Inconel 625 Sheet

Introduction 

Inconel 625 Sheet is a high-performance nickel-based alloy sheet, mainly composed of nickel (Ni content 58%-71%), chromium (Cr about 20%-23%), molybdenum (Mo about 8%-10%), and a small number of other elements. It is widely used in key fields such as aerospace, petrochemical, marine engineering, and energy with its excellent high temperature and corrosion resistance. As a solid solution-strengthened alloy, Inconel 625 Sheet shows excellent stability and reliability in high temperature, high pressure, and strong corrosion environments.

Excellent corrosion resistance

The chromium in Inconel 625 Sheet can form a dense oxide film on the surface of the alloy, effectively blocking the erosion of corrosive media. The addition of molybdenum further improves the corrosion resistance of the alloy in reducing media, especially in strong acid environments such as sulfuric acid and hydrochloric acid. The corrosion rate of Inconel 625 Sheet in concentrated sulfuric acid at 90°C is only 0.1mm/a, which is much lower than the corrosion rate of ordinary stainless steel.

High-temperature resistance

The large amount of solid solution atoms (such as nickel, chromium, and molybdenum) in the Inconel 625 Sheet alloy improves the high-temperature strength of the alloy by hindering lattice deformation, so that the tensile strength of Inconel 625 Sheet can still maintain about 690MPa and the yield strength is about 275MPa at 1000℃, showing excellent high-temperature resistance.

Fatigue resistance

Thanks to the stable microstructure and fine and uniform grain distribution of Inconel 625 Sheet, the possibility of stress concentration and crack initiation is reduced, making it perform well in high-stress and cyclic load environments. These characteristics significantly improve the fatigue life of the material, which is usually more than 30% higher than similar materials.

Processing Technology

Forging

Heating Temperature: Typically heated between 1150°C to 1230°C to ensure optimal plasticity and deformation capabilities.

Start and Stop Forging Temperatures: Begin forging at a minimum of 1030°C and cease not below 930°C to prevent material embrittlement or cracking during the process.

Forging Deformation: Adjusted according to specific requirements to guarantee ideal microstructure and mechanical properties.

Rolling

Preheating Temperature: Ranges from 1120°C to 1160°C before rolling, ensuring ease of deformation during the process.

Rolling Temperature: Initiate at no less than 1050°C, with the stopping temperature not falling below 930°C, to maintain material uniformity and density.

Deformation Rates: Suggested deformation for semi-finished products is 25%-30%, while finished products should undergo no less than 30% deformation.

Heat Treatment 

The heat treatment regimen for Inconel 625 encompasses annealing and solution treatment among others, aimed at enhancing the material's mechanical attributes and corrosion resistance.

Annealing: Conducted approximately at 900°C to alleviate internal stresses and reinstate material plasticity.

Solution Treatment: Undertaken within the range of 930°C to 1040°C, duration tailored to specific needs, to bolster corrosion resistance and high-temperature strength.

Surface Treatment

Inconel 625 sheet surface preparation involves two primary stages: alkaline cleaning and acid pickling.

Alkaline washing removes surface oxide scales and oils, whereas acid pickling in an aqueous medium further purifies the surface, eliminating potential contaminants. These treatments ensure the material's surface finish and flatness meet standards, enhancing its corrosion resistance and aesthetic appeal.

1. Components of organic chemical process equipment containing chlorides, especially in the case of using acidic chloride catalysts

2. Digesters and tanks for the pulp and paper industry.

3. Absorption towers, reheaters, flue gas inlet dampers, fans (wet), agitators flow guides, and flues in flue gas desulfurization systems.

4. Equipment and components for use in acidic gas environments.

5. Acetic and acetic anhydride reaction generators.

6. Sulfuric acid condensers.

Corresponding grades of Inconel 625 in various countries are

UNS N06625 (Unified Numbering System, USA)

DIN 2.4856 (Deutsches Institut für Normung, Germany)

ISO NW6625 (International Organization for Standardization)

JIS NCF 625 (Japanese Industrial Standards)

Three common questions about Inconel 625 sheet include: