Why do we need marking and most importantly - what does it mean? First of all, this is a kind of applied code that displays the properties of the goods. Each product has its own code. Any industry (chemical, automotive, heavy, light) requires labeling or barcodes.
Industrial marking (for example, marking of steels and alloys) helps to qualitatively carry out further work where this product subsequently appears. Suppose pipe marking allows builders to work with the water supply system correctly, which, in turn, will not lead to unexpected accidents and pipe breaks during loading.
Steel is marked with indelible paint. The classification and marking of steels is briefly presented below. So...
On steel, ordinary (of ordinary quality), the letters C and the number are applied. It looks like St3, St2, St1, St0. Qualitative (carbon) steels are marked with double-digit numbers, and the number indicates the percentage of carbon in percent (hundredths): 40, 25, 10, 08, etc., and the letter G in the marking indicates an increased content of manganese in steel (18G , 14G, etc.)
Machine guns are marked with the first letter of the Russian alphabet A (A30, A12, etc.). On the carbon steel tool steels put the letter U (U12, U10, U8, where the numbers indicate the content of steel in 10 parts of a percent).
Alloy steel grades contain letters indicating the components that make up a particular steel, characterizing their average content: nitrogen is designated as A, aluminum is U, vanadium is F, boron is P, manganese is G, cobalt is K, silicon is C, manganese - G, molybdenum - M, copper - D, nickel - H, selenium - B, carbon - U, titanium - T, chromium - X, phosphorus - P, zirconium - C.
The first figures indicate the content in the steel of a component called carbon, in hundredths are determined for structural steels and in tenths for stainless steels and tool steels. Then the letter designates the alloying element. The letter is followed by numbers indicating the average content of this element in units (integers). If the content of alloying elements is less than one and a half percent, the numbers after the corresponding letter are not put down. The presence of the letter A at the end indicates the high quality of the steel presented. The letter is a special difference in quality (especially high-quality steel).
Steel of ordinary quality: BSt0, VSt0, St0 (color red, or green); VSt1kp, St1 (yellow), Bst3, St3, VST3kp, Bst3kp, Bt3 (red), Bst4, St4, Bst4kp, Stt4, Bt4 (black), St5 and Bt5 (green) and finally St6 (blue )
High-quality carbon steel: 20, 15, 10, 08 (white); 40, 35, 30, 25 (white, yellow); 60, 55, 50, 45 (white, brown).
Structural alloyed steel: chromium (green, yellow); chrome vanadium (color green, black); chromomolybdenum (either green or purple); chromomanganese (black, blue); manganese (brown or blue); chromosilicon manganese (blue, red); chromium-aluminum (aluminum); chromonickel molybdenum (purple or black).
Corrosion-resistant steel: chromium-nickel (red or aluminum color); chrome chromium (aluminum, or black), chromotitan (yellow, or aluminum); chrome nickel-titanium (blue, aluminum); chrome-nickel-siliceous (green, aluminum); chromium-manganese-nickel (aluminum or brown), nickel-chromium-lithium (white, or aluminum) and chromium-nickel-molybdenum-titanium steel (purple, aluminum).
High-speed steel, designated as P18 (bronze or red) and P9 (bronze color).
Hard sintered alloys. The following steel markings are applied to such alloys: VK2 (white strip on black); BK3-M (orange strip on black), BK4 (orange color); VK6 (color blue); VK6-B (purple); VK6-M (white strip on blue); BK8 (red color); VK8-B (blue strip on red); BK15 (white); T30K4 (blue); T15K6 (color green).
Using such simple rules, it is quite easy to determine the composition and properties of steel. Labeling was developed back in the USSR, but it is still valid throughout the CIS and throughout Russia.