ThePipingMart Blog Metals Incoloy 800 vs Inconel 625 – What’s the Difference

Incoloy 800 vs Inconel 625 – What’s the Difference

Incoloy 800 vs Inconel 625

Choosing the right material for your industrial application is critical for ensuring its longevity, cost-effectiveness, and overall performance. Two popular materials in the industry are Incoloy 800 and Inconel 625. While they share some similarities, they differ in many aspects, such as composition, properties, and applications. This blog post will compare Incoloy 800 and Inconel 625 to help you decide which is best for your particular needs.

What is Incoloy 800?

Incoloy 800 is a versatile alloy designed for applications requiring excellent corrosion, high strength, and heat resistance. It offers exceptional features such as excellent creep rupture strength and outstanding oxidation resistance up to 1050°C (1922°F). This makes it ideal for use in harsh environments such as petroleum refining.

What is Inconel 625?

Inconel 625 is a nickel-based superalloy known for its exceptional strength and corrosion resistance at high temperatures. It is ideal for seawater, chemical processing, heat exchangers, etc. Its many beneficial properties make it an invaluable material in numerous industries worldwide.

Difference Between Incoloy 800 and Inconel 625


Incoloy 800 is a nickel-iron-chromium alloy with high resistance to oxidation, carburization, and sulfurization. Its nominal composition includes 32% nickel, 46% iron, 21% chromium, and 0.5% manganese. It also contains traces of aluminium, titanium, and copper. In comparison, Inconel 625 is a nickel-chromium-molybdenum alloy with excellent corrosion resistance in many environments. Its nominal composition includes 58% nickel, 22% chromium, 9% molybdenum, 3.5% niobium, and 1% iron. It also contains traces of titanium, aluminium, and cobalt. Therefore, Incoloy 800 has a higher iron content and a lower nickel content than Inconel 625.


Incoloy 800 and Inconel 625 have slightly different mechanical and physical properties. Incoloy 800 has a higher yield strength, tensile strength, and elongation at room and elevated temperatures than Inconel 625. It also has a lower coefficient of thermal expansion, lower thermal conductivity, and higher specific heat capacity than Inconel 625. However, Inconel 625 has a higher melting point, better fatigue resistance, and superior corrosion resistance than Incoloy 800 in many aggressive environments, such as chloride, fluoride, and acid solutions.


Incoloy 800 and Inconel 625 find various applications in different industries because of their unique properties. Incoloy 800 is used in high-temperature and corrosive environments, such as heat exchangers, petrochemical processing, power generation, and furnace components. Its high resistance to oxidation and carburization makes it suitable for ethylene cracker tubes, steam methane reformers, and coal-fired power plants. On the other hand, Inconel 625 is used in extreme environments, such as marine, aerospace, chemical processing, and nuclear reactors. Its excellent resistance to pitting, crevice, and intergranular corrosion makes it suitable for seawater pipes, aircraft ducting, heat shields, and reactor core applications.


The cost of Incoloy 800 and Inconel 625 varies depending on the specific grades, forms, and quantities required. In general, Incoloy 800 is less expensive than Inconel 625 due to its lower nickel content and simpler production process. However, the cost difference may be insignificant for some applications, especially when other factors, such as performance, availability, and maintenance, are considered.


In summary, choosing between Incoloy 800 and Inconel 625 depends on your specific requirements, budget, and conditions. If you need a material that can withstand high temperatures, oxidation, and carburization, Incoloy 800 may be the right choice for you. If you need a material that can resist corrosion in aggressive environments, such as seawater, acids, and chloride solutions, Inconel 625 may be a better choice. Ultimately, consulting with a material expert or supplier who can recommend the most appropriate material for your industrial application based on your needs and specifications is essential.

Related Post