High-Performance Inconel Nickel Alloy —— Selection of Materials for Corrosive Environment

Material selection is critical to engineering design. Corrosion may be minimized by employing an appropriate design. The selection of appropriate materials in a given environment is a key factor for corrosion control strategy. The material selected has to meet the criteria for mechanical strength, corrosion, and erosion resistance for specific service conditions.

 

Inconel alloys is widely used in pollution control and waste processing, where driving demand has brought about a need for high-performance alloy materials that can withstand hazardous waste management and aggressively corrosive environments. For instance, high-performance corrosion-resistant alloys are specified for valves and piping systems in aggressive environments encountered in refineries and chemical processing plants.

Inconel 625 offers high strength, excellent fabricability and has superior resistance to a wide range of corrosive environments of unusual severity, including high-temperature effects, such as oxidation and carburisation. It is also resistant to pitting and crevice corrosion.

 

Inconel C-276 is also corrosion resistant in a wide range of severe environments. The high molybdenum content makes the alloy especially resistant to pitting and crevice corrosion. The low carbon content minimizes carbide precipitation during welding to maintain corrosion resistance in as-welded structures. It is commonly used in pollution control, chemical processing, pulp and paper production, and waste treatment.

Inconel 622 gives excellent resistance to both oxidising and reducing acid environments, as well as those containing mixed acids. It is resistant to pitting and crevice corrosion in acid-halide environments. This versatile alloy is found in chemical processing, pollution control, fluegas desulfurisation, waste incineration, and pulp and paper processing industries.

 

Inconel 625 and Inconel 622 are also deployed in chlorine injection systems for waste water streams, whilst supercritical water oxidation technology has adopted Inconel 625 as a preferred material in reaction chambers. They are are used for gas cleaning components, slurry systems and exit ducts.

 

The list of factors affecting the performance of materials are: expected performance and functions of the product, physical characteristics, strength and mechanical characteristics, corrosion and wear characteristics, fabrication parameters, and recycling possibilities.

 

The corrosion resistance of materials depends on the nature of the corrosive environment. A material may be extremely corrosion resistant in an environment and yet fail in another environment. Therefore, the knowledge of corrosion resistance of a material in a given environment is of fundamental importance to its successful application.