What is tig welding, what electrodes are it used for?
There are several modes of conducting the welding process. They differ from each other in the conditions for forming a weld in metals, their applicability, and the equipment used. Among these modes, tig welding (Tungsten Inert Gas) occupies an important place, the name of which indicates that it is carried out in an inert gas environment.
This method of joining metals is used in production and in car services. As a result of the work performed, it is possible to obtain a seam of excellent quality and aesthetics, effective penetration of the edges of workpieces, as well as high-quality connection of parts with a large cross-sectional area.
- Peculiarities
- Equipment
- Consumables
- Modes
- Flaws
Peculiarities
If you translate the name of the mode into Russian, which gives the abbreviation TIG, you get “tungsten with inert gas.” Let us examine in more detail the purpose of each element in the welding process. Metal penetration is carried out under the influence of an electric arc, which is created between two electrodes under high voltage. The role of one electrode is played by the part being welded, and the other is played by a special tungsten rod, which is controlled by the welder.
The tungsten electrode melts at a temperature of 4000°C degrees. This indicator is significantly higher than that of other metals and alloys, so this electrode can be used to weld almost any type of steel. To obtain an accurate and neat seam, the electrode should be periodically sharpened. The tungsten rod is fixed in the torch collet, and the unused part is placed in a special cap that prevents short-circuiting.
The welding machine torch is designed in such a way that an electrode is placed in the middle of the nozzle, and gas is supplied in a circle. Since argon acts as a shielding gas, this welding method is called argon arc welding. The idea of inert gas protection is to displace oxygen.
If it penetrates into the weld pool, hydrogen will begin to be released as a result of chemical reactions, which will lead to the appearance of many cracks during metal crystallization.
For each alloy, its own welding mode is determined, characterized by a certain amount of gas and voltage value on the electrodes.
With sufficiently precise processing of the edges of the parts being welded, their penetration and subsequent crystallization occur. If there is a gap between the surfaces that cannot be eliminated, then a special filler substance is used, which is fed into the welding zone in the form of a wire.
The TIG welding type has become widespread. Due to the fact that the arc temperature is quite high, it is possible to work with carbon steel, as well as non-ferrous metals and their alloys.
TIG welding is used when processing cast iron, copper and aluminum products, but it shows its main advantage when welding stainless steel.
Stainless steel can also be welded using MMA inverters, however, argon arc welding produces a neat and precise seam, which should not be subsequently cleaned of slag.
The wire for the additive must be made of the same material as the elements being welded. TIG welding allows you to weld aluminum. If there is no protective gas, the molten aluminum quickly oxidizes. In an argon environment, the characteristic oxide film does not form, and the edges melt evenly.
TIG welding is most often used in the following jobs and industries:
- mechanical engineering;
- work with food steel, production of tableware;
- production of containers for storing chemically aggressive substances;
- car repair.
Like any other type of welding, argon arc welding has a number of requirements and has certain features. Every welder should know about them, since otherwise it will be impossible to guarantee a high-quality result.
- The parts to be welded, in particular the edge surfaces, must be cleaned of foreign elements and degreased.
- The tungsten electrode is connected to the negative terminal of the inverter.
- Welding aluminum requires equipment that operates in AC mode (alternating current).
- It is necessary to correctly calculate the welding current based on the operating conditions. In particular, the choice of its value is influenced by the diameter of the electrode. Excessively high current will cause the electrode to melt, which is undesirable.
- In the absence of proper experience, it is recommended to form a small arc.
- Before welding, it is necessary to prepare the torch. The tungsten electrode should protrude 3-5 mm from the collet.
- It is necessary to pay attention to the uniform distribution of gas across the cross-section of the burner nozzle.
Equipment
The production of inverter welding machines has revolutionized the welding equipment market.
It is traditionally believed that in order to work in the TIG mode it is necessary to have a rectifier on hand, however, remembering that the welding parameters must be adjusted based on the initial conditions, it is necessary to understand that the mere presence of a rectifier will not allow the TIG welding process to be carried out. Modern TIG inverters convert electric current in a special way, which allows significant benefits in the cost of the device, its dimensions and functionality.
The kit includes a ground power cable and a burner. A cylinder with a reducer is also required. More powerful heaters, designed to work with metals whose thickness exceeds 3 mm, are equipped with a water cooling system. Alcohol and distilled water are used as a carrier. The standard functions of the TIG inverter include the ability to adjust the current, polarity, and gas flow rate.
Any inverter has a certain limitation on the duration of continuous welding; it is caused by overheating of the power plant when operating at high powers. The duration of continuous welding is one of the parameters that you should pay attention to when choosing a device. There are a number of other nuances that should be kept in mind.
- Adaptability of the inverter to changes in the parameters of the supply network. Power surges often occur, this is especially evident in rural areas. A functional inverter is not only capable of maintaining a stable arc at low voltage, but also adjusting other parameters, stabilizing the welding process. Typically, such capabilities are available in welding machines with synergic control.
- A functional inverter must have an AC/DC switching mode, that is, work with direct and alternating voltage. This significantly expands the scope of applicability of this device.
- The design of the heating pad can allow for vertical, horizontal or ceiling work.
- The protection system allows you to automatically turn off when the temperature exceeds a critical value. To resume operation, the inverter must cool down.
Consumables
Welding with a non-consumable electrode does not imply that it is not consumed in the process. Let's say more, a tungsten electrode is considered one of the types of consumables, the condition of which must be constantly monitored.
It is indeed 99 percent tungsten. This material was not chosen by chance, since tungsten has a high melting point. Components such as tantalum, yttrium, thorium, and lanthanum are used as impurities.
The concentration of the additive is indicated by conventional colors: white, green, blue.
The setup procedure includes work on sharpening the electrode. The shape of the end of the rod affects the shape of the arc; it should be different under different conditions. When welding with direct current, it is necessary that the arc resembles a cone. If the current is alternating, then a rounding at the point of contact is characteristic. The surface of the rod is additionally polished.
Another consumable is gas. In TIG welding, its role is played by argon. Argon is heavier than air, so it displaces oxygen from the torch. In some cases, it is necessary to protect the combustion zone from hydrogen. Here it is more advisable to use helium (the lightest gas, with the exception of hydrogen).
Helium welding increases arc power and, as a result, productivity. After weighing all factors, including the cost of the process, helium is used only when working with refractory metals. If it is necessary to carry out complex work, a mixture consisting of argon and helium is used. The share of argon is 40%. Argon provides stable welding parameters, and helium allows metal to be penetrated to a great depth.
Modes
TIG welding can be carried out with either direct or alternating current. This is why it is recommended to purchase AC/DC inverters for greater functionality. According to statistics, most often it is necessary to use a unipolar mode (direct current), which is suitable for welding many metals and alloys. But to work with aluminum, titanium and some refractory materials, you have to switch the inverter to AC (alternating current) mode.
Differences in welding methods can appear even at the arc formation stage. The first method is implemented by passing a needle along the surface of the metal. In this case, it is necessary to accurately set the value of the welding current. If the current is too high, through penetration of the workpiece may occur. Low current causes the electrode to stick.
Ignition of the arc by point contact is carried out on most welding machines in the mid-price segment. This is an additional function, which consists of supplying an additional pulse current exactly at the moment when the electrode touches the metal surface.
The simplest and most effective method of ignition is considered non-contact. Not all inverters are equipped with this function. Those welding machines that allow you to form an arc when the electrode is brought to a certain distance are quite expensive.
Regardless of the selected welding mode, it must be remembered that in order to ensure an even and aesthetic seam, as well as stable penetration of metal at the edges, it is necessary to maintain a gap of 3 mm between the needle and the surface. As this gap increases, the arc will remain stable, but the area of the weld pool will increase and the depth of metal penetration will decrease. When welding thick workpieces, the edges of the joints are cut at an angle of 45° degrees.
When welding with direct current, the power cables are connected so that the positive terminal is connected to the workpiece, and the negative terminal is supplied to the electrode.
With this connection method, you can achieve optimal welding speed, and the tungsten rod will be consumed to a lesser extent. In addition, a deep bath is obtained, which ensures high-quality metal penetration.
DC TIG welding is used when working with alloy and high-alloy steels, as well as with various types of stainless steel.
Alternating current implies a change in the polarity of the electrodes. With direct polarity, a weld pool is formed. Changing the polarity entails cleaning the metal surface and destroying the protective film. During the welding process, the master has the ability to balance the time of forward and reverse polarity.
Flaws
Despite the fact that argon arc welding is considered universal, it has some disadvantages. First of all, it should be understood that shielding gas is only effective in calm weather or when working in enclosed spaces. It is often necessary to install barrier shields or increase the argon consumption.
The next drawback that many welders highlight is the need for high-quality surface preparation. Indeed, if MMA welding can be carried out due to contamination or rust, then the metal should be cleaned and degreased before TIG welding. The design features of the burner do not allow work to be carried out in hard-to-reach places. In such cases, you have to sacrifice the electrode, because replacing the cap with a smaller one requires cutting the tungsten rod.
Source: https://svarkoy.ru/teoriya/tig-svarka.html
Mma and tig welding what is it
To date, dozens of welding methods have been developed. The most common types are mig, mag, tig, and mma welding. All of them belong to the thermal class according to the method of obtaining energy for the welding process.
The thermal energy released during the formation of an electric arc allows you to weld any metals. The main heat is generated in the arc itself due to the fact that its resistance is greater than the resistance of the electrode and the part being welded, so melting occurs near the arc. This, in turn, leads to the formation of a weld pool, which, when cooled, provides a permanent connection.
Application of inert gases
MIG welding is the international designation for the welding process of metals in an inert gas environment. Argon, helium or mixtures thereof are used as inert gases.
Gas is supplied from cylinders through high-pressure hoses to the burner. It displaces atmospheric air around the electric arc, thereby eliminating the harmful effects of oxygen on the welding joint.
The seam is of high quality and dense, without pores. The disadvantage of MIG welding is the high cost of inert gas. Argon costs 45 times, and helium 156 times more expensive than carbon dioxide.
MAG welding is the international designation for the welding process in an active gas environment. The most widely used active gases are carbon dioxide and nitrogen. Their function is the same as that of inert gases - protection from atmospheric oxygen.
Carbon dioxide in the welding area decomposes into oxygen and carbon monoxide, which leads to harmful effects such as weld porosity. To avoid this, it is necessary to use electrodes or filler wire containing manganese and silicon .
They bind the released oxygen and deoxidize the welding medium. Gases are stored in high-pressure cylinders; reduction reducers are used for use. When using carbon dioxide, it is recommended to turn the cylinder over and release water vapor, only then start MAG welding.
With tungsten electrode
TIG welding is the international designation for the welding process of metals in an inert gas environment using a tungsten non-consumable electrode.
In Russia and the CIS, TIG welding is called argon arc welding due to the inert gas used. Thanks to the constant length of the electrode, the welding process is greatly simplified; the absence of other impurities allows us to obtain seams of the highest quality.
Pulsed TIG welding is a variation of conventional TIG, but uses pulsed current instead of direct current. In some MAG TIG welding machines, this mode is present along with the main one.
It is useful when working with thin sheets, it does not overheat them, and there is no warping during welding. Typically, several modes are set at a frequency of 1 Hz, 10 Hz, 500 Hz. The result is a beautiful scaly seam.
MMA welding is the international designation for manual electric arc welding. It is produced by electrodes coated with a special protective coating. The MMA welding process occurs due to the formation of an arc between the electrode and the part being welded.
The electrode, melting, enters the weld pool, which was formed due to the melting of the edges of the workpieces. The coating also melts and forms a protective layer on the surface of the bath, after cooling it turns into slag. Easily removed with a hammer.
Semi-automatic welding
The choice of equipment for a welder is huge. The MIG MAG welding machine is very popular. It is used in almost all auto repair shops due to the high quality weld it produces.
Most welding machines now use inverters. The frequency of the welding current in them is practically independent of changes in the mains voltage. At the same time, they have compact dimensions and weight, which allows them to be mobile.
Since the power source for most types of electric arc welding has the same parameters, manufacturers began to create universal models capable of operating in different modes and different types of torches. Semi-automatic MIG MAG and TIG welding has especially developed.
Welding wire
Semi-automatic MIG MAG TIG welding involves the use of welding wire, which is threaded into the machine. The quality of the seam also depends on its characteristics. In some cases, you can even do without shielding gas when using cored wire.
There are four types of additives: aluminum, steel, copper and powder. The last two are the most popular. Their use guarantees no splashes and high productivity.
In addition to cored wire, filler wire must be used in a protective gas atmosphere. When purchasing, be sure to check compatibility with the materials and tips being welded.
Universal semi-automatic
A striking example of universalization is a semi-automatic welding machine of the Triton MIG MT 250 brand. This semi-automatic machine belongs to professional equipment and is a small-sized inverter on wheels that produces 250 A in peak mode.
It provides high-quality welding in MIG, MAG, TIG DC, MMA modes and can weld with Spot Stitch technology. For this purpose, the delivery package of the welding machine includes torches for three types of welding.
In peak mode, the on-time is 60%, at currents up to 200 A - 100%. For easy and reliable initiation of the electric arc, the Arc Force and Lift TIG function is provided.
To supply filler wire, a 4-roller drive is used; it is possible to use a 300 mm reel.
Source: https://master-kleit.ru/origami/mma-i-tig-svarka-chto-jeto-takoe/
What is tig and mma welding
To date, dozens of welding methods have been developed. The most common types are mig, mag, tig, and mma welding. All of them belong to the thermal class according to the method of obtaining energy for the welding process.
The thermal energy released during the formation of an electric arc allows you to weld any metals. The main heat is generated in the arc itself due to the fact that its resistance is greater than the resistance of the electrode and the part being welded, so melting occurs near the arc.
This, in turn, leads to the formation of a weld pool, which, when cooled, provides a permanent connection.
TIG welding
It is difficult to imagine aviation, space, mechanical engineering and construction without welding work; welding is also in demand in everyday life.
A wide variety of methods for joining metals and their alloys are widely used today, and a special place here is occupied by the inexpensive but effective TIG welding method. We will review the working methods, technologies and metals that are welded using this method.
Special attention should be paid to equipment, equipment and consumables, as well as the principles of operation in a protective inert gas environment.
Advantages and disadvantages of argon arc welding
One of the metal welding methods is MMA, in which the work is carried out with consumable coated electrodes, alternating or direct (AC/DC) output current. In addition, semi-automatic MIG/MAG welding in shielding or active gas 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 with an infusible tungsten electrode in a protective gas environment that prevents oxidation in the open air.
A welding inverter equipped with a Euro connector is used as a source of AC/DC current, through which gas and output current are supplied to the torch, as well as control signals.
Unlike the MIG method, which uses a moving wire as the electrode, TIG welding uses a refractory tungsten electrode with a high melting point. Gas is supplied through the burner with a grid, and then voltage is supplied with a delay of 1 second.
This is done so that welding begins in a shielding gas environment, which is supplied under pressure and, being heavier than air, prevents the oxidation of the workpieces.
A better understanding of what TIG welding is can be achieved by assessing the advantages and disadvantages of this method of joining metals, especially in comparison with MMA and MIG methods. The advantages of argon arc welding include the following parameters:
- the ability to work with both thin-walled parts and workpieces of considerable thickness;
- operation in AC/DC modes;
- wide ranges of adjustment of welding current parameters;
- the use of non-flammable gases, which increases work safety;
- reusable refractory electrodes;
- reliable, collet clamp of the torch for replaceable electrodes of various thicknesses;
- the presence of an oscillator for improved arc ignition;
- ability to work with direct and reverse polarity.
This method also has certain disadvantages 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 in enclosed spaces to avoid excessive gas consumption;
- low mobility;
- manual feeding of welding wire.
Equipment composition and scope of TIG welding
Each type of welding has its own purpose, advantages and disadvantages, as well as a set of necessary equipment and consumables for high-quality work with the best result. The list of TIG welding equipment includes the following components:
- MMA+TIG inverter with an adapter for a gas mixture and a Euro connector, with adjustable output parameters, with AC input power 220/380 V and a current from 10 A to 180 A;
- eurohose used to supply inert gas, control signals and welding current;
- gas supply hoses from cylinders;
- cylinders equipped with reducers and pressure gauges;
- torch with control button and collet clamp for tungsten electrode;
- welding or filler wire, similar in composition to the working material;
- inert gas or its mixture with CO2 to create a protective environment in the weld pool;
- refractory tungsten electrodes.
Tig welding is used in industry, construction and domestic needs. The great capabilities 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 fused with direct and alternating pulsed current:
- structural and carbon steels;
- various aluminum alloys;
- stainless steel, including for sanitary, hygienic and food needs;
- titanium alloys;
- copper, brass and bronze, as well as their combinations;
- galvanized metal and nickel-plated surfaces.
To ensure good welding quality, you need to monitor the cleanliness of the tungsten electrode and sharpen it regularly, since the thickness and cleanliness of the TIG weld largely depends on it.
Operating modes and TIG welding technology
Metals and alloys, depending on their physical and chemical properties, are welded in different modes of operation of the current source. The reason for this is the refractoriness of the oxide film or the thickness of the workpieces. Using a variety of welding modes, the required penetration depth 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 different current-voltage characteristics for a gentle effect on parts;
- a method of non-contact high-voltage arc ignition 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 the destruction of the refractory oxide film on the surface of the workpiece.
In addition, appropriate welding rods are used, which are fed into the melting zone manually in translational movements.
Other types of metals are welded using direct current of straight polarity with filler wire and selection of current strength.
Work using alternating current is called pulsed welding, since the metal is heated at peak values of high-frequency oscillations.
With basic current readings, the heating of the workpieces is reduced, which prevents overheating of the (especially thin-walled) metal.
The refractory electrode must be held at an angle close to 90°, but tilted towards the direction of the welding process without transverse movements, and the rod must be fed with light translational vibrations into the weld pool.
By supplying a high-voltage low-current voltage to the workpiece, the oscillator allows ignition of the arc in a non-contact manner, which prevents contamination of the working surface of the electrode. As for inert argon, it is produced in the highest and first stages of purification and is often used in a mixture with helium. This combination allows you to achieve the best results, but sometimes argon is used in a mixture with carbon dioxide to save money.
Conclusion
We tried to talk in as much detail 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 once you master it, you will get a universal way to connect a wide variety of parts and the ability to repair metal products of different thicknesses.
Source: https://electrod.biz/vidy/svarka-metodom-tig.html
MIG/MAG and MMA and TIG: what is it and explanation, how to choose a universal machine for welding technology
Few readers understand the meaning of the abbreviations mig mag mma used in welding, but a professional welder understands the difference between these methods. Manufacturers of welding equipment and related materials strictly adhere to these designations, so we will talk in detail about each.
Types of welding
With the help of mig mag and mma welding, metal structures and individual parts are firmly connected by melting the edges and forming a single whole. As a result of welding, a strong seam is formed, which has high strength, even under oscillatory loads. You will learn what TIG and MMA are, as well as the decoding of the abbreviations MIG and MAG, in the following sections.
Manual welding option
MMA welding, what is it, the abbreviation literally translates as manual arc welding , which uses an electrode coated or coated with flux. A transformer or inverter is used as a current source. When melted, the rod coating becomes liquid and protects the molten metal from oxidation by air.
After the welding process is completed, the slag covers the seam joint with a durable layer, which is removed by the welder to visually check the quality of the joint. Similar welding is performed when connecting direct or alternating current, with the first option using direct and reverse polarity. MMA is the most common welding in any production.
MIG/MAG
What is MIG welding - a semi-automatic process of joining metals by feeding filler wire, and protection is performed by inert gas . The difference in the abbreviations MIG/MAG is due to the spelling in English or German. The performer guides the torch along the junction of the structure or workpieces, and the thin wire, melting, forms a seam of ideal width.
MIG welding is a process based on the use of an inert gas, which is heavier than air and envelops the weld pool, preventing oxidation of the molten metal. MAG - uses aggressive gases, which include oxygen molecules; welding of metals occurs by combining the created and natural environment.
Advantages of the method
The main advantages of these progressive methods of joining metals:
- The prostate of welding technology, accessible to novice welders.
- High quality seam connection and similar productivity, since there is no time spent changing electrodes.
- Welding is performed in all spatial positions, with low heat input, which is suitable for joining thin sheet metal.
- There is no need to carry out subsequent processing of the seam.
- Long seams are performed without stopping and re-activating the arc, which greatly simplifies the entire process.
It is because of these advantages that MIG/MAG is used in automatic automobile assembly lines where robots are used for welding work.
Rectifier or inverter?
Experienced welders choose an inverter for everyday work , because additional modes and built-in functions simplify the technology, this is especially true when connecting parts and structures made of aluminum, stainless steel and complex refractory alloys. The weight of the device and the ability to connect to any electrical network also matter.
The transformer is characterized by exceptional operational reliability and low cost, but consumes much more electricity . Its mass is significant, so it is not very mobile, and it is used for the simplest types of welding.
TIG
The exact decoding of the abbreviation means tungsten in an inert gas ; a thin rod of a similar metal is used as an electrode, which is sharpened in a certain way. When welding, filler wire is used, which, when melted, fills the recess between the workpieces.
Of particular importance is the design of the burner, where a non-consumable electrode is located in the center, and a protective gas consisting of pure argon or its mixtures is supplied around it. This technique requires thorough preparation of the performer and high-quality equipment; heating here is minimal, so overheating of the metal does not occur.
Used for alloying aluminum and thin stainless steel sheets.
Equipment
You already know what MMA TIG MIG is, now let’s talk about the types of machines for each type of welding work.
With inert gas
The gas is in cylinders with specific markings; a reducer is installed on top that regulates the amount of gas supplied. The MIG method uses inert gases , which are much more expensive than active analogues, for example, the price of carbon dioxide is 45 times less than argon, and compared to helium, the cost is reduced by another 3.5 times.
When welding MAG, carbon dioxide or nitrogen is used as protection, but to avoid a negative impact on the result, wire with the addition of manganese or silicon is used, since they do not allow the molten metal to oxidize.
With non-melting rod
In the CIS countries, the TIG method is argon arc welding, named after the gas used for protection; a non-consumable electrode simplifies the entire process, and the absence of foreign inclusions allows you to obtain a high-quality seam.
The pulsed version of the welding process is similar in its properties to TIG, only a non-constant current is used, this mode is found in MAG/TIG units. It is used for joining thin sheets, because...
there is no overheating or warping of the surface, and the seam joint has the appearance of scales.
The MMA welding process was described in detail earlier, recall that it is characterized by the formation of an arc between a consumable electrode and the workpiece.
After hardening, the seam is covered with scale from the frozen slag, which is easily removed by tapping the surface with a hammer.
Semi-automatic
Almost all service stations have a MIG/MAG welding machine installed, because its use produces a high-quality seam that does not require additional processing. Inverters are used because they are connected to a regular electrical network, have small dimensions and weight, and are also mobile.
Source: https://greendom74.ru/svarka/kak-rasshifrovyivaetsya-tig-mig-mag-i-mma-svarki
Tig welding type – What is MMA, TIG, MIG/MAG
It is sometimes difficult for a non-specialist to understand the terms and definitions used in welding. The complexity is additionally caused by the fact that there are no strictly regulated and classified methods and techniques. However, manufacturers of welding equipment and materials adhere to generally accepted English abbreviations, which will be discussed in this article.
MMA (rds)
MMA (Manual Metal Arc) - manual arc welding with piece (coated) electrodes using an inverter or transformer. The technical literature of Soviet times used the designation RDS.
The welding process occurs due to the melting of a metal rod - an electrode, coated with a special coating, which have their own classification. Its main purpose is to protect the weld pool from air, preventing oxidation of the metal.
The molten rod forms a weld and the used coating remains as slag.
Covered electrode welding
RDS is possible on both direct and alternating current. With direct current, there are two options for connecting the ground clamp and the electrode holder, so there is welding with direct and reverse polarity. Alternating current does not have this feature - how to connect the electrode in this case does not matter. The given reliability rating of welding inverters will help you choose a machine that will last for many years.
Since the MMA method is the most popular due to its simplicity and relatively inexpensive equipment used, you should definitely familiarize yourself with the question of how to learn how to weld with electric welding yourself.
TIG(WIG) or RADS
TIG (Tungsten Inert Gas) – technology of arc welding in an inert gas environment with a non-consumable electrode. Tungsten is a very refractory metal with a melting point of about 3500 C, so it is the basis for the production of this kind of electrodes. Sometimes you can find other variations of this method:
- WIG (Wolfram Inert Gas) – the name is derived from the German spelling;
- GTA (Gas Tungsten Arc) – this abbreviation omits the chemical reaction of the shielding gas.
The choice of materials is carried out according to the color marking of tungsten electrodes, indicating the types of metals being welded, as well as welding modes.
Because the electrode is non-consumable, the argon welding process occurs according to a different scenario:
- an electric arc is excited between the end of the electrode and the metal being welded;
- the welding seam is filled by supplying a special filler material - a rod - into the welding zone;
- the weld pool is protected by a gas cloud.
TIG welding process
Protective inert gas, i.e. a gas whose molecules do not chemically interact with the base and filler materials during the welding process; in this case, argon is used. That is why the name “manual argon-arc welding” or RADS was assigned to it.
It is worth noting that this name is not entirely correct, because Other gases, such as nitrogen, helium, and gas mixtures, can be used as a shielding gas.
Argon can be used when welding consumable electrodes - the MIG method, which will be discussed below.
In the technical characteristics of welding equipment, in addition to the TIG designation, it is always supplemented by a mention of the type of welding current DC (Direct Current) - direct current or AC / DC (Alternating Current / Direct Current) - alternating / direct current. In this case it is very important. For example, welding aluminum with argon is carried out using alternating current.
MIG/MAG
MIG/MAG (Metal Inert/Active Gas) is a method of arc welding in a protective atmosphere of inert/active gas using a consumable electrode in the form of steel or other wire, depending on the type of metal being joined.
Schematic representation of the mig/mag method
MIG or MAG welding usually means semi-automatic welding. The main objective of this method was the idea of creating an “endless electrode”, thereby achieving significant welding productivity. Indeed, with the RDS method, you often have to change the electrode as it is used up, which in some cases is extremely inconvenient. As with TIG welding, shielding gases are used here.
The inert agent is usually argon and its mixtures, which is suitable, for example, for semi-automatic welding of aluminum and its alloys. The active gas, i.e., interacting with the metal being welded in the process, is usually carbon dioxide (carbon dioxide). You may hear from a welder the phrase “semi-automatic welding in a carbon dioxide environment,” meaning the MAG method.
This method is the most common due to its increased productivity compared to MMA, and gives a better result in the quality of the weld. The rating of household semi-automatic machines based on reviews of experienced welders will help you decide on the choice of a welding machine.
We hope that this article will help you understand the classification of basic welding methods, and will also be useful when choosing equipment and materials with English abbreviations.
Source: https://pkfst.ru/raznoe/tip-svarki-tig-chto-takoe-mma-tig-mig-mag.html
Description of TIG welding technology
Many different methods of joining metal parts by fusion with electric current are known and widely used, but TIG welding rightfully occupies a special place. This is an inexpensive method of reliably joining various metals using a non-consumable electrode. It can be used to weld aluminum, cast iron, copper, bronze, stainless steel, titanium and other materials that cannot be processed with other types.
TIG welding is primarily argon arc welding, so you will have to buy a special inert gas for it. Argon is heavier than air, so it is used to displace it from the welding area to prevent oxidation of parts at the welding site. It is this factor that is sometimes key when performing similar work by another type.
Unlike MMA arc welding or semi-automatic with MIG / MAG wire, TIG technology is performed with a special tungsten electrode. This material is ideal for working with all types of metals, since their connection occurs in an airless environment. Welding in this mode is carried out from an AC/DC inverter machine. Only it must have a special Euro connector. A burner with a hose will be connected through it.
Application area of TIG welding
TIG welding is a universal method in its properties, because it can be used to reliably join different types of metals. In some cases, it is even possible to weld dissimilar alloys together. Its scope of application is limited only by the fact that you will have to constantly carry a heavy gas cylinder with you.
Therefore, such welding is more stationary than mobile, but in some cases it is still popular with on-site work.
It is mainly used for welding non-ferrous metals, because it allows you to work in an environment with an inert gas without access to oxygen, which is a powerful oxidizing agent.
When argon enters the melting area, the air is squeezed out by it, which creates optimal conditions for melting without scale. It also perfectly welds various metal parts from other types of alloys, creating bimetallic joints, so it is universal and can be used to work in any situation.
It is especially worth mentioning the possibility of welding thin-walled parts, pipes, thin profiles, which cannot be said about the electric arc welding mode. By fusing metal over the parts, a thick seam is formed due to the deep penetration of the melt between the parts.
Pros and cons of TIG welding
The TIG welding mode has many features because it is a slightly different working method. Therefore, it is necessary to work with it in a certain way. First, it’s worth talking about the advantages:
- Welding can be done with any type of current, AC or DC.
- Weld seams are more even and smooth.
- This type of welding allows you to work with thin-walled workpieces without melting them, since the additive is supplied manually.
- During operation, non-flammable gas is used, which contributes to compliance with safety regulations.
- This type of welding is good for beginners, and a regular inverter can be used for the job.
- Since the electrodes do not melt, one rod can be enough for a long time.
- The design provides a convenient collet clamp for electrodes of various diameters on the valve burner.
- Typically, professional welding machines are equipped with an oscillator, which ensures stable ignition of the arc.
In addition to the positive aspects, TIG welding also has a number of negative features. Considering that welding is performed in a heavy gas environment, the work must be performed indoors with a minimum amount of air flow.
There is also uneven thickness of the weld due to the fact that the welding rod is fed manually. In addition, such welding is very limited, because you can only work near an argon cylinder, which is very difficult to transport due to its heavy weight. If welding using this technology is carried out automatically, the seam will be perfect.
Description of TIG welding technology
To get a high-quality seam with your own hands when using TIG welding, you need to properly prepare. That is, depending on the thickness of the parts being welded, it is necessary to correctly select the electrode diameter, current strength and filler rod. If any of the above are chosen incorrectly, the welded joint will be poor.
As for the method of igniting the arc, there are also several of them. Each of them has its own characteristics, which indicates the level of the welding machine that is used for work. Let's consider three main ones:
- Strike or contact. This is exactly what inexperienced craftsmen do. After this, the tip of the electrode is deformed and a characteristic mark remains on the workpieces. You have to spend a lot of time to remove traces.
- Ignition by point touch or TIG LIFT. The most rational method, used in most devices. The arc is ignited at a short distance from the part or at the slightest touch, which is ensured by the control circuit of the power modules in the device.
- The third method is non-contact, but it is not implemented in all welding machines.
When welding parts, keep the electrode at a distance of 3 mm from the workpieces. If it is larger, then there is a high probability of sagging and, as a result, loss of seam strength.
If parts made of thin metal are welded, then cutting them is not necessary, but when working with thick metal, it is necessary to process the edges and take into account the gap so that the molten metal can completely fill it.
To perform high-quality welding of aluminum, cast iron or stainless steel using TIG welding, watch a video about the work process from a master. If you don't undergo some kind of instruction, you can make a lot of mistakes. For example, when using CuSi alloy for welding copper parts.
It is important when working with welding equipment with currents of up to 180, 200 or more Amps to use a welding mask, gloves and a fire-resistant gown. Of course, this method produces much fewer sparks than the arc method. Then you can better concentrate on the work process, and the result will be excellent.
Equipment and materials required to perform TIG welding
You can weld iron using TIG argon arc welding with a conventional inverter. It operates in pulse mode, which promotes normal ignition of the arc and the further fusion process. As for the list of equipment, the following set of devices and accessories will be required for work:
- An inverter device that has a valve to control the gas supply with a 1 second advance.
- A sleeve with a current-carrying wire and a burner in which an integrated electrode holder and a gas outlet are provided.
- An argon cylinder that is connected to the inlet on the device.
- Some models also have a pedal to control the gas supply, but then you need to wait a while before igniting the arc yourself.
- Burner cooling system. It is used in cases where welding is performed on thicker parts at a greater distance to them. The liquid used is distilled water circulating through the handle.
Before you start working with TIG welding, it is recommended to watch videos from professionals. There, the masters describe in detail not only the equipment, but also the process of what is happening, the nuances and features. It is important to note that it is easy to weld with such a machine, but without practice you will not get a high-quality seam the first time.
Source: https://svarkaspec.ru/svarka/vidy-svarki/tig-svarka.html
Metal expansion dowel for aerated concrete
- 1 Which Fasteners to Use for Aerated Concrete: Overview of Types
- 2 How to choose fasteners for aerated concrete, types of fasteners
- 3 Dowel for aerated concrete, dowel for aerated concrete, MUD, crocodile
- 4 Fasteners for aerated blocks, what to choose: dowels, anchors or self-tapping screws
- 5 Dowel for aerated concrete: types, features and installation rules
- 6 Review of dowels for aerated concrete walls
- 6.1 Types and features of fasteners
- 6.2 Installation nuances
Conventional hardware for aerated concrete is not suitable
Having a long list of positive characteristics, aerated concrete is a rather fragile material. This causes problems when attaching structural elements of the building, cladding, electrical and plumbing equipment, and furniture to it. Therefore, special fasteners for aerated concrete were developed, with the help of which these problems are solved simply and effectively.
This article will describe the most common fasteners and how to use them.
Fasteners for cellular concrete
Using ordinary wood screws, only very light objects such as photo frames can be attached to aerated concrete. In all other cases, special fasteners will be required.
Fastening requirements
When choosing which fasteners to use for aerated concrete, you need to consider the following points:
- Density of wall blocks , indicated in product labeling by numbers after the letter D. The higher it is, the fewer pores in the material, and the stronger it is. The load limit when pulling out fasteners depends on this indicator, and the manufacturer’s instructions on the packaging contain this information.
The numbers show how many kilograms are in a cubic meter of material
- Fastener parameters - its length and diameter . The larger they are, the greater the load it can withstand. The load-bearing capacity must also be indicated on the packaging or certificate.
Chemical anchors have the highest load-bearing capacity
- Corrosion resistance . This parameter is especially important when fastening into aerated concrete is carried out from external walls or in unheated rooms. Steel hardware must be coated with a protective layer.
It is important! Even properly selected fasteners for aerated concrete will not work effectively if they are installed incorrectly. It is very important to make holes in the base with a non-impact tool - a brace, a hand drill with a special punch.
Mounting options
Let's take a closer look at which aerated concrete fasteners are used most often.
Let's start with the traditional types:
| Image | Application |
| When a smooth steel nail enters the sleeve, its base opens and enters the material at an angle. Suitable for all types of concrete. | |
| Universal façade dowel | Allows you to attach a profile to aerated concrete to fasten facade panels and hang wall cabinets and shelves. |
| Universal nylon expansion dowel | Used only for small loads: fastening light shelves, curtains, baseboards, switches, cable ducts, etc. |
| Helps to fasten window and door frames and wall cabinets to aerated concrete. | |
| Nylon dowel for aerated concrete | Special development for aerated concrete. It is used with conventional self-tapping screws when installing wooden and metal facade subsystems, windows, doors, suspended ceilings, sanitary equipment, and pipelines. |
| Steel dowel for aerated concrete with zinc coating | Designed for any cellular concrete, the scope is wide. |
| Steel anchor for aerated concrete | Solves the problem of how to attach heavy objects to aerated concrete: water heaters, air conditioners, hanging pipes, heavy wall cabinets, etc. |
All these elements may have other varieties that differ from the images shown in the table. For example, turbo dowels with self-tapping threads are made from nylon.
And made of galvanized steel - four-leaf toothed expansion dowels. Their segments move apart when the screw is screwed in, reliably biting into cellular materials.
Steel expansion dowel
As already mentioned, one or another hardware and fastening method are chosen depending on the expected load.
- If you need to fasten aerated concrete shelves, you need to carefully drill at a right angle, insert a dowel into the hole and screw a screw into it.
Shelves with covered mounting on aerated concrete wall
- And to hang a light picture or install an electrical switch, a simple self-tapping screw screwed at an angle of 45 degrees to the wall is enough.
- If you need to securely fasten heavy equipment or install a metal entrance door, it is best to use chemical anchors.
When installed, they are capsules made of synthetic resins and organic polymers that seal holes in a wall made of aerated concrete, firmly holding a metal rod or threaded rod in it.
The advantages of such fastening include exceptional reliability and durability, the adhesive base is not susceptible to thermal expansion and resistance to aggressive environments.
Note. Marking for such fasteners must be done very accurately and carefully, since it will be impossible to pull it out of the wall. However, this also applies to other hardware for aerated concrete.
No special qualifications are required for fastening with chemical anchors; everything can be done with your own hands.
For this:
- A hole of the required depth is drilled in the wall, its bottom is slightly expanded by oscillating movements of the drill;
- Construction dust is blown out of the hole, and a sleeve is inserted into its neck;
- The cavity is filled with adhesive solution using a mounting gun;
- An anchor rod is immediately installed into it;
- After the solution has hardened, fastening can be done.
The price of such fasteners is higher than that of other types, but the reliability does not raise the slightest doubt.
Fastening building structures to aerated concrete
On such fragile walls it is necessary to fix not only wires and pipes, but also heavy structures: floors, roofing elements, etc. In such cases, fixing self-tapping screws into aerated concrete is not a solution; a serious decision is needed.
As a rule, it is carried out during the process of laying walls, when a monolithic reinforced concrete armored belt is made at the installation level of such structures. During pouring, studs and other embedded parts are installed into it, onto which the fastening is subsequently carried out.
If for some reason you did not make an armored belt, or did not provide mortgages in it, fastening is carried out only with chemical anchors.
Types of welding. mma, mig, tig, mag – Ice advice
It is sometimes difficult for a non-specialist to understand the terms and definitions used in welding. The complexity is additionally caused by the fact that there are no strictly regulated and classified methods and techniques. However, manufacturers of welding equipment and materials adhere to generally accepted English abbreviations, which will be discussed in this article.
MMA (RDS)
MMA (Manual Metal Arc) - manual arc welding with piece (coated) electrodes using an inverter or transformer. The technical literature of Soviet times used the designation RDS.
The welding process occurs due to the melting of a metal rod - an electrode coated with a special coating, which have their own classification. Its main purpose is to protect the weld pool from air, preventing oxidation of the metal.
The molten rod forms a weld and the used coating remains as slag.
Covered electrode welding
RDS is possible on both direct and alternating current.
With direct current, there are two options for connecting the ground clamp and the electrode holder, so there is welding with direct and reverse polarity.
Alternating current does not have this feature - how to connect the electrode in this case does not matter. The given reliability rating of welding inverters will help you choose a machine that will last for many years.
Since the MMA method is the most popular due to its simplicity and relatively inexpensive equipment used, you should definitely familiarize yourself with the question of how to learn how to weld with electric welding yourself.
Welding types: MIG MAG TIG MMA
Welding allows you to obtain permanent connections that are exceptionally strong. This indicator at the seam must be no lower than the base material, which is achieved by strict technology requirements and the addition of alloying substances.
In addition, this process is characterized by connection speed, complexity of the acceptable form, and the ability to control and vary basic parameters. MIG/MAG welding is developing most dynamically in industrial applications, but other types are also being improved.
The choice of a specific approach is determined by a number of parameters:
MMA
mma technology diagram
In our country, the definition of manual arc welding (and the abbreviation RDS) is common. It is cheaper and easier to organize production and less demanding on equipment.
The connection of two elements in MMA occurs using an electrode - a metal rod coated with a coating containing substances that help maintain the arc, protect the welding zone, and form a seam with the desired properties. When voltage is applied, a stable short circuit is formed between the rod and the workpiece, leading to their mutual melting.
The difficulty may come from requiring welder qualifications. To obtain a neat and reliable joint, skill and long experience are required.
In MMA, special attention is paid to the condition of the electrodes, which should not be wet or crumbling. Do not neglect pre-drying and checking.
Flux
Among the types of arc welding, in addition to MIG MMA TIG, it is also worth mentioning that it proceeds under a layer of flux. What flux is has many variations.
All possible materials have in common such qualities as flowability, the ability to influence the formation of a seam at all stages of remelting (including under unfavorable external conditions), and the ability to form a monolithic crust after cooling.
The use of flux shows very good results, but complicates the process itself and implies additional costs. MIG, TIG and MAG are more economical and easier to implement.
Source: https://LEDsovet.ru/tipy-svarki-mma-mig-tig-mag/
What is MMA, TIG, MIG, MAG welding and their technologies
- Explanation of welding abbreviations MMA, TIG, MIG, MAG
What is MMA, TIG, MIG, MAG welding and their technologies
Many novice welders are interested in questions about how the abbreviations for welding types stand - MMA, TIG, MIG, MAG. Of course, it is very difficult for a non-specialist to understand all these concepts. Also, the difficulty lies in the fact that to this day there are no strictly classified and regulated methods and techniques.
However, many manufacturers of welding machines and equipment still adhere to certain abbreviations. In this article from the website about MMA welding mmasvarka.ru we will talk about what MMA, TIG, MAG and MIG welding is.
Explanation of welding abbreviations MMA, TIG, MIG, MAG
MMA is a manual arc welding that is performed exclusively with one electrode. This welding method is the most popular, especially in everyday life. The MMA welding process is based on the melting of metal and an electrode in the form of a rod with a special coating.
The materials used to manufacture electrodes for MMA welding, as well as the composition of the coating, may vary. Thus, manual arc welding can be used to weld different metals, steel, cast iron, etc. Manual arc welding is the simplest process of joining metals, which requires a welding inverter and electrodes of a suitable type.
TIG is an arc welding, which, unlike the previous one, is carried out with a non-consumable electrode in an inert gas environment. For TIG welding, special tungsten electrodes are used, with a very high melting point, over 3000 C.
TIG welding technology
TIG welding technology is carried out as follows:
- An arc is created between the end of the tungsten electrode and the workpiece, as in MMA welding;
- Since a non-consumable electrode is used for welding, the weld pool is filled not with it, but with a special filler material, wire or rod;
- In addition, during the TIG welding process, inert gas is used to protect the weld pool.
Argon is most often used as a shielding gas. This gas does not interact with welding filler materials, but serves only as protection against negative external factors.
MAG and MIG - arc welding in an active and inert gas environment, abbreviations MIG and MAG, respectively. For welding, melting wire is most often used, and these names usually mean semi-automatic welding. The main goal pursued by the creators of semi-automatic welding was to obtain an “endless electrode”, which makes it possible to achieve significant results in work.
Source: https://mmasvarka.ru/chto-takoe-svarka-mma-tig-mig-mag.html
