What to Consider When Choosing Stainless Steel

As is well known, metals that resist rusting are called stainless steel. Stainless steels contain a variety of elements in their composition, and these elements give each stainless steel its particular properties. One of the most important of these elements is chromium. Stainless steels contain at least around 10% chromium. Chromium combines with oxygen to form an extremely thin, invisible layer on the surface of the steel, and this thin layer protects the elements within the steel from oxygen. This mechanism is what gives stainless steel its name. The higher the chromium content of a stainless steel, the greater its resistance to rust; in short, rust resistance depends entirely on chromium. Another element found in stainless steel is carbon, which gives the steel its hardness. Stainless steels contain roughly up to 1.2% carbon. Stainless steel takes on different properties depending on how it is produced. To put it simply, adding nickel to stainless steel creates one set of properties, while increasing the carbon content produces another. For this reason, stainless steels are divided into families.

• Austenitic stainless steels

• Ferritic stainless steels

• Martensitic stainless steels

• Duplex stainless steels

• Precipitation-hardening stainless steels

Stainless steel is divided into these five families. Their importance lies in the fact that their different structures suit them to different applications, which in turn means a broader range of uses for stainless steel. Because these stainless steels contain different elements in their composition, their microstructures also differ, and this is what allows stainless steel to be used in so many different fields.

The main points to consider when choosing stainless steel are as follows:

• Is the stainless steel resistant to corrosion?

• Does the stainless steel have the required mechanical strength?

• What are the physical properties of the stainless steel?

• Pay attention to the surface properties of the stainless steel.

• What is the operating temperature of the environment?

• What corrosive agents will it be exposed to?