Steel and flux cored welding wire

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Welding wire is produced in accordance with GOST 2246-70. Self-shielded wire is used on semi-automatic machines as the main one without using gas to close the bath. The classification is made by type of material, coating and diameter.

Each cassette has a passport, which indicates the technical characteristics of the material, the recommended current strength, voltage, article number. The coil is most often plastic and 15 kg of wire is wound on it. Material grade, diameter and manufacturer are indicated on the reel. The marking contains the main parameters of the material.

Chief Technologist of the Section for the Production of Rolled and Drawn Products of the Steel Rolling Metallurgical Plant Yuryev N. It is made from metal strips by twisting and rolling on special rolls while hot. Wire rod can be used as blanks for the production of thin steel thread and packed into coils. For construction, it is produced in the form of long rods cut to size. They make electrodes from wire rod. "

Copper-plated

Copper-plated welding wire has high current conductivity, low contact resistance. Welding performance is significantly higher than that of coated electrodes. Little spatter is generated. The emission of harmful substances during the combustion of copper flux is minimal.

Copper-plated wire is used for welding parts made of low-carbon and low-alloy steels:

• pipelines;
• pressure tanks;
• shipbuilding;
• mechanical engineering;
• in the production of rolling stock.

Copper plating technology requires sophisticated equipment. The copper plating process is an electrochemical reaction that takes place within the strict limits of the temperature regime and the concentration of the solution. Compared to the coating with a layer of protective flux, copper plating is much more expensive. Materials are used for welding the elements of critical parts and structures.

What is needed for welding

• Power source (semiautomatic device);
• welding wire;
• shielding gas.

The welding wire must be identical to the metal to be welded. In our case, choose a stainless steel for a semiautomatic device.

Welding wire stainless steel for semiautomatic device

There are wires of Russian and foreign manufacturers on the market, which are subdivided into flux-cored and solid wires. Diameter from 0.13 to 6.0 mm. At home, diameters of 0.6 and 0.8 mm are used, and over 1.0 mm in production.

1. Solid wire is used for gas-shielded and submerged-arc connections. This method eliminates the ingress of air into the welding zone, thereby improving the quality of the weld.
2. Flux-cored stainless steel wire (self-shielded) - a thin-walled tube filled with flux and gas. The mixture of components allows welding products without protective gases (carbon dioxide and argon).

Semi-automatic stainless steel wire, produced with heat treatment or cold drawn. And it is subdivided into oxidized (T) and light (white, TC).

Stainless wire is available in 2 accuracy classes:

• increased accuracy (P);
• normal precision.

The wire is used with increased accuracy to improve the quality of the seam.

According to their chemical composition, stainless steels are divided into different grades and the wire also has different markings. The table (below) will acquaint you with the brands, diameter and weight of stainless wires:

The cost of stainless wire for a semiautomatic device

The price varies depending on the manufacturer and the region of residence of the buyer.

Average indicators:

• ER 308 LSI 0.8mm 1kg - 825 rubles;
• ER 308 LSI 0.8mm 5kg - 4237 rubles.

Video:

Gas selection

It is impossible to cook with a semiautomatic device without gas, except when using flux-cored wires. Welding of stainless steel with a semiautomatic device can be performed in an environment of carbon dioxide or a mixture of carbon dioxide and argon.

Carbon dioxide is an affordable and cheap gas for joining stainless steels. When used cleanly, the welder is faced with excessive metal spatter and a gnarled weld bead.

The percentage of carbon dioxide to argon can be adjusted using two separate cylinders. Connect the outputs from the two gearboxes using a tee taken from a domestically produced car windshield wiper. Details of a similar design in the video:

That's it, you just have to connect the selected shielding gas and wire to the device. Be aware: the conductive tip must be the same diameter as the wire.

Video: how to set up a semiautomatic device for work (for beginners).

How to weld stainless steel in carbon dioxide

After chamfering, join the parts with the help of clamping pliers, leaving a gap between the products (at least 1.5 mm).

The gap should be along the entire length of the workpiece, it will allow the metal to be boiled to its full thickness. Connect the mass and set your settings on the semiautomatic device, depending on the design of your device and the thickness of the metal.

Simple semiautomatic devices on the front panel have 2 adjustments:

• welding voltage;
• wire feed speed.

The inductance setting changes the arc hardness, penetration depth and bead shape:

1. With low inductance: cold arc - we get a thin bead with deep penetration;
2. With high inductance: hot arc - wide bead with shallow penetration.

Holding the torch with a slope of 20-60 degrees (distance from the nozzle to the weld pool 10-20 mm), make a stainless steel connection with short tacks. We pulled the trigger - released it, pressed it and released it, just like that, slowly, the cut edges are filled with metal. You can cook both with an angle back (towards yourself) and with an angle forward (away from you).

The tables (below) will help you determine the settings for the semiautomatic device:

When welding with an overlap, chamfers do not need to be cut, it is enough to clean the surface, superimpose the parts on top of each other and make the connection.

When welding, bite off the weld bead on the tip of the wire before making a new weld.

In the process of joining stainless steel with a semiautomatic device in an environment of carbon dioxide, change the wire feed speed, with such manipulations you will achieve a high-quality seam.

Video:

P.S. After reading the article, watching the tables and videos (for beginners), you will master the automatic technology of stainless steel joining - quickly. Good luck!

Steel

The wire is distinguished by its purpose: for welding or surfacing.

In total, about 80 brands of wire are produced.

The letters "Sv" mean that the wire is welding. The brand of steel from which the wire is made is indicated with a hyphen. The first number corresponds to the carbon content in hundredths of a percent. Letters indicate the presence of alloying elements in percent, which are indicated by the number following the letter designation.

Six grades are used for welding low-carbon steels: Sv-08, Sv-08A, Sv-08AA, Sv-08GA, Sv-10GA, Sv-10G2,

For low and medium alloy steels - 30 grades, for example: Sv-08GS, Sv-08G2S, Sv-18KhGS, etc.

For welding high-alloy steels, 41 grades of wire Sv-08X14GNT, Sv-12X13, etc. are used.

If there is no number after the letter, then the amount of this element does not exceed 1%. The letter "A" at the end of the marking indicates a reduced content of sulfur and phosphorus, and the letter "AA" - about even less of them.

Low-carbon and alloyed wires are produced non-copper-plated and copper-plated (symbol - O). Copper plating protects the wire from oxidation and improves the current supply.

At the end of the marking, there may be the letter "E". "E" means that the wire is used to make electrodes. The letters "Ш", "ВД" or "VI" indicate that the steel for the wire was made, respectively, by electroslag, vacuum-arc remelting or in vacuum-induction furnaces.

An example of a symbol for a welding wire with a diameter of 3 mm, grade Sv-08A, with a copper-coated surface made of steel obtained by electroslag remelting:

Welding wire for medium carbon and heat resistant steels

Steel welding wire is produced in the following diameters (mm): 0.3; 0.5; 0.8; 1.0; 1.2; 1.4; 1.6; 2.0; 2.5; 3.0; 4.0; 5.0; 6.0; 8.0; 10.0 and 12.0, The wire is supplied in coils with a diameter of 150-750 mm, weighing from 1.5 to 40 kg, as well as wound on spools and cassettes.

The surface of the wire must be clean and smooth, without cracks, delamination, captivity, sunsets, shells, nicks, scale, rust, oil and other contaminants.

If necessary, the wire is cleaned with a sandblaster or etching in a 5% hydrochloric acid solution. You can clean the wire by passing it through special mechanical devices, as well as with sanding paper to a metallic sheen. Before cleaning, it is recommended to anneal a coil of wire at a temperature of 150-200 ° C for 1.5-2 hours.

A certificate is required indicating the manufacturer, wire symbol, heat and batch number, surface condition and its chemical composition. If the certificate is lost, the wire can be used only after determining its chemical composition.

Inert gas arc welding wire

Characteristics of SV08G2S welding wire, application features and tips

To obtain a high quality weld, it is necessary to select the appropriate materials, called consumables. Welding wire SV08G2S by most of the indicators has high characteristics and is used in many industries. Product specifications are reflected in GOST No. 2246 of 1970.

Application feature

For welding carbon, low-alloy steels belonging to group 1 with strength class up to K54. The use of this wire reduces the risk of electrode sticking and reduces the intensity of metal spatter. The ability to work with various types of welding equipment is provided.

Seam characteristics

• Temporary tear resistance - from 500 (MPa).
• Ultimate fluidity - 400 (MPa).
• Elongation (relative) - from 18%.
• Viscosity (impact) - from 50 J / cm2 (at t0 = 20 0С).

Decoding of marking

• Sv - for welding.
• 0.8 - the percentage of carbon (and in hundredths).
• D - alloying chemical / element (manganese).
• The next figure "2" is its content (in%).

Delivery specifics

Wire SV08G2S comes to the market, as a rule, in spools of 15 or 5 kg. However, the best option is to purchase material in packaging (without winding on a reel) - 80, 250 kg. In this case, the minimum wear of the feeding system is ensured, since the wire comes out "directly". And its cost per unit of weight is lower.

The wire can be both non-copper-plated and with a copper coating (in the designation letter "O"). The latter is "hard" calibrated to reduce tip wear.

What can be replaced

In practice, it often happens that due to the lack of the necessary material, in order to avoid downtime and disruption of the work schedule, you have to look for a "backup" option, using one or another product of similar characteristics, the use of which will not affect the quality of operations for the worse. Wire SV08G2S can be replaced with such samples as "ER" 70-S or 49, OK 12-51, Novofil G3Si1 or W10.

Price

It depends on many components (section, with copper plating or not, manufacturer, purchase volume). Approximate price - from 64 rubles / kg. For example, copper-plated wire 1.2 mm weighing 15 kg will cost about 1,450 rubles.

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Features and benefits of copper-plated welding wire.

This type differs from other types of wire used for welding by the presence of a special coating of copper alloys. Its thickness is 6 microns, and the main task is to ensure maximum contact with the workpiece to be welded during the welding process.

In this case, the diameter of the wire itself can be different and depends on the specific requirements for the product and the characteristics of the parts to be welded. The most popular on the market is wire with a diameter of 0.8 to 1.6 mm.

The copper coating not only simplifies the process of welding the steel product itself, but also gives the weld seam additional technical characteristics. The seam acquires the ability to easily withstand mechanical loads (shock), does not collapse from high-temperature exposure and a sharp temperature drop, and also has a high tensile strength.

The most important requirement that a high-quality copper welding wire must meet is the uniformity of the coating. Only this characteristic makes it possible to fully guarantee the stability of its supply during the welding process at a variety of, including the most powerful, modes of operation of the welding equipment.

Another feature that copper-plated welding wires and copper electrodes have for welding is the low amount of spatter produced during operation. This allows you to more economically spend consumables (in some cases, the savings can be up to 40%) and at the same time to obtain a weld of a higher quality, which does not have irregularities, metal sagging, uncooked spots and other shortcomings.

Finally, it should be noted that a filler wire with a perfectly flat coating can increase the feed rate of consumable material during the welding process, which leads to an increase in the productivity of the welder. This is also facilitated by a special orderly technology of dense winding of the wire on a coil - along its entire length it does not have overlaps or other winding defects that can complicate the process of its feeding to the place of welding.

Classification

The signs by which the welding wire is classified are as follows:

• appointment;
• type of surface;
• structure;
• chem. composition.

According to the intended purpose, the products are of general and special purpose. Special-purpose wire is intended for specific work - underwater welding, welding of fittings, bath welding, etc. This wire has a chemical composition that simplifies the above work and contributes to obtaining a welded joint of the highest quality.

General-purpose wire is intended for welding, used in surfacing and in the manufacture of various types of electrodes (the letter E is present in the marking).

By the type of surface, the wire is produced non-copper-plated and copper-plated (the letter O is present in the marking). Copper-plated wire is used for welding structures and products made of carbon or low-alloy steel. Its purpose is to create anti-corrosion protection for the seam, as well as contribute to the stability of the arc burning.This is especially true when carrying out gas welding.

The structure of the wire is solid, flux-cored and activated.
The composition of the steel from which the wire is made is of great importance when choosing it for welding a particular grade of metal and depends on the conventional designation - marking.
Wire designation

Chem. the composition of the steel grades from which the wire is made is stipulated in GOST 2246-70 and according to it there are 6 grades made from steel grades with a low carbon content, 30 grades - from alloy steel and 41 grades - from high-alloy steel. A wire is considered low-carbon if the total content of alloying elements in it is less than 2.5%, alloyed if the total content of these elements is in the range from 2.5 to 10%, and highly alloyed - more than 10%. The wire has a symbol that indicates the quantitative content of various elements in its composition.

The marking consists of numbers and letters, where numbers are the number of elements that make up the wire in%, and letters are the name of the chemical element. The welding wire can be composed of the following elements:

• A (N) - nitrogen;
• B (Nb) - niobium;
• B (W) - tungsten;
• D (Cu) - copper;
• M (Mo) - molybdenum;
• H (Ni) - nickel;
• C (Si) - silicon;
• T (Ti) - titanium;
• Yu (Al) - aluminum;
• F (V) - vanadium;
• X (Cr) - chromium;
• C (Zr) - zirconium.

A number must be put in front of the marking. After it, St. is written through a hyphen. The number indicates the Ø of the wire in mm, and St. indicates that it is intended for welding. After St. there are numbers indicating the amount of carbon (in hundredths of a%).
At the end of the marking, there may be letters:

• A - the content of phosphorus (P) and sulfur (S) is reduced in steel;
• AA - the wire is made of metal, in which P and S are the minimum amount, i.e. the metal is cleaned as much as possible from these impurities.

Sulfur and phosphorus negatively affect the weldability, therefore, when welding critical structures, it is imperative to choose wire grades with a reduced amount of them.

An example of a symbol for the most used wire grade during welding and its decoding:

3-Sv08G2S

where:

• 3 - diameter in mm;
• Sv - welding wire;
• 08 - contains 0.08% carbon;
• G2 - contains 2% manganese;
• C - contains up to 1% silicon.

Sv08G2S is also used for manual arc welding, when surfacing and when performing work with the help of semiautomatic devices and automatic machines. It is used to weld critical pressure vessels, structures made of various steels, pipelines, boilers, etc. Solid wire is available from Ø 0.3 to 12 mm.

Selection and configuration of equipment

Semi-automatic welding machine for aluminum

Welding of aluminum with standard MIG machines is conditional, i.e. you can cook with it, but you should not expect a good result.

The optimal solution in the selection is a semiautomatic device for welding aluminum with a pulse mode. The pulses break through the oxide film, reduce overheating of aluminum and reduce the likelihood of burn-through.

DC pulsed aluminum welding

Synergic pulse-arc devices equipped with a special program make the task even easier. The welder needs to decide on the choice of alloys to be welded and select the appropriate program. Next, set the current value with the push-button regulator. The selection of the rest of the parameters is carried out by the microcontroller automatically.

I would like to note that these semiautomatic devices are not a cheap pleasure and are justified in professional use. At home, it is quite possible to do with equipment without fancy programs, however, the quality of the weld will be incomparable.

When buying a universal welding semiautomatic device in the price range up to 40 thousand rubles, designed for welding non-ferrous metals, incl. aluminum, you can take a closer look at the following models:

• Svarog REAL MIG 200 (N24002)
• Svarog PRO MIG 160 SYNERGY (N227)
• Svarog PRO MIG 200 SYNERGY (N229)
• Grovers MULTIMIG 200 SYN
• Aurora PRO OVERMAN 180

Semi-automatic wire

When welding aluminum with a semiautomatic device, certain requirements are imposed when choosing a welding wire

Important points to pay attention to:

• the melting temperature of the wire should be comparable to the temperature of the metal being welded. Less spread - the welding process is easier;
• optimal wire diameter 1.2-1.6 mm;
• larger diameter - easier feeding into the welding zone.

Common types of aluminum welding wire are ER4043 and ER5356. Designed for welding and repairing products made of aluminum and its alloys with a silicon content of no more than 5%.

Welding modes for ER4043 and ER5356 wires

ER 4043 Aluminum Welding Wire

Welding torch

The welding torch uses a Teflon guide to reduce the friction of the wire. It is advisable that the sleeve for welding aluminum is intended only for welding aluminum and not too long - 3 m.

Push-pul- torch

The contact tip must be designed for welding aluminum (in addition to the wire diameter, the AL marking is stamped on them); simple ones used for welding ferrous metals and stainless steel are not suitable. This is due to the strong expansion of aluminum during heating. The diameter of the hole should be about 0.4 mm larger than the diameter of the wire, and at the same time not too large to ensure good electrical contact.

It is difficult to use an aluminum wire with a diameter of 0.8 mm due to the ductility of the metal and the complexity of broaching. The solution to this problem can be the use of a Push Pull welding torch. A special built-in mechanism will improve wire feed and allow longer torch length.

Wire feeder

Due to the increased ductility and softness of aluminum wire compared to steel, the feeder must have a number of features, such as:

• four-roller feeder. It is necessary for uniform pressing of each pair of rollers;

• feed rolls with U-grooves specially designed for aluminum wire.

Shielding gas

The most commonly used shielding gas is argon, which has a good cleaning effect and good penetration into the weld pool. When welding aluminum alloys with a high magnesium content, mixtures of argon with helium (up to 75% helium in the mixture) are used as a shielding gas. Such mixtures prevent the formation of magnesium oxides.

Here the question may arise, how to cook aluminum in an atmosphere of carbon dioxide or without gas at all, because argon is quite expensive?

The cheaper carbon dioxide used for welding low carbon steels will not work in this case. CO2 is an active gas, it will protect the weld pool from air, but at the same time it will react in aluminum, preventing the formation of a strong joint. Therefore, in this case, it is an inert gas that is used.

Welding with a semiautomatic device without gas is possible using a special flux-cored wire that protects the weld pool.

2 Requirements for the composition and properties of Sv-08G2S

Technical characteristics and chemical composition of the described products for welding (they can be copper-plated and ordinary) are set out in Gosstandart 2246-70. It regulates the content of the following elements in SV08G2S (values ​​are given in percent):

• nickel - up to 0.25;
• chrome - up to 0.2;
• manganese - 1.8-2.1;
• silicon - 0.7-0.95;
• sulfur and phosphorus - no more than 0.025 and 0.03, respectively;
• carbon - 0.05-0.11.

Copper-bonded and ordinary Sv-08G2S are not alloyed with aluminum, vanadium and other chemical elements. The presence of manganese in it (from 1.65 to 2.1%) is allowed if the product has a diameter of not more than 1.4 mm. When conventional wire (not copper-plated) is produced, it can contain up to 0.25% copper. GOST also allows the presence of up to 0.01% nitrogen in such products for welding and surfacing.

Coils of welding wire Sv-08G2S

SV08G2S is produced with a section of 0.3–12 mm.It is packed in skeins, the weight of which must be at least 2–30 kg. Copper-bonded wire can be completed in rectangular coils with a cross section of 50–90 mm in height, with an inner diameter of 100–400 mm and an outer diameter of 175–600 mm.

Alloy wire products (including copper-plated products) are supplied in cassettes and spools with a consumer's permission. Moreover, it must consist of a segment without breaks. Products are wound tightly, in even rows, excluding the possibility of unwinding or fluffing of the material during transportation and storage.

Copper-plated welding wire Sv-08G2S

The tensile strength of the products of interest to us varies from 882–1372 MPa (welding wire 0.3–0.5 mm) to 686–1029 MPa (more than 2 mm). Copper-plated and ordinary products can be thermally treated if the standard technology for their production does not provide the specified indicators of the specified resistance.

Copper-plated Sv-08G2S sometimes has residues of a soap lubricant on its surface, which is not a violation of the requirements of GOST

Please note - the presence of sulfur and graphite is not allowed in the lubricant