STEEL GUIDE

According to the chemical structure, steel is classified into carbonic and alloy-treated.

In terms of quality, steels may be of commercial quality, due-quality, enhanced quality and high-quality.

The below Russian letters in steel names stand for the following elements

А - nitrogen Ю - aluminium Р - boron Ф - vanadium В - wolfram К - cobalt С - silicon Г - manganese Д - copper

М - molybdenum Н - nickel Б - niobium Е - selenium Т - titanium У - carbon П - phosphorus Х - chromium Ц - zirconium

Influence of alloying elements:

Nickel

Nickel contributes to the corrosion resistance of steel, its high durability and ductility, and also improves its hardening characteristics and impact resistance.

Wolfram

Wolfram generates very firm compounds in steel, such as carbides, which sharply increase both hardness and red-hardness of the treated steel. Wolfram prevents grain growing when heated and promotes elimination of the tempering fragility.

Vanadium

Vanadium raises hardness and durability, refines grains, and increases steel density.

Silicon

When added in quantities of more than 1 %, silicon proceeds with its special influence on steel properties: the content 1-1.5 % of Si increases durability, though viscosity is preserved. Any greater content of silicon increase electrical resistance and magnetic permeability. The silicon also contributes to the elasticity and oxidation resistance.

Manganese

When its content is more than 1 %, it improves hardness, wear resistance, and shock load resistance, without reducing plasticity.

Cobalt

Cobalt promotes heat-resistance, improves magnetic properties, and increases impact resistance.

Molybdenum

Molybdenum works for red-hardness, resilience, tensile strength, corrosion-resistance, and oxidation resistance at high temperatures.

Titanium

Titanium raises steel durability and density, promotes grain refinement, and improves workability and corrosion-resistance.

Niobium

Niobium improves acid resistance and reduces corrosion in welded structures.

Aluminum

Aluminum improves resistance to heat and oxidation.

Copper

Copper contributes to corrosion resistance.

Cerium

Cerium raises durability and plasticity.

Zirconium

Zirconium allows receiving steels with the pre-determined granularity.

Lanthanum, cerium and neodymium

Those elements reduce porosity, reduce sulfur contents in steel, improve its surface condition, and refine grains.

When speaking of the degree of alloying, alloy-treated steels are subdivided into low alloyed (alloy elements up to 2.5 %), medium-alloyed (from 2.5 up to 10 %), and high-alloyed (from 10 up to 50 %). High-alloyed steels include:

• Corrosion-resistant (stainless) steels and alloys resistant to electrochemical corrosion, chemical corrosion, inter-granular corrosion, stress corrosion, etc.;
• heat-resistant (oxidation-resistant) steels and alloys resistant to chemical corrosion in gas environments at the temperatures higher than 50° С, which work in non-loaded and low load conditions;
• heat-resistant steels and alloys that work in the loaded condition at high temperatures during certain periods of time, maintaining a sufficient heat resistance.

Steel Grades

Commercial Quality Carbon Steel, GOST (State Standard) 380-94.

Area of Use

A commercial quality carbon steel is intended for manufacturing various hot-rolled products: profiled, shaped,  items made of both thick and thin steel sheets; and also products made of broadband sheets and cold-rolled thin sheet: ingots, blooms, slabs, billets, rolled and casted blanks, tubes, forged parts, and press forms, strips, wire, hardware, etc.

Classification 

Commercial quality carbon steels are manufactured in the following grades : Ст0, Ст1кп, Ст1пс, Ст1сп, Ст2кп, Ст2пс, Ст2сп, Ст3кп, Ст3пс, Ст3сп, Ст3Гпс, Ст3Гсп, Ст4кп, Ст4пс, Ст4сп, Ст5пс, Ст5сп, Ст5Гпс, Ст6пс, Ст6сп.

The letters Ст designate steel (St).

Figures 0, 1, 2, 3, 4, 5, and 6 stand for respective reference grade numbers, depending on the chemical composition. The higher the number, the more carbon such steel contains and the higher breaking point it possesses.

A degree of the steel de-oxidation is specified by the letters following the figures: кп - rimming; пс – semi-killed; СП - killed.

Carbon Due-Quality Construction Steel, GOST (State Standard) 1050-88.

General Specifications

Area of Use

The standard establishes general specifications for hot-rolled and forged bar sections made of carbon due-quality construction steel of grades 08, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 58, and 60, whose diameter or thickness achieve up to 250 mm, and also gauged bars with special finishing of all grades.

In terms of the chemical composition, this standard applies to other kinds of rolled steel, ingots, forged parts, and stamps made of the steels of grades listed above, and also of steel grades 05 кп, 08 кп, 08 пс, 10 кп, 10 пс, 11 кп, 15 кп, 15 пс, 18 кп, 20 кп, and 20 пс.

Classification

Such steel is designated with two first figures: 08, 10, 15, 20, and so on, up to 60. Those figures show an average carbon content in two decimal places. The Russian letters кп and пс after figures correspond to “rimming” and “semi-killed” steels, respectively.

Surface Quality:
1 ГП - hot slump (tests)
2 ГП - for hot pressure processing
3 ГП - for cold mechanical treatment

Mechanical Properties:
М 1 - in a normalized condition
М 2 - hard-drawn or standardized mechanical properties
М 3 - with standardized mechanical properties
ТО - annealed, high tempered

Hardness:
ТВ 1 - no heat treatment
ТВ 2 - standardized hardness
ТВ 3 - hard-drawn rolled metal

Low Alloyed Construction Steel and Alloy-Treated Steel

• Low alloyed heavy-duty construction steel, GOST (State Standard) 19281-89
• Alloy-treated construction steel, GOST (State Standard) 4543-71
• Spring steel, GOST (State Standard) 14959-79
• Corrosion-resistant, heat-Resistant, and temperature-resistant, GOST (State Standard) 5632-72

Designation

The first two figures in its name specify an average carbon content in two decimal places. The letters following the figures speak of the presence of alloying elements, while the figures following the letters designate the content of alloying elements in percentage (35 Г2,  30 Х 2)

If the content of alloying elements is less than 1.5 %, no figures are added (50 Х, 15 ХР).

Classification

According to State Standard 4543-79 (GOST):

Letter A at the end of a grade designation stands for a high-quality steel (15 ХА, 20 ХН 3 А)

Russian letter Ш speaks for the extra quality steel

Surface Quality Groups:
1 - hot slump
2 - hot pressure shaping
3 - for mechanical treatment

Also, in terms of the material condition, there are those:

• With no heat treatment
• Tempered - Т
• Hard-drawn - Н

Carbon Instrumental Steel, GOST (State Standard) 1435-74.

Designation: Russian letter У and figures that show an average carbon content in one decimal place (У7, У10), while letter A after figures designates high-quality steels (У8А).

Alloy-Treated Instrumental Steel, GOST (State Standard) 5950-73.

Designation: the first figures specify an average carbon content in one decimal place, if it is more than 0,1 % (9 Х 1, 9 ХС). Figures standing after the letters designates the alloying element and its average percentage content (Х 12, 8 Х 3).

Construction Steel of Enhanced and High Cutting Properties, GOST (State Standard) 1414-75 . Designation: letter A and figures showing average carbon content in two decimal places (А 12)

Bearing-Grade Steel, GOST (State Standard) 801-78.

Designation: Russian letters ШХ and figures showing the chromium content in one decimal place. Letters after the figures specify the presence of any additional alloying elements (9 ШХ 15 СГ)