Blog Post Austenitic vs Ferritic Stainless Steel: The Key Differences

Stainless steel is one of many different types of steel - but did you know there are also various different types of stainless steel? All stainless steel is made up of iron, carbon and chromium (with nickel sometimes added too). However, different types and grades of stainless steel contain different amounts of each of these elements.

The two most common types of stainless steel are austenitic and ferritic. Both are slightly different in their crystalline structure and composition, which gives them both different qualities. It’s worth comparing austenitic vs ferritic varieties of stainless steel to work out which has the most benefits for your proposed application. This guide helps to outline some of the main differences between the two types of stainless steel, as well as their individual uses.

What is Austenitic Stainless Steel?

Austenitic stainless steel is the most common type of stainless steel. It is used to manufacture various parts and tools in all kinds of industries including medical, automotive and aerospace sectors. Many steel washbasins and dishwashers are also made from this form of steel.

It uses a form of iron known as austenite, which is good at absorbing carbon. A large amount of nickel is often added to this metal, which helps to reduce corrosion. This high corrosion resistance is one of the metal’s most attractive qualities. 

It is often not possible to harden austenitic stainless steel through heat treatment. However, cold-rolling is an option, which can be used to harden this steel and improve its aesthetic appearance. 

What is Ferritic Stainless Steel?

Ferritic stainless steel is not as heavily used as austenitic stainless steel, but still has its uses. You are likely to find it in many automotive parts, water tanks and refrigeration cabinets. 

It uses a form of iron known as ferrite, which absorbs only a small amount of carbon. Unlike austenitic stainless steel, this metal contains little to no nickel, instead containing higher amounts of iron. This high iron content makes it magnetic.

Ferritic stainless steels are generally stronger than austenitic stainless steels, however they cannot be hardened as easily as austenitic stainless steel.

What is the Difference Between Austenitic and Ferritic Stainless Steel?

When comparing austenitic vs stainless steel, there are a few differences to consider. These are summarised in the table below:

Austenitic stainless steel Ferritic stainless steel
10.5 to 30% chromium 16 to 26% chromium
Up to 35% nickel Little to no nickel
Higher carbon, lower iron content Lower carbon, higher iron content
Non-magnetic Magnetic
Higher corrosion resistance Lower corrosion resistance
Can be strengthened through cold rolling Cannot be as easily strengthened, but naturally a little stronger

If you are looking for a metal with high corrosion resistance, you should choose austenitic stainless steel. For added hardness and magnetism, choose ferritic stainless steel.

It is important to use good quality grades so that you can truly benefit from the unique qualities of each metal. By using a reliable manufacturer, you can guarantee that this will be the case.

 

Leengate Metals offers premium steels in a range of grades and next-day delivery. Leengate Metals' call-off facility, in addition to their next-day delivery guarantee and guaranteed quality, can optimise your company's cash flow and reduce the cost of your inventory. For more information about our products and services please contact us.