A guide to welding with an inverter for beginners. DIY arc welding

Apartment, and even more so a private house, require regular maintenance and repair work. A home craftsman has to be a generalist, capable of performing many various works. This is why craftsmen want to master as many technologies as possible.

One of the most popular is welding. Practice shows that electric welding for beginners is simple and accessible to anyone who wants to learn how to use it.

Electric is one of the welding methods when an electric arc is used to heat and subsequently melt metals. The temperature of the latter reaches 7000 degrees C, which is much higher than the melting point of most metals.

The electric welding process proceeds as follows. For education and maintenance electric arc current is supplied from the welding device to the electrode.

During the welding process, the base metal and the metal core of the electrode are melted and mixed, forming a strong and unbreakable weld

When the electrode rod touches the surface to be welded, welding current. Under its influence and the influence of the electric arc, the electrode and the metal edges of the elements being welded begin to melt. From the melt, as welders say, a weld pool is formed, in which the molten electrode is mixed with the base metal.

Molten slag floats to the surface of the bath, which forms protective film. After the arc is turned off, the metal gradually cools, forming a seam covered with scale. After the material has completely cooled, it is cleaned off.

Non-consumable and consumable electrodes can be used for welding. In the first case, filler wire is introduced into the melt to form a welding seam, in the second this is not required. To form and subsequently maintain an electric arc, special equipment is used.

What do you need to weld at home?

To carry out the work you will need, first of all, welding machine. There are several varieties of it. Let's decide which one to give preference to.

• . Distinctive feature lies in the ability to produce electrical energy and use it to create an arc. It will be useful where there is no current source. It has impressive dimensions, so it is not very convenient to use.
• Welding transformer. The device converts AC voltage, supplied from the network, into an alternating voltage of a different frequency, which is necessary for welding. The devices are easy to use, but have significant dimensions and react negatively to possible jumps mains voltage.
• Welding rectifier. A device that converts mains voltage into D.C., necessary for the formation of an electric arc. They are compact and highly efficient.

For work at home, an inverter-type rectifier is preferable. They are usually called simply inverters. The equipment has very compact dimensions. When working, it is hung on the shoulder. The principle of operation of the device is quite simple. It converts high frequency current into direct current. Working with this type of current ensures the highest quality weld.

The welding generator can operate in the absence of a network. It generates the current itself. The system is very cumbersome and quite difficult to work with.

Inverters are economical and operate from a household network. In addition, it is better for a beginner to work with them. They are extremely easy to use and provide a stable arc.

The disadvantages of inverters include higher cost than other devices, sensitivity to dust, moisture and voltage surges. When choosing an inverter for home welding, pay attention to the range of welding current values. The minimum value is 160-200A.

Additional features of the equipment can make the job easier for a newbie. Of these pleasant “bonuses”, it is worth noting Hot Start, which means an increase in the initial current supplied at the moment the welding arc is ignited. This makes it much easier to activate the arc.

The Anti-Stick function automatically reduces the welding current if the electrode rod is stuck. This makes it easier to pull off. The Arc Force function increases the welding current if the electrode is brought to the workpiece too quickly. In this case, sticking does not occur.

In addition to any type of welding machine, you will need electrodes. It is best to select their brand using a special table, which indicates the type of material being welded.

You will also need a welding helmet. The best one is the one that goes on the head. Models that need to be held in the hand are extremely inconvenient.

When working with welding, you only need to wear a protective suit. A special mask will protect your eyes from ultraviolet radiation and splashes, a thick suit and canvas gloves will prevent burns.

The mask may have a simple tinted glass or a so-called “chameleon”. The latter option is preferable, since when an arc appears, the glass automatically darkens. It is necessary to work only in special clothing that protects from splashes and ultraviolet radiation. This could be thick cotton overalls, boots or high boots, canvas or rubberized gloves.

Electric welding technology

It is better to learn how to properly weld parts using electric welding under the guidance of experienced welders. If for some reason this does not work out, you can try it yourself. First you need to properly organize workplace. This is very important, since welding is a high-temperature and therefore fire-hazardous process.

To work, you need to choose a workbench or any other base made of non-flammable material. Wooden tables and them similar products are strictly prohibited. It is advisable that there are no flammable objects near the place where welding will be carried out.

Be sure to place a bucket of water near you to eliminate possible fires. In addition, you need to determine a safe place where the remains of used electrodes will be stored. Even the smallest of them can cause a fire.

You can find it on sale welding electrodes different diameters. Right size The rod is selected based on the thickness of the metal being welded

For the first independent seams, you need to prepare an unnecessary piece of metal and select electrodes for it. Experts recommend using 3 mm rods in such cases. Smaller diameter is used for welding thin sheets, which are inconvenient to study. Larger diameter electrodes require high power equipment.

We start by stripping the area of ​​metal where the seam will be located. There should be no rust or any contamination. After the part is prepared, take the electrode and insert it into the clamp of the welding machine. Then we take the “grounding” clamp and firmly attach it to the part. Let's check the cable again. It should be tucked into the holder and well insulated.

Now you need to select the operating current power for the welding machine. It is selected according to the diameter of the electrode. We set the selected power on the panel of the welding equipment.

The next step is igniting the arc. To do this, you need to bring the electrode to the part at an angle of about 60° and very slowly move it along the base. Sparks should appear. As soon as this happens, lightly touch the part with the electrode and immediately raise it to a height of no more than 5 mm.

The welding inverter is ready for use. Two cables are connected to it: one with a clamp for the electrode, the second with a grounding clamp

At this moment, an arc flashes, which must be maintained throughout the entire operation. Its length should be 3-5 mm. This is the distance between the end of the electrode and the workpiece.

When maintaining the arc in working condition, you need to remember that during operation the electrode burns out and becomes shorter. If the electrode gets too close to the workpiece, sticking may occur. In this case, you need to slightly swing it to the side. The arc may not ignite the first time. Perhaps there is not enough current, then it needs to be increased.

After the novice welder has learned to ignite the arc and keep it in working condition, you can begin to weld the bead. This is the simplest of all operations. We light the arc and begin to very smoothly and carefully move the electrode along the future seam.

At the same time, we perform oscillatory movements resembling a crescent with a small amplitude. We seem to be “raking” the molten metal towards the center of the arc. This way you should get an even seam that looks like a roller. There will be small wave-like metal sagging on it. After the seam has cooled, you need to knock the scale into it.

Arc welding techniques - welding methods

To get a high-quality seam, you need to learn how to maintain and then move the arc. The length of the electric arc especially affects the quality. If it is more than 5 mm, then it is considered long. In this case, nitriding and oxidation of the molten metal occurs. It splashes out in drops, making the seam porous and not strong enough. If the arc is too short, lack of penetration may occur.

The electrode rod can move along different trajectories. With experience, each welder chooses his own option, or more often a combination of several movements

Various techniques are used to perform welding. Let's look at the main ones in detail.

Option #1: Bottom Butt Joints

The most common and simplest way to connect parts. For metal thicknesses up to 0.8 cm, double-sided welding is used. For connections made of metal thinner than 0.4 cm, only one-sided welding is performed. For work, electrodes are selected whose diameter is equal to the thickness of the metal. If it exceeds 8 mm, welding is carried out with cutting edges. In this case, the cutting angle is about 30°.

Welding is performed in several passes. It is advisable to use removable pads made of steel or copper to avoid burns. The first pass is performed with a small diameter electrode, no more than 4 mm. When making the first seam, its accuracy and penetration depth are very important. After applying it, there should be no fused metal behind the edges.

For the second and all subsequent passes, larger diameter electrode rods are used. They are chosen for high-quality filling of the recess formed between the edges. The electrode is slowly moved along the seam, performing oscillatory movements, as if rocking the electrode from side to side, in order to completely fill the voids with molten metal.

Option #2: Bottom Corner Joints

Experienced welders say that good results can be achieved by welding the corners “into a boat”. This means that the parts to be connected are installed at an angle of 45° or other. This ensures the highest quality penetration of the product walls, and the danger of undercutting and lack of penetration is reduced. This welding method allows welding of large cross-section seams to be deposited in one pass.

Craftsmen remind that when welding a T-type corner joint, the electric arc should be ignited only on a horizontal plane

There are two types of boat welding - symmetrical and asymmetrical:

• In the first case, the inclination of the parts is 45°. The likelihood of sagging or undercutting one of the walls is minimal. Welding of reverse and direct polarity is carried out at maximum current values. When carrying out reverse polarity welding, the length of the electric arc should be minimal.
• An asymmetrical “boat” suggests that the parts are tilted at an angle of 60° or 30°. This option is very convenient if the work is carried out in hard to reach places, since the amplitude of electrode movement is small. The welder directs the arc to the very root of the seam, and care must be taken that it does not go beyond the boundaries of the future seam. It is also not allowed to deposit too much in one pass. a large number of metal

Corner joints can be T-type, so you need to learn how to weld metal correctly and without errors using electric welding in several passes. The use of one pass is only possible when welding simple designs with sides that form a 45° angle in a fillet weld. The diameter of the electrode in this case cannot exceed the thickness of the metal by more than 0.15-0.3 cm.

Standard multi-pass T welding is performed as follows. For the first pass, an electrode with a larger diameter is taken than those selected for subsequent passes. For example, an electrode is used whose dimensions vary from 0.4 to 0.6 cm.

Some welds are made in multiple passes. In this case, the size of the electrode for the first pass and for all subsequent passes is different.

Welding is carried out smoothly, without transverse oscillatory movements. When performing other passes, they are necessarily carried out. It is important that the vibration amplitude is within the permissible seam width. Another significant point. When performing T-welding on a fillet joint, the electric arc should always be ignited on a shelf positioned horizontally.

When doing electric welding of corners with your own hands, you can use an overlap type of connection. In this case, the parts to be welded are placed one on top of the other with an overlap. The arc during direct polarity welding should be short, and during reverse polarity welding it should be as short as possible. Direct the arc exactly to the root of the connection.

During the welding process, it is necessary to perform small amplitude reciprocating movements with the electrode. This will allow the entire joint area to be heated evenly. In this case, the weld pool will be evenly filled, and the seam will be convex and full-sized.

Option #3: vertical seams

Seams directed vertically are made only with a short arc. Work force The current should be 10% -20% less than when welding parts in the lower position. These requirements are easy to explain. A lower current strength means that the molten liquid metal will not drain from the weld pool. A smaller arc is more convenient to use.

Welding vertical seams has its own characteristics. They are explained by the fact that in this position, liquid metal can flow down the seam. Therefore, the welding current and electrode angle must be selected correctly

Experienced welders prefer to weld vertical seams from the bottom up. The arc is set on fire at the lowest point of the future seam. After that, a small horizontal platform is prepared, the dimensions of which correspond to the cross-section of the future seam. Then slowly move the electrode rod up. In this case, movements across the connection must be performed.

They can be in the form of a herringbone, corner or crescent. The last option is the easiest to implement. In addition, it is important to comply correct position electrode. Theoretically, penetration is best achieved if the rod is positioned perpendicular to the seam, that is, horizontally.

Practice shows that in this position of the electrode rod, liquid metal flows down the seam. To avoid this, the angle of inclination of the rod is chosen within 45°-50°. This is the optimal option for vertical welding. To weld parts in the bottom-up direction, select electrodes whose diameter does not exceed 0.4 cm.

Option #4: Pipeline Details

At home, you often have to remember how to brew using electric welding. metal pipe. A vertical seam is usually made on the side of the part, and a horizontal seam along the circumference. Steel pipes are butt welded. All edges must be well boiled.

In order to minimize sagging inside the pipe, the electrode is brought to the product at an angle of no more than 45°. The seam width should be 0.6-0.8 cm, height – 0.2-0.3 cm.

Pipe welding is carried out using various seams and in different areas. Depending on the wall thickness of the part and its location, the diameter of the electrode and the type of seam are selected

Before starting welding work, the parts to be joined are thoroughly cleaned. The ends of the pipe are inspected. If they are deformed, they are straightened or trimmed. Then the edges of the parts are cleaned from the inside and outside to a metallic shine at a distance of at least 1 cm from the edge. Then start welding.

The joint is welded without interruption until it is completely welded. For non-rotating joints of pipes with walls up to 0.6 mm wide, two welding passes are performed, for products with walls from 0.6 to 1.2 cm wide - three passes, for parts with walls wider than 1.9 cm - four passes. In this case, each subsequent seam is applied only after the scale has been removed from the previous one.

The quality of the first seam is most important. During the process, all blunts and edges should completely melt. There should be no cracks, even the smallest ones. If they exist, they are smelted or cut down. After which the fragment is welded again. Welding of rotary pipes is performed in the same way.

Possible defects in welding joints and seams

Electric welding is a complex process and not always everything goes smoothly. As a result of operational errors, seams and joints may become various defects, among which:

• Craters. Small depressions in the weld bead. They may appear as a result of a broken arc or an error in the execution of the final fragment of the seam.
• Pores. The welding seam becomes porous as a result of contamination of the edges of the parts with rust, oil, etc. In addition, porosity can appear when the seam is cooled too quickly, at high welding speeds and when working with undried electrodes.
• Undercuts. They look like small indentations on both sides of the suture bead. Appear when the electrodes are displaced in the direction of the vertical wall during welding corner connections. In addition, undercuts occur when working with a long arc or when the welding current is too high.
• Slag inclusions. There are pieces of slag inside the welding bead. This can happen if the edges are dirty, the welding speed is high or the welding current is too low.

These are the most common weld defects, but there may be others.

Conclusions and useful video on the topic

Features of pipe welding:

How to choose the right welding inverter:

Any if desired House master will be able to master the basics of welding. It is not so difficult. It will require patience, accuracy and, of course, precise execution of all instructions. Everything will be much easier if the process of mastering a new skill takes place under the guidance of an experienced specialist.

Please check with the managers for the exact cost of training.

Training welders in welding from scratch

Electric welders course- this is a training program for those who want to master the profession of a welder, a specialist in manual arc welding “from scratch”. To take the course, students do not need to have basic knowledge or experience in welding and cutting metals.

Training program is built on a consistent, step-by-step mastery of the profession and technology of welding work using electric welding machines and manual arc welding. Training of welders (electric welders) begins with studying the basic theory of welding and cutting metals. By understanding the profession from scratch, students will receive all the necessary knowledge to conduct a successful labor activity.

Begins electric welding course from studying the physical foundations of welding, becoming familiar with electrical safety techniques, safety rules when carrying out welding work, as well as providing first aid in case of injury. Having laid the foundation for safe welding work in accordance with the rules, regulations and requirements, students will continue their professional education, studying in detail the types of welding machines, welding quality control, technologies for manual arc welding with coated electrodes and technological process production of welded structures.

The educational center GCDPO offers you unique opportunity master an in-demand profession by completing short-term welding training courses. A welder (electric welder in particular) is a specialist in demand both in mechanical engineering and in construction. High-quality manual arc welding, mastered in our center, will guarantee your constant demand and high level of remuneration for your work.

Course curriculum

Lesson No. 1.

• Basic information about welding.
• Basic welding methods.
• Welding arc.
• Safety precautions when carrying out welding work.

Lesson No. 2.

• Classification of steels.
• Electrical safety.
• Rules for connecting an electric welding machine.

Lesson No. 3.

• Welding materials.
• Filler materials for manual argon arc welding (MAW).

Lesson No. 4.

• The concept of deformation.
• Deformation and stress during welding.
• Reducing tension and strain.

Lesson No. 5.

• Concept and indicators of weldability.
• Hot and cold cracks.
• Corrosion resistance of welded joints.

Lesson No. 6.

• Argon arc burner. Types of burners.
• Welding station connection diagram.

Lesson No. 7.

• Power supply for RADS.
• Ensuring arc stability and requirements for sources.

Lesson No. 8.

• Argon arc welding.
• RADS technique.
• Improving RADS performance.

Lesson No. 9.

• Design of cylinders and requirements for them.
• Gearbox device.
• Active and inert gases.

Lessons No. 10.

• Preparing metal for welding.
• Designation of seams and welded joints.
• Auxiliary signs for marking seams.

Practical lessons of the course

Lessons No. 11. Preparation of equipment for manual electric arc welding.

• Instruction on workplace organization and occupational safety.
• Preparation of equipment for manual electric arc welding.
• Preparing parts for welding.

Lessons No. 12. Assembly and welding of pipes, truss fragments and metal structures.

• Manual arc welding pipelines d pipes from 50 to 120 mm. Wall thickness from 2 mm.
• Manual electric arc welding of truss fragments.
• Manual electric arc welding of metal structures.

Lesson No. 13. Assembly and welding of rotary and fixed pipe joints.

• Welding of fixed pipe joints. Quality control of welded joints.

Lesson No. 14. Preparation of equipment for manual argon arc welding in inert gases (argon).

• Equipment for manual argon arc welding in inert gases (argon) MagicWave device.
• Technology of welding with non-consumable electrodes in inert gases (argon). Welding methods, techniques.
• Arc ignition when performing manual arc welding with MagicWave machine

Lesson No. 15-16. Welding by manual argon arc welding of metal structures.

• Performing tacks in the lower position of the seam.
• Argon arc welding of stainless steel.

Lesson No. 17-18. Welding by manual argon arc welding of metal structures.

• Argon arc welding of aluminum and its alloy.
• Final examination.

Passing tests and the final exam.

For welding metals, a laser beam, torch flame or plasma can be used, but one of the simplest and compact options 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.

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 electrical network;
• wire feed mechanism.

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

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

1. The welding current is supplied to the torch simultaneously with the shielding gas.
2. The torch uses a welding wire as an electrode, which is fed automatically using a special mechanism.
3. 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.

Basic safety rules when working with semiautomatic welding machine the following:

• the body of the welding machine must be grounded;
• Do not use the device even for minor mechanical damage or any other malfunction;
• 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

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 do right choice feed speed welding wire, 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 more high 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.

Video instruction: 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. Modern products have a special adjustment in their design, which allows you to configure the protective mechanism in such a way that high-quality protection is provided 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 it. protective device. Such welding helmets will be especially convenient for novice welders; outdated models had too much shade protective glass, which made the welding process very inconvenient due to poor visibility of the weld seam after the arc extinguished.

Welding technology

When all preparatory work will be 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 metal table, to which the corresponding conductor is connected.

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

Before the beginning 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 a short time 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 above the surface of the parts being welded.

Video: connecting thin metal.

Video: welding thick metal for beginners.

Aluminum welding

The use of shielding gases in semi-automatic welding allows quality connection aluminum parts in this way. 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 switches on to the mode alternating current high frequency;
• connect a cylinder with argon or argon-helium mixture;
• 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 supply wire, 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. Video lessons will allow you to quickly master a semi-automatic machine at home.

Welding is used in many sectors of the Russian economy. Welders work on construction sites, creating underground and above-ground structures. They work in automobile factories, energy complexes, agriculture and at oil refineries.

Many men use welding from time to time when solving repair work in their homes; a welding seam is considered one of the most reliable methods for joining parts

In addition, galvanized pipes have a pleasant appearance, so they are often used when creating original design of a building or structure.

Welding of galvanized metal, which is used in construction, is done in the same way.

Do-it-yourself welding is considered a difficult task. Before starting such work, you need to study the rules of the welding process and learn how to perform light welding work for beginners in this matter.

Now many people want to learn the basics of welding. This can always be useful in everyday life. Welding for beginners does not require professional skills and special knowledge. This level is sufficient for work in a garage or farmstead.

When learning the basics of welding, you need to use electrodes with a diameter of no more than 3 mm.

Basics and basic concepts about electric welding

First of all, in order to master manual welding, you should purchase a welding machine and stock up on electrodes. There should be as many of them as possible, since they will often spoil until the first positive result is obtained. When learning the basics of welding, it is better to use electrodes with a diameter of 3 mm. Thinner ones are used by specialists to work with thin metal, while thicker ones overload the electrical network.

Universal and simplest type of connection metal surfaces— manual arc welding method. It lies in the transition electric current from a source with the formation of an arc between the electrode and the material being processed. With this welding technology, the combustion of the coating on the surface of the electrode ensures the release of gas, which prevents the area being treated from coming into contact with oxygen from the air.

Any welding manual states: the first thing you should learn is the correct welding seam. Therefore, the introduction contains information about the equipment used. Among the power sources, the following designs are distinguished:

• welding transformers;
• welding rectifiers;
• welding inverters.

For those learning the basics of welding, the third option is optimal choice. You can weld metal semi-automatically. Welding wire is often used for this.

After you have purchased the equipment, you must first provide yourself with protection from harmful effects. Safety precautions when welding require a special mask that protects the skin of the face and eyes, with a built-in light filter selected in accordance with certain criteria. These include amperage, ambient lighting, and the welder's vision. The welding procedure implies strict adherence to safety rules.

In order to use welding, you should choose a tarpaulin apron or suit with fire-resistant impregnation from workwear, as well as split leather leggings. Shoes must be durable and stable.

Return to contents

During welding, the electrode must be held above the surface of the metal. The resulting gap is called an arc gap. Control over it is especially important when working, so it should be mastered first. The electrode is lowered because it is consumed moving towards the seam. Always keep the gap between the metal and the edge of the working tool at the same level. You need to cook with electrodes carefully so as not to spoil the consumables.

Features:

1. If the gap size is insufficient, there will not be enough time to warm up the material being processed. The seam will be convex and the edges will be unfused.
2. With a larger gap, significant arc jumps are observed. The quality of the penetration will be poor, and the management of the laying of the metal that is being welded will be difficult.
3. By keeping the optimal gap size at a constant level, you can easily control the bathtub and form a good seam.

Current welding technology is as follows: while passing through the gap, the arc creates a weld pool, transferring into it the molten metal located on the surface of the electrode. If the current value is insufficient, the base metal will not warm up, and the electrode will move faster than the weld pool. With a higher current, the arc will penetrate the metal to a certain depth, pushing it back. When the values ​​are optimal, the bath spreads and has thin edges, so it can be expanded and moved using an electrode, controlling the work process.

Current settings often change depending on welding technology and additional options. For example, the heat dissipation properties of thick metal will require a higher current value. For smaller thicknesses you need a different one high level. The exact setting of current indicators in order to cook correctly will depend only on how the bath behaves. Therefore, you need to start with the manufacturer’s recommendations, and then experiment with decreasing or increasing the current.

When finishing the seam, before removing the electrode, you need to make a little more metal deposition.

This will help prevent splashing from the lower layers of the joint, which will cause a crater. To do this, just make one circle, and then strike in reverse side seam directions.

Return to contents

Manual arc welding: features of the technological process

The flow of both direct and alternating current from the power source in the direction of the electrode and the metal ensures the formation of an arc and holds it. This type manual welding with straight polarity is produced when connecting the anode to the product. When connecting a negative pole, welding is done with reverse polarity.

When welding, hands and face must be protected.

The metal that makes up the electrode rod melts under the influence of the arc along with its coating, as well as the surface of the workpiece being welded. From this moment, the electrode material represents drops in the slag, which enter the weld pool and mix with the metal being processed.

The size of the bath is directly dependent on the following criteria:

• the mode in which welding is carried out;
• design of the welded joint;
• cutting shape and dimensions of connecting edges.
• position in space;
• the speed of arc movement across the product.

The standard size of the bath is 6 mm deep, 8-15 mm wide and 10-30 mm long.

Distance between two active areas(at the weld pool and the end of the electrode) is called the arc length. During the melting of the coating, a layer of gas is formed around the arc and bath, which displaces oxygen from working area, prevents it from interacting with the molten material.

The slag, which covers droplets of metal of the electrode, as well as the weld pool, prevents exposure atmospheric air on the material being processed. The gradual removal of the arc ensures crystallization of the metal, which results in the formation of a connecting seam covered with a layer of hardened slag.

The advantages of this type of welding include the following:

• work can be performed with limited access;
• many types of electrodes allow welding different types become;
• relatively quick change of materials to be joined;
• the process can take place in any position;
• The working equipment is light and transportable.

Disadvantages include low productivity compared to other types of welding, harmful conditions and the need for worker qualifications high requirements to quality.

It is not necessary to know everything about welding; for simple everyday situations, it is enough to follow the rules and basic requirements for work.

Return