The marking of alloy steels in Russia is a strict and detailed system that allows you to quickly and accurately determine the key characteristics of metallic materials. It includes letters and numbers that reflect key chemical elements and their quantitative values, as well as methods for producing alloys, which makes it easier to select them for specific tasks in various industries.
A unified labeling system is important for several reasons:
Thus, a unified labeling system is an important tool that contributes to the safe use of materials and more effective interaction between industrial market participants.
The metallurgical industry of the Russian Federation uses a special alphanumeric method of naming alloy steels. The marking reflects chemical composition, which determines the basic properties of materials. This helps specialists quickly determine the purpose of the alloy and its performance characteristics. This system includes several key rules and designations that are important to understand in order to navigate the classification of alloys and steels.
Each alloying element in the marking is indicated by a Cyrillic letter. It is important to know the key values for a correct understanding of the alloy grade (Table 1).
Table 1 — Alloying elements and their designations
In addition to nitrogen, the letter BUT, if it is at the end of the brand, indicates the high quality of the material — the minimum quantity harmful contaminants in its composition.
Marking structural steels starts by specifying the content carbon (C). The first two digits represent the percentage of C in hundredths of a percent. For example, steel 70 contains 0.70% carbon. This allows you to quickly assess the level of strength and hardness.
For tool steels the approach to labeling is slightly different. Here, the number in front of the letters indicates the carbon content in tenths of a percent. If the C count is 1% or more, this figure is omitted. Thus, it is possible to immediately distinguish tool steels from structural steels.
When the content of a certain alloying element in alloys exceeds 1%, the corresponding letter is followed by a figure denoting its percentage. If the percentage of the element is equal to or less than 1%, the number is not placed after the letter.
So in the brand 12X18N10 contains 0.12% carbon, 18% chromium and 10% nickel. If the amount of alloying element is minimal (for example, chromium is less than 1%), then it will be indicated only by the letter X without numbers after it. For example, 70S2HA contains 0.7% carbon, approximately 2% silicon and less than 1% chromium, the letter A at the end of the marking indicates the minimum amount of harmful impurities in the composition.
The average percentage of the main alloying elements in structural steels is presented in Table 2.
Table 2 — Main alloying elements of structural steels
In addition to chromium et nickel structural steels often include elements such as molybdenum, tungsten, vanadium et titanium. These additives improve the strength, resistance to wear and tear, as well as the thermal stability of the material. The use of complex alloying elements makes steel more suitable for use in extreme conditions, such as high temperatures or aggressive environments.
For some groups of materials, there are special designations that indicate their purpose and applications (Table 3).
Table 3 — Marking of special-purpose steels
Electrical steels have a more complex system of designations. For example, in steel grades 20895, 20880, 20860, 20832, 21895, 21880, 21860, 21832 and similar, each digit in the marking carries certain information:
This system allows you to accurately specify steel parameters for specific tasks, such as the production of transformers, electric motors and other electrical devices.
High-quality steels may have additional letters at the end of the marking, indicative of remelting methods that have improved the material's characteristics (Table 4).
Table 4 — Letters of remelting methods
These methods improve the purity of steel, increase its uniformity and performance characteristics, which is important when using materials under extreme conditions, for example, in aeronautical and space industries.
Some steel mills, such as the Elektrostal plant, are developing experimental alloys, which are referred to as EI (research electrostal) or EP (Elektrostal test). After the letter designation, the serial number of the new alloy is indicated. These brands are developed for specific purposes, and after successful testing and implementation, they receive generally accepted designations. For example, EI 814 was later transformed into 17HNGT — precision alloy for elastic elements, and EP 414 — in 12X18N9SMR — corrosion-resistant steel.
Let us consider the marking of some steels produced by the St. Petersburg Precision Alloy Plant:
Each brand has unique properties that are provided both by the chemical composition and by the methods of processing and smelting. PZPS releases high quality products with accurate marking, which ensures that materials meet all technical requirements and current GOST.
The plant's products are widely used in various industries due to their reliability, durability and compliance with international quality standards. For more information about the grades of alloys produced by PZPS, as well as to place an order, contact our experts. We are always ready to offer you high-quality products that meet your production requirements.
