Among all the manual welding methods that exist today, welding in an argon environment, or TIG, is considered the most versatile. Inert gas welding achieves a high quality weld by completely isolating the weld pool from atmospheric oxygen, making it possible to weld metals such as magnesium and titanium alloys and aluminum, although they are considered highly active.
The principle of operation of argon welding
The principle of TIG welding is to heat the welding spot with an electric arc created by a refractory tungsten electrode.
Due to the strong heating of argon burners during operation, they use a water cooling system. The electric arc melts not only the joints of the parts to be welded, but also the filler wire fed into the welding zone. Wire feeding can be carried out both mechanically and manually. The place of welding is protected from atmospheric oxygen with inert gases, and in most cases argon is used, in connection with which this type of welding is called argon-arc, and the inverters used for its implementation are TIG-welding machines.
Features of TIG welding
TIG-welding combines the advantages of other types of welding: the continuity and cleanliness of the seam, characteristic of semi-automatic welding, the ability to work with deep penetration at high currents, for which manual arc welding using piece consumable electrodes is used. Since the arc is formed without the participation of the metal fed into the weld pool, it is much easier to control the quality of the seam: a seam made by a TIG welding machine cannot be confused with any other.
Inert atmosphere welding is performed on any metal, only the filler material and current characteristics differ.
Design of TIG inverters
TIG welding machines for TIG welding consist of a torch and a welding power source.
The ignition of the arc and maintaining it with the specified parameters is provided by the welding current source. A TIG welder can be used to weld a wide variety of materials but requires different adjustments, which is why combined models of semiconductor inverters with combined output are used today:
- TIG DC mode for welding copper alloys and stainless steels;
- TIG AC mode - for welding magnesium and aluminum;
- Pulse mode with intermittent current is used for welding thin parts.
The design of such devices is very close to devices for manual arc welding, which leads to the appearance of combined weldingMIG TIG MMA machines, in which the change of type of welding is carried out after replacing the welding torch with a holder.
Types of welding
In industrial and domestic conditions, electric arc welding machines are widely used, which differ in the type of technology used in the work and the type of welding.
MMA welding
The simplest and most common method of welding cast iron, stainless steel and plain steel parts is manual arc welding using coated electrodes. The principle of operation of such welding is to ignite an electric arc between the edges of the parts and the electrode, which melts the metal being welded. In this case, the electrode material is used as an additive, which makes it possible to form a seam. Its coating guarantees stable arc burning and forms a protective slag coating, which is easily removed after the surfaces have cooled.
TIG welding
Argon-arc welding used when working with steel and non-ferrous metals - nickel alloys, aluminum and copper. The advantage of this type of welding is the absence of slag and a high-quality seam, the disadvantage is the slow speed of work. When working with aluminum and its alloys, there are no alternative welding methods. TIG welders use tungsten non-consumable electrodes with automatic or manual wire feed.
MIG welding
The wire is used as an additive and an electrode at the same time and atsemi-automatic MIG welding. With this type of welding, various parameters can be adjusted in a wide range: wire feed speed, type of gas mixture, operating current, and others. MIG welding is mainly used in body work, forming perfect seams.
SAW welding
Compared to open arc machines, SAW welding, or submerged arc welding, is more productive. The process is fully automated, forms a high-quality seam and economically consumes filler wire. The arc burns under a thick layer of powder - flux - so that the welder can work without special protection
CUT CUT
Air-flame cutting is one of the types of welding used when working with products of small thickness. Inverters for such cutting are compact in size, due to which this method is considered one of the most common in industry and everyday life.
Types of welding inverters
The availability of TIG welding machines is due to the dumping of Chinese manufacturers and the reduction in the cost of power electronics, due to which a wide range of inverters is presented in welding equipment stores.
Aurora PRO INTER
MMA+TIG welding machine manufactured by Russian-Chinese company "Aurora". It can use both piece electrodes with protective coating and non-consumable electrodes. Welding light alloys requires the use of an external oscillator because the inverter only has DC running. The welding machine can work in rooms with poor electrical wiring due to its low power of 4.5 kW. At the same time, the current adjustment range is from 10 to 200 A, which allows you to work with thin-walled and massive parts. The open circuit voltage is quite high - 60V. The high-frequency ignition circuit of the device makes it easier to work with it, since the sticking of the electrode is almost completely absent. Due to its low price and good performance, the TIG 200 welding machine is an excellent option for learning argon welding.
"Svarog" TIG 160
The Svarog TIG AC/DC welding machine is small in size and has a relatively low maximum current of 160 A, but at the same time it has the possibility of a long load (according to the attached passport - PV 60%) and multifunctionality. The efficiency of the output stage of the inverter power converter is 85%, which reduces the power consumption to 2.7 kW. AC and DC welding modes can be easily switched, in TIG AC mode, polarity balance adjustment is available, and the time of final and preliminary gas supply is adjusted. For convenience of a welding post it is possible to connect a foot pedal. For such functions and characteristics, its cost of 44,500 rubles is very acceptable.
PV - the maximum time of burning an electric arc in comparison with the total time of the inverter. In the case of this machine, a 60% duty cycle means that for every six minutes of continuous operation,take a break of 4 minutes minimum.
"Svarog" TECH TIG
Widely functional TIG 200 AC/DC welding machine with three modes of operation (AC, DC and Pulse), maximum current of 200A and a large number of settings. The settings of the device are regulated by 9 knobs, which will be appreciated by professional welders. This inverter is very popular in repair shops and auto repair shops.
Argon welding at home
When preparing a workplace for argon welding, several rules must be considered:
- Despite the fact that the harmfulness of argon welding is several times less than manual arc welding, it is necessary to use protection: you will need a welding mask, leggings, a robe. Modern protective masks "Chameleon" are very convenient to use, but at the same time they have their minus - a smaller viewing angle due to the located photocell. The room should be well ventilated, ideally a forced draft.
- Flammable substances and materials should not be located in the immediate vicinity of the workplace. A carbon dioxide fire extinguisher must be available. Powder analogues are best not to use. Despite their effectiveness, the powder formed during their use is very difficult to remove, and therefore the welding machine can be damaged.
- The ventilation openings of the inverter must not be obstructed.
Depending on the material and thickness of the parts, the welding current and the thickness of the usedelectrodes. In the case of aluminum alloys, for example, the welding current should be 180-250 A with an electrode diameter of 4-5 mm. This mode will allow you to work with parts with a thickness of 3 mm. Thinner elements are welded in Pulse mode. Compared to operation with argon-helium mixture, the current is set 10-20% higher when operating in pure argon.
For easier control of the welding process, the electrode is held at a small angle to the direction of movement, while the additive is fed strictly perpendicular to the electrode. You can get a strong and beautiful seam if the bar is fed in a fixed position.
Gas pre-flow time is one of the important settings for the TIG inverter. The maximum time - up to 2 seconds - is set when working with aluminum, titanium and magnesium alloys. This is done so that the inert gas completely covers the place of ignition, otherwise the metal, upon contact with oxygen, may flare up with the formation of a cavity. The chemical activity of the metal to be welded also affects the gas cut-off delay: after the arc is turned off, the torch is held over the weld for a set time to protect the created seam.
Argon welding is one of the most demanded welding processes. Affordable prices for TIG MIG welding machines allow you to purchase such devices for personal use. The high demand for argon welding, the performance and efficiency of inverters will quickly pay back all the expenses for the purchase of suchmachine.
