How to read steel grades

When, when speaking about personal qualities of a person, they use the epithet "steel", mean an unbending character, a strong will or grip that can not be easily defeated. Steel was invented to make strong and reliable mechanisms, tools, weapons. Now without this metal can not do.

What is steel, and how does it differ from iron? The main difference in impurities, the main of which is carbon. In order to impart special properties to this metal, other components are added to the alloy.

The same brands have become different in different countries. Unfortunately, in so important a question to the common denominator have not yet arrived.

Throughout the former Soviet Union, with the exception of the exception of the Baltic countries, alphanumeric codes are used according to the GOSTs previously in force. This definition of the steel grade is very convenient and understandable, the figure means the percentage of impurity content, and the letter is a chemical element.

The brands have become simple, in which only iron and carbon are present, are called structural. They are simply denoted, Art. 2, for example. This means that the carbon in it is 0.2%.

Qualitative unalloyed steel has a similar coding, but the percentage of carbon is reflected by two digital signs, for example St.08.

If the metal is intended for the production of vessels that are to be operated under high pressure, then the requirements for it are special. As in the case of structural quality steel, the percentage is expressed in a two-digit number, but at the end the letter "K" is added (for example - St.12K).

Bole complex metallurgical compositions are divided into groups - instrumental, construction, stainless and so on. Each of them has its own peculiarities of marking, but the general meaning is the letter designation of alloying elements, such as nickel (H), chromium (X), copper (D), tungsten (B), manganese (G), molybdenum (M), silicon C), cobalt (K).

The method of deoxidation is also reflected in the coding of the steel grade. So, "quiet" is denoted by the letters of the joint venture, "half-quiet" - PS, and "boiling" - CP.

Alloyed steel grades have a longer designation, which includes both letters and numbers. It should be remembered that when the impurity content is less than one and a half percent, the figure is not set. So, code 10 X2 M-Sh will mean that the steel contains 0.1% of carbon, 0.2% of chromium and less than 1.5% of molybdenum. There is also the letter "Ш", it speaks about the lowered content of phosphate. If instead of it there was an "A", then it would concern sulfur. Such brands speak about additional qualitative characteristics.

The structural cast steel is indicated at the end by the letter "L".

For building structures, a metal with a low yield strength is required, it is reflected by the letter "C" standing in front. The letter behind it indicates additional properties (T is about thermal hardening, K is about corrosion resistance).

The definition of the steel grade suitable for the production of tools is made by the letter "Y", after which a two-digit figure of the carbon percentage, for example, V8, is put.

There are also stainless steels. Stamps, like 08H18N10T, look like a complex cipher, in fact, the same principle applies here as for alloyed structural alloys. This does not apply to special cases, when letters are awarded in honor of the factories that first melted metal with special properties.