Stainless Steel 316L vs Inconel 625 – What’s the Difference?

Both Stainless Steel 316L and Inconel 625 are highly regarded for their excellent corrosion resistance, mechanical properties, and application-specific advantages. However, when comparing these two alloys, it becomes evident that they differ significantly in composition, properties, and recommended uses. In this blog post, we’ll take a close look at these differences between Stainless Steel 316L vs Inconel 625.

Stainless Steel 316L vs Inconel 625 – What’s the Difference?

Stainless Steel 316L vs Inconel 625 – 1. Composition

The key to understanding the difference between Stainless Steel 316L and Inconel 625 lies in their composition.

Stainless Steel 316L is an austenitic stainless steel, which means it has a high chromium content, typically around 16-18%, and a low carbon content, with a maximum of 0.03% to avoid carbide precipitation. It also contains nickel (10-14%) to enhance corrosion resistance and maintain austenitic structure. Additional elements such as molybdenum (2-3%) are added to improve resistance to pitting and crevice corrosion in chloride-rich environments.

In contrast, Inconel 625 is a nickel–chromium–molybdenum alloy with a high nickel content (~60%), providing excellent resistance to oxidation and corrosion. Chromium (~22%) and molybdenum (~9%) are added for corrosion resistance, particularly against reducing acids. Inconel 625 also contains aluminum and titanium, which form protective oxide films, further enhancing corrosion resistance.

Stainless Steel 316L vs Inconel 625 – 2. Properties

The compositional differences between these alloys lead to distinct material properties.

Stainless Steel 316L is known for its excellent corrosion resistance, particularly in marine and chloride-containing environments. It maintains its corrosion resistance even in warm chloride solutions, thanks to the molybdenum addition. It is also highly ductile and can be easily formed and welded. However, its mechanical strength, particularly at elevated temperatures, is lower compared to Inconel 625.

Inconel 625, on the other hand, offers superior mechanical properties, including high strength and ductility even at elevated temperatures. It maintains its mechanical properties up to 1800°F (982°C), making it an ideal material for high-temperature applications. Its corrosion resistance, although not as extensive as 316L, is still excellent against a wide range of acids, alkalis, and oxidizing agents.

Stainless Steel 316L vs Inconel 625 – 3. Applications

The unique properties of Stainless Steel 316L and Inconel 625 make them suitable for different applications.

Stainless Steel 316L is widely used in the marine industry due to its resistance to chloride-induced corrosion. It is also commonly found in chemical processing equipment, pharmaceutical equipment, and surgical implants where corrosion resistance and biocompatibility are crucial.

Inconel 625, on the other hand, is primarily used in high-temperature applications such as jet engine components, gas turbines, and heat exchangers. Its resistance to oxidation and maintenance of mechanical properties at elevated temperatures make it an ideal material for such demanding applications. It is also used in chemical processing equipment, especially where resistance to both corrosion and high temperatures is required.

Conclusion

In summary, Stainless Steel 316L and Inconel 625 are both excellent materials with unique properties and applications. 316L excels in corrosion resistance, particularly in chloride-rich environments, and is suitable for a wide range of applications that require biocompatibility and corrosion resistance. In contrast, Inconel 625 offers superior mechanical properties at elevated temperatures, making it ideal for high-temperature applications such as jet engines and gas turbines. 

Thank you for reading our article and we hope it can help you to have a better understanding of the differences between Stainless Steel 316L vs Inconel 625. If you are looking for Stainless Steel 316L and Inconel 625 suppliers online now, please don’t hesitate to contact Sino Stainless Steel.

As a leading supplier of stainless steel products from Shanghai China, Sino Stainless Steel provides customers with high-quality Stainless Steel 316L and Inconel 625, stainless steel sheets, stainless steel tubes, stainless steel pipes, stainless steel strips, stainless steel coils, stainless steel plates, and stainless steel bars at a very competitive price.