What is steel 3

Steel St3

Steel is a material in which the main elements are iron and carbon, and other substances are included to change the performance or are controlled within a certain range. Steel 3 has become quite widespread.

It is used for the production of a wide variety of workpieces. St3 steel is known to many for its pipes, which are used to create heat supply systems.

The characteristics of steel and its features, for example, its chemical composition, determine not only the wide distribution of the metal, but also certain features of heat treatment.

Steel St3

Chemical composition

Each category of steel is characterized by its specific chemical composition. It largely determines the scope of application of the workpieces being created and the difficulties that arise during heat treatment.

The chemical composition of St3 steel makes it one of the most common materials that can be found on the market. It is difficult to imagine modern construction work without this metal.

The key points regarding the chemical composition are the following:

1. As previously noted, the main chemical elements are iron and carbon. The first element has a concentration of 97%, carbon is only 0.14-0.22%. It is carbon that determines the hardness index and some other physical and chemical properties of the structure.
2. The structure includes a relatively small amount of alloying elements. The main elements are chromium and nickel, the concentration of which is 0.3%. Copper is included in the composition at the same concentration.

Chemical composition

With a large number of varieties of steel, the concentration of harmful impurities, which are phosphorus and sulfur, is strictly controlled in the one under consideration. In addition, the composition contains nitrogen in high concentrations, which accounts for about 0.1 mass.

Physical and mechanical properties

St3 steel, the characteristics of which will be discussed in detail, is used as a basis in the manufacture of simply a huge number of different workpieces. This can be attributed to unique physical and mechanical properties. The mechanical properties of St3 steel, which are controlled during the production of blanks, are as follows:

1. Temporary resistance.
2. Yield limit.
3. The degree of bending under high force.
4. Relative extension.
5. Impact strength at a certain temperature.

The most important technical characteristics of carbon steel 3 are as follows:

1. The surface has a hardness of 131 MPa.
2. The density of steel is non-uniform, the weight can also vary over a wide range.
3. Weldability is not subject to any restrictions.
4. The structure is not prone to temper brittleness.

Steel corners

The considered properties of steel 3 determine its widespread use in the construction industry. Various rolled products, which are used in mechanical processing, have also become widespread.

Decoding of St3 stamps

Any brand can be decrypted in accordance with established standards and regulatory documentation. The designation of steel according to GOST allows you to determine the main qualities when deciphering grades. GOST 380 determines the presence of the following types of metal:

1. Steel St3sp.
2. Steel St3ps.
3. Steel St3kp.

It is worth considering that indices must be used for any marking.

Properties of various brands of St3

The brand of material can be deciphered as follows:

1. ST is a designation that indicates the ordinary quality of carbon steel. Let's use St3sp5 as an example.
2. 3 – a number that is the conventional number of the alloy grade. Depending on the carbon concentration, numbers ranging from 0 to 6 can be used.
3. G - in some cases, a similar symbol may be used to designate manganese. A certain type of steel, for example, St3gps, contains 0.8% manganese.
4. Sp is the degree of deoxidation of the material. When considering St3ps5, we can say that the structure is semi-quiet, but at the same time the degree of deoxidation is quite high. The designation “ps” is used for semi-quiet alloys, “kp” - boiling alloys.

Channel ST3PS5

St3kp2 is deciphered in a similar way relatively recently. Previously, other standards were used for labeling. In addition, previously the metal was divided into several different groups.

Download GOST 380-2005

When considering different grades of steel, you need to take into account the fact that they are classified according to the degree of deoxidation. This chemical process involves removing oxygen from the composition. Too high an oxygen concentration determines a decrease in physical and mechanical properties.

The classification is carried out as follows:

1. Calm is characterized by the fact that the composition includes from 0.16 to 0.3% silicon.
2. Semi-calm has an average concentration of the element in question.
3. Boiling differs in chemical composition from calm in that it contains at least 0.05% silicon.

St3 material is marked accordingly. Various substances can be used to carry out a chemical process.

It is worth considering that a quiet one is much more expensive than other options. This can be associated with the following points:

1. The structure is homogeneous, thereby increasing the degree of protection of the material from environmental influences.
2. The composition includes a small amount of oxygen, which determines high performance.

When using mild steel, the following products can be manufactured:

1. Rolled sheets and shapes.
2. Fittings and parts that can be used to create a pipeline. Various pipes can be used to transport coolant or gas or other media. In order for them to withstand high loads and environmental influences, materials with strength and hardness must be used during production. In addition, attention is paid to cost, since alloys that are too expensive may be less practical to use. Steel 3 is more suitable for the manufacture of such products.
3. Primary and secondary elements used in the manufacture of suspended structures and railway elements. In the railway industry, the metals that are most in demand are those that have low cost and high performance. Due to the large size of suspended structures, the price of one square meter is also of great importance.

Steel reinforcement

The semi-quiet variety of steel, which is also widely used, contains about one percent oxygen. Due to this, the characteristics of hardness and ductility are less pronounced. When using steel 3, the following can be produced:

1. Pipes. This type of material is widely used today. Pipes are used to create a heating system as load-bearing elements. It is worth considering that pipes can have different diameters and wall thicknesses. The alloy in question has relatively low corrosion resistance, so it is necessary to protect the surface from exposure to high humidity.
2. Sheet metal is also used extremely often, especially in the manufacture of cabinet products or cladding of load-bearing structures. The thickness can vary over a wide range. Rolled sheet metal can be used for cold bending or stamping. These two processes are characterized by high productivity. That is why the alloy in question is most widely used.
3. Squares and corners are often used to obtain load-bearing structures. They are characterized by high strength, since the edges significantly increase rigidity and can distribute the load. Corners and squares are characterized by a large number of parameters: sheet thickness, angle of planes, length and cross-sectional shape. The scope of application is the manufacture of load-bearing structures and strengthening of existing structures.
4. Various hexagons. They are also widely used and can be used in a wide variety of industries.

Steel sheet St3 hot rolled

Boiling alloys have become widespread due to their availability. They are the most affordable in terms of cost, and the resulting structure is characterized by a high degree of workability. In addition, the alloy lends itself well to heat treatment, but its performance is reduced due to the high oxygen concentration.

In conclusion, we note that many analogues of steel 3 have the appropriate performance characteristics. Foreign manufacturers use their own standards for labeling. At the same time, the concentration of harmful impurities is maintained within a certain range. The use of the most modern technologies makes it possible to reduce the amount of phosphorus and sulfur in the composition, making the material more durable and less fragile. In some cases, alloying elements are added.

Source: https://stankiexpert.ru/spravochnik/materialovedenie/stal-st3.html

Steel grade St3: characteristics, application | Useful articles about rolled metal

Steel is an iron alloy with added impurities, including carbon. To obtain raw materials, cast iron is processed using one of three methods: open-hearth, electrothermal, or converter. The percentage of iron is from 45%. The production of this raw material is regulated by state standard 380-2005..

Scope of use

Without the iron alloy St3, a building will not be built, communications will not be laid, industrial equipment and vehicles will not be manufactured.

St3 steel products:

• rolled products (sections and shaped types; thin and thick sheets);
• standard, rectangular pipeline;
• forged and stamped products;
• wire or steel tape;
• wear-resistant hardware.

This carbonaceous raw material is used to produce a circle, beam, channel or hexagon.

Deoxidation

The steel is melted and the oxygen is removed from it. In this way, the physical characteristics of the iron alloy can be improved.

Removing oxygen from a composition is called deoxidation. The following components are used for execution: aluminum, manganese or silicon. They differ in the strength of their influence. Manganese can be called the weak link, and aluminum can be called the strong link. The letter designation of the marking must indicate the level of deoxidation.

Types of steel:

• calm – deoxidized by three components together;
• semi-quiet - steel in which oxygen is removed with aluminum and manganese;
• boiling - steel deoxidized by the “weak link” (manganese).

Mild steel has a uniform (homogeneous) composition, due to which the alloy becomes ductile and resistant to rust. There is no oxygen in steel, and therefore it is the most expensive. Rolled sheets and pipe fittings are made from the mild alloy. The quiet alloy is used where high structural rigidity and the ability to cope with excessive loads are needed.

A semi-calm alloy is a “strong average”. He took a position between calm and boiling steel. Helps in the production of rolled products and beams, as well as the creation of hexagons, embedded mechanisms, and geometric shapes. It has a heterogeneous composition. There is a minimum oxygen content, so the alloy is less hard and ductile compared to a calm alloy.

Boiling steel is the lowest-cost alloy option that is subject to heat treatment. Used for the production of slabs, ingots, and finished sheets. Like the semi-quiet alloy, it has a heterogeneous structure. When using this steel, it is necessary to comply with the requirements and take into account the physical characteristics of the metal.

If the degree of deoxidation is not specified by the customer, this parameter remains at the discretion of the manufacturer. This rule is enshrined in GOST 380-2005.

Weldability

The demand for steel is explained by its density and degree of deoxidation. The alloy is really easy to weld. You can use arc, electroslag, contact-point methods. Decorative forged products are produced from St3 steel: fences, gratings, railings.

Rules for reading markings

Marking is a special letter meaning that can tell a lot about St3 steel. But it must be read properly to learn about the physical characteristics and chemical properties of the alloy.

Reading rules using the example of St3Gsp:

• 3 – conditional number;
• G – containing 0.8% manganese;
• Sp is a calm alloy (according to the degree of deoxidation).

Consumers are impressed by the technical characteristics of St3 steel. They are described in the state standard.

Source: https://spb-stal.ru/stati/stal-marki-st3-kharakteristiki-primenenie/

Steel St3sp: composition, characteristics, application

The most popular types of metal today include steel marked St3 sp.

Explanation and general description

This type of metal is carbon structural steel of ordinary quality. Complies with GOST 380-2005.

This marking is deciphered as follows:

• “St” is the actual name of the metal.
• “3” – brand number, determined by the chemical composition of the material.
• “sp” – calm. These letters indicate the degree of deoxidation of the steel, and “say” that when the substance hardens, almost no gas is released.

Steel with this marking is characterized by the most homogeneous composition, which makes it less brittle and gives it increased resistance to the aggressive effects of various factors. At the same time, the material remains plastic and can be processed quite easily.

Such steel is produced using the oxygen-converter or open-hearth method. In the first case, the metal is produced by exposing cast iron to oxygen. Oxygen supplied under high pressure burns carbon out of cast iron and allows the metal to acquire new characteristics.

In the second case, the steel is melted in special open-hearth furnaces under high temperatures. At the same time, regardless of the production method, the characteristics of the metal do not change.

Compound

One of the distinctive features of ST3 sp steel is its chemical composition, in which:

• carbon occupies 0.14 – 0.22%;
• proportion of manganese content – ​​0.40 – 0.65%;
• silicon share – 0.15 – 0.30%;
• nickel, chrome and copper components – up to 0.3%
• sulfur content – ​​no more than 0.005%;
• phosphorus share – 0.04%;
• nitrogen – less than 0.1%.

Everything else is iron.

Advantages of St3sp steel

Due to its technical characteristics, this type of metal has a number of advantages compared to other grades of steel. The main advantages of the material are:

• increased corrosion resistance;
• optimal combination of elasticity and hardness;
• complete absence of flake sensitivity (no defects occur during casting);
• no temper brittleness.

In addition, steel with this marking is excellent for welding without preliminary preparation and subsequent processing (this applies to material up to 3.6 cm thick - experts recommend heating thicker steel to 100°C and subsequent heat treatment).

At the same time, the qualities of the metal make it possible to use manual and automatic arc welding, resistance spot and electroslag welding methods when working with it.

Application

The following are made from St3sp metal:

• shaped metal products, which include a channel, an I-beam and other types of products;
• varietal;
• rolled sheets of various thicknesses.

In addition, the material is widely used in the production of pipes for various purposes and sections, steel strips, hardware and stampings.

Products made from this type of steel are used in a wide variety of areas: from the construction and laying of above-ground and underground communications to the manufacture of industrial machines and units operated even in difficult conditions.

The technical characteristics of the material allow it to be used in the construction of frames and supporting structures, which are subject to increased requirements.

Rolled metal from St3sp from Stroystal

The Stroystal company's range of rolled metal products includes a wide variety of products made from St3sp steel.

At our warehouse in Tushino we always have in stock:

• round and square pipes;
• sheets and blanks of different thicknesses;
• shaped steel, in particular, I-beams and angles of various sizes.

Based on your order, our workers will cut steel products to specified sizes or carry out welding work to assemble structures from individual parts.

St3sp steel, used for the manufacture of rolled metal products sold by our company, meets all state and international standards and has the appropriate certificates.

The company works with both organizations and individuals, with wholesale and retail customers - for each we have individual and most favorable terms of cooperation.

If necessary, we deliver the goods to the specified address. The speed of shipment and delivery is ensured by Stroystal’s own fleet of vehicles.

Source: https://www.stroymetall.ru/stati/stal-st3sp-sostav-kharakteristiki-primenenie/

Carbon Steel Specifications 3

Steel 3 belongs to the category of structural carbon alloys of ordinary quality, the characteristics of which have ensured its use in many areas of the national economy. One of the factors contributing to the wide distribution of the material is its low cost.

Chemical composition

Decoding the steel grade St3 indicates the main components in its composition - iron (97%) and carbon (0.14-0.22%). The main quality of the alloy—its hardness—depends on the carbon concentration. The steel also contains small amounts of:

• manganese – 0.4-0.65%;
• silicon – 0.15-0.17%;
• nickel and chromium – 0.3% each;
• arsenic – 0.08%;
• copper – up to 0.3%;
• sulfur – 0.05%;
• phosphorus – 0.04%;
• nitrogen – up to 0.008%.

A feature of the St3 alloy is the strict regulation of the content of harmful impurities - sulfur and phosphorus. Phosphorus reduces the plasticity of the metal when exposed to high temperatures, and sulfur, when interacting with iron, forms sulfides, causing the phenomenon of red brittleness. It should be noted that there is an increased concentration of nitrogen, which accounts for almost 0.1%. In accordance with GOST 380-2005, the alloy is marked with accompanying indices that indicate the degree of deoxidation, for example, St3Gsp:

• the first two letters indicate carbon steel of ordinary quality;
• the number “3” means the serial number of the brand according to this GOST;
• the sign “G” indicates a modification with a high manganese content;
• “sp”, “kp”, “ps” – degrees of deoxidation.

Substitutes for steel grade St3 can be:

• C245, according to GOST 27772-88;
• C285;
• VSt3Sp.

Foreign analogues are labeled according to different rules:

• A57036, K01804 – USA;
• 40B, 722M24, HFS4 – UK;
• 1.0038, DC03 – Germany;
• E24-2, E24-4 – France;
• SS330, SS400 – Japan;
• Fe360B, Fe360C – Italy;
• G235C – China;
• RSt360B – Austria;
• Fe235D – Hungary.

The product range includes:

• long and shaped steel according to GOST 2591-2006;
• sheets of various thicknesses and stampings;
• pipes and fittings, according to GOST 10705-80;
• tapes and strips that are produced in accordance with GOST 14918-80;
• wire of different sections.

Alloy properties

Basic physical properties of steel 3:

• density – 7850 kg/m3, the indicator may vary within certain limits;
• elastic modulus – 200 GPa;
• thermal conductivity coefficient – ​​55 W/m*K;
• a value characterizing the ratio of relative transverse compression to tension – 0.3.

Source: https://svarkaipayka.ru/material/stal/tehnicheskie-harakteristiki-uglerodistoy-stali-3.html

St3sp5 decoding what 5 means

Each category of steel is characterized by its specific chemical composition. It largely determines the scope of application of the workpieces being created and the difficulties that arise during heat treatment.

The chemical composition of St3 steel makes it one of the most common materials that can be found on the market. It is difficult to imagine modern construction work without this metal.

The key points regarding the chemical composition are the following:

1. As previously noted, the main chemical elements are iron and carbon. The first element has a concentration of 97%, carbon is only 0.14-0.22%. It is carbon that determines the hardness index and some other physical and chemical properties of the structure.
2. The structure includes a relatively small amount of alloying elements. The main elements are chromium and nickel, the concentration of which is 0.3%. Copper is included in the composition at the same concentration.

With a large number of varieties of steel, the concentration of harmful impurities, which are phosphorus and sulfur, is strictly controlled in the one under consideration. In addition, the composition contains nitrogen in high concentrations, which accounts for about 0.1 mass.

Structural carbon semi-quiet steel ST3ps: explanation, characteristics

Among the wide range of carbon-containing steels intended for the construction of supporting structures, the most popular is an alloy of ordinary quality - St3ps steel. The fact is that this specimen does not have a description of the welding regulations, is practically not susceptible to corrosion and has tempering hardness. It is produced by passing the material through open-hearth furnaces.

Steel St3ps

Mechanical and physical characteristics

A subtype of this alloy labeled as St3ps steel, the characteristics of which are similar to raw materials with the C245 index, production features and almost identical composition, belongs to the category of materials for the construction of load-bearing and non-load-bearing structures in an environment with a positive temperature. That is, welded structures operated in a temperature range from -20 °C to +425 °C, with the condition that the thickness of the material will vary from 10 to 25 mm.

For example, electric welding pipes having an operating temperature within 300 °C, pipeline and boiler elements designed to operate within a temperature range of 200 °C. It is also typical for St3ps steel to elongate during deformation in a cold state, without suffering damage or losing strength.

Mechanical and physical properties of St3PS steel

The characteristics of St3ps5 comply with the standards of materials, thin sheets of which can be stamped and bent without damage, but at the same time, a thick layer of this material can be safely deformed only in the case of bending along a large radius or using preoperative heating. Corrosion resistance is at an average level, sufficient for storing workpieces between operations or for use in a dry room, without the need for additional protection on the steel.

Mechanical requirements for products made of St3ps located indoors at a temperature of +20 °C:

Name	σв, Megapascal	σТ, Megapascal	δ5, %	Ψ, %
Pipe manufactured according to GOST 8696-74	372	245	23
Pipe manufactured according to GOST 10705-80	372	225	22
Rolled steel according to GOST 535-2005	370-480	205-245	23-26
Thick sheet of steel according to GOST 14637-89	370-480	205-245	23-26
Steel reinforcement manufactured in accordance with GOST 5781-82	373	235	25
Steel wire rod manufactured according to GOST 30136-95	490-540	60

Brand analogues

According to the production system, the St3ps steel grade is related to other similar alloys, both domestic and foreign produced. Among them we can note C245 manufactured in accordance with GOST 27772, VSt3ps6 - GOST for which is 23570-79 and foreign E-235-B (better known as Fe 360-B). All of them are united by the characteristic of universal rolled steel intended for the construction of building structures with welded and non-welded type of connection.

Steel 245

Of course, alloys of different markings cannot be called complete analogues of each other.

For example, the same domestic C245, although it has characteristics similar to 3ps steel in terms of strength, withstand temperature and pressure, conditions for welding and construction of structures, is endowed with differences in composition.

Namely, the amounts of iron and manganese are the same, but other components, such as flint or carbon, have a smaller or larger percentage of the total mass. With other analogues the situation is approximately the same.

Application of material

The main characteristics of one of the most popular materials, such as maintaining the strength of the material despite high loads and a wide range of withstandable temperatures, allow the use of 3ps steel in load-bearing structures. Another advantage is the absence of the need to heat the metal before welding and heat treatment after welding.

Steel mesh ST3PS

Channel made of ST3PS steel

Steel fittings ST3PS

Thanks to this, St3ps is used in production:

• Rolled sheet metal with a thickness of material within 10 mm, used for the construction of load-bearing structures connected by welding and used under varying influence of weight on elements from 11 to 25 mm in thickness.
• In the manufacture of reinforcement with a smooth profile used in the reinforced concrete industry.
• Production of profile parts for agricultural engineering.
• Production of expanded metal sheets.
• Manufacturing of pipeline parts.
• Production of connecting profiles for pipeline structures designed to operate under temperature conditions from -20 to +200°.
• Production of electric welding pipes.
• Production of the main layer of cladding for products requiring resistance to wear and corrosion.

Regulatory documents

The document regulating the accuracy of the composition in the production of St3ps steel is GOST 380-2005, published back in 1960. Its rules apply specifically to the field of construction steels, which includes St3ps. Compliance with GOST requirements confirms the compliance of the chemical composition and quality of products (stamped parts, pipes, wire, etc.).

Download GOST 380-2005 “Ordinary quality carbon steel”

The following is a list of the main production conditions:

• The material is produced exclusively in open-hearth or Bessemer furnaces.
• Roughness, layer breakdowns and cavities visible in the crimped workpiece with the naked eye must be removed.
• At the customer's request, the alloy can be supplied in a pre-heat-treated form.
• The composition of the steel under no circumstances changes without the customer’s desire, and must correspond to the above set percentage of chemical elements.

It also implies maintaining the standard for steel thickness and its recommended physical (strength, strength of corrosion, tensile, fluidity, resistance, etc.) and technical characteristics.

Source: https://instanko.ru/elektrichestvo/st3-gost.html

Technical characteristics of steel grade St3: explanation, analogues

The main indicators on which the properties and purpose of a metal product depend are the chemical composition and thermomechanical processing (intermediate and final). Knowing the chemical composition, you can immediately tell where this steel is used and what kind of processing it needs to obtain precise mechanical properties. One of the most common carbon structural types is St3 steel, the characteristics of which are used in all areas of human activity.

Application of structural steel grade St3

The characteristics of ordinary steel St3 are used for the production of pipes (profile, round, solid-rolled and welded), rolled profiles (angles, channels, rails), and sheets. It is not always possible to use St3; the use is often limited by the climatic component.

To work in northern climates (below -41 °C), in open conditions, it is necessary to give preference to alloyed alloys with a reduced phosphorus concentration. There are no restrictions for the execution of products intended for other climatic zones - from temperate to tropical.

It is St3 that is the steel grade that is the most common of the entire structural category. This is explained by 3 factors:

1. A set of technical parameters: the possibility of physical and chemical processing, excellent weldability.
2. Low cost due to the low content of alloying substances, low processing requirements during smelting and machining, high tolerances for phosphorus and sulfur content.
3. Large variation in the content of chemical elements (C 0.14-0.22; Mn up to 0.68; Si up to 20).

The characteristics of St3 (GOST 380-2005) are as follows:

• hardness 131 MPa;
• impact resistance;
• weldability without restrictions;
• high surface adhesion to a large number of paint and varnish coatings;
• the ability to increase strength through physical and chemical treatment.

GOST and other regulatory documents for steel

St3 is an abbreviation of Russian GOST; in the standards of other countries, steel with the same composition is marked with different alphanumeric indices. For structural grades of this type, the main importance is the content of the chemical elements C, Mn, Si, P, S, according to tabular data.

Advantages and disadvantages

Among the strengths of this brand:

• Has excellent weldability under any heat treatment.
• Tolerances for the use of elements make it possible to obtain a large variation in mechanical properties.
• Low cost with wide application variations.
• Possibility of hardening with high frequency current (one of the most effective and economical technologies).
• Not prone to temper brittleness.
• Not flake sensitive.

Source: https://punktpriema.ru/articles/tehnicheskie-harakteristiki-konstruktsionnoy-stali-st3.html

Designation of steel grade St3, characteristics and variety

Steel is an alloy consisting of carbon, iron and impurities, and the percentage of iron content in it must be at least 45. The raw materials are obtained by processing cast iron using various thermal methods - open hearth, metal converter and electrothermal.

As a result of the thermal process, the steel composition is optimized: carbon enrichment, deoxidation, etc. The composition must comply with the current GOST.

St3 grade steel is intended for the production of shaped and long sections, thin and thick sheets, cold-rolled and wide-rolled thin-sheet products. This grade of steel is also used to produce pipes , including rectangular ones, forgings and stampings, tapes, hardware and wires.

Chemical and physical properties

Without steel grade St 3, in our time it is impossible to build, construct above-ground and underground communications, produce vehicles, units and machine tools.

Impurities in steel of this grade are no more than:

• chromium - 0.30 percent;
• nickel - 0.30 percent;
• copper - 0.30 percent;
• sulfur - 0.005 percent;
• phosphorus - 0.04 percent;
• nitrogen - 0.10 percent.

Steel deoxidation

The steel deoxidation process is a chemical process that removes oxygen from the molten raw material. In this case, it is determined by an impurity that worsens the mechanical and physical properties of the alloy.

According to the deoxidation process, St3 steel is divided into the following types:

1. Calm - deoxidation occurs with the use of manganese, silicon and aluminum.
2. Boiling - deoxidation using only manganese.
3. Semi-calm - deoxidation using aluminum and manganese.

The level of deoxidation is indicated in the marking of steel with the letters “kp”, “sp” and “ps”; their modification with an increased percentage of manganese is also indicated. For example – St3Gsp or St3Gps.

Boiling steel differs in chemical composition from calm steel in that the silicon content in it is very low, less than 0.05 percent. Calm steel contains more silicon, ranging from 0.16 to 0.30 percent. Since boiling steel contains more oxygen than calm steel, its quality is much worse than calm steel.

Semi-quiet steel occupies a middle position in quality between calm and boiling steels.

For the deoxidation process, elements such as silicon, manganese, and aluminum are used. The strength of their impact on steel varies. So, the “strongest” is aluminum, and the “weak” is manganese.

Quiet Steel is the most expensive steel in terms of cost.

It lacks oxygen and is characterized by a homogeneous (homogeneous) structure, which, due to its nature, is designed to give the alloy maximum protection from environmental influences in the form of corrosion and ductility.

Calm steel alloy St3 in accordance with GOST 380-2005 adopted in 2005, is used during the construction of rigid trusses and other metal structures, non-load-bearing and load-bearing elements. This grade of steel is used to make:

• sheet and packaged rolled products (steel sheet St 3);
• blanks for fittings and parts for pipelines (square pipe St 3);
• main and secondary elements for railway facilities, overhead and ground tracks, etc.

Semi-quiet steels occupy a neutral position between boiling and calm types of raw materials. In this form, a percentage of oxygen is already present, which gives the alloy less pronounced characteristics of ductility and hardness.

The chemical composition of this type of steel cannot be considered homogeneous. This grade of steel is used to produce rolled pipes and sheets, such a popular product as the St 3 beam. Semi-quiet steels are also used for the production of circles and strips, angles and squares, embedded parts and hexagons.

If we talk about boiling steels, then these are the most popular and affordable structural steel alloys. The production cost is low, but at the same time, blanks made from this steel (slabs, ingots, finished rolled sheets) lend themselves well to various processing under different thermal conditions.

The density of grade 3 steel of this modification is completely heterogeneous, however, subject to proper use and appropriate requirements, it is one of the most popular and inexpensive, practical types of alloys.

According to GOST 380-2005, it is stated that the manufacturer has the right to independently indicate the degree of deoxidation of raw materials if the customer has not determined it.

Mechanical performance

Mechanical indicators of the properties of St3 steel, which are used to control the properties of rolled raw materials:

• resistance that occurs temporarily - all categories;
• fluidity and its limit - all except the first category;
• bending under external influence in a cold state - all except the first category;
• relative lengthening - all existing categories are here;
• KCU (impact strength) at ambient temperature +20 °C – third category;
• KCU (impact strength) at an ambient temperature of –20 °C – fourth category;
• KCU (impact strength) after mechanical aging – fifth category;
• KC V (impact strength) at ambient temperature +20 °C – sixth category;
• KC V (impact strength) at an ambient temperature of –20 °C – seventh category.

Weldability of steel grade St3

Consumers enjoy working with this grade of steel. Its technical characteristics, taking into account modifications, are very universal. One of the most important advantages of this brand is excellent weldability .

Steel allows the use of automatic arc and manual welding methods, as well as contact-spot and electroslag methods. St. 3 is also used for the manufacture of forged parts (fences, various gratings, etc.).

What does the St3 brand designation mean?

According to GOST 380-2005, the designation of steel St3 is not provided in this form “St3” - without the prefix “ps”, “kp” and “sp”.

The standard clearly defines the grades of alloys St3ps, St3kp, St3sp, as well as their modifications with an increased percentage of manganese - St3Gps and St3Gsp . Therefore, the standard does not provide for the use of the St3 alloy designation without accompanying indices.

In addition, GOST 380-2005 states that if the manufacturer has not indicated the degree of deoxidation of steel, then the manufacturer has the right to establish it.

Full indexation of the designations of any steel grade according to GOST 380-2005, which must be indicated in the order form, looks, for example, like this - St3Gsp GOST 380-2005.

Let's decipher:

1. St is a designation for ordinary quality carbon steel.
2. 3 - conditional number of the steel alloy grade (GOST 380-2005 provides seven numbers, depending on its chemical percentage composition from 0 to 6).
3. G - the letter G is placed in the designation if the percentage of manganese in the alloy exceeds 0.8%;
4. cn is a designation of the degree of deoxidation of the alloy.

Old designations of the St3 brand

Sometimes you still come across outdated steel markings St3, for example, VSt3ps5, with footnotes to the editions of GOST 380 from 1988, 1971, 1994 and even 1950 and 1960.

According to GOST 380-1971, the steel that was supplied was divided into three groups: A, B and, accordingly, C with various guarantees of chemical composition and mechanical properties.

Group A steels were marked in the same way as according to the current current GOST 380-2005, for example - St3kp. For steels of groups B and B, the corresponding group letter was added in front of the marking, for example - VSt3kp.

The current modern GOST 380-2005, in contrast to outdated editions, determines only the chemical composition of alloys. Mechanical and other characteristics determine standards for specific types of rolled steel, for example, GOST 535-88 for shaped and long rolled products, and GOST 14637-89 for thick plates.

Source: https://stanok.guru/stal/fiziko-himicheskie-harakteristiki-staley-st3.html

Steel 3

\ Main steel grades \ Steel 3

Steel class and analogues 3

Class: carbon structural steel of ordinary quality.

Some foreign analogues: A284Gr.D, K01804, K02701, M1017, SS330, SS400, E24-3, HFS3, S235J2G3, Fe360B, FE360BFU, Q235B, S235JRG2, RACOLD215S.  

The offered alloy meets domestic quality standards, as well as GOST geometry. Steel is produced in the form of strips and sheets, shaped and rolled products. Before shipment, the metal undergoes a thorough check (modern methods and equipment are used).

Chemical composition:

• carbon – 0.14-0.22%;
• silicon – 0.05-0.17%;
• manganese – 0.4-0.65%;
• nickel – up to 0.3%;
• copper – up to 0.3%;
• chromium – up to 0.3%;
• arsenic – up to 0.08%;
• sulfur – 0.05%;
• phosphorus – 0.04%.

Note. The strength of a metal can be increased by adding carbon.

Application and Use

The alloy is designed for operation at positive temperatures. Welded products of complex shape containing many welds are made from it. Also, parts are made from metal that do not require preliminary heat treatment. In particular, the following are made from steel 3 :

• covers and troughs of machines;
• cold-formed parts;
• load-bearing elements of welded structures;
• high-strength parts;
• gears;
• gaskets;
• wire, metal mesh;
• lightly loaded parts.

Alloy features

Steel is cooked by open-hearth and converter methods. If a ferrite structure does not form (at insufficient temperatures), then carbon is released in it and accumulates between the grains. This process is called aging.

It reduces the resistance of the metal and increases the yield strength. With temperature changes and mechanical stress, as well as contamination and saturation with gases, the aging process of the alloy accelerates.

Regular cleaning of the metal surface and creation of optimal operating conditions will help fight aging.

The alloy is easily stamped in hot and cold conditions, it can be drawn, and the metal does not lose its positive properties.

Weldability of steel 3

Steel 3 can be welded using almost any modern method without fear that it will lose its quality characteristics. The metal does not require heating or heat treatment before welding. That is why shields, frames and frames are mainly made from the proposed alloy.

Heat treatment of steel 3

Hardening. Helps achieve non-typical characteristics of the alloy, as well as a non-equilibrium structure.

Annealing. It is used to give the metal a uniform structure and reduce ductility.

Vacation. Helps reduce internal metal stress. Tempering makes the steel as strong and hard as possible.

Heat treatment allows you to improve the quality properties of the metal without changing its composition (direct savings). It helps to extend the service life of steel and change dimensions. After this, the steel can be used to make load-bearing elements of buildings.  

Source: https://a7r.ru/stal-3

Steel St3sp: decoding, composition, application

The raw material that is obtained by processing a material such as cast iron is called steel. Several different methods can be used for processing - open hearth, metal converter and electrothermal. This thermal process is necessary for the raw material to go through the stages of carbon saturation, deoxidation, and others. The composition of any steel must comply with GOST.

General description of the material

St3sp steel is intended for the production of shaped, sectional, thin-sheet or thick-sheet material. In addition, it is successfully used in the preparation of cold-rolled and wide-band thin-sheet products. This substance can also be used to produce rectangular and regular pipes, tapes, hardware, and stampings.

It is very important to note here that St3sp steel is the same St3 material, the letters “sp” only indicate the method of its preparation, but more on that later. Currently, this substance has become indispensable in the construction of above-ground and underground communications, in the construction of transport, as well as various other units and machines.

Impurities and deoxidation method

The following substances are used as impurities for the production of St3sp steel:

• chromium in an amount of 0.3%;
• nickel in the amount of 0.3%;
• copper in the same amount as the first two components;
• sulfur content should not exceed 0.005%;
• phosphorus in an amount not exceeding 0.04%;
• nitrogen no more than 0.1%.

Next comes the process of steel deoxidation, which is one of the most important. During this operation, all oxygen is removed from the substance, and further qualities will deteriorate depending on what substance was used. Depending on the process, there are three types:

• Calm steel - manganese, silicon, and aluminum are used as impurities for deoxidation.
• Boiling - only manganese is used.
• Semi-calm - manganese and aluminum are used.

Thus, it becomes clear that the interpretation of St3sp steel is calm steel. By this, the manufacturer indicates the degree of deoxidation of the substance.

Description and application of St3sp

This type of substance is the most expensive of all three types. There is no oxygen in it completely, the structure is homogeneous, that is, completely homogeneous. This property significantly increases the resistance of the material to external aggressive environments.

In other words, there is high corrosion resistance and increased ductility. According to GOST, St3sp steel is used in the production of rigid trusses, as well as other metal structures, load-bearing and non-load-bearing parts of objects.

The following elements can be made from this raw material:

• sheet and packaged rolled products (steel sheets marked St3);
• reinforcement blanks and components for the pipeline system (square pipes St3);
• successfully used in the manufacture of primary and secondary parts for the railway industry, overhead and ground tracks, etc.

This material lends itself quite well to influences such as welding. A wide range of technical parameters, which can also be modified using various additives, are considered universal. Excellent weldability is one of the first advantages that steel has.

The properties and parameters of the raw material allow the use of automatic and manual arc welding. In addition, the use of contact-point and electroslag methods is allowed. It is also worth noting that this material can be successfully used for the production of forged items.

Full description of the brand

If you rely on GOST, then you must use the St3sp steel grade in its entirety. Designation in the form St3 is not permitted. According to the international standard, there is a clear division into the markings St3sp, St3ps, St3kp.

Depending on the modification and increase in manganese content during deoxidation, the St3gps and St3gsp grades may also appear. It is also worth paying attention to the fact that if no index was added by the manufacturer during the installation of the marking, then the degree of deoxidation can be set by the buyer.

If you place an order for this raw material, then in the form you need to write something like this - “steel St3sp GOST 380-2005”.

These indices are deciphered as follows:

• St - designation of ordinary quality carbon steel.
• 3 is a conditional number that is assigned to any steel grade. There are seven such rooms in total. A change in number means a change in the chemical composition of the raw material.
• Sometimes you can find an additional letter G. It is placed only if the percentage of the chemical substance - manganese - exceeds 0.8% of the total mass fraction of substances.
• Sp is the degree of deoxidation of the composition.

The full decoding of St3sp steel looks exactly like this.

Technological qualities

This steel is not prone to such defects as temper brittleness. Non-floc sensitivity is also observed, and weldability is practically unlimited. Further, it is important to note that all structural materials are divided into groups depending on corrosion resistance, quality of mechanical properties and degree of weldability. If we talk about mechanical characteristics, then rolled steel is divided into three groups - regular, increased and high strength.

The basic properties of raw materials depend on its chemical components. Ferrite is the main structural material. This material itself is considered low-strength, but ductile. Such properties of the base substance do not allow the use of ferrite in its pure form, since its use, for example, for building structures is prohibited.

It is in order to improve the strength characteristics that the composition undergoes a process of carbon saturation. Regular group steels are low-carbon materials; the middle group includes substances that are alloyed with chemical additives such as chromium, nickel, silicon, and manganese.

High-strength substances are additionally alloyed using thermal hardening.

Harmful impurities for steel

During the steel rolling process, some harmful impurities are used or released, which include phosphorus and sulfur. When phosphorus reacts with ferrite, it significantly increases its brittleness when exposed to low temperatures or significantly reduces its strength when exposed to high temperatures.

Excess sulfur in steel is called sulfur content. This defect leads to red brittleness of the material. sulfur in raw materials should not exceed 0.05%, and phosphorus - 0.04%. It is also worth noting here that if the temperature is not high enough for ferrite to form, carbon will begin to precipitate. Its accumulations will accumulate between grains, as well as near defects in the crystal lattice.

This has a very negative effect on St3sp strip steel.

Source: https://FB.ru/article/370475/stal-st-sp-rasshifrovka-sostav-primenenie

Steel St3 according to GOST 380-2005

Steel grade St3 - this is what GOST 380-2005 calls it - belongs to carbon steels of ordinary quality. More often it is simply called St3 steel. But not “steel 3” and not “steel grade 3” - this is what high-quality carbon steels are called according to GOST 1050-88, for example, “steel grade 20” and often “steel 20”.

Steel grade St3 is intended for the production of hot-rolled steel - sections, shapes, thick sheets, thin sheets, as well as pipes, forgings and stampings, strips, wires, hardware.

2 Chemical composition of steel St3 according to GOST 380-2005

2.1 Alloying elements:

Table 1

2.2 Impurities, no more than: - chromium: 0.30%; - nickel: 0.30%; - copper: 0.30%; - sulfur: 0.005%; - phosphorus: 0.04%;

— nitrogen: 0.10%.

2.3 Degrees of deoxidation of St3 steel

According to the method of deoxidation, St3 steel is divided into: - calm (deoxidation with manganese, silicon and aluminum); - boiling (deoxidation with manganese only) and

- semi-quiet (deoxidation by manganese and aluminum).

The degree of deoxidation is indicated in the steel designation with the letters “sp”, “kp” and “ps”, respectively.

In terms of chemical composition, boiling steel differs from calm steel in that it contains almost no silicon (less than 0.05%). Calm steel contains silicon from 0.15 to 0.30%. Since boiling steel contains more oxygen than calm steel, it is of worse quality than calm steel.

Semi-quiet steel occupies an intermediate position in quality between boiling and calm steels.

2.4 Deoxidation of St3 steel

Steel deoxidation is the process of removing oxygen contained in it from liquid steel. Oxygen is a harmful impurity that worsens the mechanical properties of the metal.

Deoxidation of steel consists of reducing the solubility of oxygen in steel by adding deoxidizing elements and creating conditions for the possible complete removal of the resulting deoxidation products from liquid steel.

Manganese, silicon and aluminum are mainly used for deoxidation of steels. Manganese is a relatively weak deoxidizing agent. Silicon is a stronger deoxidizing agent than manganese. Aluminum is the most powerful deoxidizer of steel.

3 Designation of steel St3: old and new

3.1 Designation of steel St3 according to GOST 380-2005

Strictly speaking, GOST 380-2005 does not provide for the designation of St3 steel in such a “pure” form as “St3” - without the letters “kp”, “ps” and “sp”. This standard defines steel grades St3kp, St3ps, St3sp, as well as their modifications with a high manganese content - St3Gsp and St3Gps.

The use of the St3 steel designation without accompanying letters is not provided for by the standard. Moreover, GOST 380-2005 states that if the order does not indicate the degree of deoxidation of steel, then it is established by the manufacturer.

  By the way, the cheapest to manufacture is boiling steel.

The full designation of any steel grade according to GOST 380-2005, that is, the one that must be indicated in the order, looks, for example, as follows:

St3Gsp GOST 380-2005

Here: St: designation of carbon steel of ordinary quality; 3: conventional number of the steel grade (there are seven of them in GOST 380-2005, depending on its chemical composition - 0, 1, 2, 3, 4, 5, 6); G: the letter G is present in the designation if the mass fraction of manganese in steel exceeds 0.8%;

cn: degree of deoxidation of steel.

True, it seems that a practice has developed whereby St3 steel is understood as St3sp. However, as we have seen, GOST 380-2005 does not formally provide for this.

3.2 Outdated designations for steel St3

There are outdated designations for steel St3, for example, VSt3ps5, and with references to the editions of GOST 380 from 1971, 1988, 1994 and even 1960, or even 1950!

GOST 380-1971 provided for the supply of steels of three groups: A, B and C with various options for guaranteeing mechanical properties and chemical composition.

Group A steels were designated in the same way as in the current GOST 380-2005, for example, St3kp. For steels of groups B and C, a corresponding letter was added to the front, for example, VSt3kp.

The current GOST 380-2005 (and even the earlier GOST 380-94), unlike earlier editions, determines only the chemical composition of steels. Mechanical and other properties determine the standards for specific types of rolled steel, for example, GOST 535-88 for long and shaped steel, and GOST 14637-89 for plates.

4.1 Rental categories according to GOST 535-2005

4.1.1 Depending on the standardized indicators of mechanical properties, rolled products are divided into categories from 1 to 7.4.1.

2 Indicators of mechanical properties that are used to control the mechanical properties of rolled products: - tensile strength: all categories; - yield strength: all categories except category 1; - relative elongation: all categories; - cold bending: all categories except category 1; — KCU impact strength at a temperature of +20 °C: category 3;— KCU impact strength at a temperature of –20 °C: category 4;— KCU impact strength after mechanical aging: category 5;— KCV impact strength at a temperature of +20 °C: category 6;

— impact strength KCV at a temperature of –20 ° C: category 7.

4.2 Mechanical properties of rolled products according to GOST 535-2005 from steel St3

4.2.1 Strength properties of rolled steel St3

table 2

4.2.2 Impact strength of rolled steel St3
Table 3

5 Application of steel St3

St3kp steel is used mainly for minor and lightly loaded elements of welded elements and non-welded structures operating in the temperature range from minus 10 to 40 °C.

Steels St3ps and St3sp are used in more critical cases, for example, for load-bearing and non-load-bearing elements of welded and non-welded structures and parts operating at positive temperatures.

Steels St3Gps and St3Gsp are used to produce shaped and sheet metal up to 36 mm thick for load-bearing elements of welded structures operating under variable loads in the range from -40 to + 45 °C, as well as for load-bearing elements of welded structures operating at temperatures from -40 to + 45 °C +45 °C.

6 Weldability of steel St3

St3 steel of all grades can be welded without restrictions. Welding methods: manual arc, automatic submerged arc and gas shield, electroslag, contact spot. For thicknesses greater than 36 mm, preheating and subsequent heat treatment are recommended.

7 Forging modes of St3 steel

Forging start temperature is 1300 °C. Forging end temperature is 750 °C.

Air cooling.

9 Flocks in steel St3

Not flake sensitive

Source: http://otlivka.info/articles/%D1%81%D1%82%D0%B0%D0%BB%D1%8C-%D1%81%D1%823-%D0%BF%D0%BE -%D0%B3%D0%BE%D1%81%D1%82-380-2005/

Steel grade St3 - characteristics and application

St3 steel can easily be called one of the most popular brands of steel alloys. This material can be found almost everywhere, from garden benches to complex welded structures. What causes this?

Chemical composition 

Grade St3 is classified as carbon structural steel of ordinary quality. The composition includes the following chemical elements:

• carbon up to 0.22%;
• silicon up to 0.17%;
• manganese up to 0.65% and many others, including chromium and nickel.

GOST

Metallurgical plants produce the following range of products from the St3 grade:

1. Forgings GOST 8479-70;
2. Rental GOST 2591-2006;
3. Strip and tape products GOST 14918-80;
4. Rails GOST 5812-82;
5. Pipes and fittings for them GOST 10705-80;

Decoding steel St3

The steel supplied to the customer must be marked in accordance with GOST 380-2005. The full name of St3 should be as follows St3Gsp GOST 380-2005. Its decoding is as follows:

• St – this is the designation for carbon steel of ordinary quality;
• 3 – serial number of the alloy grade according to GOST 380-2005;
• G is the designation for manganese. If the alloy contains more than 0.8%, then it must be indicated.
• Sp – level of deoxidation.

Steel C245 can be used as a substitute; this is defined in GOST 27772-88 and C285

Application of steel St3

The technical parameters of St3 allow it to be used for the production of loaded elements of welded structures and parts of machines and mechanisms operating at positive temperatures.

Some types of rolled products, in particular those of the fifth category, are used in the production of metal structures that can operate at temperatures from -40 to 425 degrees Celsius under alternating loads.

After constructing complex structures, it makes sense to carry out heat treatment, in particular annealing. This operation is necessary to relieve stress arising after welding work.

In addition, this material is used in the production of At400s construction reinforcement.

Sheets made from this steel are used for the production of parts produced using cold stamping technology. It is used to produce troughs for collecting coolants and waste oils installed on machines, containers of various sizes and purposes, covers for machine equipment, casings, etc.

Analogs

As already noted, the St3 grade is in demand in the production of various structures, and in fact, is the most popular structural steel. This is the reason why it is produced by metallurgical plants located in all parts of the world, for example:

• USA - A284Gr.D, A57036;
• Germany - 1.0038;
• Japan - SS330;
• European Union - Fe37-3FN;
• China - Q235.

Suppliers of steel produced outside our country must submit documents confirming the compliance of imported materials with domestic GOST and TU.

Technological properties

Steel of this grade has no restrictions on welding by any available method, incl. gas, electric.

The key indicators are the following:

• resistance to corrosion;
• mechanical characteristics;
• weldability.

These indicators make it possible to divide steel alloys into groups such as: regular, increased and high strength. For parts with a thickness or diameter greater than 36 mm, after welding it makes sense to perform heat treatment, which will relieve the stresses that arise in the weld area under the influence of high welding temperatures.

Mechanical restoration

The choice of cutting modes and selection of tools is an important part necessary for creating the correct technological process for processing parts made from St3.

For its turning or milling, a cutting tool made of hard alloys VK8, T5K10 is used. To obtain threads, both internal and external, taps and dies made of steels R18, R6M5 are used. When processing on turning-milling machines, it is advisable to use water-based coolants, for example, Emulsol. By the way, when cutting threads by hand, it is advisable to use castor oil, which makes the work much easier.

The choice of processing speed is made based on the properties of the steel, the technical parameters of the machine equipment and the type of processing. For example, with a workpiece diameter of 60 to 100 mm, it is permissible to use a turning tool with a holder size of 16x25 mm. With a cutting depth of 3 mm, the feed rate of the caliper should be from 0.7 to 1.2 mm per spindle revolution. When processing on a lathe, the spindle rotation speed is allowed within 700 rpm.

Production Features

The properties of the finished material are determined by the substances that make up its composition and largely depend on what technologies were used in the production of a particular alloy.

The basis of the steel alloy is ferrite. It is a component of iron-carbon alloys. It is, in fact, a solid solution of carbon and alloying components. To increase its strength, the melt is saturated with carbon.

Impurities from which nothing but harm can be expected include phosphorus and sulfur, as well as their derivatives. Phosphorus, reacting with ferrite, reduces the ductility of the alloy when exposed to high temperatures and increases brittleness when exposed to cold. During the melting process, iron sulfide may be formed, which can lead to red brittleness. St3 steel contains no more than 0.05% sulfur and 0.04% phosphorus.

For the production of structural steels, two steelmaking technologies are used:

• open hearth;
• converter

The parameters of the St3 grade, obtained by one or another method, differ little from each other, but the converter technology is simpler and cheaper.

Deoxidation of St3 steel

The deoxidation process is performed to remove excess oxygen, which reduces the mechanical properties of steel. For this purpose, silicon or aluminum is used. They neutralize oxygen, and the resulting oxides serve as a stimulus for the formation of crystallization centers and thereby contribute to the appearance of a fine-grained structure. Steels that have undergone this operation are divided into three types:

• calm - sp;
• semi-calm - ps;
• boiling - ks.

What are their differences from each other? Calm steels get their name because they do not boil when poured. They have a more uniform structure, are better processed by welding and exhibit good resistance to dynamic loads.

But, on the other hand, they are more expensive and that is why semi-quiet ones have become more widespread. They occupy a place between calm and boiling alloys. By the way, semi-quiet steels are most often used to create structures for various purposes.

To obtain it, a smaller amount of deoxidizing agent is used, mostly silicon.

An example is the use of St3 PS steel to create building structures.

It should be noted here that the steel must meet the requirements of GOST 380-71. When purchasing this brand, the supplier must provide documents with the results of testing the material for chemical composition, strength characteristics, tensile strength, etc.

Source: https://prompriem.ru/stati/stal-st3.html

Structural steel ST3KP

ST3KP steel belongs to the structural type, is boiling, carbon. It is characterized by standard quality and is used for the production of load-bearing structures, as well as minor elements in construction, used at positive temperatures. The alloy is very popular; converter and open-hearth furnaces are used to produce it.

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Decoding

Decoding of ST3KP steel in accordance with Gosstandart 380-2005 contains the information:

• ST – carbon steel of ordinary quality;
• 3 – composition number;
• KP – boiling.

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Application of steel

The characteristics of ST3KP steel ensure the effectiveness of using the material in the manufacture of load-bearing and secondary structures, machine parts and equipment. It can only be used at positive ambient temperatures. More universal products are obtained from rolled products of category 5. They can be used at temperatures of -40/+425 degrees, as well as under variable load.

Larsen tongue and groove from ST3KP

The creation of complex structures involves heat treatment as the final stage of production. The most popular is annealing, which reduces stress in elements after welding.

The scope of application of ST3KP covers the production of At-400S fittings. Sheets made from the alloy are subjected to cold stamping without reducing technical characteristics. The most widely used are troughs for collecting cutting fluids and oils, tanks, machine covers, casings, etc.

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Specifications

The characteristics of ST3KP steel include:

weldability	weldable;
hardness HB 10-1	131 MPa;
melting temperature	1300-1400 degrees;
density	7850 kg/m3;
elongation	23-25%;

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Price

The cost of steel is about 40 rubles. per kilogram. The final price depends on the order volume and delivery method. The material must comply with the requirements of State Standards 380-71 and 380-2005. Complete with the order, documents are supplied on the content of components in the composition, strength, tensile strength, impact strength of ST3KP steel.

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Assortment

This brand is used to make:

• pipes and fittings;
• rental;
• wire rod;
• thick sheet material.

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What is the difference between ST3KP steel and ST3SP?

The steel in question is boiling, and ST3SP is calm. In the first case, we are talking about an unoxidized product, in which non-metal impurities are present in large quantities. The second alloy is completely deoxidized; there are practically no slags and non-metals in it.

Calm steel does not boil when poured; it is homogeneous, easy to weld, and resistant to dynamic influences. However, its cost is higher.

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Weldability

ST3KP steel has no restrictions on welding; for this purpose the following methods can be used:

• RDS;
• manual ADS;
• EHS;
• automatic submerged;
• mechanized by a consumable electrode in a CO2 environment;
• contact

Welding work with parts thicker than 36 mm will require subsequent annealing.

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