How to properly cook with a semi-automatic machine Vertical

Semi-automatic welding: technology, correct settings and instructions for beginners - Machine

For welding metals, a laser beam, torch flame or plasma can be used, but one of the simplest and most compact options for devices for performing this type of work is a semi-automatic device.

To ensure that the metal seam is as smooth as possible and protected from oxidation, welding metals in this way is best done using shielding gas.

Semi-automatic welding for beginners is difficult only in the first minutes of mastering. To speed up the learning process as much as possible, you should study the basic rules for handling such a device in advance.

Semi-automatic welding machine: operating principle

In order not to “kill” the device when using a semi-automatic welding machine. To avoid injury, you should know about the safety rules and the operating principle of the device.

The semiautomatic welding machine consists of:

housing containing a powerful transformer;
hose for supplying current and gas to the burner;
cables for connecting to ground and the electrical network;
wire feed mechanism.

Also, for semi-automatic welding, you will need to purchase a reel with a special welding wire and a cylinder of carbon dioxide.

The operating principle of the semi-automatic device is as follows:

The welding current is supplied to the torch simultaneously with the shielding gas.
The torch uses a welding wire as an electrode, which is fed automatically using a special mechanism.
An electric arc is formed between the product being welded and the wire, which melts the metal in a protective gas environment, which allows you to obtain a high-quality weld without oxides.

The basic safety rules when working with semi-automatic welding machines are as follows:

the body of the welding machine must be grounded;
it is prohibited to use the device even with minor mechanical damage or any other malfunctions;
in case of significant interruptions in work, be sure to disconnect the device from the electrical network and turn off the supply of protective gas;
do not work near flammable and explosive substances;
Use a protective mask and gloves while working.

As soon as the basic principles of working with a semi-automatic machine are mastered, you can begin practical work.

Semi-automatic welding: first experience

To gain practical experience, it is recommended to first practice on unnecessary metal scraps before proceeding with complex work that requires highly qualified welders.

For practical work you need to prepare:

welding machine;
gloves;
protective mask;
gas cylinder.

The first thing you need to do is set up the welding machine. Correctly adjusted strength of the supplied current will allow you to make a welding seam perfectly smooth and without breaks.

This parameter directly depends on the thickness of the metal being welded, so before starting work, you must read the instructions for the electrical device. Which should indicate the amperage recommended by the manufacturer for a certain thickness of the parts being welded.

Selecting welding modes

You should also make the right choice of the welding wire feed speed, which is regulated by a special mechanism.

The optimal diameter of the wire for welding is 0.8 mm, but when working with very thin metal, you can install a 0.6 mm electrode so that at a reduced current the metal is melted without fading the arc.

If possible, it is better to purchase Italian wire for semi-automatic welding. Imported analogues are of higher quality, but the cost of such products will be several times higher.

Despite the higher cost, such an electrode is more suitable for beginners because it is easier to obtain the desired result, even with insufficient experience in handling an electric welding machine.

instructions: setup.

Cylinder with reducer

In order to protect the welding site from exposure to oxygen, shielding gas is supplied. The cheapest option for using shielding gas is to purchase a carbon dioxide cylinder with a reducer.

A reducer with a pressure gauge must be installed to monitor the pressure of the supplied gas. To carry out high-quality welding of metals in a shielding gas environment, it is enough to set the working pressure to about 0.2 atmospheres.

Protective mask

To protect your eyesight, semi-automatic cooking should only be done using a protective mask, for example, Chameleon. Modern products have a special adjustment in their design, which allows you to configure the protective mechanism in such a way that it provides high-quality protection only during arc burning.

When the plasma combustion process dies out, the window of the mask will be transparent enough to allow you to continue working without removing the protective device.

Such welding helmets will be especially convenient for novice welders; in outdated models, the protective glass was too shaded, which made the welding process very inconvenient, due to poor visibility of the weld after the arc has died out.

Welding technology

When all the preparatory work has been carried out, it is necessary to connect the “ground” to the metal being welded. If you have to work with small parts, then welding is done on a metal table, to which the corresponding conductor is connected.

If there is no table, then the work can be carried out on a horizontally located metal sheet with a thickness of at least 2 mm, to which the “ground” of the welding machine is connected.

Before starting the welding process, it is also necessary to adjust the amount of protrusion of the welding wire from the nozzle. It is recommended to install such a protrusion no more than 5 mm. If the wire protrudes more significantly before starting welding work, it must be shortened using wire cutters.

Before making a continuous weld, it is recommended to position the parts to be welded as close as possible and to carry out spot welding in at least two places by striking the electrode against the metal at the joint. This is necessary to ensure the immobility of the parts being welded.

If you need to weld one sheet of metal onto another, then in this case you can use clamps to securely fasten the welded parts. Once the immobility of the parts is ensured using any of the listed methods, you can begin making the weld.

To weld parts, an arc igniter is made and the metal is melted at the junction of the metals to form a seam. If during the first attempts to weld parts the arc does not ignite stably, it is necessary to increase the current supplied by the welding machine.

For proper arc formation, it is necessary to briefly touch the wire to the metal parts to which the “ground” is connected. Then tear off the wire to the minimum possible distance to form a stable electric arc. In this way, the seam is welded from one edge to the other, gradually moving the arc over the surface of the parts being welded.

thin metal connection.
welding thick metal for beginners.

Aluminum welding

The use of shielding gases in semi-automatic welding makes it possible to perform high-quality connections of aluminum parts in this way. Welding aluminum is a rather complex process even for an experienced specialist; it will be even more difficult for novice welders to complete such work.

How to semi-automatically cook aluminum parts:

the surface of the welded parts is cleaned from the oxide film;
the workpieces are heated in a furnace or using a gas burner;
the welding machine is switched on to high-frequency alternating current mode;
a cylinder with argon or argon-helium mixture is connected;
The arc is ignited and its length is maintained in the range of 12-15 mm.

In this way, parts made of this low-melting metal are welded. To perform the work, you will need to purchase aluminum products as filler wire. And to ensure stable wire feeding, the device must be equipped with a larger diameter nozzle.

Conclusion

For novice welders, you learned how to weld semi-automatically with carbon dioxide correctly from this article. To consolidate the information received, it is recommended to immediately begin practical exercises and carry out a trial connection of parts using this method. Lessons will allow you to quickly master a semi-automatic machine at home.

It is recommended to start welding aluminum and other non-ferrous metals only after welding of ferrous metals is well mastered. This article tells you how to cook stainless steel with a semi-automatic machine.

Source: https://regionvtormet.ru/stanki-i-oborudovanie/svarki-poluavtomatom-tehnologiya-pravilnaya-nastrojka-i-instruktsiya-dlya-nachinayushhih.html

Welding vertical seams

There are many types and types of welding. They are divided into different classifications depending on the material used, the apparatus and the type of conductor used to create the suture. One of these is the welding of vertical seams, which has a number of features that we will now get acquainted with.

articles

Features of vertical welding
- Principles of vertical welding
- Conditions for a high-quality vertical seam
Vertical welding technology
- Creating a seam with an electrode
- Semi-automatic vertical seam

Features of vertical welding

Vertical welding has the difficulty that when creating a seam, the molten metal tends to flow down, which in no case should be allowed. If this happens, then it will no longer be possible to cook on top of this drop, since it contains slag from the electrode.

To create a high-quality track when manual arc welding, it is recommended to use a short arc at a low current. At the same time, the master must make movements from the bottom up to avoid unnecessary drips. When vertical seams are formed from a molten drop, you need to move the end of the electrode a little to the side to allow the material to harden without losing the spark.

Principles of vertical welding

To create an ideal seam, you must adhere to several principles of vertical welding:

If welding work is carried out using alternating current, then it is imperative to start from the bottom. In this case, the weld crater is filled with material so that it creates a volumetric roller, which in parallel serves as a kind of support for the molten metal located slightly above. This is how the seam is filled.
With the electric arc method, the metal in the weld crater in a vertical position should harden much faster. For this it is better to make small drops. It is very simple to achieve this effect by shortening the arc (the distance between the product and the electrode).

Conditions for a high-quality vertical seam

Not all novice welders understand how to weld a vertical seam so that it turns out aesthetically pleasing, durable and “correct” in terms of quality. There are several conditions that will ensure that you get a perfect seam almost the first time:

during arson, it is necessary to maintain a perpendicular position of the electrode in relation to the parts;
the shorter the arc, the faster the metal crystallizes and the risk of drips that spoil the seam is reduced;
during the formation of the track, the electrode must be tilted so that metal drops do not flow down;
if due to carelessness the material flows, you need to increase the current strength and the width of the seam. This maneuver will give more time for crystallization.

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With this approach to work, the seam is made easier and simpler than when moving downwards. But the quality of the seam will be slightly lower.

Considering that there are parts that need to be welded only using the method from above. To do this you need to be careful and smooth. Then the metal will not drain and damage the product. If the plates being welded are very thin, for example tin or galvanized, then you need to do the following:

clean the parts as efficiently as possible, remove dust, dirt, paint or oil residues from them, remove the galvanized layer;
make the seam with dots. In this case, the risk of drips and burns is reduced.

Vertical welding technology

The technique of welding vertical seams depends on several factors:

characteristics of the metal of the materials that need to be connected;
the type of welding that is used in this case;
welder skill:
quality and features of the equipment used.

You can create welds in several ways:

from top to bottom with arc separation:
from bottom to top with arc separation;
from top to bottom without breaking the arc:
from bottom to top without breaking the arc.

Creating a seam with an electrode

Welding in a vertical position requires more attention and effort than in a horizontal position. This is due to possible metal leaks. For novice welders, it will be easier to form a weld with arc separation. Thus, the material hardens quickly. To make the process easier, at this time the electrode can be rested on the edge of the weld crater. During the formation of the track, movements are made both with the separation of the arc and without separation - with a zigzag, crescent, loops or roller - “up and down”.

If you decide to weld a vertical seam from top to bottom, then this is done with a very short arc. It will take a little practice beforehand to learn how to melt the metal, but avoid it from spreading downwards. Here it is important to hold the electrode correctly - strictly perpendicular to the edges of the crater. When exciting the arc and creating a roller, you need to tilt it down a little (45 degrees).

The recommended electrode diameter is 4-5 mm with a current of no more than 170A.

How to properly weld a vertical seam without tearing can be seen in this video tutorial:

Semi-automatic vertical seam

Semi-automatic welding of vertical seams can be done using several methods:

“Triangle” is a technology used for thin metal, no more than 2 mm thick. It is based on the standard principle of guiding the conductor from bottom to top. In this case, the molten metal is located above the frozen metal, which has already formed a small roller and does not allow “newly made” drops to flow down the path. When making vertical welds with an inverter, it is necessary to move the conductor correctly so that the weld pool is slightly angled. Actually, this is where the name of this method comes from – triangle. For this technology, professionals recommend using an electrode with a three-millimeter diameter and operating at a current of 100A.

The “ladder” is used when there is too much gap between the parts to be soldered. The working process itself is as follows: it is necessary to make transitions from one edge to another with minimal lifting of the electrode. It is best to implement this in a bottom-up manner without tearing off the arc. Thus, a so-called ladder is obtained. As a result, the roller is not smooth, but with sharp edges. This type of joining parts is considered the easiest.

“Herringbone”. This technology is ideal for semi-automatic welding of gaps of no more than 2-3 mm. In this case, the electrode must be moved along a certain trajectory. And the result will be a seam like a herringbone. You need to start from one of the sides and guide it along the edge wall towards you. When the metal is melted, you need to lower the electrode and stop a little to melt the product. You need to do the same on the other side. Continue this way upward along the entire path. The most important thing is to prevent the drops from spreading.

In this video you can see how to properly weld parts in a vertical position:

In conclusion, it is worth noting that the vertical seam requires special attention, as there is a risk of hot metal running off. To avoid this, there are several technologies that allow you to cook iron in a vertical position.

If you adhere to all the rules and regulations, then you will get a high-quality and reliable seam without “sticking” layers of metal and slag. Such tracks can be welded using several methods - semi-automatic and manual welding.

Each of the methods has advantages and disadvantages when creating a seam, but choosing among all existing types, these are the best and simplest, especially for novice craftsmen.

Source: http://home.nov.ru/svarka-vertikalnyx-shvov/

How to weld a vertical seam correctly using a semi-automatic machine? — Machine tools, welding, metalworking

For welding metals, a laser beam, torch flame or plasma can be used, but one of the simplest and most compact options for devices for performing this type of work is a semi-automatic device.

To ensure that the metal seam is as smooth as possible and protected from oxidation, welding metals in this way is best done using shielding gas.

Methods for welding vertical seams

Welds are classified according to many parameters. The main characterizing features are the type of connection and position in space. Based on the type of connection, they are divided into butt and corner.

They can be located in space strictly horizontally (lower), vertically or at an angle to the horizon. Welding the bottom seam is the simplest. In this mode, it is easiest to control the condition of the weld pool, and therefore the quality of the connection.

When making other seams, including vertical ones, a certain skill is required and it is necessary to know the methods of welding metals and their alloys in one position or another.

Electroslag method

Electroslag welding can be used to weld parts of almost any thickness. The connection occurs in one pass, regardless of the thickness of the metal. This is its functional feature.

Moreover, welding vertical seams with this method works best, again due to the principle of the method used. Thanks to single-pass welding, energy and consumables are saved, and productivity increases by an order of magnitude. Welding of vertical joints of tanks is of high quality.

During electroslag welding, in the area between the edges of the joints of the workpieces and the copper plates, a bath of liquid slag appears. The welding process can be described as follows:

after immersing the electrode in the slag bath, the welding current passes through it and heats it to such a temperature that the edges of the parts and the electrode itself begin to melt;
the melt forms a weld pool, after cooling which crystallizes and forms a welded joint;
As the seam cools, the electrode with copper plates, forming a closed area of the weld pool, rises.

Thus, vertical welding of seams of any thickness is carried out in one pass. Liquid slag, as a lighter component, is always on top, protecting the seam from exposure to atmospheric oxygen. After completing the welding process, the cooled slag is tapped with a hammer and removed.

Electric arc method

Before any welding begins, the areas to be joined must be prepared. Depending on the thickness of the metal and the type of connection, it is prepared and the edges of the parts are cut in accordance with the requirements of the standards.

Then they are secured using special clamps or other devices. To prevent temperature deformations, parts are welded to each other at a certain distance with transverse seams, so-called tack welds.

They provide reliable fixation of products relative to each other.

When welding vertical joints of products using electric arc welding, the molten metal moves downward under the influence of gravity. The transition of the liquid alloy electrode into the weld pool occurs by droplets.

To ensure that the drops do not come off but flow smoothly, a short electric arc is used. Sometimes, it is even possible to touch the end of the electrode to the workpiece being welded to prevent it from sticking to the workpiece.

A vertical seam is welded in two ways: top-down or bottom-up.

Down up

With bottom-up technology, the weld pool is initially located at the bottom. Molten metal enters it from above. To prevent liquid metal from spilling, the welding electrode is installed at an angle to the plane of the vertical weld.

Its melting end is located above the other end, fixed in the holder. Thus, it kind of supports the weld pool and prevents the metal from splashing.

The lower layers will crystallize and become a kind of stand for the new bath. This is how the manual arc method of creating a vertical seam is carried out.

With any method, it is necessary to maintain the welding current so that the crystallization of the pool occurs faster than the melting of the electrode and edges. This is achieved through a short arc and the formation of small drops of liquid metal.

Top down

When welding vertical joints using the top-down method, the electrode is also positioned end up. The edge of the weld pool is supported by an electric arc and electrode.

The task is to advance melting of the lower edge of the bath while simultaneously holding it. The upper edge must have time to crystallize due to the lack of heat input from the molten electrode.

If splashing still occurs, then you need to increase the welding current and increase the speed of moving the electrode down. It is also advisable to increase the width of the seam.

The vertical welding seam produced by an inverter is better than when using a conventional machine. This is due to a more stable welding arc.

Use of a semi-automatic device

Welding of vertical seams using a semi-automatic device or an inverter machine is carried out using several welding technologies. The choice of method depends on the thickness of the walls of the products, the gap between the joints, and the shape of the edges.

Triangular trajectory

Triangle welding technology is used if it is necessary to connect products up to 2 mm thick. This method requires the greatest dulling of edges.

The technology can be used when welding fillet welds in a vertical position or tanks. Welding is carried out from the bottom up, so the molten metal is located on top of the cooled alloy.

The flowing slag does not interfere with the penetration of the edges, since it flows down the hardened metal. First, a shelf is formed at the bottom of the joint. By moving the electrode to one of the edges, the edges are melted and the weld pool is filled.

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The electrode is then moved to the other edge and the process is repeated. The shape of the bathtub looks like a triangle, hence the name of the technology. The recommended electrode thickness is 3 mm at a welding current of 80-100 amperes .

Trajectory in the form of a Christmas tree and a ladder

When welding products with a gap of 2-3 mm, the herringbone technology helps. In this method, it is necessary to use complex movements with the end of the electrode.

The process of welding a vertical seam begins from one of the edges, from the depth of the gap.

The electrode seems to be pulled out from the thickness of the metal, while fusing the metal onto the plane of the edge. Then it again returns deep into the future seam, and surfacing is carried out on the other side of the gap.

Gradually, the vertical gap is filled, forming a strong connection. The process is repeated until the entire gap is filled with molten metal. the task is to prevent the formation of excessive penetration of the edges and the appearance of metal leaks.

The ladder technology is used to weld vertical seams with the largest gaps, when the edges are not blunted at all. The electrode moves from one edge to be connected to the other, rising a minimum distance upward.

The movements are zigzag, with a brief stop at the edges for metal penetration. The technology allows welding products up to four millimeters thick.

Source: https://svaring.com/welding/teorija/svarka-vertikalnyh-shvov

Semi-automatic welding of vertical seams

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.

Preparing the device for operation

semi-automatic device

The semi-automatic device consists of an inverter, a burner equipped with a cable duct, 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

Semi-automatic welding of vertical seams: features

When exposed to high temperatures, droplets form on the metal surface. They begin to flow down, thereby preventing high-quality welding.

The slag remaining after using the electrode and located in such a drop significantly increases the risk of weld defects. However, if you remove the rod from the welding site for some time, the metal will crystallize and the drop will harden.

It is important to correctly calculate the time period intended for cooling the metal, otherwise lack of penetration cannot be avoided.

As a rule, the current strength when semi-automatically welding vertical seams is 5 A less than when welding seams in a different position. Such indicators ensure the integrity of the seam, minimizing the likelihood of undercutting. Semi-automatic welding involves performing oscillatory movements, during which the root of the seam will be welded properly.

As with welding in any other spatial position, a vertical seam can be made in the form of a continuous connection, a point connection, or a continuous intermittent one. In the first case, the seam gives the parts additional rigidity and is used for household and construction needs. The second type is indispensable for car body repairs. The third is also widely used in service stations, but is used for those places where thicker metal needs to be welded.

How to weld a vertical seam from top to bottom

When using this method, you should pay attention to the thickness of the welding wire. Since a large amount of slag can make the joint porous, the thickness of the electrode should be much less than the width of the intended weld. A thin electrode guarantees quick setting of the weld pool without dripping of molten metal. Thanks to this, a larger number of workpieces can be welded in a short period of time.

When welding from top to bottom, it is best to use cellulose and plastic coated wire. The first type contains a large number of organic compounds, which, during the process of melting the electrode, saturate the welding zone with hydrogen. To avoid the occurrence of so-called seams.

“fish eyes”, the structure to be welded must be kept at room temperature for some time before work. If possible, you can calcinate the parts at a temperature of 250-300 °C, this will prevent the metal from being oversaturated with hydrogen.

Plastic-coated wire is more effective: it ensures continuous burning of the arc, the seam is strong, without pores and microcracks, and the slag crust is separated quite easily.

How to weld a vertical seam from bottom to top

It is much more difficult to weld vertical joints using this method, but, nevertheless, most welders resort to it if they have to connect critical structures.

Semi-automatic welding from bottom to top implies a different location of the weld pool. It is located from below, and from above it is filled with liquid metal. To prevent the molten material from spilling, you need to concentrate on manipulating the electrode:

It is necessary to maintain the angle between it and the vertical seam.
The end fixed in the holder must be below the melting end.
The melting of the electrode should occur more slowly than the weld pool will crystallize.
Welding is performed by oscillatory movements. In this case, the heat source does not linger for a long time at one point, and metal spreading and burn-through can be avoided. vertical seam from bottom to top with root penetration

Some vertical welding technologies

You can weld a vertical seam semi-automatically using not only classical methods. Quite common methods of welding vertical seams include the following:

Triangle. The vertical can be welded using this method if the thickness of the surfaces to be joined does not exceed 2 millimeters. Before starting work, it is necessary to blunt the edges of the parts. The welding direction is from bottom to top, the optimal electrode thickness is 3 mm, and the current is in the range of 80-100A. After forming a shelf at the bottom of the joint, the electrode is moved to one of the edges, the edges are melted, filling the bath. Then the actions are repeated at the other edge, and the weld pool is obtained in the shape of a triangle.
Herringbone. It is used if the gap between the surfaces is 2-3 mm. The metal is “pulled out” from the depth of the gap, located on the plane of the edge, then it returns deeper into the gap. Welding occurs from bottom to top. This technology is much like a loop. In order for the metal to be distributed evenly in the gap, it is necessary to practice the movements until they become automatic and carefully ensure that no cuts occur on the edges.
Ladder. It is used with a gap exceeding 4 mm, if the edges of the parts are minimally blunted. With zigzag movements of the electrode, there is a slight vertical rise and small stops at the edges, necessary for metal penetration.

How to properly weld a vertical seam. Tips for beginners

Despite the fact that welding using a semi-automatic machine is easy even for beginners, some work should be approached very responsibly, armed with the recommendations of experienced craftsmen. Making vertical seams is one of these situations where the experience of predecessors will come in handy.

To achieve stable arc burning, the rod should be given a perpendicular position during arson.
To avoid drips, the electrode is kept in an inclined position during operation.
If your priority is not high productivity, but a neat seam without the slightest smudges, then you should reduce the length of the arc. Accelerated crystallization will avoid leaks.
The rate of metal crystallization can also be increased by increasing the current strength and weld width. However, when using this method, be prepared for the fact that the seam will turn out to be of slightly worse quality.

Source: https://svarkaed.ru/svarka/shvy-i-soedineniya/poluavtomaticheskaya-svarka-vertikalnyh-shvov.html

How to weld a vertical weld

Electric welding involves the application of an electric arc to the metal being processed. It is formed between the product and the used electrode made of conductive material.

Too high a temperature causes the metal to melt, due to which the individual parts are connected. The connection point is usually called a weld.

To change its indicators, the technical parameters of welding are changed, for example, the amplitude and speed of movement. The features of vertical welding should be considered in more detail.

How to cook a vertical seam

How to weld a vertical seam?

There are quite a few rules that, if followed, can improve the quality of the resulting seam. It is quite difficult to exclude the possibility of dripping of hot metal drops.

The main recommendations include the following points:

The electric arc must be extremely short. A long one can cause the alloy to spread out as it flows under the influence of gravity.
At the time of arson, the working part is placed exclusively perpendicular to the surface being treated. It is important that it is positioned perpendicular to both surfaces being processed, which ensures high quality processing.
When working, it is recommended to tilt the electrode slightly downwards. By maintaining an acute angle, it is possible to retain the hot metal, preventing it from flowing down.
In some cases, it is impossible to eliminate the possibility of metal dripping. Then it is recommended to increase the current strength and speed up the movement of the working part. However, when increasing this indicator, you need to be careful, as this leads to an increase in the arc. In addition, it is recommended to increase the width of the seam by moving the tool from side to side.

Vertical welding methods

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The above technology is much simpler to implement if we compare the option of conducting the electrode from the bottom up.

Top down technique

Moving the electrode from top to bottom can only be used to weld when using an electrode that produces a thin layer of slag. Among the features of this process, we note the following points:

By using such a rod in the weld pool, the material hardens faster. In this case, the molten material does not flow down.
It is recommended to use plastic and cellulose coated electrodes. An example is the LNO-9 and VSC-2 brands.
This technology is characterized by high productivity. That is why, if there is a need to increase labor productivity, then the technology in question is chosen.

Vertical seam from top to bottom

This technique is not suitable for beginner welders, as it is difficult to prevent the alloy from dripping.

Bottom-up technique

This technology is extremely common. It is characterized by the following features:

At the beginning of work, the welding machine rod is placed perpendicular to the surface being processed.
As soon as the arc has been excited and the first drops have formed, it is recommended to tilt the electrode slightly.
A short arc is supported by the end of the rod and the drops are collected a little, and when it is withdrawn briefly, time is given for the molten material to cool and crystallize.
Transverse oscillatory movements can be reported. This eliminates the possibility of a long delay of the heat source at one point.

Vertical seam from bottom to top

This technique allows you to get a high-quality seam. However, it is characterized by low productivity, since it is necessary to allow the drops to cool from time to time.

How to weld a vertical seam correctly using a semi-automatic machine? — Metals, equipment, instructions

Semi-automatic welding of horizontal seams

Welding parts can truly be called an art, and welders who devote themselves to this profession are highly valued both in home welding and in industry. There are many people who know how to light a welding arc, but you need to look for professionals who can make a high-quality seam and at the same time withstand the technology. And it’s even harder to find a specialist who knows how to weld semi-automatically: only with such welding can you achieve the highest quality result.

This machine can weld any metals of different thicknesses. Therefore, most often semi-automatic and automatic welding can be found in industry . If we compare this type of welding with conventional electric arc welding, the efficiency of the machines is much higher. Semi-automatic welding for beginners includes the study of theoretical and practical aspects, and they are very closely related to each other.

Semi-automatic welding and its varieties

Before cooking with a semi-automatic device, you need to study its design and capabilities in detail. The device itself is made in the form of a mechanical device, where a wire is located, which acts as an electrode, and there is also a mechanism for feeding it automatically.

The speed of wire extension and the current strength can be adjusted on the body of the device, it all depends on the melting temperature of a particular metal, as well as the speed of movement of the torch along the surface to be welded. There are many devices of this type on the market, but the process itself can be divided into two types. Both types have one thing in common - the ability to protect the metal during the welding process:

Welding under flux layer. Flux is a substance in powder form that is found in the electrode rod. Its chemical properties help protect the process from oxidation.
A welding process in which welding occurs under the protection of inert gases.

If we distinguish machines by current consumption, then they can be either single- or three-phase.

The former are capable of operating from a regular 220 V outlet, but sometimes the device does not have enough power due to frequent power fluctuations, which can lead to an unstable arc and reduce the quality of the seam.

The three-phase unit has more stable operation and high quality indicators, but there may be a problem with its connection. Despite the fact that these devices have differences, their equipment is the same:

Energy source.
Electrode (wire) feeding mechanism.
Holder.
Cable with clip.
Control block.
Gas cylinder.
Gas supply hose.

Welding process in the middle of shielding gas

Several types of gas , but carbon dioxide, helium or argon are more often used. Carbon dioxide and helium have low consumption, and are also the most affordable to purchase.

The main purpose of the gas is to protect the welded metal from oxidation, which affects the strength properties of the weld. If carbon dioxide is used, the surfaces that will be joined by a seam must be thoroughly cleaned of rust, dust and paint.

It is recommended to use a metal brush in combination with sandpaper for this.

Three types of semi-automatic welding:

Without separation from the metal body . The seam is applied in a continuous layer from the beginning to the intended end.
Spot welding . The parts are connected by welding points, at specified intervals, along the entire length of the welded surface.
Short circuit welding . Basically, this type of welding is automatic, and it is applied to thin sheet metal. The process occurs from electrical impulses that the device generates. The short circuit melts the metal and turns it into a drop that connects the parts together.

Semi-automatic welding using carbon dioxide most often takes place in alternating current mode. Before starting work, you need to configure the semi-automatic welding machine. The parameters are adjusted depending on the type of metal.

The gas consumption used depends on the current settings of the device. Unlike carbon dioxide, the wire leaves unchanged - the average consumption is 4 cm per second.

The exact settings and material consumption can be found in the device’s passport, where, according to GOST, the standards for each type of metal are indicated.

The equipment is configured and ready for work, the parts have been cleaned, and now you can proceed directly to the welding process. The first thing to do is to unscrew the gas supply valve, and only then ignite the arc. Touch the wire to the metal and start the process. The wire is automatically fed each time you press the “Start” button. What determines the quality of the weld? It is important to keep the wire perpendicular to the workpiece, but not to block the view of the seam bath being poured.

It is necessary to maintain the required gap between the parts that are being welded. According to the technology, it looks like this: with a part thickness of up to 10 mm, the gap should not exceed a millimeter, but if the bodies being welded are thicker than one centimeter, then the gap will be 10% of their thickness. It is good to weld parts in a lying position and on an iron gasket, which is placed below close to the base metal.

How to weld aluminum

The semi-automatic machine is also designed for welding aluminum. But there are nuances in this process, due to the fact that such metal has its own characteristics. There is a thin layer of amalgam on the surface of aluminum. Its melting temperature is more than 2 thousand˚C, while the main body melts already at 650˚C. Therefore, argon acts as an inert gas in this case.

When welding aluminum, a special substrate is used for the work - this prevents it from spreading. The welding process is affected by direct current of reverse polarity - a cathode is attached to the part, and the torch plays the role of an anode. This technique improves the quality of melting of the part, and also quickly destroys the amalgam. Although the oxide layer can be removed by simply cleaning the edges of the parts with a fine abrasive.

Welding without the use of inert gas

A distinctive feature of this welding process is that the work can be done both using gas and welding can be done semi-automatically without gas, using ordinary wire. A popular method of welding parts is a seam coated with flux. But more often this method is used in industrial settings, since flux is an expensive material.

Under the influence of a high melting point, the powder creates a cloud of gas, which protects the weld pool from oxidation. And the tap on the inert gas cylinder is closed at this time. The main advantage of flux-cored wire is the ability to carry out the welding process even in strong winds. And in the case of supplying gas from a cylinder, the wind will be a hindrance.

But there are cases where the use of cored wire is not recommended: thin sheet metal and medium carbon steel. There is a danger of defects that may appear in the form of hot cracks. To increase the temperature of the welding arc and high-quality melting of the flux, you need to use the already known technique with reverse polarity - the cathode is placed on the part, the holder with the wire will act as the anode.

If your goal is to become a real professional, you need to study all the questions on the topic - how to properly cook with a semi-automatic machine and such an important factor as safety rules, and in the future apply the acquired knowledge and pass it on to the descendants of this profession. Never neglect safety rules when working with high temperatures and electricity. An important point is to protect your eyes and exposed areas of the body, so provide yourself with a mask and thick clothing that will protect you from burns.

Both beginners and experienced welders are recommended to make the first test weld on a hidden area, or better yet on a rough part, in this way the semi-automatic settings will be more accurate. When using the device for the first time, be sure to read the instructions and apply the information received in your work. Try to avoid overloading the semi-automatic welding machine - this will extend its service life.

It doesn’t matter what kind of welding, automatic or semi-automatic, you need to gain theoretical and practical knowledge of working with them. Although learning is a long process that requires patience and concentration, once you understand everything, the welding process will seem like a cakewalk. Some beginners ask the question: what is the difference between automatic welding and semi-automatic welding? Answer:

Automatic welding is an automatic process that is used mainly in production and does not require direct human participation.
Semi-automatic welding is a process in which the wire (electrode) is fed mechanically, and the ignition of the arc and movement of the holder along the body of the part is carried out by a person.

Source: https://rem-serv.com/svarka-gorizontalnyh-shvov-poluavtomatom/