Everything you need to know to weld vertical seams using manual and semi-automatic welding, even without experience

If semi-automatic welding of horizontal seams is not particularly difficult for a beginner, then welding vertical seams with a semi-automatic machine requires experience and knowledge of some nuances. During vertical welding, the molten metal is more susceptible to gravity than ever before, but when beads form, it is almost impossible to obtain a high-quality connection. We bring to your attention practical recommendations for welding vertical seams, as well as a brief description of the methods for creating them.

Peculiarities

Vertical seams are performed by welders with a grade of at least 3, since welding this type of seam is not an easy process. It has a number of the following features:

1. During the process of making a vertical weld, molten metal flows down under the influence of gravity and forms defects such as sagging and this must be dealt with in a certain way.
2. There are several welding techniques, which ones are used and in which cases we will consider below.
3. The process is performed at reduced welding current values ​​(10-15%) from the values ​​for the lower position.
4. Depending on the direction of vertical welding, the designations B1 are used - the process is carried out “ascending”, starting at the lowest point and going up, and B2 - “descent”, that is, starting at the top point and leading to the bottom.

Travel options

Vertical welding, depending on the direction of movement, is carried out using methods - from bottom to top or vice versa. The bottom-up option is simpler and more convenient. The weld pool is pushed upward by an arc. It also prevents it from falling down.

The initial location of the weld pool is at the bottom. Molten metal enters it from above. To prevent metal splashing, the electrode must be at an angle relative to the vertical plane in which the weld will be located. Since its melting end is located above the other, installed in a holder or held by the welder's hand, this supports the pool, preventing the metal from splashing. The lower layers crystallize, turning into a stand for the next bath. This is how vertical electrode welding occurs using a popular method.

When forming a vertical seam from the bottom position without breaking the arc, the electrodes are moved without changing direction and without horizontal displacements. The inclination of the electrode is within 80-90 degrees. This will ensure that you can get a flat seam. The speed at which the electrode moves must be quite high. Constant monitoring of how vertical seams are welded is required. Then, when metal flows out from one edge of the bath, you can move to the other edge without stopping the upward movement.

It is also possible to make a vertical weld with arc separation. Beginning welders can use this. During the time that separation occurs, the temperature of the parts decreases. To support the electrode, just as in the previous case, you can use the crater shelf.

Another way to weld a vertical seam with an electrode is to move from top to bottom. With this option, the electrode is also placed with the end up. The weld pool is supported by an electrode and an electric arc.

Welding from top to bottom is more problematic. When using this method, the difficult task is to stay ahead of the melting of the lower edge of the weld pool, while holding it. Since no heat is supplied from the electrode, crystallization of the upper edge should occur during this time. When liquid metal splashes, the current and downward speed of the electrode should be increased. Increasing the seam width will also help solve the problem.

Welding principles and basic requirements

The basic principle when welding vertical seams using manual arc welding (MAW) is that the process must be carried out from the bottom up continuously or with the electrode detached.

It is always more difficult to weld from top to bottom, because the metal will drain more actively and the process will have to be carried out at low current values, which often does not provide the required penetration.

When welding “uphill” from the bottom up, the metal of the weld pool will be supported from leakage by the previously deposited and already crystallized metal. The flow of metal will be especially noticeable after it heats up and becomes more fluid.

Also an important principle when welding vertical seams is the oscillatory movements of the electrode. We'll talk about how to perform the movements below.

The basic requirements for preparation and welding are as follows:

1. The workpieces to be welded must be cleaned to a metallic shine using an abrasive tool, file or wire brush.
2. Next comes assembly and tack work. A tack is a short-length welding seam performed to secure parts during the welding process. Because due to an increase in temperature, the metal expands and deforms. The size of the tack depends on the thickness of the parts being welded. As a rule, the tack height is 0.5–0.7 times the thickness of the parts. Their length is from 10 to 30 mm. The distance between tacks is 150-250 mm.
3. Check dimensions after assembly. The gap between the parts, the angle of the bevel of the edges (if provided for by the type of connection), and the displacement of the parts relative to each other are checked.

Below are the permissible values ​​of the controlled parameters using the example of a C17 butt joint with a V-shaped one-sided groove in accordance with GOST 5264-80.

Vertical welding technology

The vertical plane involves the use of different methods (depending on the type of metals being connected and the availability of appropriate skills).

Cooking with an electrode

The seams created in this way have different types.

When choosing the operating parameters of the device, the characteristics of the materials being joined are taken into account.

When welding with an electrode, the following methods of forming a seam are used:

• butt;
• overlap;
• T-bar;
• angular.

To maintain a stable arc, the edges of the parts are cleaned of dirt. The fillet weld is welded by correctly selecting the thickness of the rod. It should be smaller than the width of the treated area.

Using a semi-automatic machine

When using an inverter welding machine, take into account the following points:

1. The method of pre-processing of parts is chosen in accordance with the type of work to be done. In this case, the thickness of the metal and its machinability are determined.
2. The arc should be short, the current strength should be medium.
3. The rod treated with a special compound is placed at an angle of 80º against the products being welded.
4. To create a vertical seam, the rod is moved across the entire width of the weld pool.

A high-quality welded joint is obtained by breaking off the arc. This method should be used by beginners, because... it is simple and convenient. During the separation period, the metal cools down, the likelihood of smudges is reduced. However, this has a negative impact on performance.

During the welding process, it is important to observe the following conditions:

1. Place the tip on the crater shelf.
2. Move the working part from side to side, covering the entire treated area. You can use the principle of loops or a short roller.
3. Reduce the current intensity by 5 A from the average value, which will allow you to set a different shape and other parameters of the seam.

The main indicators are selected experimentally. Therefore, the quality of the connection depends on whether the worker knows how to properly weld a vertical seam (electric welding helps to form any connections).

Conditions for obtaining a high-quality seam

In order to obtain high-quality connections when making vertical seams using electric welding, several important conditions must be observed:

1. The welding current is less (10-15%) than when welding in the lower position. This condition will ensure minimal flow of molten metal and avoid sagging.

2. The choice of welding current should be carried out on a test workpiece. Initially, you need to set the recommended, average current values ​​and start cooking. If the electrode often goes out, sticks, and the arc burns poorly and unstably, then you need to add more current. If, during welding, the edges are burned and the metal of the bath seems to fall through, then the values ​​​​need to be reduced. The setting step is usually 5 A, that is, if you need to increase it, add it by 5 A and try cooking again, and so on until we find the optimal values.

3. The welding process should be carried out with a “short” arc. Arc length is the distance between the electrode and the weld pool. A “short” arc is considered to be an arc whose length is 0.5 - 1 electrode diameter, but not more than 1.5 mm. The longer the arc, the stronger the heating of the metal and the higher its pressure. All these factors inevitably lead to defects in the form of pores, burns, sagging and undercuts.

An undercut is a welding defect in the form of a small depression between the weld and the base metal.

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Preparing the device for operation

semi-automatic device
The semi-automatic device consists of an inverter, a burner equipped with a cable channel, a gas cylinder with gearboxes and pressure gauges. Before you begin welding, you must make sure that all system components are in good working order and connected in the correct sequence. Close attention should be paid to:

• Grounding the welding machine body.
• Correspondence of the thickness of the parts being welded to the diameter of the filler wire.
• The chemical composition of the base metal and consumables, which should be similar.
• Composition of shielding gas.
• Wire feed speed and shielding gas consumption. It is best to calculate these indicators in advance so as not to interrupt welding due to lack of materials.
• The length of the wire protruding from the nozzle. It should not exceed 5 mm.
• Current strength.

Having selected consumables and set up the semi-automatic machine, it is advisable to carry out test welding on unnecessary scraps of metal. In case of lack of penetration or burn-through of the seam, the current strength is adjusted and the optimal welding speed is selected in a new way. Also note that preparatory work must be carried out with metal blanks:

• Before welding, it is advisable to connect the surfaces to be welded together with at least two or three points. Thanks to this, the parts will remain motionless during operation.
• Surfaces are cleaned of traces of paint, varnish, dust and dirt. A semi-automatic machine can cope with welding contaminated surfaces, but in this case the connection will be fragile, and toxic fumes cannot be avoided. There is no need to clean off a thick layer of metal, as this will negatively affect the quality of the weld.
• When welding sheet metal arranged in layers, you need to use clamps for reliable fixation.

  
  clamps

How to cook vertical - methods

As mentioned earlier, there are 3 techniques: bottom-up, top-down and electrode separation welding.

Experienced welders most often use the bottom-up technique, which is designated B2. The process is performed “ascending” from the bottom to the top.

The top-down method is less commonly used - B1. Here the reverse welding situation is performed “downhill” from the top to the bottom.

Beginning welders and amateurs use a method called welding with electrode separation. The process goes from bottom to top “ascending”, at the same time the welding arc is ignited and a small area of ​​the “welding point” is welded, and the arc breaks. Afterwards the process is repeated until the cutting is completely filled.

For the first two methods, it is best to use electrodes with a basic coating, and for pull-off welding with rutile. Because rutile electrodes provide easier ignition of the arc, but it is more difficult to weld long seams with them due to the large amount of slag. During the welding process, the slag spreads greatly and it is difficult for a novice welder to understand where in the weld pool there is metal and where the molten slag is. Because of this, such a defect as seam slagging often occurs.

Let's look at each of these methods in detail below.

Down up

Using this method it is easiest to control the weld pool and weld large thicknesses. The welding seam begins at the lowest point and gradually fills the groove and rises to the top.

The process of welding a vertical seam itself is carried out in several stages: initially, a friend is ignited, the length of which is slightly more than 2-3 times the diameter of the electrode. This is done in order to warm up the metal so that the electrode does not stick. Warming up occurs for 2–3 seconds, after which the length of the others decreases to 0.5–1 the diameter of the electrode.

Next, you can begin the welding process, namely surfacing at the lower point of a small roller (flange). If the metal thickness is more than 3 mm, then welding must be performed in several passes. The first is that the root pass must be cooked without oscillatory movements, simply moving the electrode slowly from bottom to top or making reciprocating movements along the cutting edges.

During subsequent passes (filling and lining), the electrode is slowly moved from one edge to the other.

During the welding process, you need to pay special attention to the speed of the process, since if you weld too slowly, the metal will begin to flow down, forming sagging. At the same time, if welding is carried out too quickly, then there is a risk of not welding the joint. Beginner welders can use this technique here. It is necessary to weld so that the top edge of the weld pool is approximately in line with the top edge of the electrode.

When making vertical seams from bottom to top, the welding electrode is usually held at an angle of about 45–50 degrees.

In cases where it is necessary to ensure deeper penetration, the electrode angle is chosen closer to 90 degrees. And when the metal begins to flow, the electrode is tilted towards the weld pool, holding the molten metal in the weld pool due to arc pressure.

To fill the groove, the welder needs to make oscillatory movements with the electrode. The main types of movement have the form: triangle, crescent, letter Z and others. They will be described in detail below.

Top down

The top-down welding method is used less frequently, since its technique is more complex and requires certain welding electrodes that allow downhill welding. With this method, the weld will have a smaller penetration depth, but a larger width. This is good in cases where you need to weld thin metal so as not to burn through it.

The arc initiation process occurs when the electrode is positioned at an angle of 90 degrees to the surface of the part. After the arc has ignited, the electrode is placed at an angle to the weld pool so that, due to the arc pressure, the molten metal does not flow out.

The process is also performed with oscillatory movements. In this case, Z-shaped movements or crescent-shaped movements are most often used.

This method (B1) is often used in semi-automatic welding, and quite rarely in manual arc welding.

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How to weld a vertical seam with lift-off arc welding

The undoubted advantage of the pull-off welding method is that even a beginner can weld a vertical with it. Since when used, the metal will have time to cool and will not flow. This greatly simplifies the process, but there is also a disadvantage in the form that the speed of welding is greatly reduced.

The execution process is as follows:

• connect the device to reverse polarity and set the current strength (select the value on test pieces)
• the arc is ignited in the cutting of the edges and we increase its length to 1.5–2 times the diameter of the electrode;
• electrode at an angle of 45–50 degrees.
• we heat the metal at the lowest point for 1-3 seconds by moving the electrode from one part to another;
• the metal cools down changing color from bright red to burgundy at this moment the arc is ignited again;
• the arc is transferred from one part to another, lingering on each of the walls, making, as it were, movements in a spiral, superimposing points on one another.

Welding methods

Welding in a vertical position can be carried out using various methods. The most popular are electroslag and electric arc.

Electroslag method

The electroslag method allows you to weld parts of any thickness. Regardless of the size of the cross-section of the seam, it is carried out in one pass. This results in savings on energy costs and a reduction in the need for consumables. Work productivity increases significantly.

A bath containing liquid slag is formed between the edges and the metal. The electrode is immersed in a slag bath. The current passing through the bath heats it to such a high temperature that the edges and tip of the electrode begin to melt. The result of the melt is the appearance of a weld pool and the beginning of the formation of a welded joint.

As the seam cools, the weld pool with the electrode will rise upward. It is possible to weld a vertical seam of varying thickness in one pass. Slag, which is in a liquid state, is lighter in weight. Since its location is on top, the seam is protected from the adverse effects of oxygen in the air. At the end of welding, the slag that has become hard is removed by tapping. A vertical seam welded using the electroslag method is of high quality.

When a vertical seam is made using electric arc welding, the liquid metal flows down, obeying the law of gravity. The drip path is the method by which the liquid alloy passes into the weld pool. Welding a vertical seam using manual arc welding involves using a short arc so that the droplets flow smoothly and do not come off.

Before welding a vertical seam using arc welding or another method, preparation of the parts to be welded is required. The edges of the parts are cut differently depending on the method of their connection and the transverse size of the metals being welded. The parts are fixed using special devices. To prevent deformation, tacks are used - transverse seams located at a distance from each other.

Semi-automatic

A more convenient way to create a vertical seam is by semi-automatic welding. The basis of operation of the semi-automatic device is the supply of current to the burner along with protective gas. In this method, the role of the electrode is played by a wire, which is fed to the welding site in automatic mode. An electric arc is formed between it and the parts being welded. The metal is melted under gas protection, which prevents the formation of oxides.

The magnitude of the current is of great importance for obtaining a high-quality vertical seam using a semi-automatic machine. With the right choice, the seam will be smooth and without breaks. The choice of optimal current depends on the transverse size of the parts. The speed of the welding process is proportional to the wire feed speed, which is adjusted using a special mechanism. The optimal electrode diameter for this type of welding is 0.8 mm.

When welding thin sheets, it is possible to reduce it to avoid arc extinction. Shielding gas is sold in special cylinders equipped with a reducer with a pressure gauge to control pressure. For high-quality welding of a vertical seam, a pressure of 0.2 atmospheres must be set.

Before welding begins, the distance from which the wire protrudes from the nozzle is set. This value should be no more than 5 mm. Before you start welding, you should make sure that the parts are stationary relative to each other. This is ensured by semi-automatic spot welding.

The parts are fastened in at least two places. When welding is done with an overlap, the parts are held together with clamps. If at the beginning of welding the arc does not ignite, then the current strength is increased. Welding vertical seams with a semi-automatic machine is a convenient and reliable method.

Inverter

If you intend to make a vertical seam using a more modern method, it makes sense to choose an inverter. It replaced outdated transformers, which were heavy and difficult to operate. The inverter is lightweight. Another advantage is that when using an inverter, metal splashes are much less. Welding of vertical seams with an inverter occurs using an electric discharge. The advantages of the device include low sensitivity to voltage changes.

Convenience during operation is provided by handles and indicators on its body. The inverter is turned on and off using a toggle switch. The knobs on the panel set the voltage and current values. There are indicators that provide information about power supply and equipment overheating. One cable has an electrode holder at the end, and the second has a clothespin clip for attaching the product. The inverter receives power from the electrical network. Battery capacitors ensure uninterrupted operation. Electricity consumption depends on the diameter of the electrode.

The principle of operation is that the metal parts and the electrode begin to melt under the influence of the arc, which leads to the formation of a weld pool. The resulting slag after cooling is removed by tapping. There are recommendations on how to properly weld a vertical seam using inverter welding.

Work should begin with a tincture of electric current. Its value depends on the thickness of the parts. Then the ground terminal is connected to the surface to be welded. Electrode diameter is 2-5 mm. Metal parts are prepared in the usual way before welding.

How to weld a vertical seam - electrode movements

For vertical joints, 3 types of electrode movement are most often used:

1. Oscillatory movements across the joint.
2. Reciprocating movement along the joint.
3. Rectilinear (direct) movement.

Oscillatory movements of the electrode make it possible to obtain seams of large width (up to 3–4 electrode diameters in one pass). This seriously increases productivity, especially in cases where the metal thickness is 20 mm or more.

Reciprocating and straight-line motions are used when welding root pass, also for parts with small thicknesses and on stainless steels. The seam will be more accurate and durable, and during the process you can clearly see where the slag is and where the metal is. With this method it is easier to maintain the same speed and arc length, and therefore it will be easier for beginners.

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Reciprocating (for rutile electrodes)

Reciprocating motion when welding vertical seams is most often used when the thickness of the parts to be joined is small (up to 5 mm); welding is performed with rutile electrodes. This method can also be used when welding a root seam (the root seam is the seam that is performed very first in multi-layer welding).

The technique is simple and consists of the following:

1. The arc is ignited and a small section of the seam is welded (5-10 mm).
2. Next, the electrode returns to 1/3 of the welded area.
3. Afterwards, the electrode is moved upward again, welding a new 10-15 mm, and this is repeated until the end of the joint.

The result is a weld bead with a width of 1.3-1.5 electrode diameter.

Herringbone

For vertical connections, this method of movement is performed as follows:

1. A small shelf is fused at the bottom, which will prevent metal from leaking out.
2. The electrode begins to move up and to the right, after which it returns down.
3. Next, the electrode is led up and to the left and then returned down again.
4. This process is carried out until the joint is completely welded.
5. The process must be introduced evenly (at the same speed) in order to obtain the most accurate seam.

Triangle

This method of movement is most often used when it is necessary to weld large thicknesses, since it allows you to obtain the widest seam up to 4 electrode diameters in one pass. It is very convenient to use for T-joints. The technique is as follows:

1. The arc is ignited and the metal is heated.
2. In the lower part, you still need to fuse a small shelf on each of the edges.
3. We start welding in the center, light the arc and delay a little (up to 0.5 seconds).
4. We move the electrode to the right edge and linger on it.
5. We move to the left edge and linger on it.
6. We move to the center of the joint a little higher and repeat the process until completion, lingering on each of the edges and in the center.

You need to pause at points so that the seam has a smooth transition to the base metal (it is not extremely convex), and also so that an undercut does not form.

Crescent and Z-shaped movements

Z-shaped movements, as well as their complicated version with a crescent, are performed in the following sequence:

1. We direct the shelf below.
2. We light the arc and warm up the metal a little.
3. The electrode moves smoothly and at the same speed from one edge to the other

If you use these methods for cladding, it is better to use an angle close to 90° so that the seam is not excessively convex. When filling, the angle can be made more acute.

Various technologies

The technique of welding vertical seams has three options. Their choice depends on the size of the gap, the thickness of the metals being welded, and the size of the blunting of the edges.

Triangle

The technology is based on the most popular method of conducting the process from the bottom up. The molten metal is on top of a layer that has just begun to solidify. Flowing down, it covers the seam bead. This prevents new drops from flowing down the path.

The method is used when it is necessary to connect parts with a thickness of no more than 2 mm. Welding with this method can provide good results with a small gap. It is also necessary to ensure that the edges are as dull as possible. It should be in the range of 1-2 mm. When welding, the location of the bath should be at an angle.

This position gave the name to the method - “triangle”. The angle is provided as follows:

• at the beginning of the welding process a shelf is created;
• when the welding arc is raised along the wall towards the gap, the edges are dulled by melting them;
• descent along the right wall;
• transition to the left wall;
• formation of a weld seam there.

It is necessary to follow the recommendations on the selection of characteristics on how to properly weld a vertical seam using the “triangle” method. The diameter of the electrode according to this method should be 3 mm. The average value of the electric current is 90-100 A. Until the joint is filled, the electrode should be moved along the specified path. Well suited for vertical corner seams.

Herringbone

The end of the electrode makes complex movements. The essence of the method is that the electrode moves from the depths, melting the surface of the edge along the way. When returning inside, it begins to melt the second edge. Then the operations are repeated at low altitude.

This type of welding seam is suitable when the gaps between the products being welded are 2-3 mm. The edges need to be dulled. The cross section of the roller is smaller than with the previous method. The process begins along the selected edge. The electrode is fed from the depth of the gap towards itself.

The technology of the welding process is as follows:

• from the gap along one of the edges, pressing the electrode against it, apply it “towards you”, passing through the entire thickness of the workpiece;
• having made a slight rise, return the electrode to the gap location using a “pull” method;
• after the float, move to the other edge and perform the same actions;
• Repeat these operations until the very top of the weld.

Welding is carried out with a short arc. The method ensures uniform application of the welding material throughout the entire gap space. It is necessary to ensure that there are no undercuts or metal leaks on the edge of the seam. Continuity of the process is desirable, excluding moments when it is necessary to replace the electrode. There should be no excessive edge welding. The resulting seam is shaped like a Christmas tree.

Ladder

It is used when there is a large gap between the parts being welded. Its value can exceed 2 mm. The method is also possible in the absence or slight dulling of edges.

The technique for obtaining a good vertical weld in this case and how to weld it is simple. The movements of the electrode are zigzag. The electrode moves from one edge to the other. The amount of lift should be small and constant. The welding arc should be kept short. Electrode diameter - 3 mm. The current is small - 80-100 A. The process should be carried out without interruption.

The peculiarity of the method is that the electrode stops at the edges for a long time, and the transition from one edge to another occurs quickly. The cross-section of the roller with the “ladder” method is small - the so-called “light” roller is obtained. This method is not particularly difficult and is suitable for novice welders.

How to properly weld a vertical seam using semi-automatic electric welding

Semi-automatic welding of vertical seams is most often performed using wire with a diameter of 0.8 to 1.2 mm. For this welding method, the top-down method is very often used for thicknesses up to 4 mm without oscillatory movements. The angle between the burner and the product should be about 20-35°.

If the thickness is greater, then welding from bottom to top is used. The torch, in the same way as during manual welding, performs oscillatory movements. Most often this is a “triangle” type movement with a delay in the middle. The angle of inclination of the burner to the product is around 75–85 degrees.

The welding arc is oriented towards the leading edge of the bath. This is done in order to reduce the flow of liquid metal due to arc pressure and ensure deep penetration of the root.

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Vertical welding problems

The welding process involves melting the metal of parts that are connected to each other after cooling. With horizontal types of welding, everything is simple, the main thing is to learn how to ignite the arc and correctly conduct the seam. But what about vertical views? Under the influence of gravity, the metal constantly flows and it is very difficult to control the weld pool. The result is uneven joints formed by drops and smudges.

When welding in a vertical position, problems such as lack of penetration of the metal or, conversely, undercutting are possible. They arise due to the choice of inappropriate current. When the metal is not welded, the melt splashes around and spreads over the surface. An undercut is formed as a groove in a weld when an overly powerful arc cuts material out of the weld area.

Another problem with a vertical seam occurs when the arc is held at one point for a long time. The weld pool seems to “fall out”, forming burns in the workpieces.

How can you avoid defective joints during vertical welding and what techniques are suitable in this case?

Types of connections

Vertical seams are performed on such types of joints as:

• Overlapping;
• Butt (butt);
• T-bars;
• corner.

Butt-butt

Vertical welding of butt joints is most often used for pipes, sheet structures and profile products. The process can be single-pass or multi-pass, single-sided or double-sided, with or without a lining. The most common butt joint is a double-sided V-groove made without a backing.

Butt welding with a thickness of up to 3.5-4 mm is most often performed without oscillatory movements and without cutting edges in one pass. In cases where the thickness is more than 4 mm, the edges are cut and the process is performed with oscillatory movements of the electrode.

overlap

The lap joint is used when welding sheet structures, as well as welding shaped and profile products. The most common is the H1 connection in accordance with GOST 5264. Lap joints can be up to 60 mm thick according to this GOST. The welding process is carried out by performing Z-shaped oscillatory movements from bottom to top.

How to weld a vertical seam in a T-joint or corner joint

Vertical corner and T-joints are welded from bottom to top with oscillating movements of the electrode in the form of a triangle with a delay at each of the edges and in the center.

Classification of welding joints

According to the method of making seams, there are:

• one-sided;
• double sided;
• single-layer;
• multilayer.

Read more about the classification of welded joints in this article. According to location in space and length, there are the following types of welding:

• In the down position. When the weld seam is located at an angle of 0° to the ground surface;
• In horizontal. Welding is carried out horizontally, and the part is placed at an angle from 0 to 60 °;
• In a vertical position. Welding is carried out vertically, and the structure is located in a plane from 60 to 120 °;
• In the ceiling. The seam is located above the welder, and work is carried out at an angle of 120-180 °;
• In the “boat”. Welding is performed “in a corner”, and the part is located at an angle.

Welding work in the lower position is not difficult even for beginners. How they are carried out is described here. For all others, technological knowledge is required.

Electric arc length control

When welding a vertical seam, controlling the length of the welding arc is extremely important. An increased arc length leads to the formation of many defects such as:

• surges;
• undercuts;
• craters;
• pores;
• spray;
• seam unevenness;
• metal burns.

Beginning welders need to practice holding the same arc length, especially when moving the electrode.

The following arc lengths are distinguished:

1. Short arc (which is 0.5 - 1 electrode diameter, but not more than 1.5-2.0 mm).
2. Normal arc – 2.0-3.0 mm.
3. Long arc – more than 3.5 mm.

For manual arc welding, it is recommended to use a short arc. Using normal arc length is also acceptable.

Semi-automatic welding: secrets of mastery

Welding is considered the most reliable method of obtaining a permanent connection between two elements of a welded structure or product. The basic diagram of welding work depends on which welding method is chosen in a particular case. The simplest and therefore frequently used welding method today is semi-automatic arc welding.

This article will focus on welding steel pipelines. The quality of welding in this process is very important: the quality of the entire pipeline and its sealing will generally depend on the quality of the welded joints. We will tell you further about how steel pipes are welded and what is important to pay attention to.

Welding metals using different methods is used both in industry and in everyday life. Manual arc welding is especially popular: it produces a high-quality connection, does not require expensive, bulky equipment, and can be performed by beginners. We will tell you in this article what is important in the technique of welding metals in this way.

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Welding mode tables

For the most commonly used electrodes of group E50 (for group of materials M01 - carbon and low-alloy “black” steels), the welding modes for vertical joints are given below.

Transmission welding technique

Welding of pipes through transmission (in the absence of direct contact) begins with thorough preparation of the joint of the workpieces.
Only pipes of medium diameter with a wall thickness of at least 6-12 millimeters are suitable for welding using this method. In this case, it is assumed that the chamfer is selected at an angle of 65-70°, ensuring an offset of 2 mm.

For correct (coaxial) fixation of the welded pipe blanks, an internal centralizer is required, which completely eliminates any displacement of the assembly. The gap in the lumen is left about 2.5 mm (it can be easily set by focusing on the electrode of the appropriate diameter).

Any electric arc equipment is suitable for welding the prepared assembly (for these purposes, you can use an inverter, for example).

As a result, we can say that welding corner and differently oriented joints in space requires not only thorough preparation, but also the correct choice of electrodes for it.

Inverter or semi-automatic

An inverter with an MMA function is the same manual arc welding, but it works on a different principle, unlike transformer welding.
This uses a coated consumable electrode. The semi-automatic welds by melting the wire fed into the welding zone. Such devices allow you to create better quality seams, since there is no splash of molten metal, and the pulse, in fact, drives every point into the joint.

So what is better for welding a vertical seam?

In any case, a novice welder will need practice with one of these devices. Without experience, it is unlikely that you will be able to immediately make a high-quality connection.

Inverter manual welding requires more attention to the process and control of the movement of the electrode. If the position of the holder and the angle of inclination are incorrectly selected, a defect will occur. You need to cook with a tear, creating the effect of spot welding. In this case, the metal will splash and spread over the surface of the product. Only with a lot of practice will you get a high-quality seam.

Semiautomatic also requires careful control of the welding process. Here, too, the selected holder positions and welding technique are important. When using shielding gas in semi-automatic welding, the amount of splashes and leaks is reduced, but such a connection will be more expensive.

The main advantage is that you can reduce the wire feed speed, which means slowing down the process of metal overheating. As a result, with proper practice with a semi-automatic welding machine, the flow of melt down can be reduced. For a similar effect using manual welding, special electrodes are used to accelerate the crystallization of the metal.

Many welders recommend using a semi-automatic machine when welding vertical seams, which allows you to obtain a high-quality connection. But, in the absence of such a device, using the proper work technique, you can obtain high-quality fastening in terms of strength and with conventional manual welding.