Austenitic vs Ferritic Steel – What’s the Difference？

Many people have such a question: Austenitic vs Ferritic Steel – What’s the difference? While both Austenitic & Ferritic Steel belong to the larger family of stainless steels, their properties, applications, and manufacturing processes differ significantly. In this article, we aim to provide a detailed comparison between austenitic and ferritic steel, explaining their fundamental differences.

Austenitic vs Ferritic Steel – What’s the Difference？

Austenitic Steel

Austenitic steel is named after the austenite phase, which is a face-centered cubic (FCC) structure that exists at room temperature. This type of steel contains high levels of chromium (typically 16-26%) and nickel (6-10%), which are key elements in imparting corrosion resistance. Austenitic steel is non-magnetic in the annealed condition but can become slightly magnetic when cold-worked.

The most widely known austenitic steel is Type 304, also known as 18-8 stainless steel due to its composition of 18% chromium and 8% nickel. This grade is highly resistant to corrosion, oxidation, and scaling at temperatures up to 1500°F (815°C). Austenitic steels are ductile, have high toughness, and can be easily formed and welded. However, they have lower mechanical strength compared to other steel types.

Due to its excellent corrosion resistance, workability, and weldability, austenitic steel finds applications in a wide range of industries, including construction, food processing, chemical processing, and medical equipment. It is also used in automotive components, where its corrosion resistance and formability are advantageous.

Ferritic Steel

Ferritic steel, on the other hand, gets its name from the ferrite phase, which is a body-centered cubic (BCC) structure. This type of steel contains chromium levels ranging from 10.5% to 30% but has very low nickel content, typically less than 1%. The absence of nickel and the presence of carbon make ferritic steel more magnetic than austenitic steel.

Ferritic steel is known for its high strength and hardness, making it suitable for load-bearing applications. However, it is less ductile and tough than austenitic steel, and its weldability is also poorer. Ferritic steel is resistant to stress corrosion cracking and has good resistance to oxidation at high temperatures.

Applications of ferritic steel include automotive exhaust systems, where its resistance to high temperatures and corrosion is beneficial. It is also used in construction, chemical processing, and oil and gas industries due to its strength and corrosion resistance.

Austenitic vs Ferritic Steel – Comparison

When comparing austenitic vs ferritic steel, the key differences lie in their microstructures, mechanical properties, and applications. Austenitic steel has a face-centered cubic structure, is ductile and weldable, with excellent corrosion resistance. On the other hand, ferritic steel has a body-centered cubic structure, is stronger and more resistant to stress corrosion cracking, but less ductile and weldable.

From an application perspective, austenitic steel is preferred in industries where corrosion resistance and formability are crucial, such as food processing and medical equipment. Ferritic steel, on the other hand, is ideal for load-bearing applications where strength and high-temperature resistance are paramount, such as automotive exhaust systems.

Conclusion

In conclusion, both austenitic vs ferritic steel offer unique advantages depending on the application requirements. 

Thank you for reading our article and we hope it can help you to have a better understanding of the differences between Austenitic vs Ferritic Steel. If you are looking for Austenitic & Ferritic Steel 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 offers customers high-quality 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.