How to weld a fillet weld with a semi-automatic machine

How to make a beautiful seam with a semi-automatic machine

For a person who has never welded metal in his life, it can be difficult to understand how to start correctly, what to do at different stages in order to ultimately learn how to create an even and reliable connection. Let's look at what steps need to be taken, how semi-automatic welding occurs, for beginners - a video that clearly demonstrates some points.

Why semi-automatic?

Semi-automatic gas-shielded welding for a beginner or inexperienced welder has its advantages:

1. The electrode wire is supplied by the device itself, there is no need to monitor the length of the electrode, it is easier to maintain the optimal distance for an even arc. In addition, the feed speed is adjustable, which allows anyone to adjust it in a way that suits them.
2. The semi-automatic machine makes it relatively easy to work with thin metal, which makes it practically irreplaceable for auto body repair shops, especially with low qualifications of the welder.
3. Sufficiently long seams can be produced without stopping the process to replace the electrode. For a beginner, this will allow him not to interrupt a successful seam before it is completed.
4. Easy to learn welding process.

The list of advantages of semi-automatic machines is different for everyone; it can consist of several dozen items. For a beginner, the points listed above will be enough to start learning on this type of welding machine.

Preparing the welding machine - wire and gas

The semi-automatic machine uses a special welding wire as an electrode. Its diameter can range from 0.6 mm to 1.2 mm. The most common wire is 0.8 mm. It is clear that before work you need to load a spool of wire into the apparatus, stretch it until it exits the burner, and adjust the pressure of the wire with the roller of the pulling mechanism. The wire material must match its characteristics as closely as possible to the material of the parts being connected.

Before installing the conductive tip, you need to check it for compliance with the wire being used. That is, for 0.8 mm wire, a ferrule with a nominal value of 0.8 should be used.

It is not recommended to cook with a semi-automatic device without gas. An exception to this rule can be considered devices that use special flux-cored wire. When the arc burns, the flux that is part of the electrode wire, burning, creates a cloud of gas that protects the weld pool from oxygen and, accordingly, from the formation of oxides.

In standard semi-automatic machines, inert or active gas in cylinders is used to protect the seam from oxides. It can be carbon dioxide CO2 or a mixture of carbon dioxide and argon CO2+Ar. The first one is cheaper and more common; for welding steels it is a completely workable option, but the spattering of metal is quite high. A mixture of argon (82%) and carbon dioxide (18%) provides a more stable arc and reduces metal spatter.

Before work, connect the gas cylinder to the tip of the device and set the operating pressure.

Preliminary adjustments and actions

Most inexpensive semi-automatic welders have only two adjustments on the panel - the operating voltage and the wire feed speed. The drawing of welding wire is often marked with the letter A, as the current strength, since the feed speed and the welding current are interrelated. Additionally, semi-automatic machines are sometimes equipped with a two-position wire feed speed switch - high and low drawing speed.

In devices that can be considered more advanced, there is also an inductance regulator. By setting this parameter you can change the nature of the arc. “Cold” arc (less inductance) - the seam is narrower, the metal penetration is deeper. With a “hot” arc (higher inductance), the weld bead is wide, smooth, and the metal is melted to a lesser depth.

To correctly adjust the parameters of the device in accordance with the thickness and properties of the material, the diameter of the wire used and other characteristics, you need to use the table included in the accompanying documentation for the semi-automatic welding machine.

It is advisable to keep the angle between the nozzle and the workpieces at about 60°, the distance between the end of the nozzle and the surface is 8–20 mm. Before starting a new welding section, you need to bite off the ball that forms at the end of the wire (it conducts current poorly and makes it difficult to ignite the arc).

Before starting welding work, the edges of the surface of the workpieces are cleaned of dirt, traces of corrosion, old paint, and additionally processed with a grinder so that the melt “grabs” the metal better. On parts of significant thickness, special chamfers are removed.

Adjustments during welding

After starting work, the adjustments change depending on how the arc behaves and what the test seam turns out to be. When welding, distinct clicking sounds are heard - this means the voltage is too high and the wire feed is slow. If the wire does not have time to melt, then the feed is too fast.

When training and making a test seam, the parameters are adjusted to obtain high quality joints and ease of operation. As you can understand from the video, semi-automatic welding for beginners is not very difficult.

With a little technical skill and careful attention, anyone can learn how to cook with a semi-automatic machine.

If you need to make a vertical seam, remember: with thin metal (up to 3 mm) the seam is made from top to bottom, with metal thicker than 3 mm - from bottom to top. Thin sheet metal is spot welded to prevent warping due to overheating. This allows you to preserve the geometry of parts and elements.

Defects in welds, reasons for their occurrence

It is almost impossible for a novice welder to avoid mistakes that lead to the following flaws:

• undercut appears when the torch moves too quickly, the arc is long, or the current is high;
• if the movement is too slow, the metal flows down under the influence of gravity, an influx is formed;
• pores are formed due to poor gas protection, poor-quality surface pre-treatment, or too high a work speed;
• low welding speed at high current can cause through-burning of the metal, which is also caused by an incorrect initial gap (too large);
• lack of penetration occurs due to a small gap, contaminated metal and insufficient welding voltage.

The appearance of defects in welding seams can be completely avoided; it is enough to know the reasons for their occurrence and try to avoid mistakes. With experience, the number of flaws will become less and less.

Welding workpieces of considerable thickness

When joining workpieces with a thickness of more than 4 mm, preparation should be taken more carefully. In addition to cleaning the surface from dirt, paint and rust, the edges of the elements along which the welding seam will be carried out should be chamfered. How to properly remove a chamfer, at what angles, is regulated by GOSTs; information is also available on the Internet.

To ensure reliable connection of thick workpieces, it is necessary not only to conduct an arc along the edges being welded, but to make oscillatory movements with the torch. There are many types and methods of these movements, but most often the usual zigzag or reciprocating movements are used. The width of the molten weld metal approaching the surface of the part should be equal to the thickness of the workpiece.

Before starting work, you need to set the gap between the parts to be welded. Without a gap, the metal will not be welded to its full thickness, the seam will remain superficial and the necessary strength will not be provided. To strengthen T-joints made of thick metal, two more are placed on top of the finished seam - along the upper edge of the seam, extending onto the workpiece, and in the same way along the lower edge. This allows you to strengthen the seam, which can be important for parts with a thickness of 8 mm or more.

Despite the mistakes and some subtleties during training, semi-automatic welding is widely used; a video for beginners helps to visually distinguish the features, find out why certain errors appear and how to eliminate them. The importance of clarity is difficult to overestimate at the initial stages of using a welding machine, especially when independently mastering the equipment.

The most reliable and durable way to connect parts is a welding seam. Today, no production can do without welding; it is also used in everyday life. Almost every home craftsman necessarily uses welding.

Source: https://ostwest.su/instrumenty/kak-sdelat-krasivyj-shov-poluavtomatom.php/

How to cook with a semi-automatic machine. Ending

MIG/MAG - Metal Inert/Active Gas is arc welding with a consumable metal electrode (wire) in an inert (MIG) or active (MAG) gas. This process does not present any great difficulties, but it is necessary for any welder to know the details of the technology.  

The national construction encyclopedia ProfiDom.com.ua completes the story about semi-automatic welding methodology - MIG/MAG

Welding modes

Even professionals, before welding any structure or part, perform several test seams on materials of the same type. The purpose of the tests is to establish optimal settings for stable arc burning and temperature conditions corresponding to the thickness of the parts being welded.

To set the welding mode, there are two regulators: V - voltage and A - wire feed speed and the corresponding welding current. There is also a toggle switch for switching the speed mode: wire 0.8 mm or less should be welded at increased speed, thicker wire should be welded at reduced speed. Some devices have a third regulator of the inductive current component; it is designed to adjust the profile of the welding seam.

A trial setting is performed directly next to the device, with the controls initially turned to the far left position. After ignition of the arc, it is necessary to gradually increase the feed speed and voltage to achieve the appropriate welding mode.

With a seam depth of up to 2 mm and a width of up to 4 mm, it is optimal to weld in a cyclic manner. The speed must be increased until rare clicks are replaced by a stable crackling sound with a frequency of about 20 Hz.

If skipping is heard, you should increase the voltage slightly, but if the metal splashes heavily, reduce it.

In cases where excess metal accumulates in the weld pool, the feed speed should be reduced or the torch movement should be accelerated, but only if the temperature allows this. To increase the melting rate, the burner nozzle must be moved closer to the part. If it is necessary to apply a filling seam with a thickness of more than 2 mm or a width of 5–7 mm, welding is carried out by spraying, for which the voltage must be raised almost to the maximum.

In this case, the feed speed increases from zero until the moment when the machine begins to weld in a cyclic mode, and then decreases until it is acceptable to maintain the welding seam in accordance with its width and depth.

The inductance adjustment is performed after the welding mode is stable.

An increase in inductance leads to an increase in arc temperature, due to which the weld bead spreads more and becomes flatter, but only the top layer of material is heated.

With low inductance, heating occurs deep into the seam, but the bead is more convex. The inductance must be adjusted so that the edges of the roller melt and softly mate with adjacent surfaces.

Spatial position of the seam

The advantages of semi-automatic welding are most clearly manifested when welding volumetric structures, where it is necessary to periodically change the position of the seam. In this case, minimal adjustments to the settings are made; in most cases, no additional manipulations are required. However, the technique of making seams has specific differences.

Beginning welders should learn the basics of semi-automatic welding in the lower position of the seam. The torch is held at an angle of 60°, the wire should be directed towards the seam. At the same time, it is extremely important to constantly maintain a distance from the surface to the nozzle of about 5–10 mm. By raising the burner vertically, you can increase the temperature and adjust the flatness of the roller without changing the settings of the device.

The speed of the torch must be constant and at the same time correlated with the wire feed speed so that the wire is always in the front part of the crater and the same thickness is maintained throughout the entire length of the weld, while the molten metal should solidify in wave-like growths 10–15 mm from the weld pool .

After mastering the seams in the lower position, you can move on to the horizontal one. The burner is held at 45° to the surface and directed upward at an angle of 15–20° from the vertical to compensate for the fluidity of the metal. The burner is guided with its nose forward, the wire is held at the front edge of the crater. It is recommended to reduce the wire feed and weld speed slightly for better control over the weld pool.

Vertical seams are made using a similar welding technique, but in this case, the nozzle must be held parallel to the seam at an angle of 45° to the surface, the wire is directed to the center of the welding crater.

The movement of the torch is carried out from top to bottom, it must be fast enough to overtake the flowing drop of metal. Ceiling seams are not much more difficult to weld, but much less convenient. The burner must be guided with the spout forward, the wire is directed to the front faucet of the bathtub and the joint in front of it.

The ceiling seam is made thin enough to prevent molten metal from flowing down.

Root, filling and cosmetic sutures

In conclusion, we should talk about the difference between semi-automatic welding of parts of different thicknesses. The practical maximum seam thickness when working with amateur devices is 1.5..2.5 mm with a wire thickness of up to 0.6–1 mm. Deeper welds should be made in several stages.

Parts with a thickness of 1.5 mm or less are not welded with a continuous seam to prevent warping of the metal when heated. The seam consists of points with a diameter of 3–4 mm, which corresponds to holding the button on the burner for about 1 second, located in increments of 10 to 25 mm.

Parts up to 4 mm are welded from both sides: first they are positioned with a gap of about 0.5 mm and a regular weld is made from the front side in a cyclic closure mode.

After this, the tension is raised slightly and welding is carried out from the inside out, leaving a thin, flat seam bead.

Welding parts with a thickness of 6 mm or more requires thorough preparation: first, the edges are ground for a tight fit, then a steep chamfer is removed from the front side at 30°, leaving a straight section of the edge of 1 to 2 mm at the bottom of the seam. Before welding, the parts must be reliably immobilized with the formation of a gap of 0.5–2 mm depending on the thickness, for which they can be temporarily connected to each other by plates on the edge on the back side.

The first stage is making a root seam. It is cooked in a cyclic closure mode, ensuring that the seam fills the bottom of the joint to the level where the chamfer begins. Next, the machine is switched to spray welding mode and the seam is filled to the full depth in several passes.

At the same time, it is imperative to ensure that the edges of the joint are thoroughly heated, as evidenced by the tarnished colors on the surface of the metal in the adjacent area. After completing the root seam and between passes of the filling seam, the bottom of the joint must be cleaned with a wire brush, or better yet, with an abrasive disc.

When the joint between the parts is filled almost flush with the surface, it is covered with a cosmetic seam. In this case, the feed speed is slightly reduced, and welding is carried out with a wide front - about 8–15 mm, depending on the thickness of the part.

In this case, the wire is drawn from side to side along the leading edge of the weld pool; the oscillation speed must be so high that both edges are maintained in a heated state, while the metal deposits on the weld are quite small. In this case, the burner is directed towards itself, the spout is directed towards the front of the bath. The edges of the cosmetic seam must be properly melted for adhesion to the metal surface, the height of the roller should not be more than 1.5–2 mm.

Source: http://ProfiDom.com.ua/stati/tehnika/29101-kak-pravilno-varit-poluavtomatom-okonchanie

How to properly cook thick pieces using a semi-automatic machine? Technological features

The connection of massive parts using semi-automatic welding is carried out in accordance with GOST 14771-76. To ensure the strength of the joints, it is necessary to follow the general rules: correctly prepare the edges of the parts, set the welding current in certain ranges, and ensure the supply of the required amount of carbon dioxide to the welding zone.

Technological features of semi-automatic welding of thick metal

In order for welded metal structures to withstand loads, it is necessary to create reliable connections:

• seams must firmly connect all elements of the product;
• it is necessary to relieve the stresses that arise after welding inside the alloys . You can use preheating for this. After welding, it is recommended to ensure slow cooling;
• It is important to obtain a weld leg determined by technology ; this also strengthens the metal structure.

It should be taken into account that when working at high currents there is a risk of deformation, this means that the control dimensions of the part will change, and the shape of the structure will differ from that which was planned.

Necessary equipment and materials

To work you will need:

1. Powerful welding machine . The maximum value of welding current is not less than 250 A.
2. Cylinder for storing and transporting carbon dioxide . There are containers with a volume of 5, 10 and 40 liters. The cylinders are painted black.
3. Reducer for reducing gas pressure . A special CO2 device is required. It is desirable to have a heating element.
4. Hose and clamps - for connecting the cylinder.

For semi-automatic welding of steels, use wire type Sv-08G2s or similar for welding carbon steels 08x18n9t, as well as an equivalent for welding corrosion-resistant steels. Diameter – 1 to 1.6 mm. Common reels weigh 5, 15 and 18 kg.

Approximate cost of wire for welding carbon steels on Yandex.market

Some devices operating on a 220-volt network can only accommodate small coils of wire.

Setting up the device and gas equipment

Semi-automatic welding machines from different manufacturers are designed differently. There are at least two or three regulators on the front panel:

• setting the wire feed speed – the rotation speed of the electric motor that moves the wire is adjusted;
• change in current strength - the parameter affects the melting rate of the additive in the weld pool;
• inductance adjustment - the change concerns the current characteristics. At minimum values, the depth of metal penetration is less and the seam is more convex. For welding thick workpieces, it is recommended to increase it to medium or even higher.

Tip: you can set up the device by ear. During welding, the melting of the wire occurs very smoothly, the semi-automatic machine produces an even rustling sound.

After connecting the reducer to a carbon dioxide cylinder, you need to set the outlet pressure. For indoor work, 1-1.5 kg/sq.m. is sufficient. cm. If a flow meter is installed on the gearbox, then it should be set to 10-12 liters per minute.

Preparation for work. Edge processing

Welding work using a semi-automatic machine should be carried out only with clean workpieces. The surface should be free of rust, oil and dirt. Otherwise, pores will appear.

Proper cutting of edges is an important stage in preparing parts for welding. To ensure the formation of high-quality seams, chamfers should be removed in accordance with GOST 14771-76 - depending on the type of connection. If everything is done correctly, the connection will be strong. It is important to ensure that the metal is fused throughout its entire thickness.

Welding process

Thick pieces should not be cooked in one pass. Sequence of actions after preparatory work:

1. Assembling elements on tacks.
2. Checking the dimensions of the future part.
3. Boiling the root of the seam.
4. Filling the groove between the edges in several passes.
5. Creating a facing seam.
6. Processing joints using a grinder with a grinding wheel.

The tack is a full-fledged short seam about 15-25 mm long with a pitch of 45-50 cm. It is welded at the same current as the entire product. The tacks should be positioned so that the future product becomes rigid and does not “lead” during welding.

If you want to eliminate (or minimize) deformation from heating, it is recommended to fix the part on the assembly table using clamps or clamps. You can temporarily grab it to a workbench or steel plate.

First pass. Root of seam

The root seam is the first and most important welded connection between the edges, which is as far as possible from the front part of the parts. It is important to ensure that a roller is formed on the reverse side, smoothly connecting both elements.

If the root weld is welded with defects, cracks may appear during operation of the part, which can lead to destruction of the entire structure.

During operation, you must ensure that the part does not heat up too much. If the cascade welding method is used, a root weld is not required.

Filling the space between welded edges

Thick metal must be welded in several passes, filling the space between the edges. The cascade welding method or the “slide” method is often used:

• “cascade” - this option involves the simultaneous formation of the root of the seam and filling the space between the edges. First, a section of the root connection about 20-25 cm long is welded. Next, a second seam 40-50 cm long is applied, half of which lies on the root. The third - 60-65 cm long - partially (by two thirds) overlaps the previous ones, and ⅓ will become root. The fourth seam (also about 60-65 cm) should overlap the third and reach the thickness of the metal above the root part of the second. This method is similar to step welding;
• “slide” - after welding the root, a second seam is welded, connecting the edges and overlapping the first. After it, the third and fourth (facing) are applied.

Due to the fact that the semi-automatic machine allows you to continuously feed wire into the weld pool, you can form long seams at high speed.

Welding in vertical and overhead positions

The peculiarities of working in positions other than horizontal are that the metal is difficult to hold; under the influence of gravity, it tends to flow out of the weld pool. To avoid this, two methods are used.

1. Reducing the welding current by 15-20% . The metal heats up less intensely and crystallizes faster.
2. Welding with separation . Short sutures are applied one after another. In a vertical position, you should go from bottom to top. Welding from top to bottom is not allowed due to possible lack of penetration.

Whenever possible, avoid working in positions other than horizontal. Welding vertical and ceiling seams requires more careful preparation of the edges and is considered less productive and more labor-intensive.

Features of flux-cored wire welding

If shielding gas is required when working with copper-plated wire, then the use of powdered wire does not require it. The process is reminiscent of electrode welding - with the formation of a slag crust that must be removed. The wire coating contains elements (flux) that, when heated, protect the weld pool from exposure to air. Distinctive features:

• high mobility - no need to move cylinders around the work site;
• Many varieties of wire grades allow you to choose the one that is needed in specific conditions;
• flux-cored wire is often used during outdoor work ; in this case, gusts of wind do not interfere with the process, unlike welding with gas.

The main disadvantage is the high cost. On average, flux-cored wire is 50% more expensive than regular copper-plated wire.

Defects that occur when welding massive parts. How to avoid problems

During work, problems may arise that affect the quality of connections.

Description of the defect	Causes and remedies
Pores appear during welding	Insufficient gas pressure. Feed needs to be increased. The wind blows away the gas. It is necessary to use protective screens or carry out welding indoors. There is dirt, paint or oil on the metal surface. Any foreign particles or liquids should be removed from the edges. Low quality of welded alloys, gas mixture or wire. It is recommended to use proven materials. The welding current voltage is too high. Reduce tension.
The seam is too convex	It is necessary to configure the semi-automatic machine correctly. Adjust wire feed speed and current value. Test on unnecessary scraps of metal. The wire should flow smoothly into the welding zone and melt in a timely manner without cracking or clicking.
Spattering of metal during welding	Excessive gas pressure has been established at the outlet of the reducer; a strong flow blows away the molten metal. Reduce pressure. The device is not configured correctly. The current and wire feed speed should be adjusted.

If a metal structure has a complex shape and there is concern that it will deform during welding, assemblers often grab additional temporary reinforcements from corners, channels or reinforcement in critical places. They allow you to keep the dimensions of the product within specified limits. When the part has cooled, they can be cut off.

Welding massive parts with a semi-automatic machine is considered the most productive method. With a minimum of effort you can get beautiful and reliable connections.

Source: https://elsvarkin.ru/texnologiya/tolstye-zagotovki/

What thickness of metal can be welded with a semi-automatic machine?

Welding work is one of the most critical stages of both industrial production and small business. We should also not forget about their importance in terms of even banal household farming. In all these cases, not only the operational reliability of the finished product, but also the safety of the people who use it often depends on the quality of welding.

Welding with semi-automatic welding machines performed in an environment of inert gases is especially reliable and of high quality. Do you know how to cook semi-automatically? Today we will talk about exactly this.

General concepts

In general, this process is one of many varieties of classical electric arc welding. Since its resistance is much higher than that of the electrode, most of the energy is released into the space near the arc, melting the surface to be welded and the electrode itself, resulting in the formation of a so-called weld pool.

After the connection cools and crystallizes, a weld is formed, which at this stage of technology development is considered the most reliable way to join metal parts.

Basic principles of semi-automatic welding

Unlike classical arc welding, in the process we are considering, two things are of primary importance: the electrode (welded wire) and the inert gas that protects the weld pool. Before cooking with a semi-automatic device, it is very advisable to buy the latter in sufficient quantities.

The last circumstance is extremely important.

The fact is that they try to protect the weld seam by all available means from interaction with environmental oxygen during work: firstly, otherwise a lot of scale is formed, and the joint surface becomes far from ideal. Secondly, a huge amount of oxides appear in the weld metal itself, which have an extremely negative effect on the quality of the finished joint. That is why argon and carbon dioxide are widely used in welding.

To learn how to cook with a semi-automatic device, you must understand the main principles of its operation.

During the welding process, the electrode (wire) passes through the torch nozzle, where it melts due to the high temperature of the arc. Since the welding wire is fed continuously, constant quality and speed of the process can be achieved. Direction and speed are selected manually. The welder himself also has to monitor the continuity of the electrode supply. In the international classification, such a process is designated as GMAW (gas metal arc welding). There are welding in inert or active gas.

The latter is used in cases where the properties of the metal do not allow achieving any special characteristics of the weld. Here's how to cook semi-automatically.

What equipment is required for this?

The equipment set should include the welding machine itself, a welding current source, a wire feeder, and a gas cylinder. Devices of this type are available both in portable versions and in chassis form for use in the field. Since it is difficult to learn how to cook with a semi-automatic device of this type, only specialists who have undergone the necessary training are allowed to work.

What are the characteristics of conventional equipment of this type?

• Current strength from 40 to 600 A.
• At the welding arc itself, the voltage ranges from 16 to 40 V.
• The speed of passage of the fastened area can reach 2 cm per second.
• For various purposes and materials, wire is used, the thickness of which ranges from 0.5 to 3 mm.
• From 30 to 250 mm of electrode is consumed per second.
• The consumption of inert gas can reach 60 liters per minute. The minimum value is considered to be a consumption of three liters per minute.
• One welding cylinder can hold up to 100 liters of inert or active gas.

Preferred types of feeding mechanism

Semi-automatic welding machines differ in many respects in the design of the mechanism for feeding the electrode welding wire, so this point should be discussed in more detail. The most common version uses a pusher type: it greatly simplifies the design of the burner, but in this case the length of the gas supply hose is limited to a maximum of three meters. It is better to use a pulling design: the length of the hose in this case can reach 20 meters.

Before purchasing a welding machine, you should pay close attention to the torch. Since the nozzle is the element that wears out almost the fastest, it must be manufactured with the highest possible quality. Please note that when welding you need to constantly clean it of adhered pieces of scale. You need to carefully monitor the condition of the tip, since if it is damaged, the quality of welding drops sharply.

Important! Before cooking stainless steel with a semi-automatic machine, buy replacement kits. Stainless steel requires a lot of wire and inert gas. Welding it requires a powerful electric arc, the metal gets very hot, and the nozzle wears out quickly.

What materials should be used in the work?

As we have already said, wire can be used from 0.5 to 3 mm thick. The thinner it is, the better the arc combustion, the deeper the penetration of the material being welded. Please note that you can use an electrode thicker than 3 mm, but for each “extra” millimeter there should be 100 additional amperes.

Inert gases can be used both in pure form and in mixtures. The average gas consumption is easy to calculate, knowing the average speed of passage of the treated area and the specific consumption of consumables, which can be found in reference books for welding specialists.

A little about current and voltage

Of course, the current strength depends on the thickness of the material being welded, as well as on the diameter of the wire used. The greater the thickness, the depth of penetration of the material and the lower the overall work productivity. The higher the voltage, the deeper the metal penetration. But you need to remember that this increases the volume of burnt material and scale, and the width of the seam increases greatly. The voltage is set according to the current strength. For more detailed information, please refer to the instructions for the welding machine.

The electrode feed rate is set based on the characteristics of the material and the required strength of the seam. Welding time depends both on the thickness of the material being joined and on the expected width of the seam. At high speed, therefore, it is strongly recommended to make only narrow joints, since with wide joints you will get terrible joint quality and a large amount of dross.

About gas consumption

The thicker the wire, the more inert gas is consumed to protect the surface of the material being welded. You can reduce consumption by pressing the burner nozzle more tightly to the working surface, or simply by reducing the speed of welding parts. Attention! If you go overboard with the speed (increasing it to increase productivity), the nozzle tip may go beyond the weld pool, undergoing accelerated oxidation and destruction as a result.

Correct work with electrodes

The stability of the welding process largely depends on the output and consumption rate of the electrode wire. The longer the reach, the less stable the arc becomes. In addition, in this case, a huge amount of material goes into scale. This is largely due to the fact that the area of ​​the weld pool is sharply reduced, the tip and the material itself begin to oxidize at an accelerated rate. If the overhang is too small, visibility during welding deteriorates sharply.

Aluminum cooking

How to cook aluminum semi-automatically? Aluminum is a chemically inert metal, since there is a thick amalgam on its surface. To burn through it, you need a powerful arc. Thin aluminum wire is used as an electrode. It is imperative (!) to use an inert gas, since with the slightest access to oxygen the amalgam is instantly restored.

Important Tips

If you are welding thin metal, then the seam must be made from top to bottom. The seam must be made as thin as possible, since in this case its thickness is approximately the same on both sides. If you make an excessively wide joint, you are unlikely to be able to avoid burning through the material. To avoid damage to the material, we recommend increasing the welding speed while reducing the welding current voltage.

In the case when you cook the material on a lining base, ensure that it is pressed as tightly as possible. The fact is that the arc heats up the metal very strongly, as a result of which its thin sheets begin to bend strongly due to temperature deformation. To reduce this physical effect, bend the seams toward the lining. Since it can be difficult to weld correctly using a semi-automatic method using this method, make several test seams before work.

If the metal being welded is more than 1.5 mm thick, we recommend carrying out the work by weight. We strongly recommend that you place the electrode in a vertical position, pointing it directly at the bath. When welding metal with a thickness of 1.3 to 2 millimeters, choose modes so that the seam is completed in a maximum of one pass. Before properly welding a car using a semi-automatic machine, be sure to fit the parts together and mark out the area of ​​work: the body can be easily damaged, so you need to work very carefully.

If the gaps between poorly fitting parts are too large, we recommend doing the following: also welding from top to bottom, experimenting with power fluctuations, and stopping work from time to time to allow the finished sections to strengthen. Let us remind you once again: before properly cooking with a semi-automatic machine, it is advisable to fit the parts to each other. You will spend very little time, but the welding process will go much faster.

We cook metal without using inert gases

All of the above is true for welding metals in an inert gas environment. But what to do in the case when you simply do not have the opportunity or funds to buy cylinders, how to cook with a semi-automatic device without gas? Manufacturers produce special types of electrode wire especially for these cases.

In its manufacture, two technologies can be used: pressing flux into a thin metal tube or incorporating its components directly into the metal of the electrode.

What is so good about this wire? It's all about physics: when an electric arc discharge begins to melt it, a cloud of those compounds that are part of the flux forms around the weld pool. Thus, the classic inert gas is replaced, since the burnt flux does not protect the material being welded much worse.

  How to use a grinder when cutting metal

Here's how to cook semi-automatically without gas.

A little about safety

Our article would not be complete if we did not mention safety requirements. Let us remind you that safety precautions when carrying out electric arc welding require the creation of at least a ten-meter protective zone around the work site. If the distance is less, then people present seriously risk suffering severe retinal burns. To learn more about specific regulations and rules, you should carefully read the instructions for your equipment.

The specialist must use personal protective equipment and thoroughly check all available equipment before starting work. It is strictly forbidden to start welding if even one mechanical or electrical fault is detected. Always remember that welding work poses an increased risk of fire.

Since you often have to weld with semi-automatic welding indoors, remove all flammable material from the work area.

conclusions

In conclusion, it must be said that the quality of welding is truly high only when the surface of the parts is thoroughly cleaned of dirt and grease before carrying out work. In addition, the correct configuration of the equipment plays a huge role: if you overdo it with power, you can burn through sheets of iron. Decide to do the work more slowly - there is a high probability of sloppy wide seams and the appearance of a large amount of scale.

The latter not only consumes the metal of the part itself. As we said above, scale contributes to rapid wear of the torch nozzle and other important parts of the welding machine. It is very important to remember this before cooking a car with a semi-automatic machine: the metal of the body is not particularly thick, and therefore can burn through.

Source: http://ooo-asteko.ru/kakuyu-tolschinu-metalla-mozhno-varit-poluavtomatom/

Welding corner joints: what it is, what the technology is, how to weld, a useful device

A corner connection is obtained when the edge of one part is connected by welding to the edge of another part, forming an angle between each other (usually 90 degrees, but the angle can be at any angle of at least 30°, if less, then it is an end connection).

with one-sided edge groove

The electrode must be positioned so that the welding arc melts the edges of both parts.

The welder must perform any welded joint efficiently the first time, since any defects obtained during the welding process affect the strength of the weld.

without beveled edges

with two bevels on one edge

single-sided seam with flange on one edge

Where is it used?

Widely used in construction, installation of small to huge structures, mechanical engineering, metal furniture, frames, trusses, containers, reservoirs, bridge construction and much more.

without edge cutting

Advantages and disadvantages

The fillet joint is strong and common, but it is important to note that the fillet weld is also complex and requires certain skills and experience. If the rules for welding fillet welds are not followed, defects will occur in the form

• burns (a through hole in the seam, the cause is high current, the electrode is held in one place, a large gap),
• fistulas (this is a tubular cavity in the weld. Formed due to short circuits of the electrode or sudden interruption of the arc, it can also be caused by the lack of good technological preparation of the parts being welded),
• undercuts (recesses formed due to incorrect welding technique, incorrect position of the electrode, which leads to a weakening of the cross-section),
• lack of penetration (arising due to current strength, high speed of electrode movement, poor-quality stripping, electrode displacement, etc.),
• sagging (dripping metal, also formed due to incorrect welding technique), etc.

By following the technology, all defects can be prevented and a reliable, durable connection can be obtained. An advantage will also be cost-effectiveness, obtaining structures of complex shapes and different thicknesses. The downside is also the danger of the process and deformation.

How to cook, technology

It is important to position the electrode correctly; in one plane it tilts in the direction of its movement, and in another plane along a bisector relative to the angle between the parts.

The current is adjusted depending on the thickness of the metal and the diameter of the electrode according to the formula, it is important to know that if the current is low, then the electrode will stick, if the current is high, then burns will occur accordingly.

The electrode itself is selected and safety precautions are observed. Technological preparation of the parts to be welded is carried out, a gap of approximately 2 mm is made, and tack welding is performed.

This video clearly shows how important it is to make tacks before welding.

If one part to be welded is thinner than the second, then lack of penetration and burning must be avoided by grabbing and transferring the metal of the thicker part to the thin one . The movement of the electrode can also be from left to right, right to left, up and down. You should also choose the oscillatory motion of the electrode that is most convenient and suitable for high quality welding.

The slag is removed and the surface is cleaned with a metal brush. If during work the electrode runs out, you should beat off the slag to avoid lack of penetration, clean it and continue welding from the end point.

To avoid sagging, undercutting, lack of penetration and other defects, maintain the correct angle and monitor the weld pool. The welding speed must be such that a weld with the specified dimensions is formed.

Advice! Just like in a T-joint, it is convenient to make a fillet weld in a “boat” manner, if such a position is possible.

Device: video

Source: https://WeldElec.com/svarka/nauchitsya/soedineniya/uglovye/

How to cook with a semi-automatic machine

Its advantage is that this equipment can weld both parts up to 1 mm and more than 4 mm.

How to weld a semi-automatic machine, welding methods

There are several methods:

• butt method
• overlap welding
• “electric rivet”.

“Butt” technology is a type of welding in which the parts used (pipes, metal plates, etc.) are welded at all points of contact. Work occurs at high temperatures. This technology is used when only part of a part needs to be welded, for example, part of a wing.

The method has a big disadvantage for a beginner. Its essence lies in the fact that the parts must be adjusted very precisely when welding, that is, if possible, do not leave any gaps or leave only very small ones.

If the gaps are large enough, a large hole can be found at the seam site.

Among the advantages of this method are the strength of the seam (sometimes it is even stronger than the part itself) and the presence of simplifying materials (wire, electrodes). However, it will be better if the work is carried out by an experienced professional. If you need to gain experience in this type of welding, then it is better to take metal with a thickness of 2 mm. It forgives most errors and poor fit.

Semi-automatic welding panel.

In auto mechanics, it is better to use this method for working with external parts or in cases where high professional training is needed.

If you don’t have enough professionalism for butt welding, then you can use the simplest method - overlap welding. In this case, the metals are completely and partially superimposed on each other and welded. The method should not cause problems for a beginner. This method is used when working with power elements or when soldering boards.

The technique of the “Electro-rivet” method is similar to spot welding, which is used in factories. The method is a variation of overlap welding, and therefore welding is also understandable to beginners.

This welding method is used in various situations - when welding sills, wings, etc.

Types of welding seams

There are several types of welding seams:

• continuous interrupted seam;
• continuous seam;
• spot stitch.

A continuous intermittent seam consists of alternating seams of the same (sometimes different) lengths and spaces between them. The length of the seams and gaps can be chosen arbitrarily (depending on the task at hand).

Safety rules for welding work.

This type of seam in auto mechanics is used when connecting side members, reinforcements and other elements with a thick layer of metal.

A continuous seam can consist of individual points very close to each other (a continuous spot seam), or it can be one single seam. This type of seam is not used in auto mechanics, since it does not give the car elasticity, as a result of which it can often break. In addition, the continuous seam is quite rigid, which can negatively affect the repair, because the car will be more difficult to disassemble.

A spot seam, as the name implies, is a collection of welded points separated by spaces. In auto mechanics, like a continuous seam, it is not used.

All seams can be soldered to parts oriented differently in space. Main types of orientation:

• horizontal orientation, or “lying down” position;
• horizontal orientation, but inverted, i.e. "on the ceiling";
• vertical orientation, or “standing”.

It is easiest to work in a lying position, since in other positions the metal tends to flow out of the recess and the quality of welding decreases.

Preparation for welding

The welding process can be divided into the following stages:

1. Clearing the area of ​​foreign objects.
2. Installation of material using clamps.
3. Preparation of welding equipment.
4. Heating welding areas to the required temperature.
5. The work itself is semi-automatic.
6. Cooling down of parts and checking operation.

Installation and cleaning of metals

Torch for semi-automatic consumable electrode welding: 1 - mouthpiece; 2 — replaceable tip; 3 - electrode wire; 4 - nozzle.

When installing, you need to clamp the parts as tightly as possible using wires, clamps, bolts and other means. If this rule is not followed, gaps may form, which can result in a large hole instead of a beautiful seam.

Welding requires metal without any contamination. Welding contaminants include:

• rust;
• painting and extraneous stickers (model codes, price tags, etc.);
• anti-rust coatings, they can be applied after welding;
• lubricants of any kind.

Disadvantages when working with unrefined metal:

1. If there is a lot of dirt, then it will not conduct current from the semiautomatic device, and welding will not occur.
2. During operation, certain types of contaminants can pour liquid metal out of the welding hole. The result may not be impressive: only a hole will remain in place of the metal, the metal will spread and, in the worst case, lead to a fire or burns.
3. Some contaminants not only pour out liquid metal, but also ignite. The consequences of such an incident are unpredictable and best avoided.

Setting the required current value of the semiautomatic device

Butt welding diagram.

Before performing work, it is important to adjust the current value so as not to burn the metal. But the exact value of the current is difficult to find out. For this reason, before welding automotive parts, it is better to practice on a regular metal plate with a wire inserted into it.

Semi-automatic welding requires certain skills. To practice, you need to try to melt the protrusion of the wire (about 2-3 cm) so that it coincides with the protrusion of the metal plate.

There may be several results:

1. The wire does not spread and almost does not melt. This means that the current selected is too low. You need to increase the voltage and try again.
2. The wire spread well, and a “drop” appeared on the reverse side. This means the current is normal.
3. The wire formed a small depression, and the drop hung on the back side. This means that a slightly higher current value has been selected. You need to take another workpiece and repeat the experiment with less voltage.
4. A hole appeared where the wire used to be. This means that the current selected is too high. You need to repeat the experiment on another workpiece and use a lower voltage.

Important! You cannot use galvanized workpieces for training - zinc fumes during welding can seriously harm the human body.

If you are sure that the current is set correctly, the metal is cleaned and clamped tightly enough, and semi-automatic welding will be a success, then you can proceed to the main stage - welding. Don’t forget about safety precautions: you need to prepare a welding suit in advance.

It would be a good idea to decide in advance which welding method will be used and what seam the part will be sealed with. There is no need to be afraid of welding: once a welder gains experience, he will be able to do the job without thinking about the process.

It will be much better if someone more experienced stands next to the beginner during the first welding. If problems arise, the newcomer will be able to get support or advice.

1. Observe safety precautions.
2. Pre-practice on other blanks.
3. Correctly set up clamps and equipment.
4. Plan your actions in advance: choose a welding method, etc.

How to cook with a semi-automatic machine is not necessary:

1. Trying to work on a car right away: if you have no experience, this can only lead to problems with the car.
2. Do not check the current setting in the welder: if the voltage is very high, there will be a hole in the car.
3. Start your first welding alone: ​​if any important question arises, it will remain unanswered.

The most important rule when welding is don’t be afraid to work.

After several times, working with a semi-automatic device will become familiar.

How to cook with a semi-automatic video recipe - step by step

Below you will find a step-by-step video recipe that will help you with preparation.

How to cook with a semi-automatic photo

Having all the necessary ingredients and using our tips from this article, you will prepare this wonderful dish without much difficulty and (we hope) with pleasure.

See other recipes:

How to fry chicken liver with onions.

How to cook soup with rice.

How to fry pike in a frying pan.

Tags for this dish::
How to cook semi-automatically, cook semi-automatic welding correctly

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Source: http://luzk.ru/kak-pravilno-varit-poluavtomatom.html

How to weld thin metal semi-automatically

For a person who has never welded metal in his life, it can be difficult to understand how to start correctly, what to do at different stages in order to ultimately learn how to create an even and reliable connection. Let's look at what steps need to be taken, how semi-automatic welding occurs, for beginners - a video that clearly demonstrates some points.

How to operate a semi-automatic welding machine: technique, modes, stages

During the construction of a building or major repairs of a car, you cannot do without a welding machine. It is used to qualitatively connect metal parts that are part of a certain structure. Today, semi-automatic welding machines are often used. It allows you to qualitatively and reliably connect parts made of both ferrous and non-ferrous metal.

How does a semi-automatic welding machine work?

To understand how to cook with a semi-automatic device, you need to understand the principle of its operation. When welding with such a device, electrodes are not used. A special welding wire is used that melts in a gas environment. Inert gas (or carbon dioxide) must be supplied continuously from a gas cylinder.

When performing semi-automatic welding, thermal energy melts the part. Thanks to this, a welded joint is created and a reliable seam is formed. The semi-automatic device consists of:

• control unit;
• power supply;
• gas tank;
• wire feeding unit;
• containers with wire;
• gas supply hose;
• gas burner;
• gas equipment.

The performance indicators of a semi-automatic welding machine should be as follows:

• electric current strength - 40-600 amperes;
• welding arc voltage – 16-40 volts;
• welding speed – 20 millimeters per second;
• wire consumption per second – 3-25 centimeters;
• inert gas consumption per minute – 3-60 liters;
• cylinder volume – up to 100 liters.

Welding modes

The worker selects the welding mode, taking into account the thickness of the metal. If the metal has a thickness of more than 5 mm, it must be welded in 2 stages. Each layer must be placed exactly on top of each other. In this case, you will receive a high-quality seam.

Semi-automatic welding technology can be as follows:

• Butt. Usually carried out when a vehicle is being repaired. It is necessary to ensure that there are no gaps between the welded parts. The seam is spotty and continuous.
• Overlapping. The easiest method. A piece of metal is placed on the prepared surface. It is welded with it using the spot method.
• Through the holes. The patch with drilled holes is welded to the required part. The seam is created according to the existing holes.

Preparing wire and gas, setting up the apparatus

In semi-automatic devices, the electrode element is a special welded wire. Its radius is 0.03-0.06 cm. Usually welders use wire with a radius of 0.04 cm. Before you start working with the device, you need to place a coil in it, pull the wire until it exits the torch, and adjust the degree of its pressure using a special roller.

The semi-automatic welding technique requires the mandatory use of gas. Gas may not be used in devices equipped with flux-cored wire. How does such equipment work? When burned, the flux that is part of the wire forms a gas cloud. It protects the weld pool from air and prevents oxidation.

Typically, semi-automatic welding uses carbon dioxide or its mixture with argon. The first option is cheap, common, and suitable for welding steel. The second option ensures high arc stability and reduces the amount of spatter when processing the part.

Before you start working with a semi-automatic welding machine, connect the cylinder to the tip of the device and set the working compression. For most devices, it is possible to set only 2 parameters: voltage and wire feed speed.

Modern devices are equipped with an inductance switch. By changing this indicator, it is possible to influence the type of arc. If the arc is “cold”, a narrow connection is formed, and the steel is melted deeply. With a “hot” arc, the opposite is true.

In order to correctly adjust the parameters of the device, according to the thickness and characteristics of the material, the radius of the wire used, and other indicators, it is necessary to use the table. It is present in the accompanying documents for the welding machine.

Welding rules

There are certain rules, the observance of which, coupled with knowledge of the operating principle of a semi-automatic welding machine, will allow you to create a high-quality welded joint.

1. Set up the device correctly. In this case, you will avoid the occurrence of breaks and ensure even burning of the arc.
2. The electrode wire must be installed facing forward. In this case, the arc will not break even with sudden movements. In addition, it will set fire almost instantly.
3. There is no need to replace electrode elements or clean seams from accumulated slag.

How welding is performed in a carbon dioxide environment

Carbon dioxide, which protects the metal being welded from air, provokes the onset of oxidative processes. To reduce the effect of oxidation to a minimum, wire containing copper, silicon, and manganese elements is used.

One of the popular metal processing methods today is patch welding. It is performed according to the following algorithm:

1. Thorough removal of rust.
2. Treating metal with a rust-converting agent.
3. Application of anti-corrosion spray or primer.
4. Cutting out the hole to be welded from thick cardboard.
5. Cutting a hole.
6. Creating holes around the perimeter of a metal patch. The gaps between the holes should be approximately 20 millimeters.
7. Applying patches to holes, performing semi-automatic welding.

How to weld without gas

Today, semi-automatic pipe welding without gas has become widespread. A similar procedure is carried out according to the following algorithm:

• Set the desired electric current and welding speed (wire feed speed). Consider the thickness of the material you are processing. You can use the table in the manual for the device.
• Select and install replacement gears. This will give you the opportunity to adjust the feed speed of the electrode element, that is, the wire. If there is a gearbox, use it.
• Adjust the power supply to normalize the voltage and current. Thanks to this, the arc will be stable. In addition, the roller will form correctly, you will receive the amount of flux that you need, which will melt.
• In order for the wire to start feeding, switch the selector to the “Forward” mode. If you set the “Back” mode, the wire will begin to wind onto the spool.
• Fill the funnel with flux. The holder should be oriented so that the end of the mouthpiece is located above the welding area. Move the flap of the flux funnel and click “Start”. At the same time, move the holder longitudinally along the future welded joint.

Welding metal of small thickness

Welding pipes made from thin sheet metal semi-automatically makes it possible to quickly and efficiently create a welded joint. A thin sheet of metal is considered to be no thicker than 5 millimeters. This material is often used in the manufacture of automobile parts and pipe products. The problem when welding thin sheet material is that it can be damaged, therefore, burns will appear.

There should not be even a small gap between the workpiece and the electrode, otherwise the arc will break. In view of this, before you start welding thin sheet metal, you need to learn how to weld thick metals.

How to perform semi-automatic welding for beginners if we are talking about thin metal? The welding procedure consists of three stages:

1. Adjust the wire feed speed. Select the appropriate wire. The electric current must have a strength corresponding to the characteristics of the material being processed. Usually the manufacturer prescribes the optimal current for each case in the manual. The wire should have a diameter of 2-5 millimeters. Place it in the holder, attach the ground terminal to the surface to be welded. To prevent sticking, do not bring the terminal to the workpiece too quickly.
2. Light the arc. Touch the electrode element to the weld at a slight angle. This will activate the electrode. There must be a gap between the electrode and the workpiece corresponding to the diameter of the wire.
3. If you did everything correctly, you should get a high-quality weld. Remove scale and scale with a hammer.

How to weld thick metal

When welding parts whose thickness exceeds 4 millimeters, it is necessary, in addition to cleaning the edges of dirt, paint and varnish materials, and rust, to remove the chamfer. The chamfering procedure is described in detail in the relevant GOST.

In order to reliably connect thick parts, it is necessary not only to move the arc longitudinally to the edges being joined, but also to carry out oscillatory movements with the torch. Typically the burner is moved in a zigzag or reciprocating manner. The width of the molten joint metal approaching the surface of the workpiece must be equal to the thickness of the part.

Before starting welding, it is necessary to establish a gap between the workpieces to be joined. Without a gap, the material will not be cooked through, the seam will be superficial and weak.

Safety precautions

It is necessary not only to comply with GOST standards and take into account the characteristics of the welding machine (welding polarity, wire feed speed), but also to follow safety regulations. They are:

• When turning on the device, make sure that the switch and push-button switch are working properly.
• First of all, turn on the switch. Only then turn on the power supply.
• Check the hoses carrying the shielding gas to identify any defects.
• To protect yourself and others, clear the work area of ​​debris, fence it off, and use special glasses.
• When welding is complete, turn off the power and stop the gas flow.

If you have any questions regarding welding modes or gases used, take a look at GOST. In GOST you can find information that will help you choose the optimal welding mode and gas suitable for a particular case.

In addition, you can watch video lessons. Here are some training videos that allow you to quickly understand how welding is carried out with a semi-automatic device.

Download GOST

GOST 11533-75 “Automatic and semi-automatic submerged arc welding. Welded connections at acute and obtuse angles. Basic types, structural elements and dimensions”

GOST 14771-76. Gas shielded arc welding. Welded connections. Main types, structural elements and dimensions

Source: https://oxmetall.ru/svarka/tehnologiya-raboti-poluavtomatom

T-welded connection

Welding joints in the shape of the letter "T", called "T-joints", are present in all loaded structures. They are fillet welds with a perpendicular arrangement of the workpieces. For a small area, the connection must support the design load. T-joints subject to torsion and fracture are subject to special treatment - the seams are checked for internal defects. Following technology helps to avoid them. The type of seam is indicated in the drawing.

Application area

Installation of pipelines, creation of frame structures, ceilings, fences involves the arrangement of parts at right angles. Reinforcing elements are usually attached perpendicularly by welding: beams, channels, rolled profiles. Parts at an angle of 90° are connected by T-welding. Beginning welders at home try to avoid such joints because of the difficulty of fixing parts in a given position.

In production and construction, T-joints are often used. All types of connections are regulated by GOSTs for various types of welding. They can be single-sided or double-sided, with or without edge cutting. It all depends on the expected load, alloy, thickness of the parts being welded.

Types of T-welded joints

Techniques and features of welding T-joints

When making corner joints, they control the size of the suture leg and the appearance of the roller - they make it as flat as possible. To weld the T-joint evenly, do not make sudden movements with the holder. The arc during welding should not break off during the formation of the bead. The preparatory stage includes:

• stripping of metal in the work area;
• laying workpieces at the desired angle while maintaining the required gap size;
• fixing elements with clamps or tacks.

Pipe welding

When RDS of plugs, flanges, shut-off valves in pipelines is carried out, they are guided by the requirements of GOST 16037-80. It is also used when inserting pipes of smaller diameter. On thick-walled workpieces, preliminary cutting of seams is carried out. Then tacks are made in 4 places, they are arranged in pairs symmetrically around the circumference, dividing it into 4 parts. Then a fillet seam is made.

When inserting, the end of the pipe is adjusted to fit the pipe so that it fits tightly to the surface without forming large gaps. Pipes of small diameter are “finished” with a grinder. When cutting large workpieces for welding, reamer stencils or standard templates are used.

When there are rotary tables, rotary position welding technology is used. The seam forms faster and is even. It is more difficult to weld fixed seams; the bead is formed along curved lines.

In this case, welding is carried out in several stages, in sections. The second one begins on the resulting roller, overlapping, so that the T-joint becomes airtight. Depending on the wall thickness, the pipe is welded in one pass or several.

Such T-joints must be checked using non-destructive testing methods.

Source: https://svarkaprosto.ru/tehnologii/tavrovoe-svarnoe-soedinenie