Tig welding machine budget review. TIG welding machine: specifications, comparison of the best models and reviews of the manufacturer. Types of welding inverters

Powerful argon burners use water cooling, as they heat up very much during operation. The arc melts not only the joints of the parts to be welded, but also the filler wire fed into the welding zone. Feeding can be done both manually and mechanically (). To protect the welding site from exposure to oxygen, inert gases are used - most often argon, which is why this type of welding is commonly called argon-arc, but helium, nitrogen and mixtures of gases can also be used.

Argon arc welding combines all the advantages of other types of welding: cleanliness and continuity of the seam, characteristic of semi-automatic welding, with the ability to work at high currents and with deep penetration, for which manual arc welding with a consumable (piece) electrode was traditionally used. Since the filler metal fed into the bath does not participate in the formation of the arc, quality control of the weld becomes easier: a weld made by TIG welding cannot be confused with any other. Welding in an inert atmosphere can be carried out on almost any metal: only the current characteristics and the material of the additive being introduced change.

The video tells about TIG welding and the device device using the example of one of the models

Apparatus design

Functionally, the apparatus for argon arc welding consists of a welding current source and a torch.

• Welding power source ensures the ignition of the arc and its maintenance with the specified parameters. The wide range of materials for which a machine of this class can be used requires a large number of adjustments, and therefore semiconductor inverters are now used as a current source with a combined output: TIG DC (direct current) mode is used for welding stainless steels, TIG AC (alternating current) - and magnesium. For welding parts of small thickness, intermittent current is used (Pulse mode).
  The proximity in design to manual arc welding (MMA) machines often leads to the appearance of combined TIG-MMA inverters, in which to change the type of welding, it is enough just to change the welding torch to the holder.
• Burner- this is a device in which a tungsten electrode is fixed and there is a nozzle for blowing inert gas into the welding zone. Depending on the design of the arc, gas is supplied either in the center (as in semi-automatic welding torches), or from the side through a separate nozzle. The second method is preferable outdoors, when the wind is able to blow off the inert gas covering the weld pool. Unlike a conventional semi-automatic torch, the TIG torch is supplied with gas before the arc is ignited in order to avoid burnout of the metal at the moment of ignition.
• In devices for high-performance feeding of filler wire is carried out automatically feed mechanism, similar to what everyone is familiar with in conventional semi-automatic welding machines.

Dear novice welders, this article is written for you. We have studied all the frequently asked questions about TIG and MIG welding and made a short article in which we answered these questions. Perhaps this will help you when working with the equipment.

For TIG TIG welding you will need:

• Welding machine for argon arc welding.
• Gas cylinder (Argon or Helium)
• Reducer.
• Attachment rod.

What is the first thing you should pay attention to.

• Most TIG machines weld metals with direct current DC. If you need to weld aluminum, you need to purchase a machine that welds metals on AC alternating current. A DC machine will never weld aluminum! Only on alternating current AC can aluminum be welded.
• TIG welding can weld: steel, aluminum, copper, titanium and two dissimilar metals. This process is ideal for welding hard-to-reach seams, S-shaped seams, corners. TIG welding will allow you to make very thin and high-quality seams, especially where it is important that the seam is not noticeable. Since you control the entire welding process yourself with a welding torch, you can make cosmetic seams, automotive seams, and weld thin metals.
• Gas. In 99% of cases you will need Argon. Helium is very rarely used, for example the American Welding Association recommends using Helium for welding copper, but Helium is very expensive and therefore everyone uses Argon. Gas is needed so that air does not enter the weld pool, which will destroy the connection. Argon is an inert gas, it is harmless to breathe and non-explosive.
• . As a rule, it is sold in tubes. When you bring the torch to the metal and a current flows through the tungsten electrode to the products that you will weld, you will need to slip the filler rod. The current will melt the metal and the filler rod, which in turn will form the weld. As the burner advances, the seam will cool down and weld the products firmly.
• Reducer. You will need a special one that attaches to a gas cylinder.
• - before you choose a tungsten electrode, you need to understand what metal you will weld, in principle there is a universal version of WC 20 (gray). If you are welding aluminum, then the tip of the electrode must be sharpened in the shape of a ball, and if you are welding steel products, you need to sharpen it in the form of a sharp tip. You can sharpen the electrode on any grinding machine.

Buyers choice. TIG machines for aluminum welding (alternating current AC).

Buyers choice. TIG machines for steel welding (direct current DC).

MIG welding in semi-automatic mode.

In our opinion, one of the most practical types of welding is semi-automatic welding in an active gas environment.

For correct operation welding semi-automatic you will need carbon dioxide (CO2) or a mixture of inert gases, such as Argon + CO2, a gas-appropriate reducer, and welding wire (solid or flux-cored. During the welding process, welding wire and shielding gas are supplied from the torch nozzle. The task of the gas is to create a protective sheath , pushing the air out of the weld pool, thereby protecting the weld from oxygen and nitrogen.The mixture of argon and carbon dioxide helps to increase the stability of the arc, and also improves the formation of the seam when welding thin sheet metal.

To select the diameter of the welding wire below, we have provided a universal table.

At a gas flow rate of 20 l/min. carbon dioxide turns into dry ice. To prevent freezing of the reducer, we advise you to purchase heated gas flow regulators. As a rule, the heating is connected to a 36V socket, which most semi-automatic welding machines are equipped with.

When choosing an apparatus, pay attention to the maximum wire diameter you can use. As a rule, all "household" devices have a maximum diameter of 1.0 mm. The settings of the machine are adapted to this thickness of the welding wire and the correct operation of the machine is possible only if this diameter is observed. Industrial machines can weld thicker wire. If you take the device to the garage or to the country, a device that produces up to 140A will be enough for you. Many manufacturers make such devices with a maximum current of up to 180 amperes.

Usually inverter equipment is bought, but someone likes to work with transformer. For example, a semiautomatic device is very often bought in our online store. The inverter machine from the company can weld aluminum.

Without welding, it is difficult to imagine aviation, space, mechanical engineering and construction; welding is also in demand in everyday life. The most diverse methods of joining metals and their alloys are widely used at the present time, and a separate place here is occupied by inexpensive, but effective method TIG welding. We will review the working methods, technologies and metals that are welded with this method. Special attention should be paid to apparatus, equipment and consumables, as well as the principles of operation in a protective inert gas environment.

One of the metal welding methods is MMA, in which the work is done with consumable coated electrodes, alternating or direct (AC / DC) output current. In addition, semi-automatic MIG / MAG welding in a shielding or active gas environment is widely used. The next, intermediate in price category, is TIG welding, which is otherwise called the argon-arc method. In it, the process of welding metals with a short-circuit arc is carried out by an infusible tungsten electrode in a shielding gas environment that prevents oxidation in the open air.

As a source of AC / DC current, a welding inverter is used, equipped with a Euro connector, through which gas and output current are supplied to the burner, and control signals pass through. Unlike the MIG method, where a moving wire serves as the electrode, a refractory tungsten electrode with a high melting point is used. Gas is supplied through the torch with a grid, and then, with a delay of 1 second, voltage is supplied. This is done so that welding starts in a protective gas environment, which is supplied under pressure and, being heavier than air, prevents the oxidation of workpieces.

To better understand what TIG welding is, an assessment of the advantages and disadvantages of this method of joining metals will help, especially in comparison with MMA and MIG methods. The advantages of argon arc welding include the following parameters:

1. the ability to work with both thin-walled parts and workpieces of considerable thickness;
2. work in AC/DC modes;
3. wide ranges of adjustment of welding current parameters;
4. the use of non-flammable gases, which increases the safety of work;
5. refractory electrodes of reusable use;
6. reliable, collet clamp of the burner for replaceable electrodes of various thicknesses;
7. the presence of an oscillator for improved arc ignition;
8. Ability to work with direct and reverse polarity.

This method also has certain drawbacks that do not have a significant impact on the workflow. They are as follows:

• low welding speed compared to other methods;
• the need to work indoors to avoid excessive gas consumption;
• low mobility;
• manual feed .

It is important to know that welding work is a source heightened danger, and it is necessary to use special clothing, leggings and a protective mask Chameleon or identical to it.

The composition of the equipment and the scope of TIG welding

Each type of welding has its own purpose, advantages and disadvantages, as well as a set necessary equipment and Supplies for high-quality work behavior with the best result. The list of TIG welding equipment includes the following components:

• MMA+TIG inverter with gas mixture adapter and Euro connector, with adjustable output parameters, AC 220/380 V input power supply and current from 10 A to 180 A;
• euro hose used to supply inert gas, control signals and welding current;
• gas supply hoses from cylinders;
• cylinders equipped with reducers and pressure gauges;
• burner with a control button and a collet clamp of a tungsten electrode;
• welding or filler wire, similar in composition to the working material;
• inert gas or its mixture with CO 2 to create a protective environment in the weld pool;
• refractory tungsten electrodes.

Tig welding is used in industry, construction and domestic needs. The great possibilities of the method make it possible to use it when welding not only various metals, but also their combinations, as well as alloys. The following materials can be alloyed with direct and alternating pulsed current:

• structural and carbon steels;
• various aluminum alloys;
• stainless steel, including for sanitary and food needs;
• titanium alloys;
• copper, brass and bronze, as well as their combinations;
• galvanized metal and nickel-plated surfaces.

It is very important to select the welding and filler wire closest in composition to the material being welded, alloys and dissimilar combinations.

To ensure good welding quality, it is necessary to monitor the cleanliness of the tungsten electrode and sharpen it regularly, since the thickness and cleanliness of the TIG weld is more dependent on it.

Operating modes and TIG welding technology

Metals and alloys, depending on the physical and chemical properties, are welded in different operating modes of the power source. The reason for this is the refractoriness of the oxide film or the thickness of the workpieces. In various welding modes, the required depth of penetration is achieved in relation to a specific task and a specific metal. The following operating modes are available for the TIG method:

• method using direct current (DC) of different polarity;
• operation on alternating output, high-frequency current (AC) using various current-voltage characteristics for a gentle effect on parts;
• a method of non-contact high-voltage ignition of the arc using an oscillator that forms a discharge.

Direct current is used when welding aluminum and magnesium alloys with reverse polarity, which provides good strength characteristics of the weld and allows you to destroy the refractory oxide film on the surface of the workpieces. In addition, appropriate welding rods are used, which are fed into the melting zone manually in translational movements. Other types of metals are welded with direct current of direct polarity with a filler wire and selection of current strength.

Work using alternating current is called pulse welding, since the metal is heated at peak values ​​of high-frequency vibrations. At basic current strength readings, the heating of workpieces is reduced, which prevents overheating (especially thin-walled) metal. The refractory electrode must be held at an angle close to 90 °, but with an inclination towards the direction of the welding process without transverse movements, and the bar should be fed with slight translational vibrations into the weld pool.

It is very important to monitor the cleanliness of the workpieces, the welding rod and the tungsten electrode, otherwise the quality of work drops sharply.

The oscillator, by applying high-voltage low-current voltage to the workpieces, allows the ignition of the arc in a non-contact way, which prevents contamination of the working surface of the electrode. As for inert argon, it is produced in the highest and first degree of purification and is often used in a mixture with helium. This combination gives the best results, but sometimes argon is mixed with carbon dioxide to save money.

Conclusion

We tried to tell as much as possible about TIG welding and its application when working with various metals and in DC and AC modes. The method requires costs and certain qualifications, but having mastered it, you will get a universal way to connect a wide variety of parts and the possibility of repairing metal products of different thicknesses.

Argon welding (TIG) is a common welding technology, which is the best way to join aluminum parts and structures. Welding of this metal under normal conditions is extremely problematic, since when heated aluminum comes into contact with oxygen, an oxide film is formed on its surface, which degrades the quality.

TIG welding of aluminum involves the supply of a protective gas, argon, to the point of contact between the electrode and the metal, the pressure of which displaces oxygen, which allows you to make the connection of the best quality. This article discusses the features this method, instructions for its implementation by one's own hands are given and a home-made apparatus for TIG welding is shown.

1 Advantages and disadvantages of the method

Argon arc welding, in addition to joining aluminum structures, is also widely in demand when working with other metals, which include steel, copper, cast iron and titanium, as well as precious alloys - gold and silver. This argon welding is indispensable in cases where it is necessary to join difficult-to-weld metals.

The advantages of this method include:

• the minimum heating zone of the part, which allows you to save its original shape;
• argon is an inert gas that has a greater weight than air, which allows it to completely displace oxygen from the heating zone of the workpiece;
• the thermal power of the arc when using argon increases, due to which the speed of work increases;
• argon arc welding is quite simple to implement, learning the process does not take much time;
• the weld is neat and minimal in size, it does not spoil appearance blanks.

However, the technology also has disadvantages. The key one is the risk of deterioration of the quality of the joint when working in a draft or wind, since part of the supplied argon can be blown away by an air stream. We also note the rather high complexity of setting up welding equipment with your own hands and the need for additional cooling in the high-temperature arc mode.

1.1 Technology features

A characteristic feature of the TIG method is the use of a refractory tungsten electrode - tungsten is a metal whose melting point is 3410 degrees. In the process of joining, a hundredth of a gram of tungsten is enough to penetrate a seam 1 meter long, which leads to a minimum consumption of electrodes during operation.

Special electrodes made of tungsten coated with a doping layer of oxides of rare earth metals can also be used, due to which it receives additional temperature stability. These metals include cerium, zirconium, lanthanum and yttrium.

TIG electrodes are designed for reusable use. Whichever consumable is chosen, during the welding process, it is inserted inside the ceramic nozzle of the apparatus, through which a protective gas, argon, is blown out.

In a simplified outline, the process looks like in the following way: initially, a welding machine is connected to the part and a mass is supplied, after which the welder takes a torch with an electrode and an additive (a wire made of aluminum or a special alloy), the torch turns on and an electric arc occurs between the tip of the tungsten electrode and the mating parts. The arc melts the filler wire and the edges of the joining structures, which leads to the formation of a weld that becomes solid after solidification.

At first glance, everything is extremely simple, but the final quality of the weld depends on many factors - power, the quality of the electrode used, the degree of protection of the melting zone with argon, the experience of the welder. In fact, TIG welding is a hybrid technology that combines the methods of gas and electric arc welding.

1.2 Welding equipment

Requirements for equipment used in TIG welding are specified in normative document GOST No. 5.917-17. According to the provisions of the standard, burners of the RGA type should be used for implementation. The most common 2 models - RGA-150 and RGA-400.

The 150th model is designed for a welding current of 200A, the electrode is naturally cooled, the weight of the burner is 350 grams. The device is produced in different modifications with a nozzle diameter from 0.8 to 3 mm.

When using a welding current of 500A, an RGA-400 torch should be used, the weight of which is 625 g. It implements water cooling of the electrodes, the nozzle diameter is 4-6 mm.

There are also requirements for the shape of the burner nozzle, which can be cylindrical, conical or profiled. As a rule, when welding indoors, cylindrical nozzles are used, when working outdoors - profiled nozzles with a large outlet diameter. If it is necessary to work in hard-to-reach places, elongated nozzles can be used.

Kedr TIG 200P - equipment for welding

There are quite a number of TIG welding machines on the market. Most of them are combined and have the ability to work in two different modes - argon-arc (TIG) and manual arc (MMA) welding.

Among the devices of the middle price category, we single out the following devices:

• Cedar TIG 200R;
• Resanta SAI 230 AD;
• Svarog TIG 250R.

In terms of price and quality, as evidenced by consumer reviews, the best option is Cedar TIG 200R, the cost of which is 40 thousand. This unit has a power of 6.2 kW, the range of operating currents is from 4 to 200 A. The device operates from a 220 V power supply. The diameters of TIG electrodes are 1-4 mm, MMA are 1.6-5 mm. The kit comes with an argon burner with a 4 meter hose.

It is quite possible to assemble a device for argon-arc welding with your own hands. The self-made unit will consist of the following nodes:

• current source - a conventional device for electric arc welding with AC or DC current is suitable;
• a cylinder with argon, ideally with a built-in pressure gauge;
• gas reducer and valve;
• argon burner (sold separately in specialized stores);
• oscillator.

The key component in terms of importance is - this is a device that is necessary for non-contact ignition of the arc. Due to the fact that ignition in TIG welding cannot be performed by touching the electrode to the surface on which the mass is applied, a high-voltage charge (power from 4 to 8 kW) that breaks through the arc gap must be generated by an oscillator.

1.3 Features of TIG welding (video)

2 DIY TIG welding technology

The key to the correct implementation of the TIG method is a properly selected welding mode. It is necessary to choose the mode based on the thickness of the surfaces to be welded. We present to your attention a normative reference table.

Do-it-yourself argon-arc welding is quite difficult to perform, in order to implement the technology, follow the following recommendations:

1. The electrode must be kept as close as possible to the mating surfaces in order to ensure the shortest arc - with an increase in its length, the width of the weld will increase and, as a result, the reliability and quality of the joint.
2. In the process of making a seam, the burner must move along its axis, transverse movements are not allowed. Due to this orientation, it provides an aesthetic seam of minimal thickness.
3. To prevent saturation of the weld zone with oxygen, it is necessary to strictly ensure that the filler wire and electrode do not leave the shielding gas supply area.
4. The wire should be fed extremely smoothly, with a sharp feed, there is a high risk of metal splashing.
5. The filler wire must be placed in front of the burner, at an angle to the mating surfaces, and to prevent transverse vibrations.
6. At the preparation stage, it is necessary to degrease the surfaces to be joined and clean them from oxides and contaminants.