In a private house, country house or garage, quite often there is a need to connect various metal parts and create structures from them. It makes no sense to turn to professionals for help every time in such a situation, because you can purchase an automatic welding machine yourself.
A wide selection of different devices are available in stores in different price categories, so welding with an inverter for beginners is the best that the market has to offer.
Inverter devices are characterized by fairly high efficiency and ease of operation. The main load for the operation of such equipment falls on the electrical network.
It has storage capacitors that allow you to accumulate electricity and ensure an uninterrupted welding process and soft ignition of the arc.
Unlike old devices, which provide a maximum boost of electricity for work, which can result in traffic jams, an inverter allows you to safely operate from a household power supply.
Defects in welds.
To understand how to cook using inverter welding, you need to understand the basics of its operation.
In such manual welding machines, the arc is formed as a result of contact of the electrode with the product. Under the influence of temperature, the metal and electrode melt. The molten part of the rod and the product form a bath.
The coating of the rod also partially melts, turning into a gaseous state and closing the weld pool from oxygen. This allows you to protect the product from oxidation.
Each electrode, depending on its diameter, is designed for a certain current strength. If you reduce it below the required value, then the seam will not work. Increasing this parameter will allow you to form a seam, but the rod will burn out too quickly.
At the end of the welding work, the coating cools down, turning into slag. It covers the connection of metal parts from the outside. By tapping the seam with a hammer, it is quite easy to get rid of the slag.
There is also simple rules welding To ensure that the arc does not go out during work, the welder should maintain a constant distance between the rod and the workpiece.
This is not easy to do because the electrode melts, so it must be fed into the welding zone at a constant speed. In addition, you must try to guide the electrode evenly along the joint in order to obtain a seam of maximum quality.
Welding methods
Nowadays there are many methods used for welding. They are divided according to various criteria. This information will be useful for a beginner, so you should definitely read it.
Depending on the heating, the edges of the product may completely melt or be in a plastic state. The first method also requires applying certain forces to the parts being joined - pressure welding.
In the second, the connection is formed as a result of the formation of a weld pool in which there is molten metal and an electrode.
There are other welding methods in which the product does not heat up at all - cold welding, or is not brought to a plastic state - connection using ultrasound.
Methods and types of welding.
Other types of welding are listed below:
- Forge.
In this method, the ends of the joined products are heated in a forge and then forged. This method is one of the most ancient and is currently practically not used. - Gas press.
The edges of the products are heated with oxygen acetylene over the entire plane and brought to a plastic state, after which they are subjected to compression. This method is highly efficient and productive. Used in the construction of gas pipelines, railway, mechanical engineering. - Contact.
The parts are included in the electrical circuit of the welding equipment and current is passed through them. A short circuit occurs at the point of contact of the parts, as a result of which a large amount of heat is released at the junction. It is enough to melt and join metal. - Butt, point and suture are varieties of the contact method of fastening the product.
- Roller.
Used in joining sheet structures that require high-quality and reliable seams. - Termite.
The metal is held together by burning thermite, a mixture of iron oxide powder and pure aluminum. - Nuclear-water.
The edges of the product are melted by the action of an arc burning between two tungsten electrodes. The electrodes are connected to special holders through which hydrogen is supplied. As a result, the arc and liquid metal of the weld pool are protected by hydrogen from the harmful effects of atmospheric gases such as oxygen and nitrogen. - Gas.
The essence of the method is to use a flame to heat and melt parts. A flame is produced by burning a flammable gas in an oxygen atmosphere. The gas-oxygen mixture is produced using special burners.
Under the action of an atomic-hydrogen welding arc, hydrogen molecules are split into atoms and then recombined upon contact with cold metal. As a result of this process, a large amount of heat is released. The method is used for welding metals of small thickness, copper and alloys based on it.
The gas welding method refers to fusion welding. The gaps between the products are filled using filler wire. This method is widely used in various areas of human life. Most often found when joining thin-walled products, non-ferrous metals, cast iron.
When working with an inverter device, the polarity of the electrodes is of no small importance. Depending on the circuit, the heating intensity of the part changes, which allows you to create various conditions welding
Step-by-step instructions for welding with an inverter
First of all, for welding you need to have protective elements:
- gloves made of rough fabric;
- welding mask with a special filter protecting the eyes;
- a rough jacket and trousers made of material that will not catch fire from sparks that appear during welding;
- closed shoes with thick soles.
Electrode position during welding.
Before you start welding with a welding inverter, you must comply with necessary measures aimed at creating safe working conditions.
Proper preparation of the workplace consists of:
- ensuring the necessary free space on the table, you should remove all unnecessary objects that could get splashed;
- creating high-quality lighting;
- Welding work must be performed while standing on a wooden floor that protects against electric shock.
Then the current is adjusted depending on the thickness of the parts and the electrodes are selected. The latter need to be prepared. If they were just purchased in a retail chain and their quality is beyond doubt, then this step can be skipped.
If the rods have been in an unheated, damp room for a long time, then they need to be dried for two to three hours at a temperature of 2000 degrees. For these purposes, you can use an old oven or special equipment, if available.
After preparing the electrodes, the ground terminal is connected to the product.
To get quality and reliable connection metal must be prepared:
- rust is completely removed from the edges of the product;
- using solvents, various contaminants are cleaned;
- At the last stage, the edges are checked for cleanliness; the presence of grease, paint and other contaminants is unacceptable.
Next you need to connect the welding inverter. It is better to carry out training on a thick metal sheet, forming a seam in the form of a roller. Make the first connection on metal lying horizontally on the table. Draw a straight line on it with chalk along which the seam will go.
Electrical circuit of the inverter.
In the process of training on such an object, you can significantly improve your welding technique.
The welding process begins with ignition of the arc.
There are two ways to perform this action:
- scratching on metal;
- tapping on metal.
The choice of method depends on the person’s preferences; the main thing when igniting is not to leave traces of welding outside the joint area.
After igniting the arc from contact with the metal, the arc is ignited, the welder removes the electrode from the surface of the part a short distance corresponding to the length of the arc and begins welding.
As a result, a weld is formed at the junction of two metal parts. It will be covered with scale - scale on the surface. It needs to be removed. This is very easy to do by tapping the seam with a small hammer.
Forward and reverse polarity
Melting of the metal for welding occurs under the influence of an arc. It, as noted above, is formed between the surface of the product and the electrode, since they are connected to opposite terminals of the device.
There are two main options for welding, differing from each other in the order of connection and called direct and reverse polarity.
In the first case, the rod is connected to the minus, and the part to the plus. In this case, an increased flow of heat occurs into the metal. As a result, a deep and narrow melting zone is formed.
Direct and reverse polarity.
With reverse polarity, the electrode is connected to the positive, and the product to the negative. In this case, the melting zone is wide and shallow.
The choice of polarity is entirely determined by the product you are working with. Welding can be performed with two types of polarity. When choosing, you should take into account the fact that the element connected to the positive is subject to greater heating.
For example, it is difficult to weld thin metal products due to possible overheating and burning. In this case, the part is connected to the minus. Currents are also selected according to the diameter of the electrode and the thickness of the metal. This data is taken from a special table.
Effect of electrode feed speed
The feed speed of electrodes for welding must ensure required amount supplied molten material. Not having enough of it can lead to undercutting. This factor is very important in both direct and reverse polarity when welding.
During electro arc welding due to the rapid movement of the rod along the connection, the arc power may not be enough to heat the metal. The result is a shallow seam that lies on top of the metal. The edges remain unmelted.
Slow advance of the electrode leads to overheating. In this case, it is possible to burn the surface and deform the thin metal.
Modern welding machines have a wide range of different functions and capabilities. Nevertheless, at the moment, most of the quality work done is still determined by human skill.
Effect of current
Welding current selection table.
When mastering the basics of welding with an inverter, it is important to understand what current strength needs to be set in each individual situation. A properly configured inverter welding machine is the key to success.
Data on the current value are taken from the table, which also shows the size of the electrodes. However, these current values are not exact; they are plus or minus several tens of amperes.
Features of welding thin metal
In everyday tasks, we are most often faced with the need to join thin metal. In this case, it is necessary to remember the basics of inverter welding for beginners, namely the importance of connecting the product to the correct pole. Thin parts are connected to the “minus” of the welding machine.
To learn how to weld correctly and get beautiful seams, you need to practice.
Here are a few useful tips who can improve their skills:
- start cooking using the minimum current;
- form the seam at an angle forward;
- use reverse polarity;
- secure the part to reduce distortion during welding.
Common mistakes made by newbies
Arc welding diagram.
Beginner welders tend to make mistakes due to ignorance of the basics regarding the use of welding equipment. For example, beginners may not know how to choose the correct polarity for welding with an inverter, which will lead to poor-quality joint formation or even burning of the part.
The following main errors can be identified:
- neglect of safety precautions;
- Not right choice welding machine;
- use of low-quality or unprepared electrodes;
- work without trial seams.
For beginners, it is worth separately noting one feature if you cook Resanta by welding. This equipment is very popular, but it has short connection cables, which can create inconvenience in operation.
Let's sum it up
Having learned to work with welding equipment, it will be possible to solve many everyday problems that often arise when working in the country or in the garage. Beginners should pay special attention to the polarity of welding parts of different thicknesses with an inverter.
By understanding how to properly configure the equipment and choose an electrode, you will be able to obtain high-quality seams on any product. Be sure to pay attention to the forward and reverse polarity of connecting the welding inverter.
When welding thick parts, direct polarity is used when welding with an inverter, and for thin parts, reverse polarity is used.
Welding is one of the affordable and reliable ways to firmly connect metal products. In a private house, in a garage or in a country house, there is always work related to welding: repairing a hole in a watering barrel, building a fence, repairing a metal table, and more. Usually they turn to professionals, but if you need to do simple work and the beauty of the seam is not of great importance, then you can do the welding work yourself. It is better if the first lessons are taught by an experienced master, but in some cases you have to learn the basics of electric welding yourself. The simplest, most accessible and popular is electric arc welding, which is why almost all craftsmen whose work is related to metal use it.
What is manual arc welding?
The manual arc welding process involves using an inverter or transformer to create an electric arc between the tip of the electrode and the surface of the metal. The elevated temperature melts the metal and electrode, promoting fusion of the materials. (Fig. 1) The place where the metal is connected to the electrode is called the weld pool. Standard sizes baths:
- width 7-15 mm;
- length 10-32 mm;
- depth 5-6 mm.
The parameters of the weld pool are arbitrary and depend on various factors: welding mode, shape of the edges of the products being welded, speed of movement of the electrode, and others.
When the electrode melts, its coating forms a protective gas layer that prevents the metal from burning through and also protects it from exposure to oxygen. A weld seam is formed, covered with a layer of slag. The slag is subsequently removed using the welder's hammer.
Manual arc welding is very popular due to the advantages:
- availability;
- available Consumables and equipment;
- does not require re-adjustment of equipment for welding different materials;
- good seam quality.
Tools and protective equipment for welding
For manual welding you will need: a welding machine, consumables in the form of electrodes, a metal brush, a hammer, a chisel and a mask with a light filter (welder mask).
If you have never seen an electrode holder and you are not even familiar with the general concepts and rules of electric welding, seek help from professionals. In the Enkor24 online store, experienced sales consultants will give competent advice and help you choose the necessary tools and equipment for both beginners and experienced welders. If you want to save your time and money, go to the Enkor24.ru online store, look, choose and buy only what you really need, without imposition and brand bias, at very attractive prices. Only here you will find a huge selection of welding equipment and can buy electrodes, welding machines, welder’s masks, leggings, presented by both leading Russian and foreign manufacturers: ESAB, Elitech, RESANTA, Enkor, Fubag, Plasmatec, TIGARBO, LEZ, Telwin and others .
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Welding machines for manual arc welding:
Transformers - work with alternating current. They are heavy, make a lot of noise, form an unstable arc and affect the electrical network, causing voltage surges. Only an experienced welder can make an even weld on a transformer. However, if you learn how to weld on a transformer, then with other devices it will be much easier.
Rectifiers - convert alternating current into direct current, operate on the basis of semiconductor diodes. The rectifier is universal; it can be used to weld a wide variety of metals and use any electrodes. Unlike a transformer, a rectifier produces a stable arc, which makes the welding process easier.
Welding inverters – have compact dimensions, automated settings, they are quieter than transformers. This device converts alternating current into high power direct current.
Advantages:
- accuracy of settings;
- multifunctional;
- forms a stable arc;
- does not depend on voltage surges;
- Works with any types of electrodes.
All these advantages provide an even, high-quality seam.
Flaws:
- need to be frequently cleaned of dust;
- Do not work at temperatures below -15°C.
Some useful tips:
- If you are just starting to learn welding in practice, then it is better to start with an inverter. It's much easier and more convenient to work with
- Don't forget the hammer and chisel you'll need to knock the slag out of the seam. Next, the seam is cleaned with a wire brush.
- We must not forget about protective equipment. You must have a welding mask with a light filter that protects your eyes.
- The suit should be canvas, with long sleeves. The trousers are smooth, without cuffs. It is better to choose shoes that are as closed as possible, for example, leather.
- Another attribute is canvas or suede gloves or mittens of sufficient length.
- It also doesn't hurt to take care of fire safety, for example, prepare a bucket of water.
Preparation for the process
Before starting work, you need to prepare the welding machine:
- Check the voltage and frequency values, the data must match both in the network and on the device body;
- If there is a voltage selection mode, it is better to set it right away, then set the current value. The power parameter must correspond to the electrode number, that is, the diameter.
- Check the cable insulation. Securely fasten the grounding clamp.
- Check all cables, whether they are insulated, connections, plugs.
- Insert the electrode into the holder, which can be screw or spring. Be sure to make sure that the electrode is held tightly.
For example, an inverter has two cables. One is connected to the part, the second holds the electrode. They are served different meanings current: plus - to the part, minus - to the electrode with “straight polarity”. In some cases, it is necessary to cook in the “reverse polarity” mode, that is, plus on the electrode, minus on the part.
The welding site must also be prepared. It is necessary to clean the metal surface from any dirt, rust, scale, oil. Most weld defects are caused by a poorly prepared surface. Before welding, electrodes must be checked for integrity: its coating must be uniform, without chips. It is also often necessary to dry or calcinate consumables.
Another important question: what current to set. The higher the current, the more stable the arc, but a very high value can burn through the metal. The set current directly depends on the electrode number and the thickness of the part. For horizontal welding, you can focus on the following amperage values: (Table 1)
For vertical welding, the values should be reduced by 15%, for ceiling seams - by 20%. However, in practice, many other factors interfere with the welding process, so the correct amperage can only be determined experimentally.
How to cook correctly?
Welding begins with ignition of the arc. There are two ways to ignite an arc:
- Touch. The electrode is held at an angle of 60°, then the end of the electrode touches the metal and immediately raises the electrode to a distance of 3-5 mm. An arc is formed.
- Scratching. The tip of the electrode is quickly passed along the surface of the metal and then quickly raised by 2 mm.
It is optimal to maintain an arc length of 5 mm. If you bring it too close, the electrode will stick, but a long arc does not cook the metal and creates a lot of splashes. If sticking occurs too often, it means that the current is not enough and you should add more. The length of the arc can be controlled by sound: if the sound is smooth, monophonic, then the length is constant, but if sharp sounds with pops are formed, then the length is too long.
As soon as the welder catches the arc, he begins welding. The electrode is slowly and smoothly moved horizontally, performing light oscillatory movements. If suddenly the arc breaks or the electrode burns out before the seam is completed, then you need to continue working correctly. At the end of the seam a depression (crater) is formed. You need to step back about 12 mm from it and light the arc. Moving slowly forward, carefully weld the crater and continue welding the seam.
As a rule, they are welded in several layers:
- parts up to 6 mm thick in two layers;
- workpiece 6-12 mm - in three layers;
- parts with a thickness of more than 12 mm - 4 layers.
The trajectory of the arc is divided into types:
- Translational - the electrode simply moves along the axis of the electrode;
- Longitudinal - for forming a thin thread seam;
- Transverse - oscillatory movement of an electrode of a certain width (Fig. 2)
Usually the master combines all three trajectories. At the same time, it is necessary to control the distance between the electrode and the surface, since the electrode burns out and decreases in length. You also need to monitor the condition of the bathtub, its size, in order to increase or decrease the speed of movement in time.
It must be remembered that it is impossible to weld parts immediately with a continuous seam, this will lead to distortion of the metal. Two workpieces are connected with clamps or in another way, then spot seams are made at a distance of 8-25 cm from each other, depending on the length of the seam. It is recommended to make spot welds on both sides to avoid stress on the metal. And only then start making the main seam.
Types of seams
Connecting seams are:
- T-bars;
- butt;
- corner;
- overlap
Based on their location, welds are divided into: ceiling, horizontal, and vertical. (Fig. 3)
The horizontal seam is the simplest; the electrode is lowered to the bottom at an angle of 60-70 degrees. (Fig. 4)
Vertical seam - the electrode is guided vertically from bottom to top or top to bottom. It is better to hold the electrode at an angle of 45-50° down from the vertical position so that the metal does not drain. It is advisable to make the seam in one pass. (Figure 5).
The ceiling seam is the most difficult. The weld pool is located at the top, above the welder and turned upside down. The electrode moves towards itself, over a very short arc. It is advisable to cook with 3-4 mm electrodes (Fig. 6)
Basic mistakes of newbies
To learn how to cook correctly, you need not only to know the basics, but also what common mistakes beginners make:
- The electrode is moved too quickly, which results in an uneven seam with uncooked areas; (Fig. 7)
- Moving the electrode too slowly leads to burning in the metal and the formation of holes (Fig. 8);
- Incorrect current supply: a very high current can burn through the metal, and an insufficiently strong current may not weld the seam and will cause the electrode to stick to the surface.
- An incorrectly chosen angle can lead to an uneven and flat seam.
- Incorrect gap between electrode and metal. If it is too small, then the workpiece metal does not heat up well. An arc that is too long results in a shapeless, weak seam (Fig. 9).
In general, the speed of movement of the electrode must correspond to the current strength; the greater it is, the higher the speed of movement of the electrode should be.
Features of welding thin sheet metals
Welding thin sheet metals is more difficult, since such metal is easier to burn through. It is recommended to do the following:
- Cook in reverse polarity mode, the current is minimal.
- The shorter the length of the seam, the less warping, so they weld with an intermittent seam, sometimes moving to another joint area.
- When butt welding, a minimum gap between the edges is achieved.
- In overlap welding, the sheets are pressed tightly against each other during welding to prevent gaps.
- If the metal thickness does not exceed 1.5 mm, it is recommended to use semiautomatic welding machines with wire, since conventional electrodes will burn through the workpiece.
Manual arc welding is a complex process, but with due diligence you can learn this business.
Today, welding is the most popular, simple and reliable way to connect metal parts. To do this, you need to have knowledge and practical skills on how to use welding. To understand how to properly weld, you first need to go through the theoretical part, and then begin to develop practical skills. This process is not complicated, but it is necessary to become familiar with many aspects before mastering the practical aspects of this process. We will teach you how to use a welding machine to get a perfectly straight and correct seam, even if you have never encountered one before.
Before learning how to weld, you need to understand the essence of how a welding machine works. It is as follows: a unit connected to an electrical network provides a powerful welding current, under the influence of which an electric arc of high temperature is created between the conductor and the part that needs to be welded. Under this heat, the metal melts and a bath is formed - a melt area. At this moment, the parts are connected to each other and, when they cool, they form a strong and durable monolithic connection.
Due to the fact that do-it-yourself welding work is simply irreplaceable in construction, during repair work and simply in everyday life for repairing any iron parts, you must remember that there are several technologies for working with welding:
- , which is implemented using special conductors - electrodes. These are small pieces of metal coated with a chemical coating that creates an electric arc. The advantage of this type is its simplicity. Even a novice welder will figure out how to learn to work with such a machine. It does not require the use of gas cylinders or special skills. It is enough to practice in order to get high-quality and beautiful seam. The disadvantage of the arc type of connection of products is that you can only work with stainless and ferrous metals;
- , which is produced by a device using a special gas that creates protection for the metal from oxidation, which occurs as a result of the combination of oxygen with the molten material. Such welding work can be done with your own hands both in industrial and at home conditions.
Welding equipment
Do-it-yourself welding work cannot be done without the help of special equipment - a welding machine. There are several types of them, depending on the technology the master is going to use to weld:
- withstands voltage surges;
- economically consumes eclectic energy;
- cooking with an inverter is much easier and faster;
- It turns out to be more accurate to weld parts, since there is no spattering at all.
You can learn how to use welding using any type of equipment. The main thing is to follow all the rules of working technology and not forget about safety.
What to look for when choosing a welding machine
Before you learn how to weld with a welding machine, you need to choose it and it is advisable to give preference to a good model that will be easy to learn and then work on. When choosing a unit, you need to take into account some nuances on which the quality of the seams depends:
- welding current is an indicator on which power and efficiency depend. To perform welding work with your own hands at home, up to 200 A is enough;
- resistance to fluctuations in electrical networks. The acceptable interval is +-20%. Others are of poor quality. How to learn to operate a unit if the electricity constantly “knocks out” or the arc disappears? Therefore, this parameter is very important;
- The power of the equipment varies. It’s worth starting from the area of its application. To weld metal at home, a simple or semi-professional machine is enough. For production purposes you need a professional;
- PV – duration of switching on. This is an indicator that determines the time frame for the operation of the unit. On average it is about 40%. That is, after a minute of working on welding machine, he needs a minute and a half of rest.
In addition to the device itself, you need to select components for it - clamps, wires, pliers, etc. And, it is important to remember that welding with your own hands requires a special form for the master. The welder must protect his face and eyes, as welding sparks negatively affect vision and can cause retinal burns. Be sure to carry out the work wearing special gloves so that when doing welding work with your own hands, you do not harm your health.
Welding process technology
When everything is ready - workplace, equipment and prepared, you can proceed to the practical part, how to cook by welding.
The welding technique is actually simple. The whole process involves exposing the metal to high temperatures. In this case, an electric arc is formed between the material and the electrode element. Thanks to it, melting occurs.
Often welding errors occur due to the inability to hold the arc. Then the melting occurs unevenly. The result is a rough and uneven seam.
A weld pool is a molten mass of metal mixed with conductor particles. To protect the metal from oxidation, a gas cloud appears above the bath and protects it. If the process occurs using a semi-automatic device, then a special cylinder with protective gas is used. When the electric arc is removed, the metal instantly solidifies and a small track remains, which monolithically holds the two parts together.
Advantages of manual arc welding:
- a variety of electrodes allows you to make different seams on different elements;
- the units are not large and can be easily transported;
- just learn how to make a seam;
- ideal for home use.
Along with the advantages, there are also disadvantages:
- release of harmful substances into the air;
- not all metals can be soldered in this way;
- The quality of work will depend on the level of skill of the welder.
For a more detailed introduction to manual arc welding, you can find out.
Welding with electric welding using gas is a little easier, but before the process itself you need to set up a semi-automatic machine:
- You can determine the current strength from the instructions;
- adjust the automatic wire feed speed;
- set voltage and current;
- check the settings on a rough version of the part.
To work with welding in semi-automatic mode, it is necessary to firmly fasten the work product. In addition, it is necessary to choose a place for this that fully complies with safety rules. For example, it is prohibited to use wooden workbenches or tables. During welding, it is necessary to strictly observe the interval between the conductor and the part - 5 mm. If you do not disturb it, the seam will turn out almost perfect. There is no need to rush, the electrode burns out smoothly and the master has time to form a high-quality track. If the arc goes out all the time, it is necessary to increase the current on the unit itself.
To quickly learn how to weld by welding, professionals have prepared several tips for beginners, which it is advisable to use to obtain a high-quality result of their work:
- To make welding with your own hands easy and quick, you need to properly prepare the parts, that is, clean them of corrosion, dirt, dust and oil. Then the seam will be strong and even;
- Don't be afraid to experiment. In the initial stages of learning, you need to try everything possible options guiding the electrode to “fill your hand”;
- In order not to miss the welding arc, you must try to maintain the same gap between the end of the conductor and the part. The most optimal distance The thickness of the electrode is considered. For beginners who are just learning how to operate the device correctly, it is recommended to use 3 mm electrodes;
- you need to learn to distinguish a bath from slag. When you first touch the metal, a red spot forms - this is not a bath, it is only a melting material that is applied to the electrode. After this, after a couple of seconds a liquid will appear White spot– this is already a weld pool;
- Do-it-yourself welding work should start with a spot weld, then it will be easier to learn how to lead a smooth path and not lose the arc;
- You shouldn’t be afraid of failure; to understand how to weld metal, you need to train a lot, try and experiment. Only then, after millions of attempts, you will get a correct and high-quality weld.
In a situation where it is necessary to connect metal parts, they most often resort to the method of creating a weld, since it can provide fairly high reliability. This method has become widespread not only in industry, but also in ordinary everyday life.
The vast majority of home craftsmen periodically use welding. Those of them who have welding skills are lucky. If they are not there, then in this case there is nothing left but to contact specialists.
But anyone can learn to cook if they want. And the first thing you should pay attention to at the very beginning is learn the basics of electric welding for beginners. We are talking about lessons that tell you about the features of creating various seams. More complex work should be started only after the owner has gained sufficient experience. Next, we will dwell in more detail on the nuances of welding work and certain tricks of this process.
Where to start the preparatory stage?
The first thing you need to do for those who want to learn how to cook is purchase the necessary equipment. The complete kit that will be required to complete such work will include:
- welding machine;
- set of electrodes;
- hammer for beating off slag;
- brush.
When choosing an electrode, you need to pay attention to its diameter, which will be determined thickness of the metal sheet being welded. You should also take care of protection. For welding we need:
- welding mask with a special light filter;
- thick clothes with long sleeves;
- gloves, preferably made of suede.
The tools required for welding work must include a welding rectifier, transformer or inverter. It is with the help of these devices that the problem of converting alternating current into direct current will be solved, which will allow welding.
Welding process technology
When starting electric welding, you should remember that this work is carried out at high temperatures. Provides such work electric arc that must be maintained between the electrode and the workpiece being welded.
It is during its contact with the workpiece that the base metal and welding electrode melt. At this moment, a phenomenon occurs, which among specialists is called a weld pool. In it, the base and electrode metal are mixed into a homogeneous mass.
The bath can have different sizes, which is determined by the welding mode used, spatial position, arc movement speed, shapes and sizes of the edge, etc. Usually it reaches a width of about 8–15 mm, a length of 10–30 mm, and a depth of about 6 mm.
Each electrode has a special coating called coating. At the moment of its melting, a special gas zone appears in the arc area and above the bath. Thanks to it, air leaves the welding zone and the interaction of molten metal with oxygen is eliminated. It also contains pairs of base and electrode metal.
Already on the seam itself an alloy appears that does not allow the melt to come into contact with air, which would deteriorate the quality of the welding. As the electric arc moves away, the crystallization of metals, resulting in a seam, thanks to which the welded parts are firmly connected. At the seam itself there is a protective layer of slag, which must be removed after welding.
Basics of electric arc welding
To get the best possible results when creating a weld, novice welders first need to familiarize themselves with the lessons where attention is paid correct execution this work in the first stages. It is also advisable to get practice in performing welding work under the guidance of an experienced specialist, who will not only point out mistakes, but also tell you how to avoid them in the future. Before you start welding parts, you need to make sure that it is securely fixed enough.
It is equally important to take care of compliance with fire safety rules: for this it would be useful to place a bucket of water nearby. This also explains the ban on welding on wooden base. Attention should also be paid to small remnants of used electrodes, which should not be left at the workplace after completion of work. Without this, it is impossible to learn how to weld metal correctly.
It is imperative to make sure that the “ground clamp” is securely fixed. Make sure that the cable is insulated and accurately inserted into the special holder. Before working with a welding inverter, you should select a calculated current power indicator, which should be determined based on the diameter of the electrode. After this you can strike the arc. This is done as follows: you need to place the electrode at an angle of about 60 degrees relative to the product. Next, you need to slowly move it across the surface. At this moment sparks appear, now you need to touch the metal with the electrode and then lift it, but not higher than 5 mm.
If all recommendations are strictly followed, the arc should light. Until the welding is completed, you need to keep the electrode at a distance of 5 mm. It should be borne in mind that during metal welding, the electrode rod will gradually begin to burn out.
Therefore, at regular intervals you need to reduce the distance between it and the metal. Approach the electrode to the workpiece slowly. A situation may arise where it sticks. In this case you need to turn it slightly to the side. If all attempts fail to ignite the arc, then you can try increasing the current.
When the arc ignites and its flame becomes stable, you can begin fusing the bead. The electrode with the other one lit must be slowly and smoothly moved horizontally, making gentle oscillatory movements. This will cause the liquid metal to begin to move on its own directly to the center of the arc. If you follow all the recommendations, you can make a reliable seam formed in the form of small waves that were created using deposited metal.
A situation may arise that during welding of products the electrode will be completely used up, but at the same time it will not be enough to create the entire seam. In this case, you need to take a break from work. After turning off the device, you need to insert a new electrode, remove slag from the surface of the weld, and then continue welding. From the depression created at the end of the seam, often called a crater, you need to make an indent of about 12 mm and light the arc. The electrode should be brought closer so that upon contact an alloy is formed from the metal of the old and newly installed electrode. Next, welding is performed as usual.
Features of welding a pipeline with an inverter
The electric arc welding method is suitable for creating a vertical seam, provided that it is located at the end of the pipe. If a horizontal seam is created, the latter should be on its circumference. If you have to make ceiling and bottom seams, then they should be at the top and bottom. Among all those mentioned, it is the last one that creates fewer problems in implementation.
If you have to deal with steel pipes, then the butt welding method is most often used, which involves welding each edge along the height of the walls. To minimize sagging inside the pipe the electrode should be positioned at an angle of no more than 45 degrees relative to the horizontal. Such a seam should reach a height of 2–3 mm and a width of 6–8 mm. If the products are overlapped, then the seam will have a height of 3 mm and a width of 6–8 mm.
Preparation
Before you begin electric welding of metal products, you need to complete the following preparatory measures:
- It is necessary to remove the top layer from the welded aliment.
- If there are any irregularities at the ends of the pipe, they need to be cut off or straightened.
- Next we begin to process the edges. Here it is necessary to smoothly brush at least 10 millimeters of the surface adjacent to the edges of the pipe outside and inside until a metallic sheen appears.
Main stages
Next, you can begin directly welding the pipe. Each joint must be processed continuously until they are completely welded. Rotary and non-rotary joints of pipes with walls no larger than 6 mm should be created in at least two layers. If the walls are 6–12 mm wide, then three layers should be created, more than 19 mm - 4 layers. When welding pipes, one thing to consider is important nuance: from the next seam created at the junction, it is necessary to remove slag, only after that you can proceed to creating a new one.
Particular attention should be paid to creating the first seam, since a lot depends on it. It must be performed in such a way that it melts every edge and dull areas. It is very important to examine it very carefully, as there may be cracks on it. If they are found, they must be melt or cut down, after which the area is welded again. When creating the remaining layers, you need to slowly turn the pipe. It must be remembered that the beginning and end of each layer should be located with an offset relative to the previous layer at a distance of 15–30 mm.
The finishing layer must be created so that it provides a smooth transition to the base metal and at the same time has a flat surface. Achieve highest quality welding pipes using welding is possible if the next layer is performed in the opposite direction with respect to the previous one, while their closing points should be scattered from each other.
Conclusion
Welding work is quite complex, so novice welders will have to spend a lot of time and effort to create high-quality and durable welded joints. But first they should get an idea of the main points from the lessons, without which it is impossible to weld metal efficiently and correctly.
It is important not only to prepare everything necessary tools and materials, but also approach the study of the technology of the welding process with special care. This is very important because any mistake can subsequently affect the quality of the weld, and if attention is not paid to this at the initial stage, then in the future all efforts will be in vain, as a result everything will have to be redone.
Thanks to the reliability and durability of welding joints, there is not a single industry that does not use this technology. In the household, it is also sometimes impossible to do without welding work. Having the skills to work with an electric welding machine will allow you to create any metal structures, from a simple fence to summer cottage and ending with an openwork garden swing or a multifunctional barbecue. We will talk about how to properly weld 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 weld using electric welding, it is not enough to study the theoretical fundamentals 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 weld using electric welding will help you understand all the nuances of this craft and tell you what other materials and tools, in addition to a welding machine, will be needed when carrying out the work.
The video of the welding process, presented in the form of step-by-step lessons, begins with a talk about preparing surfaces before welding. Next, you will learn how to make simple seams and only after that you can start joining 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 weld with electric welding, prepare yourself theoretically, and then pick up an 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 a process of joining metals using an electric arc between the surface of the part being welded and the electrode . The resulting high temperature promotes 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 the molten electrode.
Bath size directly depends on the welding welding mode, edge shapes connected surfaces, electrode movement speed, position of parts in space etc. and ranges from 7 to 15 mm wide, 10-30 mm long and up to 6 mm deep.
High temperature prevents metal from burning gas layer, formed when the electrode coating melts, which displaces all oxygen from the melting zone. After the electric arc is removed, the metal crystallizes and forms common seam for welded surfaces, covered with a protective layer of slag, which is removed after cooling.
The advantages of electric arc welding are :
- high performance;
- welding capability various materials without the need to re-adjust equipment;
- good quality weld;
- inexpensive consumables;
- availability.
IN disadvantages of this method welding, you can write down the mandatory availability of power supply and the need preliminary preparation welded edges.
Getting ready for welding. Selection of materials and equipment
Before you start welding, you need to understand 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 weld metal, you need to stock up not only with good equipment, but also with the appropriate equipment.To start electric welding you will need:
- welding machine;
- set of coated rod electrodes;
- welder's hammer;
- metal brush;
- welding mask;
- overalls, suede gloves.
You can arc welding without a factory set of overalls. It is important that the protective suit is made of thick fabric with long sleeves, and it is better to tuck the trousers into the boots.
Choosing a welding machine
A good welding machine with the ability to adjust the current from 10 to 200A will help you learn how to weld properly. Of course, you can assemble a simple welding transformer with your own hands, but then you don’t even have to think about how to weld thin metal, because such work requires minimum power values. Factory-made devices are divided into:
- Welding transformers . Designed to reduce the network voltage while simultaneously increasing the current. Being inexpensive and productive devices, they can weld metal quite well, but they have disadvantages such as an unstable arc, a strong “drawdown” of the supply voltage and a large mass.
- Welding rectifiers . Such devices are the same welding transformers equipped with a diode rectifier, thanks to which AC voltage network is converted into the constant voltage necessary for the appearance of an electric arc. Welding metal with straighteners is a little easier due to the higher arc stability. Otherwise, this type of welding machine has the same disadvantages as transformers.
- Welding inverters . True electronic welding is possible thanks to the modern technological filling of such devices. They provide a lot of opportunities to cook with electrodes with the most optimal parameters. Electronic components The circuits of modern inverters make it possible to regulate not only the current strength, but also the ignition speed, arc forcing, etc., which ensures excellent weldability of parts. In addition, inverters are compact and lightweight.
The debate among welders continues unabated about which welding method is best. Some people like the simplicity and reliability of the transformer, while others are satisfied with manual welding with a rectifier. However, the best way to learn how to weld is with a welding inverter. The ability to precisely adjust the parameters will allow you to weld metal correctly literally from the very first steps.
Selecting electrodes for welding
Used for manual arc welding rod electrodes with protective coating . The metal of the rod must match the type of metal being welded, so 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 to the surface of the weld pool, protects the melt from the influence of oxygen and nitrogen in the air. Some coatings contain gas-forming additives, which during the welding process emit gas, limiting the access of air to the melting zone.
Most often, the question of which electrodes to weld with is not worthwhile 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, electrodes brand UONII , designed for direct current operation.
Electrodes of a different brand - ANO , can be used for welding with both rectifiers and transformers; they allow you to weld with both direct 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 UONII. They cite as an argument the fact that this type of rod leaves behind significantly less slag, therefore, cleaning the seam is required much less frequently, which significantly increases the speed of work.
Depending on the thickness of the parts being 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 current strength.
The required electrode diameter can be determined using tables of the dependence of this parameter on the thickness of the parts, as well as using mathematical formulas. Novice welders rarely use thick rods more than 4mm.
Type of welding work(horizontal, overhanging, butt welding, etc.) practically does not depend on the diameter of the electrodes, which cannot be said about weld pool depth And seam width.
Since the specific welding current depends on the cross-section of the electrode, the current concentration is higher at the end of a 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 accurately answer which electrodes to weld with, since the correct 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 the same brand can differ significantly among products from different factories, so before you start welding, ask for advice from specialists.
Selecting the current strength and its polarity for electrode welding
After watching a video about how to cook by welding, you probably noticed 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 contact special tables. Electrode manufacturers often indicate the required parameters on their packaging.
To properly weld metal, the required current is determined by calculation or from tables, and then this parameter is set on the inverter control panel. The higher the current, the higher the arc power and the deeper the weld pool. . However, you should not exceed the optimal value - the metal will begin to burn out and the seam will be of poor quality.
When setting the current value for electric welding, be sure to take into account the location of the work site. Maximum current is set for horizontal surfaces. When welding vertical stitches it reduced by 15%, A ceiling will require reduce current by 20% and more.
If you weld using inverter welding or a rectifier, then the quality of work is influenced not only by the strength of the current, but also by its polarity , that is, the direction of electron flow.
From a physics course, everyone knows that electrons move from the region of negative charge to the region of positive charge. To cook correctly with an electrode, the polarity is changed, setting both forward current (the electrode is connected to the minus of the inverter, and the part to the plus) and 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 alloy alloys that are prone to burning out 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 with an electrode, for example, sheet steel.
Safety precautions when carrying out welding work
Every novice welder wants to be reminded of safety rules. Remember that welding is one of the most dangerous methods of installing metal structures, so do not neglect the following rules:
- It is prohibited to carry out welding work in high humidity or in cold weather.
- The use of a welder's mask and protective shield is mandatory. This will avoid burns to the cornea of the eyes.
- Clothing should prevent metal splashes from coming into contact with exposed skin. It is better to wear suede gloves on your hands, and the best material for the welder's suit there is a thick tarpaulin.
- Welding work is associated with high temperatures and the risk of fire, so a container of water and a fire extinguisher must be present at the welder’s workplace.
Also, be aware of the risk of injury 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 cook by welding
Before starting practical exercises, I would like to remind you once again about safety precautions. No wooden workbenches or flammable materials near the work area. Be sure to place a container of water at your workplace. Be aware of the risk of fire.
In order to figure out how to properly weld, we present to your attention detailed instructions and video of the welding process.
First try lighting the arc and holding it for the required time. To do this, follow our tips:
- Using a metal brush, you need 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 weld with electric welding using 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 relative to the workpiece at an angle of about 60° and slowly move it along the surface of the metal. When sparks appear, lift the edge of the rod 5 mm to ignite an electric arc. You may not have been able 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 properly weld with electric welding. The resulting arc is maintained with a 5 mm welding gap throughout the entire welding process.
- If the arc lights up very reluctantly, and the electrode constantly sticks to the metal surface, increase the current by 10-20 A. If the electrode sticks, shake the holder from side to side, possibly even using force.
- Remember that the rod will burn out all the time, so only maintaining a gap of 3-5 mm will allow you to maintain a stable arc.
Learning to strike an 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 welding a seam about 5 cm long, remove the electrode and let the part cool, then tap the joint with a hammer to knock off the slag. The correct seam has a monolithic wavy structure without craters or 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 about how to weld, filmed using protective filters. In such videos you can clearly see how to maintain the arc and move the electrode to obtain a high-quality seam. We can give the following recommendations:
- Translational movement of the rod maintain the required arc length along the axis. During melting, the length of the electrode decreases, so it is necessary to constantly bring the holder with the rod closer to the part, maintaining the required gap. This is precisely what is emphasized in numerous videos on how to learn to cook.
- Longitudinal movement of the electrode they create a fusing of the so-called thread roller, the width of which is usually 2-3 mm greater than the diameter of the rod, and the thickness depends on the speed of movement and current strength. A thread bead is a real narrow weld.
- To increase seam width the electrode is moved across its line, performing oscillatory back-and-forth movements. The magnitude of their amplitude will determine how wide the weld seam will be, so 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 weld using electric welding and studying the diagrams of such trajectories, you will be able to figure out which of them can be used for overlap or butt welding, with vertical or ceiling arrangement of parts, etc.
During operation, the electrode will sooner or later melt completely. In this case, stop welding and replace the rod in the holder. To continue working knock down slag at a distance of 12mm an arc is ignited from the crater formed at the end of the weld. Then the end of the old seam is fused with a new electrode and work continues.
Features of electric welding of metal pipes
Learn to weld profile pipes It is best on thick-walled products using a welding rectifier or inverter. Depending on the diameter of the pipes, their wall thickness can reach more than 16mm, but you will most likely need to weld structural steel products with a wall thickness of up to 12mm. To weld a pipe, single-layer welding is often used, but to increase the strength of the connection it is better to perform two or more passes.
When welding pipes, the seams are made two half rings top down or bottom up.
If the direction of movement of the electrode corresponds to the first option, then 4 mm rods with low slag formation and organic coating are used. This 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 are made:
- Butt (exact orientation of the ends of one pipe relative to another);
- Overlapping (by placing pipes or parts on top of each other);
- Angle;
- T-joint (one pipe is perpendicular to the other).
In order to weld one pipe to another, first clean and prepare their ends and place the products at the workplace. Next, the elements are centered relative to each other and secured in several places with spot welds. After checking the alignment of the pipes, they can be welded using one of the specified methods.
If it is impossible to rotate the pipes, they joints are made in multilayers. The first, root layer, serves to initially connect the parts. The following, filling layers, are designed to create the actual durable, monolithic seam. And, if necessary, they 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 to identify lack of fusion, pores, cracks and burns. If necessary, defects are eliminated by welding. If the seam meets all the requirements, then it is cleaned using an angle grinder.
Protection of metal from corrosion after welding
Remember, at the very beginning of the article it was said that in order to weld correctly with electric welding, it is not enough to watch the video, but you also need to prepare theoretically? Agree that the text allows you to better understand the theory. In addition, the videos somehow miss the need to protect the parts later. We will try to eliminate this shortcoming.
Everyone knows that metal quickly begins to rust when exposed to oxygen in the air. Believe me, welds corrode even faster.
In order to protect metal surfaces from corrosion, painting is most often used. To avoid repeating this work every year, do it according to all the rules.
First of all, old paint and rust must be removed . To do this, it is best to use metal brush attachments for a drill or grinder, but you can also work with a regular metal brush. Do not forget to protect your eyes with glasses or a shield.
After cleaning the surface treat it with a rust converter and then coat it with a coat of primer . Choose a primer composition specifically designed for working on metal. After this layer has dried, you can begin painting. Acrylic and pentaphthalic enamels intended for outdoor use give good results.
It is best to use a spray bottle rather than a brush or roller for painting purposes. With its help, you can apply a uniform, thin layer of paint that will not crack or peel over time.