How to work with inverter welding. How to cook correctly with an inverter welding machine. The principle of operation of the inverter device

Welding inverter - equipment that helps to significantly simplify the work of the master and to perform each stage of welding more efficiently. However, the achievement of such a result is possible only if correct use unit. We will talk about this further.

Basic rules before starting to operate the inverter

Before operating the welding inverter, it is necessary to prepare place for welding, which will not be cluttered with unnecessary items and will allow you to work without inconvenience. Do not use such equipment in cold weather or high humidity without a canopy, you should also avoid placing the device in extremely dusty rooms and placing metal shavings or other debris near the workplace.
pay attention to technical capabilities your device (coefficient of duration of inclusion - KP), such characteristics will help you find out how long it can work before overheating. This will also prevent damage to the wiring.
Time uninterrupted operation is considered on the basis that at KP - 100% the welding process at maximum current - 10 minutes. As a rule, inverters are produced with a gearbox of 60, 70%, which allows operation for 6-7 minutes. Remaining 3-4 minutes - the time for the apparatus to cool down, as well as a way to prevent deterioration of the worker's health due to the heavier air associated with the operation of such equipment.
To avoid breakdowns, do not set unbearable tasks in front of the unit that do not correspond to its capacity
The key to success when working with an inverter is current regulation and stable arc position... It is these factors that will help prevent sticking of the electrode and allow you to create correct and neat seams.

Complete with a welding inverter, it is imperative to use aids personal protection:

jacket
gloves
mask with darkened glass

Particular attention should be paid to its light filter, because they come in different degrees of toning. You need to select a light filter depending on the electrode used, so that the glass allows you to see the weld pool and protects your eyesight from sparks.

This will ensure the maximum safety of your business.

You should also pay special attention to selection of wires, which are connected with a special clamp to the main wire. Skipping ability electric current they are different from 200 to 500 A, for home use, as a rule, the minimum are used, however, it is worth choosing them taking into account the thickness of the selected electrode and the strength of the current being conducted.

Do not forget that before working with a welding inverter, it is necessary to check the quality of the connections of all wires and their integrity.

How auxiliary equipment it is also necessary to use electrode holders. These can be pliers or special welding holders.

Preparing to use the welding inverter

For successful work with such equipment, it is necessary to follow the order of performing all actions:

Start the welding process

Insert the electrode into the holder
Attach the clamp to the part to be machined
Light the arc by touching (the principle is similar to striking a match). Only the electrode is best held at an angle at a distance of several millimeters after a single tap.
Drive the lit arc in a slow forward motion over the workpiece until an angle of 75 degrees is formed. In this case, it is better to focus not on the light generated by the arc, but to focus on the weld pool in order to monitor the welding process.
During welding, the main thing to observe is distance between the electrode and the working metal (arc gap). Correct selection such a gap allows you to keep the end on the same level throughout the entire process and ensures the creation of the necessary seams with a gradual combustion of the electrode.
Excess metal shavings on the formed weld, after cooling the workpiece, must be removed with a hammer, and then brushed to a shine.

The result should be a beautiful and high-quality seam.

Help for beginners

The success and fruitfulness of work with modern beginners' inverters is ensured by built automatic systems, These include:

System Hot Start solves the most common problem faced by most beginners - the difficulty of striking the arc for the first time.
Function Arc force allows you to prevent sticking of the electrode in the event of a rapid approach of the latter to the work piece by increasing the welding current.
If the electrode is still stuck, you can use the Anti-Stick function, which turns off the welding current and helps prevent overheating of the welding inverter.

Thus, the operation of the welding inverter will significantly facilitate the work of both professionals and smooth typical mistakes newbies, allowing them to make better products. Such equipment is convenient to use and ensures the creation of welding seams close to the ideal.

Welding inverters (at their low price of 7-10 thousand) form high-quality seams, even if they are in the hands of beginners. Of course, the work will turn out to be good if you follow some simple rules. All of them are described in the article. However, before starting work, beginners should read the instructions for the device. There are usually several useful tips as well as safety precautions. Remember that everyone can learn how to weld metal.

How does a welding inverter work

Welding inverter is a tool for welding metal. It got its name due to the fact that it transforms alternating current to permanent. Although the efficiency of the inverter is about 90%, its power consumption is low, so you don't have to worry about high electricity bills.

Most often, the welding inverter operates from a 220 volt network, some types - from 380. At the same time, it is possible to work at a reduced voltage: an electrode of 3 mm, for example, can be used at 170 V.

Welding with an inverter is much easier compared to a transformer or rectifier. In addition, even a beginner can keep the arc. That is why most people learn the art of welding on it.

Preparation for work

Which electrodes to use

The electrode is a metal rod covered with a special coating - a slag mixture. Gas-forming substances are sometimes added to it. The coating will protect the molten metal from oxidation.

The rod is selected depending on the type of metal to be welded. For example, to work with carbon steel or corrosion-resistant steel, you will need the UONII electrode grade. There are also universal electrodes. These include the ANO brand. They are used with reverse and forward current of any polarity.

The electrodes are also divided according to their diameter, which varies from 1.6 mm to 5 mm. The size is selected depending on the thickness of the welded metal: the larger it is, the larger the diameter. Working with welding machine a table may come in handy.

The thicker the rod, the more power the inverter welding machine should have. Therefore, for beginners, a diameter of no more than 4 mm is suitable; thin metal can be welded with an electrode and 2 mm.

Polarity and value of welding current

The thickness to which the metal can be melted directly depends on the set amperage. The arc power is also determined by this indicator. Electrode size specifies necessary strength current.

Depending on the surface, the value of the welding current is selected. On horizontal surfaces it is maximum, on vertical surfaces it is less by about 15%, on overhanging surfaces - by 20%.

A household type welder can deliver up to 200 amperes. On the professional tool values go up to 250 and above. The direction in which the current moves will determine the polarity. The inverter has the ability to reverse polarity.

As you know, the current moves from minus to plus. Therefore, the "+" terminal gets hotter. This feature allows high-quality metal welding. In the event that the parts to be welded are thick, then the positive terminal is connected to one of the parts. This method is called straight polarity.

A negative terminal is attached to thin products. This connection method is called reverse polarity.

Welding instruction

Basics of welding

Before proceeding directly to welding metal products, you need to study the basic design features inverter welding machine. They are presented in the diagram.

The inverter itself has average weight: up to 7-8 kg. A high-quality instrument has a ventilation grill on the side of the metal case, which prevents the transformer from overheating.

There is an on / off button on the back panel. There are two connectors on the front: "+" and "-". A cable is connected to them, at one end of which there is an electrode, and at the other - a clamp. The cables themselves must be long enough and flexible.

Step-by-step instructions on how to cook with an inverter correctly.

Inverter welding begins with the preparation of protective equipment. At your disposal is a welding mask, a thick jacket, rough, but not rubber gloves.
Select an electrode. If you are a beginner, then do not use a rod thicker than 4 mm. On the front panel, adjust the desired amperage. Wait a little; if you bring the electrode directly to the metal, sticking will occur.
We attach a clamp (also called a mass terminal) to a metal surface.
The arc is ignited. Then we bring the electrode to the metal and touch it a couple of times. Thus, the rod is, as it were, “activated”. The distance at which the electrode is held is usually equal to its diameter.
When welding, the rod can move according to such patterns.

Arc ignition at the start of welding + (Video)

Striking the arc is the first step, and with it beginners have problems. First, the rod is tapped a little against the metal to remove the grease from it. Then a method similar to lighting a match is applied. The electrode is led over the surface of the product and slightly touches it. If suddenly the rod sticks to the metal, it is either abruptly pulled to the side, or the inverter is completely turned off.

You need to strike until a bright arc appears. To prevent the arc from being lost, keep the electrode 4 mm from the metal.

How to move the electrode during welding + (Video)

The electrode can only move along certain paths. They have already been shown. If you move the electrode only straight, then the seam will come out breaking. The speed of its movement affects the properties of the seam. If you move quickly, the seam will be narrow and not convex, if slowly, it will be wide and convex. In the place where the seam ends, the electrode is delayed for 3-4 seconds.

How to form a weld and avoid defects + (Video)

An uneven seam is most often formed when the electrode moves too quickly. Speaking about creating an even and high-quality seam, it is necessary to introduce the concept of a weld pool. The weld pool is that part of the metal that is in a liquid state when welded. This part contains the filler material. The appearance of a bath is a good sign that the welding is proceeding correctly.

The bath contour is below the surface metal part... Bath forms good seam, if the welding arc penetrates evenly and to a great depth into the product. It is necessary to ensure that the seam does not go down, but remains at the level of the surface. Good connection it is easier to create if you make circular movements with the electrode. In this case, the bath should be distributed in a circle.

When seaming the corners, remember that the bath moves with heat. To control the size of the tubs, adjust the strength of the arc.

The seam will not come out too bulging if you hold the electrode close to the vertical position. If you tilt the rod (for example, 45˚), the seam will begin to pop up. And when the electrode is very close to the horizontal position, the bath begins to diverge, and the seam bends. So optimal angles tilt - from 45˚ to 90˚.

Arc gap monitoring

The arc gap is the distance between the metal surface and the electrode. The gap at each stage must be the same in order for the welding to be of high quality and without defects.

If the gap is small, the weld will be too convex and the material will not melt well. This happens because the product cannot heat up. With a large gap, the welding arc will move from side to side, and the seam will come out crooked and fragile. The correct gap shown in the figure will give good penetration and an even seam.

How to weld thin metal sheets + (Video)

For welding thin metal, it is preferable to use the reverse connection of the inverter, i.e. "-" is attached to the sheet. In this case, the current strength should be at average values. It is better to choose an electrode that has long time melting. The MT-2 model works well. It is used by welders for a long time, therefore it has proven itself well.

The rod, in the case of thin metal, can be tilted by about 35˚. First, you gently bring it closer to the metal, then wait for a red spot to appear, turning into a drop. Move the electrode smoothly so that the drop remains the same size. This will make the seam even.

In a private house and in the country, there is always a need to cook something. In order not to go to the pros on trifles (and not pay them), you can buy an inexpensive welding machine and learn it yourself. To acquire these skills, it is recommended to purchase DC welding machines, and in particular, welding inverters. They have small dimensions, weigh little, with their help you can get a high-quality seam even without a lot of experience. Equally important, this category has good devices at a low price (5-10 thousand rubles). Therefore, inverter welding for beginners is the best that the market has to offer today.

What is a welding inverter and how does it work

This device was called an inverter because it converts the alternating current of the 220 V network with a frequency of 50 Hz into high-frequency oscillations, and then into direct current. At the same time, the device has a high efficiency: about 85-90%, and even at rather heavy loads, the counter "shakes" a little. In any case, you will not have to pay crazy bills. Consumption will be slightly higher than without welding, but not much.

Most inverter welding machines operate on a 220 V household network (there are machines from 380 V). And this is one of their advantages. Moreover, they practically do not affect it in any way, i.e. do not "squeeze" tension. As for your neighbors, be calm: they will not even know that you are welding. The second important plus is that they can work more or less normally even at reduced voltage. Of course, you need to look at the characteristics, but at 170 V, most of them still allow you to work with a 3 mm electrode. This is especially important in rural areas where low voltage is the norm rather than the exception.

What's also good for beginners is that the arc in inverter welding is easier to get and hold. And in general, according to many, it cooks from "softer" and his arc is "lighter". So if you want to learn how to cook - try it first inverter welding.

Inverter Welding Basics

First, let's look at the design of the welding inverter. We will not consider the "filling", we will examine what is on top and what will have to be used.

What an inverter welding machine consists of (To enlarge the picture, right-click on it)

This device is a small metal box, which, depending on the power, weighs from 3 kg to 6-7 kg. The case is usually metal, some manufacturers make in it ventilation holes- for better cooling of the "filling" (for the most part - the transformer). There is a belt for carrying, sometimes there is also a handle: the belt is put on the shoulder if the work requires movement.

One of the panels has a power on key or toggle switch. On the front there are power and overheating indicators. There are also knobs for setting voltage and welding current. Also on the front panel there are two outputs - "+" and "-" to which work cables are connected. One cable ends with a clip-on, which is hooked to the part, the second with an electrode holder. The power cable connector is usually located on the back. That's all, actually.

When buying an inverter, make sure that the cables are long and flexible enough to work more comfortably. It is the insufficiently long and rigid working cables that most of the complaints from the users of the popular brand.

General principles work with an inverter welding machine is described in this video.

Inverter welding for beginners

As with any electric welding, metal melting occurs due to the heat of the electric arc. It occurs between the welding electrode and the metal to be welded. To create an arc, they are connected to opposite poles: one is fed "+", the second is "-".

When connecting the electrode to "minus" and parts to "plus", the connection is called "direct". If "plus" is applied to the electrode, the connection is reversed. Both options are used in welding, but only for metals of different thicknesses: the opposite - for direct - for welding thick metals (more than 3 mm thick). But this is not an immutable rule; sometimes they do the opposite.

What is the reason for this division in practice? Physics of the process. When an arc occurs, the electrodes move from minus to plus. And at the same time they transfer their energy to the positively charged surface, increasing its temperature. Therefore, the element that is connected to the positive output heats up more. When welding metals of sufficient thickness, they need to be well heated so that they fuse and the seam is of high quality. Therefore, they are served "+". Thin metal, on the contrary, can burn out from overheating and "minus" clings to it, heating up the electrode more strongly, from which more molten metal enters the seam.

It is possible to properly cook metal with an inverter only if the electrode is well controlled by you. To do this, you need to take the grip correctly. How to do this, see the video.

How a seam is formed during welding

Now about the actual welding process. An electric arc is formed when the electrode core and metal come into contact (read below how to ignite an arc). At the same time, the coating starts to burn. It partially melts, passing into a liquid state, and partially turns into gases. These gases surround the welding area - the weld pool. They do not allow oxygen from the air to "break through" to the molten metal. The part of the coating that has passed into a liquid state covers the molten metal, creating a second layer of protection. After cooling, it turns into slag, which covers the seam with a crust. And at this stage, the slag protects the still hot metal from oxygen.

But slag and protection are far from the only process that occurs in this case, and which must be controlled. When welding, it is necessary to ensure that the junction of the two pieces of metal warms up evenly and sufficiently. Both parts should melt the same distance from the edge. In order for the heating to be uniform, you need to keep the same distance from the tip of the electrode to the part. It is not very easy to do this: the electrode melts during welding, and particles of its molten metal are transferred to the seam by the arc. Therefore, you have to gradually move the electrode holder closer to the part. But this is not the end of the electrode welding technique. It is also necessary to "write out" some figures with its tip - zigzags, circles, Christmas trees, etc. They allow you to make the seam wider and fuse the two pieces together. The most common electrode movements are shown in the photo below.

That is, you need to move the electrode from side to side by the width of the seam along one of these trajectories, while monitoring the state of the welded pool, and lowering the electrode as it burns out, keeping the distance to the part constant. This is such a difficult task for those who want to learn how to cook metal. It is easier with a welding inverter - the arc is constant and does not jump, but at first you may not succeed.

In this video with a very great deceleration shows the process of transfer of metal particles from the electrode to the weld pool and how it is formed.

How to learn to weld metal with an inverter

Start learning by lighting the arc. To do this, you will need, in addition to the apparatus, metal (5-6 mm thick) and the electrode, a mask and leggings (thick leather gloves) of the welder, as well as thick clothing and boots made of thick leather to protect against sparks and dross.

Work begins by connecting the welding cables. Then the selected electrode is inserted into the holder (for a start, take an MP 3 with a diameter of 3 mm - they are easy to ignite and cook well). Then turn on the power, set the welding current (see table). For an electrode 3 mm in diameter, a current of 90-120 A is set. The current during the welding process can be adjusted. If you see that the result is not a roller, but just some kind of incoherent stripes, increase it. If, on the contrary, the metal is very liquid and it is difficult to move the weld pool, reduce it. The settings are very dependent on the device and the electrode selected. So try, change. By setting the current, put on a welder's mask (it will be easier for beginners to work in, you can work.

Inverter welding for beginners starts with learning how to light the arc. There are two methods: hitting the part with the tip of the electrode several times, or striking it like a match. Both methods work. Use whichever is more convenient for you. But for the future, keep in mind that you need to strike along the seam line - so that there are no marks on the product. You will have to practice for a while and burn a few electrodes to strike the arc steadily.

When the arc ignites without any problems, you can move on - master the movements. This is done by padding cushions on thick metal. On a metal plate, draw a line with chalk, which will replace your seam. Then strike the arc. In the place where it rested, the metal melts and becomes covered with a film of liquid slag. This place is called the welding bath. So you have to move it along the drawn line. Do this with one of the movements shown in the figure above.

In order for the bath to move, the electrode must be tilted slightly, approximately at an angle of 50-45 °. Some have a larger angle, some have a smaller one. In general, by tilting the electrode, you change the dimensions (width) of the weld pool. You can experiment: there are a lot of different techniques in welding and it is only important that the seam is of high quality, and how you achieve this is up to you, especially since you will work for yourself and for yourself.

There are two main working positions for the electrode: forward angle and backward angle. When welding with an angle forward, we get less heat, the seam will be wider. This technique is used when welding thin metals. . Thick ones are usually welded backward.

But the angle of inclination is not all the parameters that will have to be maintained. There is also the length of the arc. This is the distance from the tip of the electrode to the surface of the part. The middle arc is 2-3 mm, the short one is 1 mm or generally end-to-end, the long one is 5 mm or more - until it comes off. Practice begins by working on a medium arc. Maintain 2-3 mm to metal. Then the seam will be smoother and of better quality: if the gap is too large, the arc begins to jump, the heating of the metal is insufficient, the seam turns out to be smeared, the connection is unreliable. With a short arc, another problem arises - the seam is too convex due to the fact that the hot zone is too small. This is also not good, since undercuts remain - grooves along the seam on the part - which reduce the strength of the connection.

After practicing for some time on laying the rollers in different movements, after the rollers are of the same width, the surfacing flakes have approximately the same dimensions, you can try to weld the seams. You can read, or you can watch another lesson "Welding for Dummies".

The basics of inverter welding for beginners everything. You just have to practice: you need to lime more than one electrode per workout. Even, maybe, more than one kilogram. When the hand makes all the movements by itself, everything will seem quite simple to you.

To consolidate the knowledge gained, first try to train your hand a little without an electrode, practicing the movements with a pencil in your hand. It's also a good option, maybe it will seem more acceptable to you. In this video tutorial on welding with an inverter for beginners, everything is very sensible, simple and accessible. If you still have any ambiguities, take a look. You will understand how to cook with inverter welding correctly. A lot of useful things for novice welders.

And finally, about some of the features of the operation of welding inverters. They are very afraid of dust, especially metal. Therefore, it is advisable not to use a grinder next to them and to carry out regular cleaning with a vacuum cleaner inside (after the warranty period has expired). It is not recommended to work with them in the rain or in damp rooms. This is especially true for inexpensive household models. Although they have protection against electric shock, it's still better to play it safe.

When choosing electrodes, pay attention to the area of their use: they must be suitable for working with direct current. When welding at the highest current or voltage, the operating mode is intermittent. It is indicated for each device in the passport.

Due to the reliability and durability of welding joints, there is not a single industry left that does not use this technology. V household also sometimes it is impossible to do without welding. Possession of skills in working with an electric welding machine will allow you to create any metal structures, from an unpretentious fence to summer cottage and ending with an openwork garden swing or a multifunctional barbecue. We will tell you how to weld with welding correctly, and reveal all the tricks and secrets of this craft, so that your first seam is not only strong, but also neat.

Learning to cook with electric welding. Video tutorial

In order to learn how to cook with electric welding, it is not enough to study theoretical basis and learn the secrets of the craft. Only the experience that is gained with every centimeter of the weld can bring you closer to the ability to weld metals.

A video on how to cook with electric welding will help you understand all the nuances of this craft, tell you about what other materials and tools, besides the welding machine, will be needed during the work.

Made in the form step by step lessons The video of the welding process begins with a story about the preparation of surfaces before welding. Next, you will learn how to perform the simplest seams, and only then can you start joining the parts.

Thanks to the recommendations from the video, welding your first structure will not be difficult, and quality control of the seams will show how well you have mastered the welding technique. Watch a video on how to cook with electric welding, prepare theoretically, and then pick up the electrode and start creating.

Welding process technology

In order to learn how to cook by welding, you need to know that electric arc welding is the process of joining metals using an electric arc between the surface of the workpiece and the electrode ... The resulting high temperature contributes to the simultaneous melting of the electrode and the metal base. In this case, the so-called weld pool in which the base metal is mixed with a molten electrode.

Bath size directly depends on the welding welding mode, edge shapes surfaces to be joined, electrode movement speed, the position of parts in space etc. and ranges from 7 to 15 mm in width, 10-30 mm in length and up to 6 mm in depth.

Metal does not burn from high temperature gas layer formed during melting of the electrode coating, which displaces all oxygen from the melting zone. After removal of the electric arc, the metal crystallizes and forms common seam for the surfaces to be welded, covered with a protective layer of slag, which is removed after cooling.

The advantages of electric arc welding are :

high performance;
possibility of welding various materials without the need for equipment changeover;
good quality of the weld;
inexpensive consumables;
availability.

V limitations this method welding, you can record the mandatory presence of power supply and the need for preliminary preparation of the edges to be welded.

Getting ready for welding. Selection of materials and equipment

Before you start welding by welding, you need to understand for yourself that this process is accompanied by the formation of sparks and splashes of molten metal, the release of toxic gases and danger to the eyes.

Therefore, in order to safely cook metal, it is necessary to stock up not only good equipment, but also the appropriate equipment.To start cooking with electric welding you will need:

welding machine;
set of rod coated electrodes;
welder's hammer;
metal brush;
welding mask;
overalls, suede gloves.

You can cook with arc welding without a factory set of overalls. It is important that the protective suit is made of thick fabric with long sleeves, and trousers are better tucked into boots.

Choosing a welding machine

A good welding machine with the ability to adjust the current strength from 10 to 200A will help to learn how to cook by welding correctly. Of course, you can assemble a simple welding transformer with your own hands, but then you don't even need to think about how to cook thin metal, because such work requires minimum power values. Prefabricated devices are subdivided into:

Welding transformers ... Designed to lower the mains voltage with a simultaneous increase in the current strength. Being inexpensive and productive devices, they can weld metal quite well, however, they have disadvantages in the form of an unstable arc, a strong "drawdown" of the supply voltage and a large mass.

Welding rectifiers ... Such devices represent the same welding transformers equipped with a diode rectifier, thanks to which the alternating voltage of the mains is converted into constant pressure required for the appearance of an electric arc. Welding metal with straighteners is slightly easier due to the higher arc stability. Otherwise, this type of welding machine has the same disadvantages as transformers.

Welding inverters ... Real electronic welding is possible thanks to the modern technological stuffing of such devices. They provide many opportunities to cook with the most optimal electrode parameters. The electronic components of the circuit of modern inverters allow you to adjust not only the current strength, but also the ignition speed, arc forcing, etc., which ensures excellent weldability of parts. In addition, the inverters are compact and lightweight.

About what kind of welding is the best to cook, disputes among welders go on unabated. Someone likes the simplicity and reliability of the transformer, someone is satisfied with manual welding with a rectifier. However, learning how to weld by welding is best done with a welding inverter. The ability to accurately adjust the parameters will allow you to weld metal correctly from the very first steps.

Selection of electrodes for welding

For manual arc welding, use rod electrodes with protective coating ... The metal of the rod must correspond to the type of metals to be welded, therefore, different electrodes are used for welding steel, bronze or magnesium alloys.

During the welding process, the coating of the rod melts and turns into slag, which, floating on the surface of the weld pool, protects the melt from the influence of oxygen and nitrogen in the air. Some mixtures contain gas-forming additives, which, during the welding process, emit gas, which restricts the access of air to the melting zone.

Most often, the question of which electrodes to cook with is not worth it for novice welders, since they usually begin to learn the craft by welding simple low-carbon structural steels.

The use of welding rectifiers makes it possible to use for such, as well as stainless alloys, UONII brand electrodes designed for direct current operation.

Other brand electrodes - ANO , can be used for welding both with rectifiers and transformers, they allow you to cook with both forward and reverse current, so amateurs use them much more often than UONII.

Meanwhile, professionals in the question of which electrodes are better, give preference to exactly UONII... They cite as an argument the fact that this type of rods leaves behind much less slag, therefore, cleaning the seam is required much less often, which significantly increases the speed of work.

Depending on the thickness of the parts to be welded, electrodes with a diameter of 1.6 to 5 mm are used. In addition, 4-5mm rods are used for cutting metals, setting the maximum amperage.

You can determine the required electrode diameter from the tables of the dependence of this parameter on the thickness of the parts, as well as using mathematical formulas... Novice welders rarely use rods with a thickness more than 4mm.

Type of welding(horizontal, overhanging, butt welding, etc.) practically does not depend on the diameter of the electrodes, which cannot be said about the depth of the weld pool and seam width.

Since the specific welding current depends on the cross-section of the electrode, the concentration of the current is higher at the end of the thin rod, so the penetration depth will be greater than when using a thick electrode. In turn, the use of rods with a diameter of 4-5 mm melts the metal less, forming a wider seam.

As you can see, it is impossible to answer exactly which electrodes to cook, since right choice must take into account a lot of factors, ranging from the type of welding machine to the required width of the weld. In addition, it should be borne in mind that the quality of electrodes of even one brand can differ significantly among the products of different factories, therefore, before starting to weld by welding, ask the experts for advice.

Choosing the current strength and its polarity for electrode welding

After watching the video on how to cook by welding, you probably drew attention to the need current adjustment depending on the thickness of the parts and the diameter of the electrode. As a rule, it is not difficult for experienced welders to set the required value. For beginners, it is better to turn to special tables... Often the required parameters are indicated by the manufacturers of electrodes on their packaging.

In order to properly weld metal, the required current strength is determined by calculation or from tables, and then set this parameter on the inverter control panel. The higher the amperage, the higher the arc power and the deeper the weld pool ... However, do not exceed optimal value- the metal will start to fade and the seam will be of poor quality.

When setting the magnitude of the current in order to cook with electric welding, be sure to take into account the location of the place of work. Maximum the current is set for horizontal surfaces. When welding vertical seams it decrease by 15%, a ceiling will require decrease in current strength by 20% and more.

If you cook with inverter welding or a rectifier, then the quality of work is influenced not only by the current strength, but also by its polarity , that is, the direction of the flow of electrons.

From the course of physics, everyone knows that electrons move from the area of negative charge to the area of positive. To properly cook with an electrode, the polarity is changed, setting both the forward current (the electrode is connected to the minus of the inverter, and the part to the plus) and the reverse. Most often, a direct connection is used, since the part in this case heats up more, however, for welding thin products, the polarity is changed by switching the inverter terminals. Reverse polarity is also used for welding alloyed alloys prone to burnout of low-melting alloys.

The good news for those who want to know how to weld with electrodes is that Reverse connection makes it easier to ignite the arc ... In addition, it is characterized by higher stability, which is an invaluable advantage when welding thin parts, for example, sheet steel, with an electrode.

Safety precautions during welding

Every novice welder wants to be reminded of the safety rules. Remember that welding is one of the most dangerous ways mounting metal structures, so do not neglect the following rules:

It is forbidden to carry out welding work when high humidity as well as in the cold.
The use of a welder's mask and protective shield is mandatory. This will avoid burning the cornea of the eyes.
Clothing must be free from splashes of metal on open areas skin. It is better to wear suede gloves on your hands, and a thick tarp is the best material for a welder's suit.
Welding work is associated with high temperatures and the risk of fire, therefore, a container with water and a fire extinguisher must be present at the welder's workplace.

In addition, be aware of the risk of electric shock, therefore, exclude the possibility of moisture getting on the welding machine, make sure that the cables do not touch hot surfaces..

Manual arc welding technique. How to weld properly

Before proceeding to practical training, I would like to remind once again about safety precautions. No wooden workbenches and combustible materials near the place of work. Be sure to place a container of water at the workplace. Be aware of the danger of fire.

In order to figure out how to properly cook by welding, we present to your attention detailed instructions and video of the welding process.

First try to strike the arc and hold it for the required amount of time. To do this, follow our tips:

Using a metal brush, it is required to clean the surfaces of the parts to be welded from dirt and rust. If necessary, their edges are adjusted to each other.
It is best to learn how to cook with electric welding with direct current, so connect the "positive" terminal to the part, install the electrode in the clamp, and set the required current value on the welding machine.
Tilt the electrode in relation to the workpiece at an angle of about 60 ° and slowly slide it over the metal surface. If sparks appear, raise the end of the rod 5 mm to ignite the arc. Perhaps you were unable to get sparks due to a layer of coating or slag on the edge of the electrode. In this case, tap the tip of the electrode on the part, as suggested in the video on how to cook with electric welding correctly. The resulting arc is maintained with a 5 mm welding gap throughout the entire welding process.
If the arc ignites very reluctantly, and the electrode sticks to the metal surface all the time, increase the current strength by 10-20 A. When the electrode sticks, wiggle the holder from side to side, perhaps even forcefully.
Remember that the rod will burn out all the time, so only maintaining a gap of 3-5 mm will allow you to keep a stable arc.

Learning to light the arc , try to slowly move the electrode towards you, while making movements with an amplitude of 3-5mm from side to side.Try to direct the melt from the periphery to the center of the weld pool. After boiling a seam about 5 cm long, remove the electrode and let the parts cool, then knock with a hammer at the joint in order to knock down the slag. Correct seam has a monolithic wavy structure without craters and irregularities.

The cleanliness of the seam directly depends on the size of the arc and correct movement of the electrode during welding. Watch a video on how to weld with a protective filter. In such rollers, you can clearly see how to maintain the arc and move the electrode to obtain a high-quality weld. We can give the following recommendations:

By translational movement of the rod the required arc length is maintained along the axis. During melting, the length of the electrode decreases, so it is necessary to constantly bring the holder with the rod to the part, observing the required gap. This is what is emphasized in numerous videos on how to learn how to cook.
Longitudinal movement of the electrode create a fusion of the so-called thread roll, the width of which is usually 2-3 mm larger than the diameter of the rod, and the thickness depends on the speed of movement and the strength of the current. The thread bead is a real narrow weld bead.
To increase the seam width the electrode is moved across its line, carrying out oscillatory reciprocating movements. From the magnitude of their amplitude, the width of the weld will depend, therefore, the magnitude of the amplitude is determined based on specific conditions.

The welding process uses a combination of these three movements to form a complex path.

After watching the video on how to cook with electric welding and having studied the diagrams of such trajectories, you can figure out which of them can be used for overlapping or butt welding, with vertical or overhead parts, etc.

During operation, the electrode will melt completely sooner or later. In this case, the welding is stopped and the rod in the holder is replaced. To continue working knock down the slag and at a distance of 12mm an arc is ignited from the crater formed at the end of the seam. Then the end of the old seam is fused with a new electrode and work is continued.

Features of electric welding of metal pipes

Learn to weld shaped pipes best on thick walled workpieces using a welding rectifier or inverter. Depending on the pipe diameter, wall thickness can be over 16mm, but you will most likely need to weld structural steel products up to 12mm wall thickness. Single-layer welding is often used to weld the pipe, but to increase the strength of the joint, it is better to perform two or more passes.

When welding pipes, the seams are performed two half rings top to bottom or bottom to top.

If the direction of movement of the electrode corresponds to the first option, then use 4-mm rods with low slagging and organic coating. Such a coating burns out more slowly, forming a visor at the end of the electrode, on which they rest, performing transverse vibrations of small amplitude.

When welding from bottom to top, the amplitude is increased to 3-5 mm, and the speed of the rod is reduced.

Pipe connections perform:

Butt (exact orientation of the ends of one pipe relative to another);
Overlapping (overlapping pipes or parts on top of each other);
Corner;
Tee joint (one pipe is perpendicular to the other).

In order to weld one pipe to another, first clean and prepare their ends and lay the products at the workplace. Next, the elements are centered relative to each other and tacked in several places with dotted seams. After checking the alignment, the pipes can be welded using one of the following methods.

If it is impossible to turn the pipes, their the joints are made multilayer... The first, root layer, serves for the initial connection of parts. The next filling layers are designed to create a solid, solid seam proper. And, if necessary, perform a finishing, facing seam, which covers all defects and irregularities. A video on how to weld a pipe will help you better understand the features of such work.

After cleaning the seams from slag, the surface is carefully inspected for lack of penetration, pores, cracks and burn-throughs. If necessary, defects are eliminated by welding. If the seam meets all the requirements, then it is cleaned with an angle grinder.

Protection of metal against corrosion after welding

Remember, at the very beginning of the article, it was said that in order to cook properly with electric welding, it is not enough to watch a video, but you also need to prepare theoretically? Agree that the text allows you to better assimilate the theory. In addition, the videos somehow miss the need to protect parts later on. We will try to eliminate this defect.

Everyone knows that metal, under the influence of atmospheric oxygen, quickly begins to rust. Trust me, welds corrode even faster.

In order to protect metal surfaces from corrosion, painting is most often used. In order not to repeat this work every year, do it according to all the rules.

Primarily, need to delete old paint and rust ... To do this, it is best to use metal brush attachments for a drill or grinder, but you can also work with an ordinary metal brush. Do not forget to protect your eyes with glasses or a visor.

After surface cleaning treat it with a rust remover and then coat with a coat of primer ... Select a primer formulation specifically designed for metal work. After this layer has dried, you can start painting. Acrylic and pentaphthalic enamels designed for outdoor use.

It is best to use a spray gun rather than a brush or roller for coloring purposes. It can be used to apply a uniform, thin layer of paint that will not crack or flake over time.

Modern welding machines, inverters, represent a small device that is accessible to carry and facilitates welding (compared to previous transformers). Learning to cook with an inverter is much easier than with a transformer device. Therefore, welding is no longer the prerogative of professionals, it has become a popular occupation, available for mastering and use on own site... Consider how to learn how to weld metal using an inverter.

The device and principle of operation of the inverter welding machine.

Welding inverter device: how does the arc originate?

The inverter is a metal box small size(up to 0.5 meters), weighing up to 10 kg. The main task of the welding machine is to produce a current of specified parameters. To do this, the inverter converts the current from the network (alternating 220 volts) into the welding one. The welding current of most household appliances is constant.

Direct and reverse connection of current.

Each inverter has two terminals: a cathode (indicated by "-") and an anode (indicated by "+"). An electrode is inserted into one terminal, and the second is connected to the metal to be welded. After the electric current is applied, a common electrical circuit is formed. With a small break in the circuit (with a distance of several millimeters), instant ionization of the air occurs at the break point and a welding arc arises.

The main heat release occurs in the arc. Its combustion temperature is 5000-7000 ºC. This is above the melting point of all metals used. When the arc burns, the edges of the metals and the electrode are melted and mixed. Slag - more light material, it floats to the surface and protects the base metal from oxidation and nitrogen saturation. After solidification, a weld seam is formed.

Current polarity and welding parameters - what are they?

The welding current can move from the cathode to the anode and, conversely, from the anode to the cathode. This results in a different polarity of the current. When the current moves from the cathode, the polarity is direct. In the opposite direction (from the anode) - reverse. What is forward and reverse polarity for?

The use of different polarity is due to the fact that a higher temperature will be at the terminal to which the electric current flows. If the current is of direct polarity, a higher temperature is generated at the anode (that is, on the surface to be welded). This is the most common type of welding and most novice welders work with it. If the current is reversed, a higher temperature is generated at the cathode (an electrode is connected to it). This is required when working with thin sheet metal and those grades of steel that cannot be overheated (for example, high-alloyed ones).

The diameter of the electrode is selected depending on the thickness of the parts to be welded. The size of the electrode and the strength of the electric current are in proportional relationship from each other: the thicker the electrode, the stronger the current. For approximate calculations, it is assumed that the current strength is equal to the diameter multiplied by 3.5. That is, for a 3 mm electrode, the current strength will be: 3 * 3.5 = 105 A.

Since the current strength is also influenced by the location of the seam (horizontal, vertical or overhead), the material of the electrode, it is easier for a novice welder to use the table of correspondence between the current strength and the diameter of the electrode and the choice of the diameter according to the thickness of the welded elements (Fig. 1 and 2, respectively). Next, you can cook the metal with an inverter.

Advantages of an inverter over a transformer

Figure 1. Correspondence table of metal thickness and electrode diameter.

It is easier to master the art of inverter welding with training. Welding metal with an inverter is easier because the device provides a constant welding current (regardless of voltage fluctuations in the network). As a result, the arc burns steadily, the metal is spattered slightly. The value of the welding current is infinitely adjustable.

Cooking with a welding inverter is convenient for beginners due to the presence additional functions... For example, the inverter can be configured with Hot-Start, it increases the welding current at the start of work (which makes it easier to ignite the arc). The other Arc-Force function is triggered when the welder moves the electrode too close to the metal. In this case, the inverter will automatically increase the current, accelerate melting, and prevent sticking.

In case of sticking, the Anti-Sticking function is activated. It reduces the current and makes it possible to detach the electrode from the metal and continue welding. Inverter operation consumes relatively little electricity. For example, for welding with an electrode with a diameter of 3 mm, a current of 4 kW is required (which corresponds to the operation of two electric kettles). The savings in electricity pay off the relatively high cost of the inverter.

Welding safety precautions

Figure 2. Electrode diameter and current strength.

Before starting work, the space within a radius of several meters is cleared of wood and other flammable objects. This is important for the novice welder. Welding electrode or its fragments have a high temperature, they are capable of setting fire to boards, boxes, paper debris that are nearby. Clothes that cover the whole body must be worn (long trousers, a jacket with long sleeves). This is also important for the beginner, as the splashing process can cause metal droplets to get onto the exposed skin of the hands or feet. A protective mask with dark glass (light filter) must be worn on the face. This glass is impenetrable to sunlight. The burning of the arc through the light filter will be visible.

Observe the arc without protective glass dangerous, burns your eyes. A weak degree of burn (once or twice looked at the arc) leads to the formation of light spots in front of the eyes ("bunnies picked up"). With a moderate degree of burn, the eyes ache and itch (there is a feeling of sand in the eyes). Severe burns result in partial or complete loss of vision.

How to light the arc?

Safety rules for welding.

For welding metal surfaces it is necessary to learn how to light the arc and maintain it. First, you need to connect the terminals of the inverter. We will work with a current of direct polarity, so we insert an electrode into the cathode terminal ("-"). For ease of use, let's take an electrode with a diameter of 3 mm. Welding with a thicker electrode is more difficult, leads to fluctuations in arc length and unstable combustion, and requires more professionalism. We set a current of 100 A (for an electrode of 3 mm and a horizontal arrangement of the surfaces to be welded). We take the handle of the terminal with an electrode in our hands, turn on the inverter (supply current) and put on a protective screen.

Welding without protective screen prohibited to avoid loss of vision.

The feeling of some discomfort is not worth the health of the eye apparatus. Before striking the arc, the end of the electrode is tapped against the metal to remove the coating from its edge. This makes ignition easier. There are and are used two types of ignition:

Chirping. It is necessary to bring the electrode to the metal surface and strike it (the action is similar to lighting a match). This is how a new electrode is kindled.
Touching. The electrode is brought to the metal and lightly touched its surface, after which it is immediately withdrawn to a distance of several millimeters. This is how the electrode is ignited when welding is interrupted (sticking has occurred or the welder has removed the rod from the metal surface too much).

Welding process: how to maintain the arc?

It is important to maintain a small (3-5 mm) distance between the metal and the electrode. This distance is called the arc length. When it increases, the arc stops burning.

The length of the arc is approximately equal to the diameter of the electrode. That is, for stable combustion and a smooth weld with an electrode of 3 mm, it is necessary to maintain a distance of 3-5 mm from the surfaces to be welded.

If the electrode is too close to the metal surface, a short circuit occurs: the electrode sticks to the metal. To detach the electrode from the surface to be welded, it is necessary to tilt it to the other side or turn off the inverter. When the supply of electricity is cut off, the electrode will come off.

The angle of inclination of the electrode can be different. For the novice welder, it is best to stick to about 70º from the metal surface (that is, with a slight deviation from the vertical position).

Figure 3. Trajectories of movement of the electrode in arc welding.

In order to cook efficiently, it is necessary to learn visually (through the filter flap) to assess the size of the welded pool. The width of the reddish puddle in the filter should be 2 times the thickness (diameter) of the electrode.

The size of the bath is influenced by the speed of movement of the electrode. If it moves too slowly, it creates too much molten metal and a wide weld pool, which prevents the arc from interacting with the base to be welded, resulting in lack of fusion. If the arc is moved too quickly, there will be insufficient edge melting and, as a result, also lack of fusion.

First steps in welding

You should try to perform the first welding operations on any unnecessary metal surface. After the arc has been ignited, it is necessary to lead the electrode over the metal, trying to get an even welded trace. When it has become stable to ignite the arc, you can start welding the surfaces. They are placed end-to-end to each other, an arc is obtained and an electrode is drawn along the connection line. In this case, the movements should not be rectilinear (along the seam), but oscillatory (now to the right, then to the left). A typical pattern of electrode movement during welding is shown in Fig. 3.

After cooling, the slag layer is knocked down from the outside with a hammer and the quality of the joint is assessed visually. A good weld bead should be of uniform thickness, with no visible voids or gaps.

After exercising for one to two hours, most novice welders are consistently able to light the arc and keep it burning. Can be done simple connections metal surfaces. When you learn how to work with a welding inverter, you will be able to perform various works on your own plot on your own.