What makes stainless steel?
Stainless steel is a term for a group of steels primarily used because they are resistant to corrosion. It's made of iron, chromium (in some cases), nickel, molybdenum or other metals. A metal alloy (a combination of two or more metallic components) must contain at minimum 10.5% Chromium to be called stainless steel. This composition prevents iron in stainless from rusting, and also provides heat resistance.
This is the "all that is needed" for stainless steel. However, a large number of metals fall into this category. The stainless steels have been divided up into five different groups or families:
- Austenitic
- Ferritic
- Duplex
- Martensitic
- Precipitation hardening steels
The austenitic family is the biggest of the five. This family comprises of two sub-groups, the 200 and 300 series - with the 300 series alone accounting for 49.7% of the stainless steel market in 2019.
You can view the entire list of our products here.
Austenitic Stainless Steels are used in many products because of their corrosion resistance. They also have good formability, strength, and resistance to temperature (the austenitic structure is maintained at any temperature). Many industries rely on austenitic stainless steels, such as pharmaceutical, food, petrochemicals, and others. This is due to the fact that they are resistant to contamination, have a high degree of cleanability, and last a long time. Despite being more expensive in the beginning, austenitic Stainless Steels have a long lifespan and are therefore less costly over their entire life cycle.
Ferritic stainless alloys are second in popularity after austenitic. They contain low levels or even no nickel, large amounts of chrome and low to low amounts of carbon. Ferritic Stainless Steels are classified under the 400 Series, and depending on their composition or application they can be further divided. Ferritic alloys have a body-centred, cubic grain structure. This is different to austenitic types, and causes them to be magnetic.
Duplex stainless is named "duplex", because it has a two-phase, ferritic/austenitic microstructure. Duplex stainless is around twice as hard as standard austenitic and ferritic steels. Its corrosion resistance ranges in the same range as that of austenitic and ferritic stainless.
The hardness, wear resistance and high strength of martensitic stainless are well known. These stainless-steels are also ferromagnetic. They can be hardened with heat treatment.
Precipitation steels are corrosion resistant alloys. In some cases, they can be heat-treated in order to increase their tensile strength to up to 3 or 4 times the strength of austenitic stainless materials such as grade 304. Heat treatments can be used to increase its hardness and strength, resulting in an extremely high strength/weight ratio.
Contact Us if you have any queries.
Your message must be between 20-3,000 characters!
