Austenitic, Ferritic or Martensitic?

Purchasing your first steel storage container is serious business, but how important is it for you to know whether your container is constructed from austenitic, ferritic or martensitic materials? In this blog, we consider the meaning of these descriptors and how they might apply to our containers so that you can make your purchase in full confidence.

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AUSTENITIC

This type of steel is a type of alloy, which means that it is mixed with other compounds to provide it with new and useful qualities that normal steel would not possess otherwise. Austenitic steels have austenite as their crystalline structure, which means that the steel has been alloyed with nickel or manganese and nitrogen. The effect of this on the properties of the steel is that the steel is no longer hardenable, but it is non-magnetic which can be very important for the transport of some objects.

Some austenitic steels will be alloyed with molybdenum to increase resistance to certain chemicals and corrosion. It may be important for you to know what the steel in your container is alloyed with depending on your use for the container.

FERRITIC

With high levels of chromium and low carbon contents, ferritic steels are known for being stainless as well as magnetic. These steels have a different atomic structure to austenitic which is part of what defines their qualities, they still possess some similarities with austenitic, however, as neither can be hardened or strengthened, but they can be cold worked.

Benefits of ferritic steels are that they are generally good for welding though some particular grades and alloys are liable to crack so caution should be exercised. Ferritic steels also tend to be less expensive than austenitic.

MARTENSITIC

These are a very particular brand of steel with 12% chromium and around 1.2% carbon. Unlike austenitic and ferritic, martensitic steels are hardenable, and when tempered it is often used for medical instruments. When martensitic steels are alloyed with nitrogen and nickel with lower carbon, they exhibit improved toughness, weldability and corrosion resistance.

DUPLEX

From mixing austenite and ferrite, these steels are a happy medium between two types, hence the name ‘duplex’. This allows duplex steels to enjoy qualities from both types, though often not to the same extent. For example, duplex steel may exhibit good corrosion resistance and low magnetism, but the corrosion resistance might not be as strong as a ferritic grade of steel.

PRECIPITATION HARDENABLE

Also referred to as PH stainless steel, these grades are often considered an in-between of martensitic and austenitic. They are known for being able to develop very high strength and hardness when subjected to the correct heat treatment, and are considered austenitic in an annealed state, but martensitic when hardened. Annealing is when the microstructure of the metal is altered, therefore changing mechanical, electrical or magnetic properties. Annealing is typically carried out in steels to increase ductility.

WEATHERING STEEL – OUR STEEL STORAGE CONTAINERS

Our steel containers in London are suitable for a range of day-to-day activities and can be altered to suit your particular needs. For example, we use a resistant paint on the exterior of your container (primer finish semi-gloss C5000) if your purchase involves the transport of goods across the sea, or to provide extra protection against the weather.

Most shipping containers are made from steels which have been designed with high weathering capabilities, meaning that they will withstand natural corrosion to provide users with a lasting and eco-friendly product. Our containers are manufactured from corten steel, so called for its cor-rosion resistance, and ten-sile strength.

Weathering steel is perfect for a shipping container because it will successfully protect the goods within by forming a protective layer of rust on the outer surface. This rust does not penetrate through to interior layers of the container and will act as a shell against further corrosion.

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If you have any more questions regarding how our containers are constructed, then please take a moment to review our specifications. Alternatively, you can contact us for more information or a quick quote.

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