraft engines, which can withstand high-temperature, high-pressure, and complex stress environments.

•Petrochemical Industry: Widely applied to reactors, heat exchangers, pipelines and other equipment in petroleum refining and chemical production, resisting the erosion of various corrosive media.

•Marine Engineering: Suitable for manufacturing offshore platforms, seawater desalination equipment, subsea pipelines, etc., with good seawater corrosion resistance and erosion resistance.

•Power Industry: Used for high-temperature components in thermal power generation and nuclear power generation, such as steam generators, superheaters, etc., which can work stably in a high-temperature and high-pressure water vapor environment.