The main alloy element in stainless steel is the element chrome. It has been found that at a chromium percentage> 10.5%, the alloy has a good resistance to atmospheric attack, for example. In addition, a number of other alloying elements are important. All of these alloying elements affect the structure of iron, which consists of ferrite at room temperature and at austenite at about 910° C. Alloy elements affect the height of the ferrite / austenite conversion temperature and are therefore subdivided into ferrite stabilizing elements such as chromium, molybdenum and titanium and the austenite stabilizing elements such as nickel, carbon, manganese and nitrogen. It will thus be clear that the structure of a steel grade, and therefore of stainless steel, is determined by the composition. The stainless steel grades are therefore generally classified based on the room temperature structure obtained by high-temperature quenching.

The following format is used:
Austenitic Stainless Steel
• Ferritic Stainless Steel
• Martensitic Stainless Steel
• Duplex Stainless Steel