Vst3sp steel is used as a substitute for steel st3.
Material hardness st.3: HB 10 -1 = 131 MPa
Weldability st 3: with no restrictions
Floken sensitivity of steel st.3: not sensitive
Tendency to temper brittleness: not inclined

Ordinary quality St3 is used for the manufacture of load-bearing and non-bearing elements for welded and non- welded structures, as well as parts operating at positive temperatures. Sheet and shaped steel of the 5th category (up to 10 mm) - for load-bearing elements of welded structures intended for operation in the range from -40 to +425 ° С under variable loads.

Alloy St3 contains: carbon - 0.14-0.22%, silicon - 0.05-0.17%, manganese - 0.4-0.65%, nickel, copper, chromium - up to 0.3%, arsenic up to 0.08%, sulfur and phosphorus - up to 0.05 and 0.04%, respectively.

Technological properties of steel grade st3

Steel st3 not prone to temper brittleness, non-flake sensitive. weldability without limits.

The quality of structural steel is determined by corrosion resistance, mechanical properties and weldability. According to their mechanical characteristics, steels are divided into groups: steel of ordinary, increased and high strength.

The main properties of steel directly depend on the chemical elements that make up the alloy and technological features production.

The basis of the structure of steel is ferrite. It is low-strength and ductile, cementite, on the contrary, is brittle and hard, and perlite has intermediate properties. The properties of ferrite do not allow its use in building structures in its pure form. To increase the strength of ferrite, steel is saturated with carbon (common-strength steels, low-carbon steels), alloyed with chromium, nickel, silicon, manganese and other elements (low-alloy steels with a high strength factor) and alloyed with additional thermal hardening (high-strength steels)

Harmful impurities include phosphorus and sulfur. Phosphorus forms a solution with ferrite, thus reducing the metal's ductility at high temperatures and increasing its brittleness at low temperatures. The formation of iron sulfide with an excess of sulfur leads to red brittleness of the metal. In the composition of steel st3, no more than 0.05% sulfur and 0.04% phosphorus are allowed.

At temperatures insufficient for the formation of a ferrite structure, carbon can be released and accumulated between grains and near crystal lattice defects. Such changes in the structure of steel reduce the resistance to brittle fracture, increase the yield strength and tensile strength. This phenomenon is called aging, due to the duration of the process of structural changes. Aging is accelerated in the presence of temperature fluctuations and mechanical influences. Gas-saturated and contaminated steels are most susceptible to aging.

Structural steels are produced by open-hearth and converter methods. The quality and mechanical properties of BOF and open-hearth steels are practically the same, but the BOF method is simpler and cheaper.

According to the degree of deoxidation, calm, semi-quiet and boiling steels are distinguished. Boiling steels are non-deoxidized. When poured into molds, they boil and become saturated with gases. Little to improve quality carbon steels deoxidizers are used - additives of silicon (0.12 - 0.3%) or aluminum (up to 0.1%). Deoxidizers bind free oxygen, and the resulting aluminates and silicates increase the number of crystallization centers, contributing to the formation of a fine-grained structure. Deoxidized steels are called calm, because. they do not boil when poured. Quiet steels are more homogeneous, less brittle, weld better and resist dynamic loads well. They are used in the manufacture of critical structures. The high cost limits the use of calm steel, and for technical and economic reasons, semi-quiet steel is the most common structural material. For deoxidation of semi-quiet steel, a smaller amount of deoxidizer, mainly silicon, is used. In terms of quality and price, semi-quiet steels occupy an intermediate position between boiling and calm ones.

From the group of low-carbon steels of ordinary power (GOST 380-71, as amended), steel grades St3 and St3Gps are used for building structures. St3 steel is produced calm, semi-calm and boiling.

Depending on the operational requirements and type of structures, the steel must meet the requirements of GOST 380-71. Carbon steel is divided into 6 categories. When supplying steel grades VSt3Gps and VSt3 of all categories, a guaranteed chemical composition, relative elongation, yield strength, tensile strength, cold bending.

Toughness requirements vary by category.

When marking steel in accordance with GOST 380-71 (as amended), they first put the designation of the delivery group, then the grade, degree of deoxidation and category.

According to GOST 23570-79, more stringent quality control of steel and limits on the content of arsenic and nitrogen are established. The brand designation includes the percentage of carbon (in hundredths of a percent), the degree of deoxidation and the letter G for manganese steels.

Features of Ss3sp steel and electroslag welding: carbon steels are the most common structural material. In terms of the scope of application, steels of this class are superior to all others. Carbon steels include steels with a content of 0.1-0.7% C, with the content of other elements not more than: 0.8% Mn, 0.4% Si, 0.05% P, 0.05% S, 0.5 % Cu, 0.3% Cr, 0.3% Ni. In table. 9.1 shows the chemical composition and mechanical properties of steels that have found application in the manufacture of welded structures using electroslag welding.

According to the method of production, open-hearth and converter steels are distinguished, according to the degree of deoxidation (in ascending order), boiling, semi-calm and calm.

Quiet carbon steels enter the industry in the form of castings and forgings in accordance with GOST 977-75, in the form of hot-rolled steel of ordinary quality in accordance with GOST 380-71, high-quality structural hot-rolled section steels in accordance with GOST 1050-74. The main distinguishing feature of these steels is their carbon content.

The strength characteristics of carbon steels increase with increasing carbon content, while their weldability deteriorates, as the risk of hot cracks in the seam increases. With a content of more than 0.5% C, steels are practically not welded by electroslag welding without special techniques.

The sensitivity to hot cracks in the weld increases with the increase in the rigidity of the welded structures. Preheating and postheating can significantly reduce the risk of cracking, even when welding rigid joints (for example, in the area of ​​\u200b\u200bclosing a girth weld). One of the radical means of preventing hot cracks is to reduce the feed rate of the electrode wire.

Carbon steels are currently welded with wire electrodes, large cross-section electrodes, or consumable nozzles. The most widely used wire electrodes and consumable mouthpieces.

The most appropriate way to increase the strength of the weld metal is to increase the manganese content, since this is not accompanied by a decrease in the technological strength of the weld metal. Manganese increases the tendency of the metal to harden and strengthens the ferrite. So, when alloying the weld metal with 1.5% Mn (0.12-0.14% C), the same strength characteristics are achieved as with 0.22-0.24% C (0.5-0.7% Mn ). The weld metal in the first case has a greater resistance to crystallization cracks and against the transition to a brittle state. Small additions of nickel, chromium and other alloying elements to the weld metal also have a positive effect on strength.

For electroslag welding of carbon steels, flux AN-8 and welding wires of the grades Sv-08, Sv-08A, Sv-08 GA, Sv-08G2S, Sv-10G2 (GOST 2246-70) are most often used. Yes, at

When welding steels 15, 15L, St2, equal strength joints can be obtained using wires Sv-08 and Sv-08A. When welding low-carbon steel StZ, wire Sv-08GS is used.

state standard

UNION SSR

GOST 380-88

Official edition

USSR STATE COMMITTEE FOR PRODUCT QUALITY MANAGEMENT AND STANDARDS

UDC 669.14: 006.354 Group B20

STATE STANDARD OF THE UNION OF THE SSR

STANDARD GRADE CARBON STEEL

Common quality carbon steel. Grades OKP 08 7010

GOST 380-88

Date of introduction 01.01.90

1. Carbon steel of ordinary quality is made of the following grades: STO, St1kp, St1ps, St1sp, St2kp, St2ps, St2sp, StZkp, StZps, StZsp, StZGps, StZGsp, St4kp, St4ps, St4sp, Stbps, Stbsp, StbGps, Stbps, Stbsp.

The letters St stand for "Steel", the numbers - the conditional number of the grade depending on the chemical composition of the steel, the letters "kp", "ps", "sp" - the method of deoxidation ("kp" - boiling, "ps" - semi-calm, " sp "- calm).

2. The method of deoxidation, if it is not specified in the order, is set by the manufacturer.

3. The chemical composition of steel according to the melting analysis of the ladle sample must comply with the standards specified in Table. one.

4. In steel grade StZsp, intended for further processing into rolled sheets, manufactured with rationing of impact strength, the mass fraction of acid-soluble aluminum must be at least 0.02%. When deoxidizing steel with titanium, aluminum is not standardized, and the mass fraction of residual titanium is not more than 0.03%.

5. The mass fraction of chromium, nickel and copper in steel should be no more than 0.30% each.

5.1. In steel made by the scrap process, the mass fraction of copper is allowed up to 0.40%, chromium and nickel - up to 0.35% each with mass fraction carbon not more than 0.20%.

Official Edition ★

© Standards Publishing, 1988 © Standards Publishing, 1991

Reissue with change

This standard cannot be fully or partially reproduced, replicated and distributed without the permission of the State Standard of the USSR

5.2. For steel grades StZkp, StZps, StZsp, StZGps and StZGsp, manufactured by the scrap process, a mass fraction of copper is allowed up to 0.40% with a mass fraction of carbon not more than 0.20% and a mass fraction of chromium, nickel and copper in the amount of not more than 0 .80%.

Table 1 .

Note. It is allowed in the NTD for specific types of metal products, provided that a standardized set of properties is provided, clarification:

lower limit mass fraction carbon or manganese;

the lower limit of the mass fraction of silicon during the deoxidation of semi-quiet steel with aluminum, titanium or other deoxidizers that do not contain silicon, as well as several deoxidizers (ferrosilicon and aluminum, ferrosilicon and titanium, etc.).

(Revised edition, Rev. No. 1).

6. In steel intended for the manufacture of long, shaped and sheet products, the upper limit of the mass fraction of manganese increases by 0.2%, except for steel grades StZGps, StZGsp, StbGps.

7. Mass fraction of nitrogen in steel - no more than 0.008%, and when smelted in electric furnaces - no more than 0.012%.

8. The mass fraction of sulfur in steel of all grades, except STO, should be no more than 0.050%, phosphorus - no more than 0.040%, in steel grade STO sulfur - no more than 0.060%, phosphorus - no more than 0.070%.

9. The mass fraction of arsenic in steel should be no more than 0.08%.

In steel smelted on the basis of Kerch ores, the mass fraction of arsenic is not more than 0.15%, phosphorus is not more than 0.050%.

10. Limit deviations in chemical composition in finished rolled products must correspond to those given in table. 2.

table 2

Note. For rolled steel grades StZps, StZsp, StZGps and StZGsp, intended for welded structures, positive deviations in the mass fraction of carbon are not allowed.

11. Chemical analysis of steel for the content of chromium, nickel, copper, arsenic, nitrogen, and in boiling steel also for silicon content, may not be carried out if the standards are provided by the manufacturing technology.

In steel smelted on the basis of Kerch ores, the determination of arsenic is mandatory.

12. Sampling methods for determining the chemical composition of steel - according to GOST 7565-81.

13. Chemical analysis of steel - according to GOST 22536.0-87, GOST

22536.1-88, GOST 22536.2-87, GOST 22536.3-^-88, GOST

22536.4-88, GOST 22536.5-87, GOST 22536.6-88, GOST

22536.7-88, GOST 22536.8-87, GOST 22536.9-88,- GOST

22536.10-88, GOST 22536.11-87, GOST 27809-88, GOST 17745-90, GOST 18895-81 or other methods approved in the prescribed manner and providing the required accuracy.

In case of disagreement between the manufacturer and the consumer, the assessment is carried out by standard methods.

14. For marking products, use the paint of the colors shown in Table. 3.

By agreement between the manufacturer and the consumer, paint marking is not performed.

Table 3

GOST 380-88 S. 5

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR

DEVELOPERS

D.K. Nesterov (Head of Department), Ph.D. tech. sciences; S. I. Rudyuk (head of direction), Ph.D. tech. sciences;

V. F. Kovalenko (supervisor), Ph.D. tech. sciences;

Steel is an alloy of iron, carbon and impurities, while the proportion of iron in it is at least 45%. Raw materials are obtained by processing cast iron using converter, open-hearth, electrothermal methods. The essence of the process is the optimization of the steel composition in accordance with the current state standards: steel enrichment with carbon, deoxidation, etc.

GOST 380-2005 normalizes the production of carbon steel of ordinary quality, which also includes steel grade St3. It is intended for the manufacture of long and shaped steel, thick and thin sheets, broad strip and cold-rolled thin sheets. Pipes, stampings and forgings, tapes, wires and hardware - all this is obtained from St3 steel.

Physicochemical characteristics

The characteristics of steel St3 are the basis for the widest application. Without St 3 steel, in our time it is not possible to build, build underground and surface communications, produce transport, and even machine tools and assemblies.

From this type of raw material, a steel sheet, a circle, a beam, a hexagon, a channel are obtained - the most popular products of ferrous metal.

About steel deoxidation

Steel deoxidation is a chemical process of removing oxygen from molten raw materials, which in this case is determined by an impurity that degrades the mechanical properties of the alloy.

For deoxidation, elements such as manganese, silicon, and aluminum are used. The strength of their impact varies. So, the "weakest" is manganese, "strong" - aluminum.

It should be noted that steel 3 (GOST 380-2005) is marked only with the specification of the degree of deoxidation (“kp”, “ps” and “sp”). There are steel grades St3kp, St3ps, St3sp, their modifications with a high content of manganese (St3Gsp and St3Gps).

Steel deoxidized with manganese, silicon and aluminum is called calm and is designated by the letter combination “sp”, manganese and aluminum - semi-calm (“ps”), only manganese - boiling (“kp”).

Quiet steel is the most expensive steel in terms of cost. It is devoid of oxygen, characterized by a homogeneous (homogeneous) structure, which is designed by its nature to give the alloy ductility and maximum resistance to corrosion. Calm steel alloy St3 (GOST 380-2005) is used in the construction of rigid metal structures, load-bearing and non-bearing elements. From this steel grade are made:

Semi-quiet steels occupy a middle position between calm and boiling types of raw materials. They contain oxygen, which gives the raw material less pronounced properties of hardness and plasticity.

The chemical composition cannot be called homogeneous. From the grade of this steel, sheet and pipe products are produced, such famous product like a beam. Semi-quiet steels are also used for the manufacture of strips and circles, squares and corners, hexagons and embedded parts.

As for boiling steels, these are the most affordable structural steels. The cost of production is low, but at the same time, products made from such steel (ingots, slabs, finished sheets) are perfectly processed under any thermal conditions.

In terms of density, steel 3 of this modification is not uniform, however, with proper use and compliance with the relevant requirements, it is one of the most inexpensive and practical types of raw materials.

GOST 380-2005 states that the manufacturer has the right to independently determine the degree of deoxidation of the alloy, if the customer has not determined it.

Features of the chemical composition of steel grade St3

In the chemical composition of St3 elements (according to GOST 380-2005), the mass fraction of carbon ranges from 0.14 to 0.22%, depending on the same degree of deoxidation. The manganese content is 0.3 -1.10, silicon - from 0.05 to 0.30. Impurities - chromium, nickel, phosphorus, copper, sulfur, nitrogen make up about 1%.

It should be noted that one of the main deoxidizers in steelmaking today is silicon. In fact, this element determines the type of steel. In semi-calm steels, its content reaches 0.10%, while in calm steels it reaches 0.40%.

Silicon increases the strength of ferrite, almost without reducing its plasticity, at a concentration in the alloy up to 0.30%, it completely dissolves. It is known that the content of this element in a larger volume (more than 0.40%) only worsens the noted steel 3 characteristics.

In combination with manganese or molybdenum, silicon provides the alloy with high hardenability, increases the elastic limit and yield strength, and imparts resistance to temperature extremes. It is the density of steel 3, deoxidized and enriched in this way, that determines its demand and a wide range of applications.

Weldability of steel St3

Consumers like steel 3: specifications it, taking into account modifications, is universal. One of the important advantages of the brand is good weldability.

The alloy allows the use of manual and automatic arc welding methods (submerged arc and gas), as well as electroslag and contact-spot methods. Steel 3 is also used for the production forged products(various gratings, fences, etc.).

Steel grade St3 in a standard order is as follows: for example, St3Gsp GOST 380-2005. Here:

"St" - carbon steel of ordinary quality;

3 - conditional number of the steel grade (depending on the chemical composition, all of them are written in GOST 380-2005 - seven)

G - marking of the mass fraction of manganese with a share in the composition - above 0.8%;

"Sp" - the degree of deoxidation of steel.

Steel is an alloy consisting of carbon, iron and impurities, while the percentage of iron in it must be at least 45. 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: enrichment with carbon, deoxidation, etc. The composition must comply with the current GOST.

St3 grade steel is intended for the production of shaped and sectional, thin and thick sheets, cold-rolled and wide-strip thin sheets. Also from this steel grade 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, build ground and underground communications, produce vehicles, units and machine tools.

Impurities in steel of this grade, 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

Steel deoxidation is a chemical process in which oxygen is removed 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, steel grade St3 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 steel marking with the letters “kp”, “sp” and “ps”, and their modification with an increased percentage of manganese is also indicated. For example - St3Gsp or St3Gps.

boiling steel, in chemical composition, differs from the calm one in that the content of silicon in it is very small, less than 0.05 percent. Quiet steel contains more silicon from 0.16 to 0.30 percent. Since boiling steel contains more oxygen than calm steel, it is much worse in quality than calm steel.

Steel semi-calm in quality occupies a middle position 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 weakest is manganese.

Calm Steel- is the most expensive steel in terms of cost. There is no oxygen in it, it is characterized by a homogeneous (homogeneous) structure, which, due to its nature, is designed to give the alloy maximum protection against impacts. environment in the form of corrosion and ductility. Calm steel alloy St3 according to GOST 380-2005 adopted in 2005, is used during the construction of rigid trusses and other metal structures, non-bearing and load-bearing elements. From this steel grade they make:

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

Semi-calm steel 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. Pipe and sheet products are made from the brand of this steel, such a popular product as the St 3 beam. Semi-calm steels are also used for the production of circles and strips, corners and squares, embedded parts and hexagons.

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

Density of steel grade 3 This modification is quite heterogeneous, however, subject to proper use and appropriate requirements, it occupies one of the most popular and inexpensive, practical types of alloys.

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

Mechanical indicators

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

Weldability of steel grade St3

Consumers like to work with this steel grade. Its technical characteristics, taking into account modifications, are very versatile. 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.).

How the designation of the St3 brand is deciphered

According to GOST 380-2005, the designation of steel St3 is not provided in this form "St3" - without the addition of "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 use of the designation of the St3 alloy without accompanying indices is not provided for by the standard. In addition, GOST 380-2005 states that if the manufacturer has not indicated the degree of steel deoxidation, then the manufacturer has the right to establish it.

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

Let's decipher:

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

Old designations brand St3

Sometimes you still come across outdated markings of St3 steel, for example, VSt3ps5, and with footnotes to the editors GOST 380 of 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, respectively, C with different guarantees of the 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. To the steels of groups C and B, a letter corresponding to the groups 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 the alloys. Mechanical and other characteristics define the standards for concrete types rolled steel, for example, GOST 535-88 for shaped and long products, and GOST 14637-89 for thick-plate type of rolled products.

Chemical composition in% steel St3sp
C	0,14 - 0,22
Si	0,15 - 0,3
Mn	0,4 - 0,65
Ni	up to 0.3
S	up to 0.05
P	up to 0.04
Cr	up to 0.3
N	up to 0.008
Cu	up to 0.3
As	up to 0.08
Fe	~97

Features of Ss3sp steel and electroslag welding: carbon steels are the most common structural material. In terms of the scope of application, steels of this class are superior to all others. Carbon steels include steels with a content of 0.1-0.7% C, with the content of other elements not more than: 0.8% Mn, 0.4% Si, 0.05% P, 0.05% S, 0.5 % Cu, 0.3% Cr, 0.3% Ni. In table. 9.1 shows the chemical composition and mechanical properties of steels that have found application in the manufacture of welded structures using electroslag welding.

According to the method of production, open-hearth and converter steels are distinguished, according to the degree of deoxidation (in ascending order), boiling, semi-calm and calm.

Quiet carbon steels enter the industry in the form of castings and forgings in accordance with GOST 977-75, in the form of hot-rolled steel of ordinary quality in accordance with GOST 380-71, high-quality structural hot-rolled section steels in accordance with GOST 1050-74. The main distinguishing feature of these steels is their carbon content.

The strength characteristics of carbon steels increase with increasing carbon content, while their weldability deteriorates, as the risk of hot cracks in the seam increases. With a content of more than 0.5% C, steels are practically not welded by electroslag welding without special techniques.

The sensitivity to hot cracks in the weld increases with the increase in the rigidity of the welded structures. Preheating and postheating can significantly reduce the risk of cracking, even when welding rigid joints (for example, in the area of ​​\u200b\u200bclosing a girth weld). One of the radical means of preventing hot cracks is to reduce the feed rate of the electrode wire.

Carbon steels are currently welded with wire electrodes, large cross-section electrodes, or consumable nozzles. The most widely used wire electrodes and consumable mouthpieces.

The most appropriate way to increase the strength of the weld metal is to increase the manganese content, since this is not accompanied by a decrease in the technological strength of the weld metal. Manganese increases the tendency of the metal to harden and strengthens the ferrite. So, when alloying the weld metal with 1.5% Mn (0.12-0.14% C), the same strength characteristics are achieved as with 0.22-0.24% C (0.5-0.7% Mn ). The weld metal in the first case has a greater resistance to crystallization cracks and against the transition to a brittle state. Small additions of nickel, chromium and other alloying elements to the weld metal also have a positive effect on strength.

For electroslag welding of carbon steels, flux AN-8 and welding wires of the grades Sv-08, Sv-08A, Sv-08 GA, Sv-08G2S, Sv-10G2 (GOST 2246-70) are most often used. Yes, at

When welding steels 15, 15L, St2, equal strength joints can be obtained using wires Sv-08 and Sv-08A. When welding low-carbon steel StZ, wire Sv-08GS is used.