How to correctly evaluate a welding seam at a competition. How to place a welding seam correctly

One of the most inconvenient and difficult positions for welding is the ceiling. But it is worth mastering this type of connection due to the automatic increase in the class of a welder who has learned to make high-quality seams in such a spatial position. This is in demand at enterprises whose activities involve laying pipelines and at construction sites. This skill is also useful in everyday life, when welding heating or gazebos. Some elements of a metal garage cannot be assembled without welding joints at the top. How to weld a ceiling seam using electric welding? What are the main precautions and optimal device settings?

Many welders do not like ceiling seams because of the difficulties in their execution. A beginner’s results can often be poor, which discourages them from learning. But if you understand the main problems and prevent them as much as possible, then pretty soon, after training, you can master this difficult connection.

Welding a ceiling seam with an inverter or transformer is significantly different from working on a similar product in the lower position. When metal is welded on the floor, the weld pool spreads over the joint, and the welder only needs to ensure that the joint is properly filled, preventing slag from getting in front of the pool. When the ceiling serves as the working surface, the molten metal tends downward under its own weight.

The slag, being in a liquid state, also constantly drips, which interferes with the welding. These splashes hitting the ground scatter even more, hitting the welder and surrounding objects. The main difficulty when arc welding in the ceiling position of the seam is connecting the sides of the product. A weld pool forms on one edge, but there is no way to bond both sides with metal.

Welding of ceiling seams is performed at a reduced current, which leads to frequent sticking of the electrode and lack of penetration. Another defect is sagging. The body position with the head thrown back and the arm raised up quickly tires the welder. Therefore, frequent breaks are simply necessary for quality work. Understanding these complexities will help you tune in to the challenges and take steps to make the process easier to implement.

Ceiling welding technology

To understand how to properly perform this type of connection, you need to know the basic rules used by experienced welders. Additionally, you can see how to weld a ceiling seam using electric welding in the video. Here are the main points:

• The sides to be welded should be brought together as much as possible. Welding with gaps on the ceiling is only available to experienced specialists, so the more closely the parts are connected, the easier it will be to apply a seam.
• Edge cutting is carried out as in the lower position. When the thickness of the sides is more than 5 mm, a V-shaped bevel is made.
• The electrode is brought to the ceiling at an angle of 45 degrees relative to the upper plane. Beginner welders can try welding with half of the electrode, as this will allow better control of its tip and control the formation of the seam.
• The welding process and the seam itself in this spatial position are possible due to the surface tension of the metal. To prevent drops of molten iron from flying off before they catch on the edge, the current should be reduced.
• If the sides are brought close together, then the first seam on even plates can be made without oscillatory movements. This will fill the joint well. The second pass is made wider to strengthen the ligament. But on pipes it is better to immediately weld with a wide seam.
• Electrode welding can be performed in several ways: crescent, horizontal figure eight, or spiral. When there is a small gap, an intermittent arc is used to allow the deposited drop of metal to cool. After a moment, without allowing the red color to pass through (this can be seen through the mask), the next drop is applied. This is a long process, so the welder does not need to rush and needs to rest periodically.
• Do not be intimidated by the appearance of the connection after the work is completed. Slag can flow down several tiers. But after beating it off, a high seam should remain. Sagging and large rollers are not critical.

Devices and electrodes

Ceiling seams can be made using an inverter or a conventional transformer. It is important to correctly set the current strength, which is 25% lower than when welding on the floor. For example, for plates 5 mm thick, 100A is sufficient. It will be easier to work if the cable is not heavy. This will make it easier to control the end of the electrode and your hand will get less tired. You can also loop the cable around your hand to reduce the strain on your wrist.

Electrodes for ceiling welding are suitable with a diameter of 3 and 4 mm. It is important to dry them well to reduce the amount of splashing. If beginners use short electrodes, this will allow them to manipulate the arc more confidently.

Precautionary measures

For ceiling seams, you should wear a thick jacket and trousers. Gloves must cover the cuffs, otherwise scale will reach the elbows and burn the skin. A hat or cap without a visor is required on the head. It is important to choose trousers of such length that they cover the collar of the shoe to prevent molten particles from getting inside.

In the modern world, welds are found almost everywhere, in every industry. But many owners resort to the services of specialists. But you can easily acquire this skill yourself, especially since the welding process is very exciting; you may be drawn from welding an ordinary garage to making an openwork fence. It’s not difficult to learn how to cook; just understand the nuances and you can safely move on to the welding process.

Before you begin any training and understand how to properly weld with electric welding, you need to stock up on certain accessories. For welding you need to purchase:

1. Welding machine – electric welding.
2. Set of electrodes. Their diameters vary and must be selected depending on the density and thickness of the metal section. Necessary for supplying current to the welding seam. For beginners, you can purchase rods with a heating and easily melting composition.
3. Long sleeve rubber gloves. It is recommended to wear suede ones.
4. Mask with a darkened light filter.
5. Thick clothes.
6. A hammer needed to knock down slag (glassy material).
7. Brush for cleaning seams.
8. Transformer – used to convert direct current to alternating current. It is used, as a rule, when there is no need for a high-quality weld.
9. Rectifier.

Instead of a transformer and rectifier, for a beginner you can use a simpler mechanism - an inverter. It is very convenient and versatile. They can be used to weld both aluminum alloys and durable steel alloys. It also comes with a pair of wires with clamps attached to them. An electrode is inserted into one end, and the parts necessary for welding are attached to the other.

When welding, do not forget about safety measures.

Before starting welding work, it is necessary to prepare the working surface. To do this, you need to remove rust from surfaces by treating it with sandpaper, a grinder or sandpaper. If you ignore this procedure, problems may arise when igniting the arc.

Electric welding process technology

Welding is a process cultivated under the influence of high temperatures. Under its influence, the treated surfaces melt, forming a so-called bath in which the base metal is mixed with the metal core of the electrode.

The size of the resulting pool can be different, depending on the initial type of welding, position to the surface, speed of arc movement, and so on. On average, the welding width can be 0.8 - 1.5 cm, height 1 - 3 cm, and depth about 0.6 cm.

Oxygen, when combined with metal, can have an undesirable effect on the joining of the seam, which is why the electrode is covered with a special coating, which, when melting, forms a zone of gas in the arc area and above the molten pool, into which air does not enter. This is why the metal does not interact with oxygen. In addition, slag forms on top of the seam, which also prevents the interaction of the alloy and oxygen. At the final stage, it is cleaned with a brush.

Arc striking training

Before any type of activity you need to gain experience. Likewise in the welding process, before you start alloying several metals, you need to practice making beads on an unnecessary sheet of metal. To do this, you need to clean the rusty surface and dirt on it.

The electrode is then clamped into the welding machine holder (inverter). Next, in order to deliver current to the melting zone, you just need to scratch. Or you can also do it with tapping movements.

After the completed electric arc is created, the electrode is directed to the workpiece. It is worth noting that the gap between the electric arc and the metal surface should be the same throughout the entire gap, but not less than 0.3 cm and not more than 0.5 cm.

Important! If the gap between the arc and the metal is changed, the electric arc will break, and the welding seam will be defective and unsightly.

The electric rod is usually held at an angle of 71 degrees. It can be tilted forward or backward, as is more convenient for the master. In the future, the tilt can be changed depending on the convenience of the master or on the specifics of welding.

And also at this training stage it is necessary to feel the required electric welding current in order for the supply to be carried out stably. If the current strength is small, then the electric arc will go out, and if, on the contrary, it is large, then the metal will begin to melt. Welding skills can be gained through trial and error.

Weld seams depending on welding speed

Correct movements with the electrode

After training with rollers, which after hard training should turn out approximately smooth and beautiful, you can begin training welding seams. It is at this stage that you can understand how to correctly lay perfect seams using electric welding. This stage is already within the capabilities of beginners who have gotten good at using rollers, felt the required current strength, the distance between the gaps, etc.

For a welded seam, you must first prepare the equipment, as described above (light an electric arc). A distinctive feature from the previous stage is that this time the master’s hand moves not in a straight line, but along an oblique path, making light oscillatory movements with a small amplitude. It looks as if the master is moving hot, melting metal from one edge of the welded element to the other.

The movement can be different and can be a zigzag, looping or reminiscent of repeated bends similar to Christmas trees and sickles.

There are trajectories produced in three directions:

1. Progressive. The electrode moves along its axis. For this purpose, maintaining a stable electric arc length will be sufficient.
2. Longitudinal. This is one of the thinnest types of seams. It looks like a thread. In order to apply it, it is necessary to maintain a height that depends on the speed at which the electric rod moves. In order to secure the resulting seam, it is necessary to make transverse directions of movement.
3. Oscillatory. This trajectory helps to obtain the required seam width. They can be done by making oscillatory movements of the hand. The height of the vibration wave is selected based on the size of the desired joint.

Electrode manipulation

The training also needs to be done on an unnecessary metal sheet. To begin, draw a line with chalk so that it can be seen through the darkened glass of the welding helmet. Next, along this line you need to draw a seam with an electrode along one of the trajectories listed above. After the joint has cooled, the slag is knocked off with a hammer, and a beautiful seam is obtained.

After obtaining these initial skills, you can safely begin welding connecting seams. They come in completely different shapes: horizontal, vertical, angular, butt, overlapping and others. After you feel that your hand is moving more or less confidently and have trained a lot, you can only then try to weld beautiful and delicate seams.

For a visual understanding of the welding process, we recommend watching this video

Thus, you can independently learn the very necessary skill of working with electric welding. To do this, you need to stock up on certain supplies and tools. It is also worth remembering that welding is a very dangerous activity, so when working with it you need special equipment and protective measures (helmet, gloves, clothing). To master this type of work, you must first practice on an unnecessary sheet of metal.

As is known, if welding is used during the construction of any building or in the manufacture of metal structures, then the reliability and longevity of the entire structure or individual metal structures largely depends on how high-quality the weld is. That is why the quality of welding seams is a factor to which the closest attention should be paid, and control of how well the welded joint is made must be carried out by all means available in one case or another.

How to determine the quality of a weld?

In order to determine how well a welded joint is made, you need to pay attention to the following nuances:

• See how the shape, size and composition of the weld matches the task at hand, the welding method used and industry regulations.
• Check for defects at the welded joint, both externally and internally visible.

• The metal at the weld joint and the area next to the weld must be equally dense and free of breaks.

• The strength of the metal at the junction must be checked using a variety of tests - it must be resistant to tearing and impact, especially if the welded structure will be operated at temperatures below 0 degrees, but also at high temperatures that may arise during operation of a certain metal structure , the metal should not be destroyed. In addition, it must be taken into account that during operation, the metal in the welded joint zone may be subject to other influences - for example, bending or stretching.

What determines the reliability of a weld?

The quality of welds, and therefore their reliability, depends on several factors:

• Of great importance is the quality of the metal that is being welded.
• The materials used for welding work must also be of high quality. Such materials include a welding electrode or welding wire, welding flux, as well as those gases that are used as shielding.
• In addition, the reliability of the welded joint also depends on how correctly all the materials for welding are selected.
• Particular attention should be paid to the choice of equipment for welding work - it must also be of high quality and reliable.
• The choice of welding mode is another factor that inevitably affects the reliability of the welded joint.
• It is also very important to properly prepare the metal of the workpieces before starting welding - clean the surface of the metal, process the edges.

And of course, we must not forget about such a factor as the qualifications of the welder himself - the experience of the person who performs the welded joint cannot but affect the quality of all the work he performs.

Welding rules.

The quality of the welded joint largely depends on how correctly the welder performs all stages of welding work. As every welder knows, much of his work depends on the length of the arc, but the ability to select it in such a way that the connection is of the highest quality is a matter of time and experience. That is, the more a welder works with welding equipment, the better and faster he determines the required arc length - as a result, all his actions in this case become automatic. For those who do not yet have sufficient experience, it is necessary to remember that the length of the welding arc depends on the diameter of the electrode used for welding and ranges from 0.5 of its diameter to 1.1.

In addition, when carrying out welding work, in order to achieve high quality welds, other rules must be observed:

• Welding can be carried out in different directions, depending on the task, the type of welding and the convenience of the welder himself - from left to right or from right to left, from himself or to himself.
• The electrode should be inclined at an angle of approximately 15 degrees in the direction where the seam is being made.
• Guiding the electrode along its axis allows you to maintain the desired arc length, and guiding it along the axis of the bead obtained during welding allows you to achieve high quality welded joints.
• When completing the welded joint, the arc should not break off abruptly - it must be led slowly until the moment when it breaks off on its own.

It is worth noting that high quality welds are most often inaccessible to a person who has encountered welding equipment for the first time, no matter how well he has theoretical knowledge regarding the rules of welding. As a rule, only experience helps to achieve high quality connections - that is, no matter how well the welder knows how to weld correctly, only practical skills will become the basis on which the high quality of all the work he performs will be based.

Electric welding is a technology for combining the structure of metals by heating and melting with an electric arc. It has become widespread in various spheres of the national economy, including the private sector.

In fact, this method can be used to weld any metals together, taking into account the temperature of the electric arc (7000-8000 degrees). But before turning to this technology, you will have to learn how to weld a vertical seam using electric welding, and understand the technique for obtaining a horizontal seam.

The technology of welding metals is closely related to the concept of a weld. This is formed during the solidification process of metal melted by electric arc welding.

Depending on the location of the welding, the seam can be positioned horizontally or vertically. In addition, the spatial location of the seam can be bottom, side, or top.

Types of welds: 1 – horizontal in the lower plane; 2 – horizontal in the upper plane (ceiling); 3 – horizontal in the lateral plane; 4 – vertical in the lateral plane

The simplest and easiest to perform is considered to be laying welds in the plane of the lower horizon. Under such conditions, the molten metal is quite easy to control.

A simple weld placed in the lower horizontal plane. This is the lightest type of seam that is found in the practice of welding technology

The remaining options for the location of seams in space (side and top) are recognized as technologically difficult to implement, requiring the study of welding techniques and the development of relevant experience.

Image gallery

By holding the electrode strictly at a right angle (90º), the welder ensures that work is performed in hard-to-reach places. Finally, the “back angle” technique allows for high-quality welding work on corner joints.

When installing the electrode at a forward angle, they usually work with thin-walled metals. In this position of the electrode, a wide seam of shallow depth is obtained. On thick-walled metals, on the contrary, they try to use the “backward angle” technique, ensuring the metal is heated to a sufficient depth.

Current parameters and electrode movement

The value of the current and the speed of movement of the electrode are significant factors that influence the quality of the seam. Welding with high currents is accompanied by heating of the metal to a great depth, which allows you to increase the speed of movement of the electrode. Provided there is an optimal ratio of current and speed of movement of the electrode, an even, high-quality seam is obtained.

Correspondence table for current, electrode, metal thickness

When moving the electrode at a certain speed, the magnitude of the arc power should be taken into account. Excessively fast supply of the electrode at low power will not be able to provide sufficient heating temperature.

As a result, it will not be possible to weld the metal to the required depth. The seam will simply “lie” on the surface, barely “grabbing” the borders of the edges.

Burnt metal at the point of unacceptably slow advance of the electrode. A common defect in welding thin-walled metals with a high-power arc

On the contrary, in conditions of excessively slow advance of the electrode, an overheating atmosphere will be created, which threatens the deformation of the metal on the welding line. If the metal elements have a thin structure, a powerful arc will simply burn through the metal.

You can successfully practice as a novice welder and hone your welding skills with a welder whose body is based on a metal pipe. We recommend that you read the useful information.

Instructions for a beginner welder

Welding work can only be performed if appropriate equipment is used.

Standard kit contains:

1. Jacket, trousers, gloves, shoes made of fireproof, durable, strong materials.
2. A headdress that completely covers the back of the head.
3. A special protective mask for the face and eyes.

To carry out welding, you should use a working device, the electrical part of which is closed with a reliable housing. The electrical cables included in the device must have complete insulation and comply with the electrical characteristics of the device.

The welder's place must be equipped with a work table, light sources, a grounding bus, means of protection against electric shock and fire-fighting equipment.

And even before starting work, you need to carefully study, consider and study the methods and options for making connections.

Conclusions and useful video on the topic

We invite you to watch a video welding workshop: how to weld horizontal and vertical seams:

It is not necessary to be a qualified welder, but proficiency in welding techniques is desirable. Thanks to existing welding skills, a person has more opportunities to implement various household projects.

If you wish, you can always study the technology, and practical experience will help you master the technique of performing work at a high level.

Would you like to talk about your own experience in making welds? Do you know the subtleties of the process that are not given in the article? Please write comments in the block below.

Answer:

This question is quite complex and the answer needs to be given in detail. There are three types of welds - vertical, horizontal and overhead. The first is considered the simplest, the last - the most difficult. Each has its own welding technology.

Vertical seam weld

This type of weld can be performed in two ways - downhill and uphill. Uphill welding is easier to perform, since less effort has to be applied to prevent the metal from flowing down, since it will be held by the already slightly hardened metal in the weld pool remaining behind the electrode. The seam will be less neat and beautiful than when welding downhill, but for beginners this is not so important.

If you want to get an even and neat seam, then try welding downhill. This method is more labor-intensive, since you have to carefully weld the place where the parts are fastened and constantly ensure that the molten metal does not leak down. The optimal angle for vertical welding is 45 degrees.

Horizontal welding seam

This is a rather difficult weld to make; during welding, metal can flow down to the lower edge. To prevent this, it is advisable to make a bevel on the top edge. And leave the bottom one unchanged, then it will act as a limiter for the molten metal.

When welding a horizontal seam, the electrode must be held at an angle of about eighty degrees, almost perpendicular to the surface to be welded. You need to walk the electrode several times. During the first pass, you should thoroughly boil the root bead, which is done without transverse movements with a short arc.

The second roller is created in one pass at an average current strength with an electrode of a larger diameter. Next, evaluate the distance between the top edge and the second roller. If it is wide enough to accommodate two more weld beads, then make a third and fourth pass. The main task is to smooth out the depression between the last roller and the top edge.

Ceiling welding seam

This weld is difficult because it involves a huge risk of metal leaking and droplets from the upside-down weld pool. To prevent this from happening, it is necessary to use thin electrodes (no more than four millimeters in diameter) and a reduced current strength, and also periodically remove the electrode from the weld pool so that the molten metal has time to solidify in time. It is usually recommended to weld ceiling seams at an angle of approximately 75 degrees using forward movements with the electrode returning or forming a zigzag line. This allows you to keep the molten metal in the weld pool, moving the electrode away from it in time. When welding ceiling seams, it is especially important to take maximum measures to protect the welder’s skin and eyes from metal drops. When making such a seam, it is better to cover all parts of the body as much as possible, including ears, neck, and hair.

The easiest way to make welds is with equipment that allows you to smoothly regulate the current. Such equipment includes inverter welding machines. In our online store you will find household, professional and semi-professional inverters. Among the first we can recommend