The system of marking of steels and alloys in Russia, produced in the world of steel and alloys have a fairly broad range. However, to date there is no unified system for marking of steels and alloys that could used throughout the world. In Russia and the CIS countries adopted early in the Soviet Union developed an alphanumeric designation system steels and alloys, where, according to state standards, conventionally denoted by letters of the names of elements and methods steel production, and the figures – the content elements. Letter symbols are also used to specify how the steel deoxidation 'KP – boiling steel, PS – poluspokoynaya steel joint venture – a quiet steel'. There are certain particularly refer to different groups of structural steel, construction, tool steel, stainless, etc. Common for all designations are the marks of alloying elements: N – Nickel, X – chrome, K – Co, M – molybdenum, V – Tungsten T – Titanium W – copper, T – manganese, N – silicon. Structural steel of ordinary quality undoped (GOST 380-94) denote the letters ST., For example ST.
3. Figure standing after the letters, conventionally denotes percentage of carbon steel. Construction unalloyed quality steels (GOST 1050-88) indicate double-digit, indicating the average carbon content in steel (for example, ST. 10). High-quality steel for production of boilers and pressure vessels in accordance with (GOST 5520-79) is referred to as structural non-alloy steel, but with the letter K (eg 20K). Structural alloyed steel according to GOST 4543-71, indicate letters and numbers.