Since it was invented a century ago, stainless steel has come to be a vitally important material, its anti-corrosive qualities making it perfect for use in a huge range of different environments and circumstances.
To the lay person, one piece of stainless steel may seem just like any other, but the truth of the matter is a little bit more complicated. The durability of stainless steel and the fact that it doesn’t have to be painted or coated in any way makes it the ideal material for use in places where cleanliness is a very high priority, such as hospitals or kitchens.
As stated previously, there is more than one type of stainless steel, with different grades being created via the addition of various other elements. These are selected to create slightly different alloys with particular properties such as heat resistance or workability, which make the steel more suitable for specific tasks.
This versatility is reflected in the fact that there are actually over 150 different grades of stainless steel, with fifteen of them being the ones most commonly used. Popular grades of steel include: 304 stainless steel and 316 stainless steel. On a more basic level, there are five types of stainless steel, which can be classified as follows:
Ferritic – These steels contain less than 0.10% carbon and are magnetic. The fact that they can’t be hardened via heat treatment and don’t weld to a high standard limits the use of these metals somewhat, but they are still suitable for a wide range of applications.
Austenitic – This is the most common type of stainless steel, accounting for up to 70% of all stainless steel production. Its versatility is in large part down to the fact that it can be formed and welded with successful results.
Martensitic – This type of steel shares some characteristics with ferritic, but boasts higher levels of carbon, up to a full 1%. This means that they can be tempered and hardened and are thus highly useful in situations where the strength of the steel is more important than its resistance to corrosion.
Duplex – Put simply, Duplex steels are a combination of ferritic and austenitic steels, a structure which renders duplex steel stronger than both.
Precipitation Hardening – With the addition of elements such as Aluminium, Copper and Niobium, these steels become extremely strong. They can be machined and worked into a wide variety of shapes without becoming distorted and, in terms of corrosion, have the same resistance levels as austenitic steels.