Every engineer absolutely needs to know the classification and labeling of materials intended for the manufacture of machine parts and structures. Such materials include metals and their alloys, metal and cermet powders of plastics, rubber, glass, ceramics, wood and other non-metallic substances. At present, metals and their alloys are most widely used as structural materials, therefore, in this work we will consider only steels, cast irons and non-ferrous metals, and their alloys (copper, aluminum, titanium, magnesium and alloys based on them).

I Classification and marking of steels

Steels are called alloys of iron with carbon, the content of up to 2.14% of carbon. In addition, the composition of the alloy usually includes manganese, silicon, sulfur and phosphorus; some elements can be introduced specifically to improve the physicochemical properties (alloying elements).

Steel, classified by a variety of signs. We will consider the following:

1. The chemical composition.

Depending on the chemical composition, carbon steel (GOST 380-71, GOST 1050-75) and alloy steel (GOST 4543-71, GOST 5632-72, GOST 14959-79) are distinguished. In turn, carbon steels can be:

A) low-carbon, i.e. containing less than 0.25% carbon;

B) medium carbon   carbon content is 0.25-0.60%

B) high carbon   in which the carbon concentration exceeds 0.60% Alloy steels are divided into:

a) low-alloyed content of alloying elements up to 2.5%

b) medium-alloyed, they comprise from 2.5 to 10% of alloying elements;

c) highly alloyed ,   which contain over 10% alloying elements.

2. Appointment.

According to the purpose, there are:

1) structural   intended for the manufacture of construction and engineering products.

2) Instrumental   from which cutting, measuring, stamping and other tools are made. These steels contain more than 0.65% carbon.

3) With special physical properties,   for example, with certain magnetic characteristics or a small coefficient of linear expansion: electrical steel, superinvar.

4) With special chemical properties,   for example, stainless, heat-resistant or heat-resistant steels.

3. Quality.

Depending on the content of harmful impurities: sulfur and phosphorus steel are divided into:

1. Steel of ordinary quality, the content is up to 0.06% sulfur and up to 0.07% phosphorus.

2. Quality   - up to 0.035% sulfur and phosphorus each separately.

3. High quality   - up to 0.025% sulfur and phosphorus.

4. High quality   up to 0.025% phosphorus and up to 0.015% sulfur.

4. The degree of deoxidation.

By the degree of removal of oxygen from steel, i.e., by the degree of its deoxidation, there are:

1) calm steel, i.e., completely deoxidized; such steels are indicated by the letters “cn” at the end of the mark (sometimes letters are omitted);

2) boiling steel   - slightly deoxidized; marked with the letters "kp";

3) semi-quiet steels occupying an intermediate position between the two previous ones; denoted by the letters "ps".

Steel of ordinary quality is also subdivided by supply into 3 groups:

1) steel group A   supplied to consumers by mechanical properties (such steel may have a high content of sulfur or phosphorus);

2) steel groups B -   chemical composition;

3) steel group B   - with guaranteed mechanical properties and chemical composition.

Depending on the normalized indicators (tensile strength σ, elongation δ%, yield strength δt, bending in the cold state), the steel of each group is divided into categorieswhich are indicated in Arabic numerals.

Steel of ordinary quality   denoted by the letters "St" and the conventional number of the brand (from 0 to 6) depending on the chemical composition and mechanical properties. The higher the carbon content and strength properties of steel, the greater its number. The letter "G" after the brand number indicates an increased content of manganese in steel. The steel group is indicated in front of the brand, and group “A” is not indicated in the designation of the steel grade. To indicate the category of steel, the number at the end corresponding to the category is added to the brand designation; the first category is usually not indicated.

For example:

St1kp2 - carbon steel of ordinary quality, boiling, brand No. 1, of the second category, is supplied to consumers by mechanical properties (group A);

BCt5G - carbon steel of ordinary quality with a high manganese content, quiet, grade 5, the first category with guaranteed mechanical properties and chemical composition (group B);

Vst0 - carbon steel of ordinary quality, grade 0, group B, first category (steel grades St0 and Bst0 are not divided according to the degree of deoxidation).

Quality steel   marked as follows:

1) at the beginning of the grade indicate the carbon content by a figure corresponding to its average concentration;

a) in hundredths of a percent for steels containing up to 0.65% carbon;

05kp - high-quality carbon steel, boiling, contains 0.05% C;

60 - high-quality carbon steel, calm, contains 0.60% C;

b) in tenths of a percent for industrial steels, which are additionally supplied with the letter “U”:

U7 - carbon tool, high-quality steel containing 0.7% C, quiet (all tool steels are well deoxidized);

U12 - carbon instrumental, high-quality steel, calm contains 1.2% C;

2) the alloying elements that make up the steel are denoted in Russian letters:

A - nitrogen K - cobalt T - titanium B - niobium M - molybdenum F-vanadium

B - tungsten H - nickel X - chromium G - manganese

P - phosphorus C - zirconium D - copper P - boron Yu - aluminum

E - selenium C - silicon H - rare earth metals

If after the letter denoting the alloying element, there is a number, then it indicates the percentage of this element. If there is no number, then the steel contains 0.8-1.5% of the alloying element, with the exception of molybdenum and vanadium (the content of which in salts is usually up to 0.2-0.3%), as well as boron (in steel with the letter P must be at least 0.0010%).

14Г2 - low alloyed high-quality steel, quiet, contains approximately 14% carbon and up to 2.0% manganese.

03Х16Н15М3Б - high alloyed high-quality steel, calm contains 0.03% C, 16.0% Cr, 15.0% Ni, up to 3, 0% Mo, up to 1.0% Nb.

High-grade and extra-high-grade steels.

They mark it as well as high-quality ones, but put the letter A at the end of the grade of stainless steel (this letter in the middle of the mark indicates the presence of nitrogen specially introduced into the steel), and after the mark of special high quality - through the dash the letter "Ш".

For example:

U8A - high-quality carbon tool steel containing 0.8% carbon;

30KhGS-III is a particularly high-quality medium alloy steel containing 0.30% carbon and from 0.8 to 1.5% chromium, manganese and silicon each.

Separate groups of steels indicate slightly different.

Ball Bearing Steel   marked with the letters "SH", after which indicate the chromium content in tenths of a percent:

ШХ6 - ball-bearing steel containing 0.6% chromium;

SHH15GS - ball-bearing steel containing 1.5% chromium and from 0.8 to 1.5% manganese and silicon.

High speed steels   (complexly alloyed) is denoted by the letter "P", the next figure indicates the percentage of tungsten in it:

P18 high-speed steel containing 18.0% tungsten;

P6M5K5 is a high-speed steel containing 6.0% tungsten 5.0% molybdenum 5.0% cobolt.

Automatic steel denoted by the letter "A" and a number indicating the average carbon content in hundredths of a percent:

A12 - automatic steel containing 0.12% carbon (all automatic steel have a high content of sulfur and phosphorus);

A40G is an automatic steel with 0.40% carbon and a manganese content increased to 1.5%.

II Classification and labeling of cast irons.

Iron alloys are called iron-carbon alloys containing more than 2.14% carbon. They contain the same impurities as steel, but in larger quantities. Depending on the state of carbon in cast iron, distinguish:

White cast iron   in which all carbon is in a bound state in the form of carbide, and cast iron, in which carbon is largely or completely in a free state in the form of graphite, which determines the strength properties of the alloy, cast irons are divided into:

1) gray   - lamellar or worm-shaped graphite;

2) high strength   - spherical graphite;

3) malleable   - flocculent graphite. Cast iron is marked with two letters and two numbers,

corresponding to the minimum value of the temporary resistance δv in tension in MPa-10 .   Gray cast iron is designated with the letters “SCh” (GOST 1412-85), high-strength - “HF” (GOST 7293-85), malleable - “KCh” (GOST 1215-85).

SCh10 - gray cast iron with a tensile strength of 100 MPa;

VCh70 - ductile iron with temporary sigma tensile 700 MPa;

KCh35 is malleable cast iron with a δv tensile of approximately 350 MPa.

To work in friction units with lubrication, castings from antifriction cast iron АЧС-1, АЧС-6, АЧВ-2, АЧК-2, etc. are used, which is deciphered as follows: АЧ - antifriction cast iron:

C - gray, B - high strength, K - malleable. And the numbers indicate the serial number of the alloy according to GOST 1585-79.

III classification and marking of non-ferrous alloys.

1. Copper and its alloys.

Technically pure copper has high ductility and corrosion resistance, low electrical resistivity and high thermal conductivity. By purity, copper is divided into grades (GOST 859-78):

After the brand designation, the method of making copper is indicated: k - cathode, b - oxygen demon, p - deoxidized. Fire refining copper is not indicated.

MOOc is a technically pure cathode copper containing at least 99.99% copper and silver.

MZ - technically pure fire refining copper, contains at least 99.5% copper and silver.

Copper alloys are divided into bronzes and brass. Bronzes are alloys of copper with tin (4 - 33% Sn even without tin bronze), lead (up to 30% Pb), aluminum (5-11% AL), silicon (4-5% Si), antimony and phosphorus (GOST 493-79, GOST 613 -79, GOST 5017-74, GOST 18175-78).

Brass   - alloys of copper with zinc (up to 50% Zn) and small additives of aluminum, silicon, lead, nickel, manganese (GOST 15527-70, GOST 17711-80). Copper alloys are intended for the manufacture of parts by casting methods, called foundries   and alloys intended for the manufacture of parts by plastic deformation - alloysprocessed by pressure.

Copper alloys indicate the initial letters of their names (Br or L), followed by the first letters of the names of the main elements that make up the alloy, and numbers indicating the number of elements in percent. The following designations of alloy components are accepted:

A - aluminum Mts - manganese C - lead B - beryllium

Mg - magnesium Ср - silver Ж - iron Мш - arsenic

Su - antimony K - silicon N - nickel T - titanium

Cd - cadmium O - tin F - phosphorus X - chrome

BrA9Mts2L - bronze containing 9% aluminum, 2% Mn, the rest Cu ("L" "indicates that the alloy is foundry);

LC40Mts3Zh - brass containing 40% Zn, 3% Mn, ~ l% Fe, the rest is Cu;

Br0F8.0-0.3 - bronze along with copper containing 8% tin and 0.3% phosphorus;

LAMsh77-2-0-0.05 - brass containing 77% Cu, 2% Al, 0.055 arsenic, the rest is Zn (in the designation of brass for pressure treatment, the first number indicates the copper content).

In simple brass in composition, only the content in the alloy of copper is indicated:

L96 - brass containing 96% Cu and ~ 4% Zn (tompak);

Lb3 - brass containing 63% Cu and -37% Zn.

2. Aluminum and its alloys.

Aluminum is a light metal with high thermal and electrical conductivity and corrosion resistance. Depending on the degree of frequency, primary aluminum according to GOST 11069-74 can be of special (A999), high (A995, A95) and technical purity (A85, A7E, AO, etc.). Aluminum is marked with the letter A and numbers indicating percent fractions in excess of 99.0% Al; the letter "E" means high iron and low silicon.

A999 - high purity aluminum, which contains not less than 99.999% Al;

A5 - aluminum of technical purity in which 99.5% aluminum. Aluminum alloys are divided into wrought and cast. Those and others can be not hardened and hardened by heat treatment.

Deformable aluminum alloys are well processed by rolling, forging, stamping. Their brands are given in GOST4784-74. Deformable aluminum alloys not hardened by heat treatment include alloys of the Al-Mn and AL-Mg systems: Amts; AmtsS; Amg1; AMg4.5; Amg 6. The abbreviation includes the initial letters that make up the alloy of the components and numbers indicating the percentage of the alloying element. Deformable aluminum alloys hardened by heat treatment include alloys of the Al-Cu-Mg system with the addition of certain elements (duraloons, forging alloys), as well as high-strength and heat-resistant alloys of complex chemical composition. Duralumin is marked with the letter “D” and a serial number, for example: D1, D12, D18, AK4, AK8.

Pure wrought aluminum is indicated by the letters “HELL” and the symbol of its purity: ADoch (\u003e \u003d 99.98% Al), AD000 (\u003e \u003d 99.80% Al), AD0 (99.5% Al), AD1 (99, 30% Al), blood pressure (\u003e \u003d 98.80% Al).

Cast aluminum alloys (GOST 2685-75) have good fluidity, have relatively little shrinkage and are mainly intended for shaped casting. These alloys are marked with the letters “AL” followed by the serial number: AL2, AL9, AL13, AL22, ALZO.

Sometimes marked by composition: AK7M2; AK21M2.5H2.5; AK4MTS6. In this case, “M” means copper. “K” is silicon, “C” is zinc, “H” is nickel; digit - average% element content.

Bearings and liners are manufactured from aluminum antifriction alloys (GOST 14113-78) both by casting and by pressure treatment. Such alloys are marked with the letter “A” and the initial letters of the elements included in them: A09-2, A06-1, AN-2.5, ASMT. The first two alloys include the indicated amount of tin and copper (the first digit is tin, the second is copper in%), the third is 2.7-3.3% Ni and the fourth copper is antimony and tellurium.

3. Titanium and its alloys.

Titanium is a low-melting refractory metal. The specific strength of titanium is higher than that of many alloyed structural steels; therefore, when replacing steels with titanium alloys, it is possible, with equal strength, to reduce the mass of the part by 40%. Titanium is well processed by pressure, welded, complex castings can be made from it, but cutting is difficult. To obtain alloys with improved properties, it is alloyed with aluminum, chromium, and molybdenum. Titanium and its alloys are marked with the letters "BT" and the serial number:

VT1-00, VTZ-1, VT4, VT8, VT14.

Five titanium alloys are designated differently:

0T4-0, 0T4, 0T4-1, PT-7M, PT-3V.

4. Magnesium and its alloys.

Among industrial metals, magnesium has the lowest density (1700 kg / m3). Magnesium and its alloys are unstable against corrosion, with increasing temperature, magnesium is intensively oxidized and even self-ignites. It has low strength and ductility, therefore, pure magnesium is not used as a structural material. To increase the chemical-mechanical properties, aluminum, zinc, manganese and other alloying additives are introduced into magnesium alloys.

Magnesium alloys are divided into wrought (GOST 14957-76) and foundries   (GOST 2856-79). The first are marked with the letters "MA", the second "ML". After the letters indicate the serial number of the alloy in the relevant GOST.

For example:

MA1-deformable magnesium alloy No. 1;

ML19 casting magnesium alloy No. 19

The following are individual assignments for decoding grades of structural materials.

BRANDS OF DESIGN MATERIALS.
	BSt3kp, 08Kh20N14S2, R9, SCh25, M006, Amch3, VT1-00, MLZ
	11X11N2V2MF, ShH30, U11, VCh45, BrA9Mts2L, AL19, VT1-0, ML4
	25HGS A, R6M5F2K8, 50, KCh50, BrA7Mts15ZhZN2TS2, A6, OT4-0, MA1
	45HNZMFA, ShH9, 20ps, AChS-4, Br04Ts7S5, AD0E, OT4-1, MA2
	10X17H13M2T, A20, St6, AChK-1, BrOF4-0, 25; ALZZ, OT-4, ML19
	St5Gpsz, 25X13H2, 15kp, AVCH-1, LS63-2, Amts, VT5, ML15
	16X11N2VMF, A40G, ShH15, SCh10, LA77-2, D16, VT9, MA18
	45X22N4MZ, U 13, VSt2ps2, VCh1SO, M2r, AL25, VT14, MA15
	31Х19Н9МВБТ, Р9, 45, КЧ45, BrSuZNZTsZS20F, A8, VT16, ML5
	12X18H9T, ShH15GS, A20, AChS-5, LTS40MtsZA, AL21, VT20, MA17
	VSt3ps, 20X, R12, AChV-2, LZhMts59-1-1, AK4M4, VT22, ML6
	15X60YU, R6M5, U13A, AChK-2, LS59-1, D12, PT-7M, ML10
	38Kh2MYuA, VSt4ps2, 50G, AChS-3, L68, A5E, PT-ZV, MA-12
	36Х18Н25С2, А30, ВСт2кбп, КЧ60, БРЖЖЮ-4-4, АЛ2, ВТ9, МА11
	40KhMFA, ROMZF2, AZ0, VCh80, BrA7Mts15ZhZN2TS2, AK9, VT5, ML8
	St0, 30X13, R6M5F2K8, Sch15, BrA9Zh4N4Mts1, Amg6, VT1-0, MA21
	09Х16Н4Б, ВСт3Г, ШХ6, СЧ18, ЛЦ23АбЖЗМц2, D16, VT16, ML19
	45KHNZMF-Sh, U11, All, VCh70, LAMsh77-2-0.05, AL23, VT5.MA18
	14G2AF, ROM2FZ, VSt5sp, SCh24, Br0Fb, 5-0, 15; D18, VT1-00, MA19
	15X7H2T-Sh, R6M5F2K8, ShH9, KCh63, LK80-3, AK4M4.VT22, ML8
	VSt1, 50HG, ROMZF2, AChS-6, BrKMtsZ-1, AK7, VT20, ML12
	08X18T1, U10A, 30ps, VCh40, Br06Ts6SZ, AL9, PT-3V, MA2

Processed materials

At present, it is no secret that machine-building enterprises produce various products from various materials, steels and alloys.

Materials, in turn, are divided into structural and instrumental.

Construction materials

Metal   - These include alloys based on iron, copper, nickel, aluminum, magnesium, titanium and other metals.

Not metal - These include various plastics, ceramics, glass, rubber and other materials.

Compositional   - heterogeneous materials are combined in these materials, and the properties of the fillers are fundamentally different from the composite material.

In engineering, pure metals are rarely used, mainly metal alloys are of great use. For this purpose, the conventions for the brands of engineering materials have been created, they include symbols, and it is possible to determine or decipher alloy grades from them.

Symbols of metal elements in alloys

Element	Black alloys	Non-ferrous alloys
Aluminum	YU	BUT
Barium	-	Br
Beryllium	L	-
Boron	R	-
Vanadium	F	You
Tungsten	AT	-
Galiy	Gee	-
Germanium	-	G
Europium	-	Ev
Iron	-	F
Gold	-	Ying
Iridium	-	AND
Cadmium	Cd	Cd
Cobalt	TO	TO
Silicon	FROM	Cr (C)
Lithium	-	Le
Magnesium	W	Mg
Manganese	G	Mts (Mr)
Copper	D	M
Molybdenum	M	-
Nickel	N	N
Niobium	B	Np
Tin	-	ABOUT
Osmium	-	Os
Palladium	-	PD
Platinum	-	Pl
Rhenium	-	Re
Rhodium	-	Rg
Mercury	-	R
Ruthenium	-	RU
Lead	-	FROM
Silver	-	Wed
Scandium	-	Skm
Antimony	-	Soo
Thallium	-	T
Tantalum	-	TT
Titanium	T	TPD
Carbon	At	-
Phosphorus	P	F
Chromium	X	X (XP)
Cerium	-	Xie
Zinc	-	Ts
Zirconium	Ts	CEV
Erbium	-	Erm
Bismuth	In and	In and

Cast iron   - This is an alloy of iron, carbon, as well as additives of silicon, manganese and other substances, with a carbon content of 2.14 ... 4.5%. There are several types of cast iron: gray cast iron is marked MF, and malleable cast iron MF.

Steel   Is an alloy of iron and carbon, with a carbon content of up to 2%.

Decoding of the grade of alloys

Based on the table, you can decipher the alloy grade, for example:

Take the most common stainless steel:

12X18H10T
  Carbon up to 1%
  Chrome 18%
  Nickel 10%
  Titanium up to 1%
  The rest is iron

The first figures (they may not be) show the percentage of carbon, do not forget the carbon in the alloys to 1%, that is, if the figure is 09 or 12, this means that carbon is up to 1% in hundredths of a percent of 0.09 and 0.12. The numbers following the letters indicate the percentage of additives, if the number is not worth it, then the% content is 1%. Let's try to decipher the aluminum alloy:

AMG6
  Carbon up to 1%
  Aluminum 1%
  Molybdenum 1%
  Manganese 6%
  The rest is iron.

Symbols of grades of materials

Ductile iron (gray cast iron) GOST 1412-85: It is indicated by the letters MF and numbers that indicate the tensile strength (MF20).

Nodular cast iron (ductile iron) GOST 7293-85: Indicated by the letters HF and numbers indicating the tensile strength (HF 45).

Ductile iron GOST 1215-79 **: Designated by the letters KCH. The first number indicates the ultimate tensile strength, the second number the relative elongation in percent (CN 30-6).

Alloy cast iron with special properties   heat resistance, wear resistance, heat resistant GOST 7769-82 **: It is indicated by the letter H, the following letters indicate the presence of alloying elements, and the numbers following them indicate the corresponding content of these elements in percent. The last letter Ш indicates that spheroidal graphite iron (ЧС5Ш).

Carbon steel of ordinary quality   GOST 380-94: It is indicated by the letters St and numbers from 0 to 6. The higher the number, the greater the carbon content and tensile strength (St1, St2 ... St6). The degree of deoxidation of steel is indicated by letters after the numbers, for example: kn - boiling, ps - semi-calm, SP - calm.

Carbon steel quality structural   GOST 1050-88 **: It is indicated by two numbers: 05, 08, 10, 11, 15, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60 showing the average carbon content in hundredths of a percent. The letters ps and kn after numbers indicate semi-calm and boiling steel.

  Low alloy structural steel   GOST 19281-89 **: the first two digits indicate the carbon content in hundredths.

Alloy Structural Steel   GOST 4543-71 *: the letters after the numbers indicate the presence of alloying elements in percent (35G2, 20N2M). If the content of alloying elements is less than 1.5%, then the figure is not set (50XA, 15XM). The letters A, W at the end of the designation indicate that the steel is high quality (15XA, 20XH3A) and especially high quality.

Carbon Tool Steel   GOST 1435-90: indicated by the letter U and numbers that mean the carbon content in tenths of a percent (U7, U8, U10). The letter A after the number means that the steel is high quality (U8A).

Alloy Tool Steel   GOST 5950-73 *: the first digits indicate the carbon content in tenths of a percent, if it is more than 0.1% (9X1, 9XC). The numbers after the letters indicate the alloying element and its content in percent (X12, 8X3).

Bearing steel   GOST 801-78 *: is indicated by the letters ШХ and numbers showing the chromium content in tenths of a percent, and the letters after the numbers indicate the presence of alloying elements (ШХ15СГ).

Aluminum alloys
  Foundry GOST 2685-75: are indicated by the letters AL, after which the alloy number (AL2) is indicated.
  Deformable GOST 4784-74 *: indicated by the letters D, AK, AN, VD, B after which the alloy number (D16) is indicated.

Magnesium alloys
  Foundry GOST 2856-79 *: indicated by the letters Ml, after which the alloy number (Ml5) is indicated.
  Deformable GOST 14957-76 *: denoted by the letters MA, after which indicate the alloy number.

Brass
  Processed by pressure GOST 15527-70 *, Foundry GOST 17711-80: denoted by the letter L. The subsequent letters indicate alloying elements. The first number indicates the percentage of copper, the rest correspond to the sequence of letters the percentage of alloying elements in percent (LMtsS58-2-2).

Foundry bronzes
  Tinless GOST 493-79, pewter GOST 613-79: indicated by the letters Br, subsequent letters indicate alloying elements, and numbers indicate their percentage (BrO4-4).

The classification and marking of steels is carried out according to their most diverse attributes. First of all, they differ in chemical composition and are divided into carbon or doped depending on it. The former, based on the percentage of carbon in them, can be low-, medium- and high-carbon and contain, respectively, up to 0.25, 0.25-0.6 and more than 0.6 percent of this chemical element. The second are classified according to the percentage of alloying components in them. If they are present in quantities, respectively, from 2.5, 2.5-10.0 and more than 10.0 percent, such steels can be low-, medium- and highly alloyed.

How to decrypt a steel grade?

The marking of steels according to GOST largely depends on their purpose. On this basis, structural steels suitable for construction purposes and the production of parts in the engineering industry are distinguished from them. Tool steels are specially marked for the manufacture of all kinds of tools, punching, measuring, cutting, and others. In a separate category, steels are allocated that are endowed with certain physical properties, such as a special coefficient of linear expansion or special magnetic and electrical parameters. Corrosion-resistant, heat-resistant and heat-resistant steels are combined into a group of steels with special chemical properties.

When marking steels, attention is paid to their quality, which is determined by the percentage of harmful impurities such as sulfur and phosphorus. In the composition of steel of ordinary quality, they are present in amounts of 0.06 and 0.07 percent, respectively. As their content decreases, they can be high-quality, high- and extra-high-quality.

For the correct decoding of the marking of steels, the degree of their deoxidation is important, that is, the indicator of oxygen removal from them. Proceeding from this sign, they become calm (completely deoxidized), they are marked with the letters "SP" affixed after the mark. The designation "KP" indicates that the steel is boiling (slightly deoxidized). And the letters “PS” are used to indicate steel that is deoxidized between calm and boiling steels by its indicators.

On the Russian metal products market, alphanumeric marking of steels and alloys is accepted. In this notation, letters are used to indicate the name of a chemical element that is contained in steel, and a number indicates its quantity. The letters also indicate the degree of deoxidation.

Index St marks steel of ordinary quality. After it follows a number - a conditional number (0-6), denoting the brand. The higher this number, the higher the strength characteristics of steel and the more carbon it contains. This is followed by an indication of the degree of deoxidation. These designations are preceded by the index of the group of steels: A, B or C, and for steel of group A the index is usually not set. The letter “A” means that the steel has guaranteed mechanical properties, “B” - chemical composition, “C” - has both. An example of marking carbon steel of ordinary quality, grade No. 2, boiling, supplied with guaranteed mechanical properties: BSt2KP.

When designating carbon-quality structural steels, the marking at the beginning should contain a two-digit number in the number of hundredths of a percentage of carbon, and at the end indicate the degree of deoxidation. An example of such a designation: 08KP. For high-quality tool carbon steels, marking begins with the letter “U”. After it comes a two-digit number, meaning the carbon concentration in tenths of a percent. An example of such marking is U8 steel. If the designation of steels contains the letter “A” at the end, then they are of high quality.

In the marking of alloy steels, their alloying components are indicated by specific letters. So, “X” stands for chromium, “B” stands for tungsten, the presence of titanium is indicated by the letter “T”, molybdenum - “M”, aluminum - “Yu”. The presence of a figure after the letter designation of the alloying component indicates its percentage in steel. The absence of such a figure means that this steel is 0.8-1.5 percent consists of the specified alloying element. When designating alloy structural steels, the marking at the beginning contains an indication of the carbon content in hundredths of a percentage. For tool alloy steels, the carbon content labeling is indicated only in cases when it exceeds 1.5%, its lower concentration is not subject to indication.

Separate steel groups have special markings. For example, ball bearing is indicated by the letters "SH." After them, the presence of chromium is indicated in tenths of a percentage. So, ball-bearing steel with a 1.5% chromium content, 0.8-1.5% - manganese with silicon is indicated by the marking: ШХ15ГС. The designation of complex alloyed (high-speed) steel marking contains the letter "P". The figure following it indicates the percentage of tungsten in the steel. And, for example, the marking P6M5K5 indicates the content in high speed steel, in addition to 6% tungsten, also 5% cobalt with molybdenum. The letter "A" with the number mark machine gun steel, for example, A12. The number in this case indicates the content of 0.12% carbon. All automatic steels are characterized by a rather high content of phosphorus and sulfur, and the designation A40G, for example, also indicates an increased content of manganese (about 1.5%).

To indicate stainless steels, the marking of their standard types is carried out in letters with numbers in the same way as in structural alloy steels. A non-standard stainless steel, along with other prototype steels, is usually marked with letter indices of manufacturers that first smelted this steel, with a serial number. For example, the letters "emergency" in the marking mean the Chelyabinsk plant "Mechel", "DI" - Dneprospetsstal, "EP" - Elektrostal. The designation of some steels may be supplemented by a letter index indicating the smelting method, for example, “VI”, that is, vacuum-induction.

When storing metal, additional color marking of steels is provided. It is applied to the ends of sheets or profiles together with the mark and the number of the act of acceptance. Certain brands have their own color, and next to the steel color designation is a number indicating its category. In order to make such marking conveniently readable, a step-by-step installation of metal rolling is provided in the warehouse.

The classification of steels is based on their chemical composition, structure, purpose, processability, quality. The chemical composition of the steel is divided into carbon and alloy. Classification by structure - hypereutectoid, eutectoid, hypereutectoid, ferritic-pearlitic, austenitic, martensitic. By appointment - structural, machine-building and instrumental.

Carbon steel.

  According to their composition, carbon steels are divided into three groups depending on the carbon content:

1) low carbon- with a carbon content of up to 0.3%;

2) medium carbon- up to 0.7% carbon;

3) high carbon- more than 0.7% carbon.

The quality of steel is classified into ordinary, high-qualityand high qualitydepending on the content of impurities.

If the sulfur content is in the range of 0.04-0.06%, and phosphorus is from 0.04 to 0.08%, then steel is attributed to ordinary quality and are marked with the letters St. If the content of sulfur and phosphorus is less and is in the range of 0.03-0.04%, then such steels are referred to high quality.High-quality carbon structural steels are marked with two numbers that indicate the oxygen content in hundredths of a percent.

When the content of impurities in the range, as a rule, is less than 0.03%, it is believed that the steels possess high quality.   To indicate their high quality use the letter BUTwhen marking carbon and most alloy steels, it is placed at the end of the brand designation. By the quality of steel is understood a set of properties depending on the method of its production . Depending on the requirements for the composition and properties of steel, carbon steels are divided into a number of groups.

Steel of ordinary quality is supplied to consumers in accordance with GOST 380–71 and it is divided into three groups: group A - includes steels with guaranteed mechanical properties (the supplied steel is not subjected to heat treatment); to the group B- steel of guaranteed composition (they are subjected to hot processing by the consumer); to the group AT- steel with guaranteed compositions and mechanical properties (for welded structures).

For steel steels BUT(St1 - St6) requirements for mechanical properties vary in a certain interval (σ 0.2 from 200 to 300 MPa; σ B - from 310-410 to 500-600 MPa, and δ from 22 to 14%, respectively). The strength of steel is the higher, and the ductility of steel is the lower, the higher the number of its subgroup. So steel St6 is stronger than steel StZ. Similar numbers are indicated for the steels of the group. B   and AT   (e.g. BStZ). But the letter BUT they do not indicate ordinary quality in the marking of steel, since it is used for marking the so-called automatic steels processed on automatic machine tools.

By the nature of deoxidation, steel is divided into calm, half calm and seething.Calm steels are deoxidized with manganese, silicon and aluminum. They contain little oxygen and harden without gas evolution (quietly). Boiling steels are deoxidized only with manganese, the oxygen content in them is increased. Interacting with carbon, oxygen forms CO bubbles, which, when released during crystallization, give the impression of boiling. Semi-calm steels are deoxidized with manganese and silicon, in their behavior they occupy an intermediate position between boiling and calm.

To facilitate understanding of the rules for marking carbon steels, we give specific examples. Steel grade VSt3ps   means that this structural carbon steel of ordinary quality, of the third category, supplied by chemical composition and properties, is semi-quiet. Marking is 08kp   means that it is a high-quality structural carbon steel containing 0.08% C, boiling. Mark 40A, means that the steel contains about 0.40% C and belongs to high quality steels.

Carbon Tool Steelscontain 0.7 - 2.3% carbon. They are marked with a letter At   and a figure showing the carbon content in tenths of a percent (U7, U8, U9, .... U13). Letter BUT   at the end of the brand shows that the steel is high quality (U7A, U8A, ... .U13A). The hardness of high-quality and high-quality steels is the same, but high-quality steels are less fragile, better withstand shock loads, give less hardening during hardening. High-quality steel is smelted in electric furnaces, and high-quality \u003d marten and oxygen converters.

Preliminary heat treatment of carbon tool steels - annealing on granular perlite, final - quenching in water or salt solution and low tempering. After that, the steel structure is martensite with inclusions of granular cementite. Hardness after heat treatment, depending on the brand, lies in the range of HRC 56-64.

Carbon tool steels are characterized by low heat resistance (up to 200 ° C) and low hardenability (up to 10-12 mm). However, a viscous, non-hardened core increases the stability of the tool against breakage during vibration and shock. In addition, these steels are cheap enough and, when not hardened, they themselves are well processed.

Fields of application of tool carbon steels of various grades.

Steel U7, U7A - for tools and products subjected to shocks and impacts and requiring high viscosity with moderate hardness (chisels, metalwork and blacksmith hammers, dies, stamps, scale rulers, wood tools, centers of lathes, etc. )

Steel U8, U8A - for tools and products requiring increased hardness and sufficient viscosity (chisels, center punches, dies, punches, metal scissors, screwdrivers, carpentry tools, medium hard drills).

Steel U9, U9A - for tools that require high hardness in the presence of a certain viscosity (punch, stamps, chisels for stone and carpentry tools).

Steel U10, U10A - for tools that are not subject to strong shocks and impacts, requiring high hardness with low viscosity (planing tools, milling cutters, taps, reamers, dies, stone drills, hacksaw blades, chisels for notching files, drawing rings, calibers files, combs).

Steel U11, UNA, U12, U12A - for tools requiring high hardness (files, mills, drills, razors, dies, clock tools, surgical instruments, metal saws, taps).

Steel U13, U1 ZA - for tools that must have extremely high hardness (razors, scrapers, drawing tools, drills, chisels for cutting files).

Steel U8 - U12 are also used for measuring tools.

When marking alloy steels, the letters of the Russian alphabet are used to indicate an alloying element:

A - nitrogen P - phosphorus B - niobium P - boron B - tungsten T - titanium G - manganese U - carbon D - copper F - vanadium E - selenium X - chromium K - cobalt C - zirconium M - molybdenum U - aluminum.

The numbers on the left side of the letters indicate the average carbon content: if two digits, then in hundredths of a percent, if one, then in tenths. If the figure is missing, this means that the carbon content in the steel is about 1%.

The numbers after the letters (right) indicate the content of the alloying element, expressed in whole percent. If the content of the alloying element is 1-1.5% or less, then the number after the letter is not put. For example, 60C2 contains 0.6% C and 2.0% silicon, 7X3 contains 0.7% C and 3% chromium.

Letter "A" at the end   brand designations - stainless steel. Example All tool alloyed and with special properties are always high quality, and the letter BUT   they are not labeled. "W" at the end   - especially high-quality steel, 30HGSA-Sh.

Letter "BUT",   denoting nitrogen doping, always stands in the middle of the marking. 16G2AF - 0.015 - 0.025% nitrogen.

In the marking of steels in the beginning sometimes put letters indicating their use:

A - automatic steel (A20 contains 0.15-0.20% C);

AS - automatic alloyed with lead (AC35G2 contains 0.35% C, 2% manganese and lead less than 1%);

P - high-speed steels (P18 contains 17.5-19% of tungsten);

Ш - ball-bearing steels (ШХ15 contains 1.3-1.65% chromium);

E - electrical steel (E11 contains 0.8-1.8% silicon).

Non-standard steels are often marked conditionally. For example, steel smelted at the Elektrostal plant is denoted by the letter Eput next letter AND   - research or P   - trial. After the letter put the serial number (EI69 or EI868, EP590). Steels smelted at the Zlatoust Metallurgical Plant indicate ZIat the Dneprospetsstal plant - CI.

Engineering cemented and nitrided steels.

Cementation (nitriding) is widely used for hardening medium-sized gears, motor transmission shafts, high-speed machine tool shafts, spindles, etc. Low-carbon (0.15 -, 25% C) steels are usually used for parts. The content of alloying elements in these steels should not be too high, but should provide the required hardenability of the surface layer and core.

After cementation, hardening and low tempering, the cemented layer should have a hardness of 58-62 НРС, and a core of 30-42 НРС. The core must have high mechanical properties, especially a high yield strength, must be hereditarily fine-grained. To grind grain size, cemented steels are microalloyed with vanadium, titanium, niobium, zirconium, aluminum and nitrogen, forming finely dispersed nitrides and carbonitrides, or carbides that inhibit austenite grain growth.

Cemented steels - 20Х, 18ХГТ, 20ХГР, 25ХГМ, 12ХН3А, etc.

Machine-Building Improved Steelscalled improved because they are subjected to heat treatment, which consists in hardening and tempering at high temperatures - improve. These are medium carbon steels (0.3-0.5% C). They should have high strength, ductility, high endurance, low sensitivity to temper brittleness, should be well calcined. Used for the manufacture of crankshafts, shafts, axles, rods, connecting rods, critical parts of turbines and compressor machines.

Stamps - 35, 45, 40X, 45X, 40XP, 40XH, 40XH2MA, etc.

Spring steel -   grades 70, 65G, 60С2, 50ХГ, 50ХФА, 65С2Н2А, 70С2ХА and others. These steels belong to the class of structural.

These steels must have special properties in connection with the operating conditions of the springs and springs, which serve to mitigate shock and shock. The main requirement is a high elasticity and endurance limit. These conditions are met by carbon steels and steels alloyed with elements that increase the elastic limit (silicon, manganese, chromium, vanadium and tungsten). A feature of the heat treatment of spring sheets and springs is the tempering after tempering at a temperature of 400-500 0 C. This treatment allows you to get the highest elastic limit.

Ball Bearing Steel   - ШХ15 (0.95 -1.05% С and 1.3-1.65% chromium). The hypereutectoid content of carbon and chromium provide, after quenching, a high uniform hardness that is stable after abrasion, the necessary hardenability and sufficient viscosity. Heat treatment includes annealing, hardening and tempering. Annealing reduces hardness and allows you to get fine-grained perlite. Hardening is carried out at 830-860 0 С, cooling in oil, tempering 150-160 0 С. Hardness НРС 62-65, structure - structureless martensite with uniformly distributed small carbides.

For the manufacture of parts of large bearings (with a diameter of more than 400 mm) operating under severe conditions with high impact loads, cementitious steel 20X2N4A is used (cementation temperature 930-950 0 C for 50-170 h, layer thickness 5-10 mm).

Wear resistant steels- 110G13L (0.9-1.3% C, 11.5-14.5% manganese). Cast austenitic steel, after casting, consists of austenite and excess carbides (Fe, Mn) 3 C, released at the grain boundaries, which reduces the strength and toughness of steel. Therefore, cast products are quenched from 1100 0 C in water. In this case, carbides dissolve and the structure becomes stable austenitic.

Steel has high strength and relatively low hardness. In the process of work under shock loads, hardening (hardening) of the steel surface occurs during plastic deformation, as a result, martensite is formed in the surface layer. It provides high wear resistance. As the outer layer wears, martensite forms in the following layers. Used for tram arrows, stone crusher cheeks, bucket visors, scoops, etc.

During cyclic contact-impact loading and impact-abrasive wear, steel 60Kh5G10L is used, which undergoes martensitic transformation during operation.

The blades of hydraulic turbines and hydraulic pumps, ship flange propellers operating under conditions of wear during cavitation erosion are made of steels with unstable austenite 30X10G10 and 0X14AG12, which undergo partial martensitic transformation during operation.

Corrosion-resistant (stainless), heat-resistant (descaling) and heat-resistant steels.

Corrosion is the destruction of metals and alloys under the influence of the environment. As a result, the mechanical properties of steels deteriorate sharply. Distinguish between chemical and electrochemical corrosion. Chemical develops when exposed to gases (gas corrosion) and non-electrolytes (oil and its derivatives). The electrochemical is caused by the action of electrolytes (acids, alkalis and salts, atmospheric and soil corrosion).

Steel, resistant to gas corrosion at high temperatures (above 550 0 C), is called scale-resistant or heat-resistant.

Corrosion-resistant (stainless) steels are steels resistant to electrochemical, chemical (atmospheric, soil, alkaline, acid, salt) corrosion. Increased corrosion resistance is achieved by introducing elements into steel that form protective films on the surface that are firmly bonded to the surface and increase the electrochemical potential of steel in various aggressive environments.

Heat Resistance (Scale Resistance)   steels are increased by alloying with chromium, aluminum or silicon, i.e. elements in solid solution and forming protective films of oxides (Cr, Fe) 2 O 3, (Al, Fe) 2 O 3 during heating. Scale resistance depends on the chemical composition, and not on the structure.

Heat-resistant ferritic steels: 12X17, 15X25T X15YU5.

Heat-resistant austenitic: 20X23H13, 12X25H16G7AR, etc.

Stainless steel   get alloyed with chromium or chromium and nickel, depending on the operating environment. Two main classes: chromic (ferritic, martensitic-ferritic, in which ferrite is not more than 10% and martensitic) and chromium-nickel (austenitic, austenitic-martensitic or austenitic-ferritic).

Grades 12X13, 20X13 - used for household items, valves of hydraulic presses. 30X13 and 40X13 are used for surgical instruments. Grades: 12X18H9 and 17X18H9 - for the manufacture of pipes, parts welded by spot welding, 04X18H10 - for the manufacture of chemical equipment.

Steels and alloys for cutting tools.

Carbon and alloy steels are called tool, having high hardness (60-65 НРС), strength and wear resistance and used for the manufacture of various tools. Usually these are hypereutectoid or ledeburite steels, the structure of which after quenching and low tempering is martensite and excess carbides. The carbon content of such steels should be a fraction of 0.6 mA. % for alloyed and more than 0.8 wt. % for carbon.

One of the main characteristics of tool steels is heat resistance- the ability to maintain high hardness during heating (resistance to tempering when the tool is heated during operation).

All tool steels are divided into three groups:

Not having heat resistance (carbon and alloy steels containing up to 3-4% alloying elements);

Semi-heat resistant up to 400-500 0 С (high alloy steels containing over 0.6-0.7% С and 4-18% Cr);

Heat-resistant up to 550-650 0 С (high alloy steels containing Cr, W, V, Mo, Co, ledeburite class), called high-speed.

Another important characteristic of tool steels is hardenability (the ability of steel to be hardened to various depths) . Highly alloyed heat-resistant and semi-heat-resistant steels have high hardenability (i.e., the depth of the hardened layer is large). Tool steels that do not have heat resistance are divided into steels of low hardenability (carbon) and high hardenability (alloyed).

The labeling of carbon tool steels was discussed at the beginning of the chapter. Alloyed tool steels X, 9X, 9XC, 6HVG, etc. mark with a figure showing the average carbon content in tenths of a percent, if its content is less than 1%. If carbon is about 1%, then the figure is often missing. The letters mean alloying elements, and the numbers following them indicate the content in whole percentages of the corresponding element.

The letter R mark high speed steels. The figure following it indicates the average percentage of the main alloying element of high-speed steel - tungsten -. The average molybdenum percentage ah denoted by a number after the letter Mcobalt - after TO, vanadium - after F   etc. The average chromium content in most high-speed steels is 4% and therefore is not indicated in the steel grade designation. The carbon content in them is about 1 wt. %

Steel for measuring tool.

These steels must have high hardness, wear resistance, maintain dimensional stability and grind well. Usually, high-carbon chromium steels X and 12X1 are used. The measuring tool is usually quenched in oil from possibly low temperatures of 850-870 ° C in order to obtain a minimum amount of residual austenite. Immediately after quenching, the measuring tool is subjected to cold treatment at -70 0 C and tempering at 120 to 140 0 C for 20 to 50 hours. Often, cold treatment is carried out repeatedly. The hardness after this treatment is 63-64 HRC.

Flat and long gauges are made of 15.15X steel sheets. To obtain work surfaces with high hardness and wear resistance, tools are subjected to carburization and hardening.

Steel for cold forming dies.

Stamps of cold deformation operate under conditions of high variable loads, fail due to brittle fracture, low-cycle fatigue and changes in shape and size due to crushing (plastic deformation) and wear. Therefore, the steel used for the manufacture of cold forming dies must have high hardness, wear resistance and strength, combined with sufficient toughness. Steel should also have high heat resistance, since during the deformation process, the dies are heated to temperatures of 200-350 0 C.

Chromium steels X12F1 and X12M are used for dies of complex shape, since they are slightly deformed when quenched in oil; molybdenum and vanadium-containing steels X12F1 and X12M with good hardenability (have high stability of supercooled austenite, molybdenum and vanadium contribute to the preservation of fine grain). The disadvantages of these grades of steel are poorly processed by cutting in the annealed state, carbide heterogeneity is pronounced, which leads to a decrease in mechanical properties.

Steel for hot deformation dies.

Such stamps work in very harsh conditions. They are destroyed due to plastic deformation (collapse), brittle fracture, the formation of a heat network (cracks) and wear of the working surface. Therefore, steels for hot deformation dies must have high mechanical properties (strength and toughness) at elevated temperatures and have wear resistance, scale resistance and heat resistance, high thermal conductivity for better heat removal transmitted by the workpiece.

Heat resistance- this is the ability to withstand repeated heating and cooling without the formation of hot cracks. Large stamps must have good hardenability. It is important that the steel is not prone to reversible temper brittleness, since the rapid cooling of large dies cannot be eliminated. Semi-heat resistant steels 5ХНМ and 5ХГМ, which have increased viscosity and are hardened as a result of martensitic transformation, are used for the manufacture of large forging dies, as well as forging tools and presses that are heated to a temperature of no higher than 500-550 0 С under moderate loads.

Medium-loaded tools working with surface heating up to 600 0 С are made of 4Kh5VFS and 4Kh5MF1S steels. These steels are hardened by martensitic transformation and dispersion hardening during tempering due to the precipitation of special carbides M 23 C 6 and M 6 C. The transformations in these steels during heat treatment are similar to those in high-speed steels. Stamp steels are often subjected to nitriding, boronation, and less often to chromium plating.

Hard alloys.

Hard alloys are alloys made by powder metallurgy and consisting of carbides of refractory metals (WC, TiC, TaC) connected by a cobalt bond.

There are 3 groups of hard alloys:

1 - tungsten (VK3, VK6, VK10);

2 - titanium tungsten (T30K4, T15K8, T5K12);

3 - titanotantalum-tungsten (TT7K12, TT8K6, TT10K8-B).

In stamps, the first letters indicate the group to which the alloy belongs: VK   - tungsten, T   - titanium tungsten, TT   - titanotantalum-tungsten. The numbers in the tungsten group are the amount of cobalt, in the titanium-tungsten group the first digits are the amount of titanium carbide, and the second digits are the amount of cobalt; in the titanotantalum-tungsten group, the first digits are the amount of titanium and tantalum carbides, the second are the amount of cobalt.

If the letter M (VK6-M) is at the end through the dash, then the alloys are made of fine powders, while the letter B (VK4-B) is made of coarse-grained tungsten carbide. The letters "OM" at the end through a dash - the alloys are made from very fine powders, and the "VK" - from especially large tungsten carbide.

Hard alloys that do not contain scarce tungsten have been developed - based on TiC + Ni + Mo (alloy TN-20, the figure indicates the total content of Ni and Mo) and based on titanium carbonitride Ti (NC) + Ni + Mo (KNT-16).

Often carbide or nitride coatings are applied to the working surfaces of multifaceted non-turning carbide inserts (cutting tool parts).

The presence of a wide range of steel and alloys produced in various countries necessitated their identification, but so far there is no single system for marking steel and alloys, which creates certain difficulties for metal trading.

So in Russia and in the CIS countries (Ukraine, Kazakhstan, Belarus, etc.), an alphanumeric system for marking steels and alloys developed earlier in the USSR was adopted, where according to GOST, letters conditionally denote the names of elements and methods of steel smelting, and numbers indicate the contents elements.

European system steel designations, regulated by standard EN 100 27. The first part of this standard defines the procedure for naming steels, and the second part regulates the assignment of serial numbers to steels.

In Japan, the name of steel gradesusually consists of several letters and numbers. The letter designation determines the group to which this steel belongs, and the numbers - its serial number in the group and the property.

IN THE USAthere are several systems designations of metals and their alloys. This is due to the presence of several standardization organizations, including AMS, ASME, ASTM, AWS, SAE, ACJ, ANSI, AJS. It is quite clear that such marking requires additional clarification and knowledge when trading metal, placing orders, etc.

To date, international standardization organizations have not developed a unified steel marking system. In this regard, there are discrepancies that lead to errors in orders and as a result of a violation of product quality.

In Russia and the CIS countries, an alphanumeric system has been adopted, according to which the numbers indicate the content of steel elements, and the letters indicate the names of the elements. The letter designations are also used to indicate the method of deoxidation of steel "KP - boiling steel, PS - semi-quiet steel, SP - mild steel." There are certain designation features for different groups of structural, construction, tool, stainless steel, etc. Common to all designations are letter designations of alloying elements: H - nickel, X - chrome, K - cobalt, M - molybdenum, B - tungsten, T - titanium, D - copper, G - manganese, C - silicon.

Unalloyed structural steels of ordinary quality

(GOST 380-94) are designated by 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) is a two-digit number indicating the average carbon content in steel (for example, ST. 10).

Quality steel   for the production of boilers and pressure vessels, according to GOST 5520-79, are designated as structural unalloyed steels, but with the addition of the letter K (for example, 20K).

Structural Alloy Steel, according to GOST 4543-71, are designated by letters and numbers. The numbers after each letter indicate the approximate content of the corresponding element, however, when the content of the alloying element is less than 1.5%, the number is not put after the corresponding letter. Qualitative additional indicators of a reduced content of impurities such as sulfur and phosphate are indicated by the letter A or III, at the end of the notation, for example (12 X NZA, 18KhG-Sh), etc.

Foundry structural steels, according to GOST 977-88, are designated as high-quality and alloyed, but at the end of the name they put the letter L.

Steel construction, according to GOST 27772-88, are denoted by the letter C and numbers corresponding to the minimum yield strength of steel. In addition, the following notations are used: T - heat-strengthened steel, K - increased corrosion resistance (for example, C 345 T, C 390 K, etc.). Similarly, the letter D denotes an increased copper content.

Bearing steel, according to GOST 801-78, are also designated as alloyed, but with the letter Ш at the end of the name. It should be noted that for electroslag remelting steels the letter Ш is indicated by a dash (for example, ШХ 15, ШХ4-Ш).

Tool steel unalloyedaccording to GOST 1435-90, they are divided into high-quality ones, indicated by the letter U and a number indicating the average carbon content (for example, U7, U8, U10) and high-quality, indicated by the additional letter A at the end of the name (for example, U8A) or the additional letter G, indicating an additional increase in manganese content (for example, U8GA).

Tool steel alloyed

According to GOST 5950-73, they are also designated as structural alloys (for example, 4X2V5MF, etc.).

High speed steel   in their designation they have the letter P (this begins the designation of steel), followed by a figure indicating the average tungsten content, and then letters and numbers that determine the mass content of the elements. The chromium content is not indicated, since it is stably about 4% in all high-speed steels and carbon, since the latter is always proportional to the content of vanadium. It should be noted that if the vanadium content exceeds 2.5%, the letter F and the number are indicated (for example, steel P6M5 and P6 M5F3).

Stainless steel standard, according to GOST 5632-72, marked with letters and numbers according to the principle adopted for structural alloyed steels (for example, 08X18H10T or 16X18H12S4TUL).

Stainless steels, non-standard experimental batches are designated by letters - indices of the manufacturer’s plant and serial numbers. The letters EI, EP, or EC are assigned to steels smelted for the first time by the Elektrostal plant, ES to steels of smelting of the Chelyabinsk Mechel plant, DI to smelting steels of the Dneprospetsstal plant, for example, EI-435, ChS-43, etc. The method of smelting the fine-tuning the names of a number of steels is supplemented with letters (for example, 13X18H10-VI), which means vacuum induction smelting.

International analogues of corrosion-resistant and heat-resistant steels

Corrosion Resistant Steels

Europe (EN)	Germany (DIN)	USA (AISI)	Japan (JIS)	CIS (GOST)
1.4000	X6Cr13	410S	SUS 410 S	08X13
1.4006	X12CrN13	410	SUS 410	12X13
1.4021	X20Cr13	(420)	SUS 420 J1	20X13
1.4028	X30Cr13	(420)	SUS 420 J2	30X13
1.4031	X39Cr13		SUS 420 J2	40X13
1.4034	X46Cr13	(420)		40X13
1.4016	X6Cr17	430	SUS 430	12X17
1.4510	X3CrTi17	439	SUS 430 LX	08X17T
1.4301	X5CrNI18-10	304	SUS 304	08X18H10
1.4303	X4CrNi18-12	(305)	SUS 305	12X18H12
1.4306	X2CrNi19-11	304 L	SUS 304 L	03X18H11
1.4541	X6CrNiTi18-10	321	SUS 321	08X18H10T
1.4571	X6CrNiMoTi17-12-2	316 Ti	SUS 316 Ti	10X17H13M2T

Heat resistant steel

Europe (EN)	Germany (DIN)	USA (AISI)	Japan (JIS)	CIS (GOST)
1.4878	X12CrNiTi18-9	321 H		12X18H10T
1.4845	X12CrNi25-21	310 s		20X23H18

High speed steel:

steel grade			Analogs in US Standards
GOST CIS countries	Euronorms
P0 M2 SF10-MP	-	-	A11
P2 M9-MP	S2-9-2	1.3348	M7
P2 M10 K8-MP	S2-10-1-8	1.3247	M42
P6 M5-MP	S6-5-2	1.3343	M2
P6 M5 K5-MP	S6-5-2-5	1.3243	-
P6 M5 F3-MP	S6-5-3	1.3344	M3
P6 M5 F4-MP	-	-	M4
P6 M5 F3 K8-MP	-	-	M36
P10 M4 F3 K10-MP	S10-4-3-10	1.3207	-
P6 M5 F3 K9-MP	-	-	M48
P12 M6 F5-MP	-	-	M61
R12 F4 K5-MP	S12-1-4-5	1.3202	-
R12 F5 K5-MP	-	-	T15
P18-MP	-	-	T1

Structural steel:

steel grade			Analogs in US Standards
GOST CIS countries	Euronorms
10	C10e	1.1121	1010
10XGN1	10 HGN1	1.5805	-
14 XH3 M	14 NiCrMo1-3-4	1.6657	9310
15	C15 E	1.1141	1015
15 g	C16 E	1.1148	1016
16 hg	16 MnCr5	1.7131	5115
16XGR	16Mn CrB5	1.7160	-
16 CGN	16NiCr4	1.5714	-
17 G1 S	S235J2G4	1.0117	-
17 XH3	15NiCr13	1.5752	E3310
18 hgm	18CrMo4	1.7243	4120
18 X2 H2 M	18CrNiMo7-6	1.6587	-
20	C22E	1.1151	1020
20 XM	20MoCr3	1.7320	4118
20 HGNM	20MoCr2-2	1.6523	8617
25	C25E	1.1158	1025
25 XM	25CrMo4	1.7218	4130
28 g	28Mn6	1.1170	1330
30	C30E	1.1178	1030
34 X	34Cr4	1.7033	5130
34 X2 H2 M	34CrNiMo6	1.6582	4340
35	C35e	1.1181	1035
36 HNM	36CrNiMo4	1.6511	9840
36 X2 H4 MA	36NiCrMo16	1.6773	-
40	C40e	1.1186	1040
42 XM	42CrMo4	1.7225	4140
45	C45e	1.1191	1045
46 X	46Cr2	1.7006	5045
50	C50E	1.1206	1050
50 hgf	50CrV4	1.8159	6150

The basic range of stainless steel grades:

CIS (GOST)	Euronorms (EN)	Germany (DIN)	USA (AISI)
03 X17 H13 M2	1.4404	X2 CrNiMo 17-12-2	316 L
03 X17 H14 M3	1.4435	X2 CrNiMo 18-4-3	-
03 X18 H11	1.4306	X2 CrNi 19-11	304 L
03 X18 H10 T-U	1.4541-MOD	-	-
06 XH28 MDT	1.4503	X3 NiCrCuMoTi 27-23	-
06 X18 H11	1.4303	X4 CrNi 18-11	305 L
08 X12 T1	1.4512	X6 CrTi 12	409
08 X13	1.4000	X6 Cr 13	410S
08 X17 H13 M2	1.4436	X5CrNiMo 17-13-3	316
08 X17 H13 M2 T	1.4571	X6 CrNiMoTi 17-12-2	316Ti
08 X17 T	1.4510	X6 CrTi 17	430Ti
08 X18 H10	1.4301	X5 CrNi 18-10	304
08 X18 H12 T	1.4541	X6 CrNiTi 18-10	321
10 X23 H18	1.4842	X12 CrNi 25-20	310S
10X13	1.4006	X10 Cr13	410
12 X18 H10 T	1.4878	X12 CrNiTi 18-9	-
12 X18 H9	-	-	302
15 X5 M	1.7362	X12 CrMo 5	501
15 X25 T	1.4746	X8 CrTi 25	-
20X13	1.4021	X20 Cr 13	420
20 X17 H2	1.4057	X20 CrNi 17-2	431
20 X23 H13	1.4833	X7 CrNi 23-14	309
20 X23 H18	1.4843	X16 CrNi 25-20	310
20 X25 N20 C2	1.4841	X56 CrNiSi 25-20	314
03 X18 AN11	1.4311	X2 CrNiN 18-10	304LN
03 X19 H13 M3	1.4438	X2 18-5-4	317L
03 X23 H6	1.4362	X2 CrNiN 23-4	-
02 X18 M2 BT	1.4521	X2 CrMoTi 18-2	444
02 X28 N30 MDB	1.4563	X1 NiCrMoCu 31-27-4	-
03 X17 H13 AM3	1.4429	X2 CrNiMoN 17-13-3	316ln
03 X22 H5 AM2	1.4462	X2 CrNiMoN 22-5-3	-
03 X24 H13 G2 S	1.4332	X2 CrNi 24-12	309L
08 X16 H13 M2 B	1.4580	X1 CrNiMoNb 17-12-2	316 cd
08 X18 H12 B	1.4550	X6 CrNiNb 18-10	347
08 X18 H14 M2 B	1.4583 X10 CrNiMoNb	X10 CrNiMoNb 18-12	318
08X19AH9	-	-	304N
08X19H13M3	1.4449	X5 CrNiMo 17-13	317
08X20H11	1.4331	X2 CrNi 21-10	308
08X20H20TY	1.4847	X8 CrNiAlTi 20-20	334
08X25H4M2	1.4460	X3 CrnImOn 27-5-2	329
08X23H13	-	-	309S
09X17H7 Yu	1.4568	X7 CrNiAl 17-7	631
1X16H13M2 B	1.4580	X6 CrNiMoNb 17-12-2	316Cd
10X13 SJ	1.4724	X10 CrAlSi 13	405
12X15	1.4001	X7 Cr 14	429
12X17	1.4016	X6 Cr17	430
12X17M	1.4113	X6 CrMo 17-1	434
12X17MB	1.4522	X2 CrMoNb	436
12X18H12	1.3955	GX12 CrNi 18-11	305
12X17 G9 AN4	1.4373	X12 CrMnNiN 18-9-5	202
15X9M	1.7386	X12 CrMo 9-1	504
15X12	-	-	403
15X13H2	-	-	414
15X17H7	1.4310	X12 CrNi 17-7	301

Bearing steel:

steel grade			Analogs in US Standards
GOST CIS countries	Euronorms
SHX4	100Cr2	1.3501	50100
SHX15	100Cr6	1.3505	52100
SHX15 SG	100CrMn6	1.3520	A 485 (2)
SHX20 M	100CrMo7	1.3537	A 485 (3)

Spring steel:

steel grade			Analogs in US Standards
GOST CIS countries	Euronorms
38 C2 A	38Si7	1.5023	-
50 HGFA	50CrV4	1.8159	6150
52 HMFA	51CrMoV4	1.7701	-
55 XC2 A	54SICr6	1.7102	-
55 HCA	55Cr3	1.7176	5147
60 C2 HCA	60SiCR7	1.7108	9262

Heat Resistant Steel:

steel grade			Analogs in US Standards
GOST CIS countries	Euronorms
10 X2 M	10CrMo9-10	1.7380	F22
13 XM	13CrMo4-4	1.7335	F12
14 HMF	14MoV6-3	1.7715	-
15 m	15mo3	1.5415	F1
17 g	17Mn4	1.0481	-
20	C22.8	1.0460	-
20 g	20Mn5	1.1133	-
20 X11 MNF	X20CrMoV12-1	1.4922	-