In Russia and the CIS, an alphanumeric system is adopted, numbers indicate the content of steel elements, and letters - the name of the elements. Letter designations are also used to indicate the method of deoxidation of steel; KP - boiling steel, PS - semi-calm steel, SP - calm steel. There are certain designation features for different groups of building steels, structural, stainless, tool steels, etc. Common designations for all are the letter designations of alloying elements: H - nickel, X - chromium, K - cobalt, M - molybdenum, B - tungsten, T - titanium, D - copper, G - manganese, C - silicon.
(GOST 380-94) denote the letters ST., for example ST. 3. The number after the letters conventionally indicates the percentage of carbon in steel. Structural unalloyed quality steels (GOST 1050-88) are designated by a two-digit number indicating the average carbon content in steel (for example, ST. 10). Quality steels For the production of boilers and pressure vessels, (GOST 5520-79), they are designated as structural unalloyed steels, but with the addition of the letter K (for example, 20K). Structural alloyed steels (GOST 4543-71), denoted by letters and numbers. The numbers after each letter indicate the approximate content of the corresponding element, however, if the content of the alloying element is less than 1.5%, the figure after the corresponding letter is not put. Qualitative additional indicators, the reduced content of impurities such as sulfur and phosphate are indicated by the letter - A or W, at the end of the designation, for example ( 12 X NZA, 18HG-Sh), etc. Cast structural steels (GOST 977-88), are designated as high-quality and alloyed, but at the end of the name they put the letter L. Construction steels (GOST 27772-88), denoted by the letter C and numbers corresponding to the minimum yield strength of steel. Additionally, the designations are used: T - heat-strengthened rolled products, K - increased corrosion resistance, (for example, C 345 T, C 390 K, etc.). Similarly, the letter D denotes an increased copper content. Bearing steels (GOST 801-78), are designated the same as alloyed, but with the letter Ш at the end of the name. It should be noted that for steels of electroslag remelting, the letter Ш is denoted by a dash (for example, ШХ 15, ШХ4 -Sh). Unalloyed tool steels (GOST 1435-90), are divided into quality, designated by the letter U and a number indicating the average carbon content (for example, U7, U8, U10) and high quality, designated by the additional letter A at the end of the name (for example, U8A) or an additional letter G, indicating an additional increase in the content of manganese (for example, U8GA). Alloyed tool steels (GOST 5950-73) are also designated as structural alloyed steels (for example, 4X2V5MF, etc.). High-speed steels They have the letter P in their designation (this is the starting point for the designation of steel), followed by a number indicating the average tungsten content, and then letters and numbers that determine the mass content of elements. The chromium content is not indicated, since it is stable about 4% in all high-speed steels and carbon, since the latter is always proportional to the vanadium content. It should be noted that if the vanadium content exceeds 2.5%, the letter F and the number are indicated (for example, steel R6M5 and R6 M5F3). Standard stainless steels (GOST 5632-72), marked with letters and numbers according to the principle adopted for structural alloy steels (for example, 08X18H10T or 16X18H12S4TUL). Non-standard stainless steels pilot batches denoted by letters - the indexes of the manufacturer's plant and serial numbers. EI, EP, EK - to the steels smelted at the Elektrostal plant, ChS - to the steels smelted at the Chelyabinsk plant Mechel, DI - to the steels smelted at the Dneprospetsstal plant. To indicate the method of smelting, finishing, the names of a number of steels are supplemented with letters (for example, 13X18N10-VI), which means vacuum induction smelting.
