All features of argon welding: principle and operating technique

Often there is a need to connect parts, for example, made of aluminum, copper, titanium, etc. In such cases, argon arc welding is used, which is a hybrid of electric arc and gas. Before cooking with argon, you need to learn how to maintain the distance between the part and the electrode and how to operate the burner correctly.

Argon welding is very popular.

Definition of argon welding

In this type of welding, an electric arc burns in an environment of inert gas argon, which protects the surfaces being welded from exposure to oxygen.

Sometimes argon is replaced with helium: it has similar properties, but is more expensive, so it is used less often. The principle of operation in helium and argon environments is the same.

Application area

This type of welding is widely used not only in various industries in arc, plasma or laser welding. Home craftsmen actively use it in everyday life to join high-alloy alloys and rare earth metals. Gas welding is quite dangerous, and it is not worth storing such equipment in the garage, but this does not apply to argon, because. it is completely safe and does not explode.

There are steel cylinders with this gas with a capacity of 15 to 40 liters on sale. If you need to cook infrequently, you can purchase a small tank that will last a long time. Since no harmful toxins are released when working with such equipment, it is not dangerous for strangers to be near it.

General principle of technology

Inert gas protects the welding site from the negative effects of oxygen. Due to the potential difference between the electrode and the workpiece, an electric arc appears and a high temperature is created. The edges of the parts begin to melt, resulting in the formation of a weld pool. An additive is constantly supplied to this zone, as well as argon under pressure: it protects the materials being welded from oxidation.

The welding principle is based on joining metal surfaces in a protective gas environment.

To understand how to cook with argon correctly, you need to understand the structure of the main working element of the equipment. This is a burner in which a tungsten non-consumable electrode and a nozzle through which argon is supplied are fixed. When the thickness of the workpieces being joined is small, welding can be performed without the use of filler material.

Connection to the electrical network is carried out in 2 ways:

• straight polarity (minus is applied to the workpiece, and plus is applied to the working rod);
• reverse (here everything is the other way around, but this leads to unstable arc burning and premature wear of tungsten).

Most often they work with direct current, and when welding aluminum and beryllium they use alternating current.

Properties of gas and effect on metal

Due to its physical and chemical characteristics, argon does not enter into chemical compounds with other substances: even at high temperatures it does not interact with oxygen. It can be used when welding various metals and alloys in industrial and domestic conditions. Inert argon almost completely isolates the molten material in the weld pool from oxygen in the air, so the seam does not oxidize .

Basic properties of argon:

• almost 40% heavier than the components that make up the air, so it easily displaces them from the welding area;
• does not take part in the direct welding of metals and does not affect their structure in any way;
• when reverse polarity is used, it acts as an electrically conductive medium.

Features of using the inverter

When performing argon arc welding in industrial and domestic conditions, an inverter is used. This equipment is used to convert alternating current into direct current. Domestic power grids often experience voltage surges, but modern inverters are well adapted to this and provide stable output values.

When performing argon arc welding, inverters are used.

The devices used in this type of welding are distinguished by their low weight and dimensions, high reliability and ease of maintenance. All this allows novice welders to easily master the equipment used and the argon welding process itself.

Inverter welding of stainless steel in an argon environment, compared to other methods of joining such alloys, is simple. Here the welder only needs to move the torch correctly along the seam.

If the edges of the workpieces are tightly connected, then the work can be done without the use of filler wire.

Welding Features

The technology and principle of argon arc welding is a symbiosis that includes elements inherent in electric arc welding and gas welding.

The process combines the use of an electric arc with electric welding, and the presence of gas and a similar operating principle are taken from the gas welding method.

The argon-arc principle of operation is that the arc heats up and gains the ability to melt the edge of stainless steel, pipes, disks and other metal joints - the entire technology of work is based on this.

The presence of argon gas is explained by the very properties of the metal: during the welding process, non-ferrous metal and alloy steel are subjected to oxidation, or to the influence of impurities and oxygen - this affects the quality of the weld, which becomes soft and is not durable.

If we talk about aluminum, it is almost impossible to work with it without argon, since it ignites when exposed to oxygen.

Video:

Welding in an argon environment qualitatively protects metal surfaces from the penetration of oxygen and harmful impurities, and improves the quality of the weld, and also helps to preserve all the physical characteristics of the metal and fully complies with GOST.

In addition, the consumption of argon when welding in this form is lower than when working with other welding equipment.

Argon weighs 38% more than oxygen, due to which it can displace it from the work area and protect the bath in the work environment from external influences.

Gas must be supplied to the work area no later than 20 seconds before igniting the arc, and stop supplying it after 10 seconds when the process is completed.

Argon is an inert gas, therefore it does not combine in the environment with external gases or metal and steel alloys.

When you work with argon with your own hands, you should remember that after the gas is supplied, the space will be saturated with electrons, which turns the argon medium into a conductor of electricity.

Argon welding involves the method of exposing a material to an electrode, which can be of two types: consumable and non-consumable.

If you decide to weld with a non-consumable electrode, then a tungsten object is used for it, because it is the most refractory of all materials. For example, incandescent filaments are made from it, which are placed in lamps.

IMPORTANT TO KNOW: Typical welding defects and types of defects

The size and what the electrode is made of depends on the type of metal you will be working with: for processing steel, pipes and disks made of stainless steel, brass, titanium, etc. you will need to impact the material with different types of non-consumable electrode.

The size and characteristics determine the energy consumption of the electrode, which will be expended during operation.

The technology of argon arc welding is done in three options: manual welding with a non-consumable electrode (MAW), automatic argon arc welding with a non-consumable electrode (AMA), automatic argon arc welding with a consumable electrode (AAW).

If you are going to purchase a ready-made device for work, then choose TIG type models - this abbreviation refers to a welding method using tungsten in an inert environment.

This device fully complies with GOST.

Types of argon welding by technology

Depending on the method of execution, there are several types of argon welding.

We recommend reading How argon welding is performed

Manual

With this method, the welder uses only non-consumable tungsten rods and independently supplies the torch and additive.

With the manual method, the welder independently feeds the torch.

Mechanized

This type is also called semi-automatic, because. here the work performer manually operates only the torch, and the filler wire is fed mechanically. This principle is often used when performing argon welding of stainless steel parts using a semi-automatic machine.

The mechanized method is also used when working with a consumable electrode.

Fully automatic

The use of an automatic type of argon welding provides that the operator remotely controls the supply of wire and torch. The most modern systems are completely robotic and operate without human intervention. The creation of stainless pipelines using this method is more efficient. Automatic welding with a non-consumable electrode in an argon environment is most often used in various industries; it is irrational to use this type at home.

Automatic welding is used in various industries.

Types of argon welding

There are several types of argon welding. It can be carried out in the following ways:

1. Manual.
2. Semi-automatic.
3. Automatic.

The classification, in addition to the degree of automation of the process, is based on the types of electrodes used.

Electrodes are either consumable or non-consumable. An example of the latter electrode is refractory tungsten wire, which allows for reliable connection of parts, even if they are of dissimilar materials in type. Graphite is used less frequently.

Electrodes are produced in different diameters and materials for different metals being welded.

Thus, there are such types of argon welding as:

1. Manual - using a non-consumable electrode (this type is labeled as RAD).
2. Automatic - using non-consumable electrodes (marked as AMA).
3. Automatic - using consumable electrodes (marking - AADP).

The two most common welding methods today are AMA and RAD.

The use of consumable electrodes is only possible in automatic mode. For this purpose, special installations and devices are used, which are welded with a special torch equipped with an electric motor that transfers the wire from the spool. The consumable electrode is simultaneously used for ignition and acts as soldering material. During the ignition process, the conductor melts and provides mass for the seam.

Argon arc welding diagram

Automatic argon arc welding is mainly used only at various industrial enterprises (in particular, for the production of metal structures, for welding copper busbars in stationary and installation conditions), which is associated with the high cost of automatic installations and the complexity of their setup. It is much easier to weld several parts manually, but if high productivity is required, then you cannot do without equipment.

Features of working with metals that are cooked with argon

The properties of argon allow this type of welding to be used not only in a wide variety of industries and everyday life, but also to work with cast iron, stainless steel, aluminum, copper, and other ferrous and non-ferrous metals and alloys.

Aluminum

Argon arc welding is practically the only method that allows you to reliably connect parts made of aluminum and its alloys. This is a common material both in everyday life and in production. Difficulties in carrying out welding work arise due to the rapid formation of an oxide film on its surface, which interferes with making a high-quality connection.

The problem is that the melting point of the oxide is much higher than that of aluminum itself. Supplying argon to the weld pool allows oxygen to be displaced from it, so the oxidation process does not start. As a result, the metal and additive melt at a suitable temperature, and the seam is strong and beautiful.

The work is performed by alternating current. With straight polarity, a stable short arc is obtained, but its power is not enough to destroy the oxide film. Reverse polarity leads to an increase in the melting temperature due to cathodic purification of aluminum oxide, which improves the quality of the weld, so the work is performed in this way.

Argon arc welding allows you to reliably connect aluminum parts.

You can cook aluminum with direct current, but in this case you need to use helium. It costs more and requires more qualifications from the welder.

Regardless of the method of welding aluminum and the skill of the work performer, preliminary preparation of parts is important. This stage cannot be neglected.

Surface cleaning is carried out in the following order:

1. The workpieces are degreased with a solvent.
2. The oxide film is removed mechanically or chemically.
3. The cleaned surface is dried.

Copper

One of the positive properties of copper is its high resistance to corrosion and aggressive influences. If it is necessary to weld copper parts, the work is performed with direct current. In this case, the electrodes can be consumable and non-consumable.

Welding of copper parts is carried out using direct current.

The additive is made of copper or a copper-nickel alloy, in the form of wire or rods. To join parts thicker than 4 mm, they are preheated to 800 °C. Copper has high thermal conductivity, so the edges of the parts must be cut before starting work. For workpiece thicknesses up to 12 mm, it is enough to process only 1 edge.

Ferrous metal and argon

Ferrous metal can be welded well using ordinary methods. The use of the argon-arc method in such cases makes it possible to obtain an even better quality connection. Use an additive without a special coating, because Argon reliably protects the weld pool from the negative effects of oxygen.

Before work, clean the surface of the future connection. If there is any remaining oil on it, remove it with a solvent. After this, the flux is laid out: it will help preserve important elements in the composition of the workpieces being joined and ensure the correct process parameters.

Ferrous metal is welded in the usual way.

During welding, the tool is brought to the parts when a weld pool is formed. It is gradually advanced and at the same time the additive is supplied.

To ensure that the seam has the same consistency along its entire length, it is not recommended to stop the process.

Stainless steel

Working with stainless steel is quite difficult. Often the welds begin to crack and come apart. To prevent this from happening, such workpieces must be joined using argon arc welding.

The technology for welding stainless steel is the same as simple, but there are several nuances:

• the additive and non-consumable electrode can only be moved along the seam; no movements can be made across it;
• to obtain a better quality weld, the joint from the front and back sides is blown with argon, but this leads to an increase in gas consumption;
• the additive should not go beyond the zone protected by argon;
• The tungsten rod must not be touched to the surface of the work being welded, even during ignition of the arc (special plates are used for this).

We recommend reading: How to cook brass in an argon environment

Stainless steel must be joined using argon arc welding.

As when welding other metals and alloys in an argon environment, after finishing welding stainless steel, you cannot immediately stop the gas supply. This is necessary to cool the electrode and seam and prevent oxidation. It is enough to supply argon for 10-15 seconds.

Often in industry and everyday life welding of stainless steel pipes is required. The technology for preparing products is the same as for sheet parts. The peculiarity is that in this case it is necessary to blow argon onto the welding seam on both sides.

This is easy to do from the outside, but to blow it from the inside, do this:

1. On one of the pipes, the hole is closed with a fabric, paper or other stopper.
2. The joint is covered with tape or tape.
3. Argon is slowly let in through the hole in the second pipe so that the plug does not fly out, and it is closed tightly.
4. Remove the tape or tape and weld the pipes, as in the case of working with sheet materials.

Features of welding machines and welding modes

Welding with argon requires a special apparatus that complies with GOST.

Typically, equipment is made by improving a classic arc welding machine, to which additional equipment is added to perform argon welding.

Video:

The following equipment is required for operation:

• a transformer for welding with an no-load voltage of at least 60V;
• contactor responsible for supplying welding voltage to the torch;
• oscillator;
• blower time regulator.

IMPORTANT TO KNOW: Tips and lessons on arc welding

Since gas for work according to GOST must be supplied 20 seconds before it starts, a device is needed that can regulate this process.

Also in the process you will need:

1. burner;
2. a cylinder equipped with a reducer containing argon;
3. electrodes;
4. transformer having the required size;
5. ammeter responsible for power supply;
6. battery and other equipment.

All equipment is available for purchase in a specialized store, or you can assemble it yourself, but in this case it must comply with GOST (you can see what conditions GOST prescribes in specialized literature).

When you assemble it yourself, you will receive a homemade welding machine suitable for working with argon.

The cost of money in this case will be much lower, and if you have the necessary knowledge, you can improve the device to reduce its consumption during operation.

The operating mode and incoming pressure are very important when you start working.

Watch the video on how to work with different metals before you start doing it yourself.

Choosing the right mode will help reduce pressure and energy consumption during operation.

Pressure and other indicators depend on the type of metal you are processing (steel, brass, stainless steel, etc.), which determines the choice of polarity and location of current supply.

Welding of copper with argon, as well as steel and its alloys, is usually performed in direct current mode with straight polarity.

Welding cast iron with argon and welding titanium is carried out under similar conditions, the pressure when welding cast iron with argon and titanium is also similar, but for welding aluminum, beryllium, magnesium it is better to use reverse polarity and alternating current, because these indicators better destroy the oxide film that is on the surface of the metal.

What pressure is needed for cast iron, titanium, aluminum and other metals can be found in a special table.

Video:

The choice of welding current depends on the characteristics of the metal (cast iron, titanium, aluminum, etc.), all these values ​​can be found in the table.

For experienced craftsmen, it is allowed to experiment with the current strength and choose it independently, using experience and knowledge. The amount of argon consumption depends on the speed at which the air moves.

Indoors it is minimal, and outdoors it is highest.

If work occurs using direct current, then the heat at the anode and cathode is released unevenly: in the first case, this figure is 30%, and in the second - 70%.

It is best to work with the electrode with straight polarity, because in this case, it will heat up better and be able to efficiently melt the desired area of ​​the part, and energy consumption will be lower.

Watch the video and photos for the entire process of welding cast iron and titanium with argon - these lessons will explain to you how to work with different materials, as well as the main stages of the work.

Types of welding equipment

The welding in question is used when connecting different products.

To perform such work, a certain type of welding equipment is required:

• specialized - used for working with similar parts (round frame, I-beam, etc.);
• special - used in large enterprises where there is mass production of parts of 1 standard size;
• universal - used for any connections made using argon welding, incl. and when working with stainless steel with semi-automatic equipment.

To perform the work, specialized equipment is required.

Pros and cons of the method

Advantages:

• Possibility of obtaining a reliable connection due to effective protection of the work area.
• Insignificant heating of the welded parts, which allows the technology to be used for welding workpieces with complex configurations (they are not deformed).
• Can be used for materials that cannot otherwise be welded.
• A significant increase in work speed due to the high-temperature electric arc.

Flaws:

• Complex equipment.
• The need for special knowledge and experience.

The method will ensure the quality and reliability of welded joints and uniform penetration of the connected parts. With this technology, parts made of non-ferrous metals of small thickness can be welded without filler wire.

Argon burners and their features

An electrode is attached to the torch (voltage is supplied to it), as well as a nozzle (through which argon enters the work area during welding).

When choosing a burner, the following criteria are taken into account:

• power and current, which are the maximum allowable for the model in question;
• The kit includes a holder for a tungsten rod;
• the material from which the nozzle is made (it is better if it is ceramic);
• cooling method (this is important when working with thick and thin-walled workpieces);
• the possibility of using it with different welding machines;
• length of the electrical cable.

When choosing a burner, take into account power and current.
When the burner starts, liquid immediately begins to circulate in the cooling system, and argon is supplied. After creating the protective layer, a gas arc is formed and the edges of the workpieces are heated. At this time, filler material begins to be supplied. At the next stage, a torch with an electrode and an additive are advanced along the joint of the workpieces.

Consumable electrodes

Consumable tungsten rods are most often used in semi-automatic and automatic argon arc welding. An arc is formed between the surface of the workpiece being welded and the filler material. The cooling system (air or liquid) depends on the performance of the equipment. The operating principle of the burner and the design of the nozzle are the same as in the case of using non-consumable electrodes.

Non-consumable electrodes

When performing manual argon welding, non-consumable tungsten rods are used. They allow high-quality joining of parts made of metals and alloys characterized by high chemical activity, for example titanium, aluminum, magnesium, and stainless steel.

When performing argon welding, electrodes are used.

The electrode is fastened in the current supply collet of the burner, and inert gas is supplied through a nearby nozzle. Depending on the thickness of the workpieces that will be connected, the current strength and diameter of the working rod are selected.

When performing such work, no splashes are generated. To distribute argon evenly, a mesh filter is installed on the burner. The semi-automatic torch additionally has a flywheel, with which the electrode is raised and lowered, and the conductive collet is fixed with a threaded connection so that the tungsten rods can be changed.

Principle of operation

The method involves creating high temperature using an electric arc. At the same time, the welding area is forcibly filled with argon, which displaces oxygen, isolates it from the external environment, and serves as protection against corrosion.

When using a non-consumable electrode, the arc is ignited without its contact with the product. The high ionization potential of the inert gas prevents the ionization of the arc gap due to a spark in the electrode-product gap. In the case of a consumable electrode, the arc is ignited by a spark due to the low ion potential of iron vapor compared to an inert gas.

When touching the metal being welded, the tungsten electrode becomes dirty and melts. The ignition problem is solved by introducing an oscillator into the power circuit. Excitation of the arc gap is ensured by pulses with high voltage. When working with alternating current, having ionized the arc, the oscillator is converted into a stabilizer. Its short pulses prevent deionization of the arc gap when the polarity changes.

When argon-arc welding of objects with a thickness of over 3 mm, as well as to strengthen the seam, filler rods (wire) are used, which match the material of the product.

Mode selection

To ensure a high-quality weld when joining ferrous and non-ferrous metals and their alloys, you must choose the right argon welding mode. To do this, it is possible to regulate the current strength in the equipment used.

Current and polarity

For this type of welding, direct or alternating current can be used. When working with reverse polarity, you must be prepared for the fact that the arc will burn poorly and too much voltage will be needed. Charged particles move towards a positive potential, and since This is an electrode, it will overheat and quickly burn out.

When argon welding, you can use direct or alternating current.

When choosing the current strength, take into account the following parameters:

• type of current (direct or alternating);
• tungsten rod diameter;
• thickness of the joined workpieces.

There are special tables with which you can quickly and easily determine the required values. For example, for parts with a thickness of 1-2 mm, you will need an alternating current of 20-100 A or constant, with an increase in thickness to 4 mm - 65-160 A: alternating current 140-220 A, direct current - 250-340 A.

Voltage height

To obtain a high-quality connection, when working with argon welding, it is recommended to set the voltage to no more than 14 V. This allows you to obtain an arc with a length of 1.5-3 mm, which is the optimal indicator for connecting products of different thicknesses, provides good penetration depth, i.e. strong and reliable seam.

We recommend reading: How to cook cast iron in an argon environment

Speed ​​mode

Each master decides for himself at what speed it is convenient to operate the burner. This parameter is selected on site on an individual basis. The main thing is not to do it quickly, because... Welding non-ferrous metals and alloys is a rather complex task that cannot be rushed.

Each master chooses his own speed mode.

Gas consumption

Gas consumption will depend on the size of the seam being created, the diameter of the electrode used, and the material of the parts being connected. In addition, the argon supply rate and external conditions influence (for example, in strong winds, the flow rate increases). Only practice will help you calculate how much shielding gas you will need to complete a certain task.

You can focus on the approximate consumption of inert gas when working with different metals:

• aluminum – 15-20 l/min;
• copper – 10-12 l/min;
• titanium – 35-50 l/min;
• nickel -10-12 l/min.

Pure argon is not used for welding: it contains up to 5% oxygen.

This is necessary to remove existing impurities that simply burn when reacting with oxygen.

Distance to part

When choosing this parameter, everything depends on the thickness of the products being welded and the method of joining them. If the work is done end-to-end, then the electrode should be kept at a distance of 3-5 mm from the part. When connecting workpieces at an angle, this distance is increased to 5-8 mm.

The distance to the part depends on the thickness of the products being welded.

Equipment and facilities

Welding work using argon is carried out using universal, special equipment. The industry has established serial production of universal devices of various capacities and purposes. The production version of argon-arc welding involves the organization of a “welding station”, which includes:

• DC/AC power source;
• burners for working with different electrodes;
• a triggering device that ignites the arc with direct current or stabilizes it with alternating current (oscillator);
• welding cycle control equipment;
• a device that allows you to compensate and regulate the direct current component;
• gas station (argon cylinder equipped with a pressure sensor);
• ventilation.

In the modern version, most of these devices (except burners) are combined in one device called an inverter. Due to its accessibility, the device is popular in everyday life.

Advantages and disadvantages

Among the main advantages of such welding, the following should be noted:

1. The operating temperature is low, so the workpieces do not change their shape and size.
2. Due to the inertness of argon, the welding zone is reliably protected from the negative effects of external factors.
3. A low-power arc ensures high efficiency of work.
4. Argon welding allows you to join metals and alloys that cannot be welded by other methods.
5. The high quality of the seam allows this method to be used in industries where the requirements for joints are high.
6. Automatic welding ensures efficiency and quality when connecting multiple parts with minimal human intervention.

In addition, there is no need to frequently change the electrode; dissimilar materials and alloys can be welded.

Argon welding allows you to join metals and alloys.

Like any other, argon welding also has some disadvantages:

1. The complex design of the argon welding machine does not allow an inexperienced welder to correctly set the operating mode.
2. When making a connection with a high-ampere arc, it is necessary to additionally cool the joint.
3. In order for the inert gas to fully fulfill its purpose, the work site must be reliably protected from wind and drafts.
4. The requirements for welder professionalism are high.

Disadvantages of argon arc welding

It is impossible to conduct training in argon arc welding without mentioning its disadvantage, which is the insufficiently high productivity with manual processing. Automatic welding is not suitable for making short and unstructured seams.

More on this topic on our website:

1. Welding cast iron with an electrode - process video Cast iron is a special iron-carbon alloy that has a high carbon content (2.14%). Due to this, in comparison with other steels, it is in a free state. TO…
2. Which welding machine for welding aluminum and duralumin should a beginner choose? The process of welding aluminum and duralumin has several features that must be taken into account both when working and when selecting equipment for it. Firstly, aluminum is...
3. Argon welding - video on how to properly perform argon welding Before starting work, you should carefully review “Argon welding. Video" in order to understand the advantages of its use, the nuances of the process itself, as well as the most common mistakes that...
4. Manual arc welding - video and principle of operation of the welding machine for beginners. The RDS method is the most common and accessible method of welding with a piece coated electrode. The manual arc welding video instructions clearly show that this method is different...

Share a link to this material with your friends on social networks (click on the icons):

How a beginner can learn to cook with argon

For beginners, the argon welding technique is available if:

1. Sign up for special courses for beginner welders. Here you will receive the necessary theoretical knowledge and learn to put it into practice. When choosing courses, you need to rely on the experience of friends or reviews of people who have already completed such lessons. Be sure to study the training program and, using common sense, choose the option that suits you most.
2. Learn it yourself. If a person has skills in gas and electric arc welding, it is not difficult to master the technique of the argon arc method. It is enough to study the available information and watch thematic videos. Please note that the cost of this inert gas is considerable, so it is better to learn argon arc welding on stainless steel parts. Having gained some experience and studied theory and technology, you can move on to joining products made of non-ferrous metals.

Aluminum TIG welding

TIG welding is usually associated with aluminum welding; it is used for repairing disks (Dmitrovskoe highway) and other important activities. However, not every TIG welder can weld aluminum correctly. Especially if we are talking about thin aluminum.

The most important thing when TIG welding aluminum is the tungsten electrode. For welding you will need pure tungsten or zirconium tungsten. Tungsten with 2% lanthanum is probably a better choice since it can handle higher currents. The tungsten must also have a ball head for proper heat distribution.

The current type of aluminum welding should always be AC ​​welding. D/C TIG welding of aluminum is possible with DCEN setting and pure helium. However, this requires in-depth knowledge, and welders usually do not have such knowledge. This also occurs when welding very thick aluminum.

Additional tips from the experts

In order to obtain a high-quality connection when performing argon arc welding with your own hands, the craftsmen give the following recommendations:

1. Cleaning the surfaces to be welded from dirt, oil, paint, etc. is a mandatory step. It is performed mechanically or chemically.
2. Gas is supplied 20 seconds before the actual welding begins. They take the torch and filler material in their hands, and after applying electricity, they create an arc.
3. The burner is led along the joint. You cannot make lateral movements.
4. The additive is introduced into the welding zone slowly so as not to provoke the formation of splashes of hot metal.
5. The wire is led in front of the torch, making quick translational movements that allow it to be added or removed.
6. Achieve the shortest possible arc. This is especially important when working with a non-melting rod: then the seam will be deep and aesthetically pleasing.
7. The additive and burner are placed inside a protective argon shell.
8. The crater is welded not by interrupting the arc, but by lowering the voltage supplied to the electrode.
9. The argon is not switched off immediately after welding is completed, but after 10-15 seconds.

Compliance with argon arc welding technology allows you to reliably join metals and alloys that cannot be welded by other methods. Proper preparation and procedure for performing work eliminate the likelihood of hazardous situations.

How to weld in argon

The main working body when performing argon arc welding is a special torch, inside of which a tungsten electrode is placed in a collet holder. A holder of this type allows you to attach electrodes of different diameters, which are selected depending on the characteristics of the workpieces being connected. The electrode fixed in the burner should protrude 2–5 mm above its end.

Three-button argon torch complete with cable, collets and ceramic nozzles

A nozzle, which is a tube made of ceramic or quartz glass, is placed around the electrode (along the outer circumference of the burner). This structural element of the torch simultaneously performs two important functions: through it, shielding gas is supplied to the welding zone, and it also protects the tungsten electrode from contact with the surfaces of the parts being joined.

In order to weld metal using argon, it is necessary to use filler wire, due to which the weld is formed. The composition of such wire supplied to the welding zone manually must be selected in such a way that it best matches the composition of the metal from which the parts being joined are made. Before starting welding, it is necessary to select the correct diameter of the filler wire, for which special reference tables are used. This parameter depends on the size of the workpieces to be cooked.

Table of parameters of some types of filler wire

The most accessible method of welding in an argon environment is manual. This method, which usually takes little time to learn, requires both the torch and filler wire to be held in the welder's hands. The essence of this method is as follows. Using a torch held in one hand, the welding arc is ignited. Argon is supplied to the welding zone, for which a special button on the holder is used. In this case, in the other hand of the welder there is a filler wire, which is introduced into the zone of action of the electric arc.

A very important condition for the formation of a high-quality and reliable weld formed using welding in an argon environment is careful preparation of the workpieces to be joined.

Such preparation consists of cleaning and degreasing their surfaces, as well as removing the refractory oxide film. To perform such procedures, which both beginners and experienced welders should be aware of, you can use mechanical devices (grinding machine) or chemical agents.

Gas tank prepared for welding

Before starting welding, ground must be connected to the parts to be joined. If you have to cook small pieces, you can simply place them on a metal table or in a working bath, and connect the ground wire to them. You can select the welding current and gas pressure, which depend on the characteristics of the parts being joined, based on reference literature or your own experience. Shielding gas, as mentioned above, begins to be supplied to the welding zone 20 seconds before it begins.

The distance from the electrode to the surface of the workpieces between which the welding arc burns should be small - about 2 mm. This will allow for good melting of the edges of the parts to be joined and obtain a high-quality weld. If you increase this distance, not only will it be difficult to melt the edges of the parts, but the weld itself will turn out to be too wide and sloppy. A wide weld, in addition, is characterized by low reliability; significant internal stresses arise in it.

When welding in argon, it is very important to correctly feed the filler wire into the work area. This is done with slow and smooth movements to prevent splashing of the molten metal.

When teaching this technology, it is very important to understand that the torch and filler wire movements are made only in the longitudinal direction - along the axis of the seam being formed. In no case should you make transverse movements, since the flow of shielding gas will be outside the zone of the weld being formed, which will cause a significant deterioration in the quality of the joint.

The torch and filler wire must be positioned at an angle to the surface of the parts being joined: this will make it possible to form a high-quality, reliable and neat weld. In this case, the filler wire is located and fed into the weld formation zone in front of the torch.

The technology of argon welding involves the use of an oscillator, with the help of which the welding arc is easily ignited. In addition, when using this device, its combustion is highly stable.

Oscillator (welding arc stabilizer) OSI-264

The essence of the oscillator’s operation is that it produces pulses of high-frequency current, characterized by a high voltage value. A typical oscillator is capable of converting electric current with standard parameters (220 V, 50 Hz) into pulses with a frequency of 500 kHz and voltage up to 6000 V.

When teaching the technology in question, a novice specialist needs to learn one more important rule: when igniting the welding arc, you must not touch the surface of the parts with a tungsten electrode, this will lead to melting of the electrode and contamination of the surfaces being welded.

By using an oscillator, the arc can be ignited without such contact. In most cases, when welding in argon and using a tungsten electrode, the electric arc is ignited on a special carbon plate. Only after this the arc is transferred to the parts being connected.

The features of this procedure are well demonstrated by video tutorials.

Sequence of work during argon-arc welding

The technology of the process is outlined using the example of welding pipes with a manual welding machine and a lesson for beginners from the “Burn the Arc” channel.

Preparation of equipment, protection and parts to be welded . For work, experts recommend using inverter-based devices powered by 220V AC (industrial models with 380V power are not recommended for use in domestic conditions, even if there is an appropriate power socket).

For a novice craftsman, it is better to choose black or lightly alloyed iron-based alloys as welded parts. Taking sheets with a thickness of 2...3 mm, you can use green (WP) electrodes made of pure tungsten, without alloying additives.

Preliminary preparation of parts is described above.

Chamfering for better seam welding

Installing a holder that fixes two sections of pipe relative to each other

Tack seam . In some cases, it can be difficult to connect parts immediately with a permanent continuous seam, so craftsmen recommend in this case to make “tack welds,” that is, short seams in several places.

Performing point tacks

If spot setting was not performed entirely successfully, it is better to clean off the metal deposits to obtain a more monolithic and even seam

Making the main seam is igniting the arc. Please note that the blower is turned on first, and only then the arc

Making the main weld with a non-consumable electrode and using an additive

Type of finished seam

Seams close up

Detailed photos and videos of seams obtained using argon arc welding clearly show that they consist of many round “patches”. This is due to the fact that heating pulses are supplied at a certain interval. Accordingly, the metal melts at a specific point, forming an influx, then at the next one, and so on.

Required equipment, supplies and protection

When planning to do argon manual welding at home (automatic machines are usually not used at home), you should stock up on everything you need in advance:

• gas cylinder. For argon, specialized cylinders are used, the difference from oxygen and propane cylinders is in the colors. They have a characteristic silver-gray color;

• reducer to reduce the pressure of liquefied gas. Can be specialized or general purpose;

• a high-pressure hose (from the cylinder to the reducer) and a similar or less durable one - from the reducer to the welding torch;

• a welding machine designed to work with non-consumable electrodes;

• electrodes of a suitable brand in the required quantity;

• tools and devices for preparing metal for welding;

• protective clothing and equipment.

It is important to understand that the compatibility of the cylinder, hose and reducer is very important. To avoid confusion, manufacturers try to produce reducers and cylinders in the same color and with similar markings.

More about the equipment

Please note that the previously provided information about the color of the argon cylinder (silver-gray) refers to PURE (specially prepared) gas.

It is also necessary to pay attention to the marking of the cylinder itself and its condition.

The condition of the threads and seals should be examined especially carefully, since the performance of the cylinder as a whole and the safety of its use depend on this.

It is advisable to use the reducer with a rotameter (one or two), that is, a gas flow sensor and regulator. Two rotameters are necessary if two welders will use the gas cylinder at the same time. The presence of a rotameter allows you to rationally use both the gas itself and tungsten electrodes - after all, with excessive gas pressure, they burn out much faster.

With regard to electrodes, it is necessary to adhere to the general rule regarding the type of welding (AC or DC).

The diameter of the product is selected depending on the thickness of the metal to be welded.

The same goes for the required welding amperage.

The last parameter, as well as the ability to use different electrode diameters, greatly influences the choice of welding machine.

We will not consider the nuances of choosing a specific device model within the framework of this article, since the topic is too broad.

Preparing parts

To weld any metal, it must first be prepared for work. This procedure includes several steps:

• editing details. Often the parts that need to be welded are deformed. The basic shape must be restored, otherwise joining for welding may be impossible or very difficult. Straightening is performed manually or using automatic equipment, “cold” or in a heated state (using a gas burner). The choice of a specific method depends on the characteristics of the part, its condition and the capabilities of the craftsman;
• cleaning surfaces. It is necessary to remove the corroded layer and any paint and varnish coatings from the part. This is usually done by hand sanding or wire sanding with a drill/grinder;
• marking and cutting. Marking at home is done only by hand; cutting is carried out with a grinder or a special metal saw (including using a jigsaw). For thin sheet metal, you can use scissors. Thermal cutting is also possible - using a gas cutter, electric arc, and so on;
• preparing edges for work. Depending on the thickness of the metal you plan to weld, straight, V-shaped and X-shaped edges are used. The mechanically or thermally cut edge of a part must be brought to any condition using a suitable hand tool. In this case, it is better to use “cold” cutting methods, since after thermal cutting, the cleanliness of the cut to form a chamfer or a flat surface may not be sufficient. Additionally, the edges can be cleaned from the oxide film using a wire brush or a grinding attachment.

Another important point is the removal of stains of oils, fats and other organic and inorganic contaminants. They are removed with appropriate solvents.

The last stage of preparation is assembling the parts in the required position. For this purpose, various stands, conductors, etc. are often used. Particular care should be taken when welding pipes and other hollow parts joined at the edges.

Types of edges for welding: 1 – straight edges, 2 – simple V-shaped, 3 – complex V-shaped, 4 – X-shaped

The assembly of parts must be carried out taking into account a significant increase in temperature in the welding zone - wood and other flammable materials cannot be used for the welding stand.

Protective equipment and clothing

The safety of the welder and the things around him is especially important when it comes to working in a home workshop or a small private enterprise. Mandatory elements of worker protection are:

• welding helmet, mask or goggles. A mask is the best option because it protects not only the eyes from the blinding light of an electric arc, but also the skin of the face (and partly the neck) from burns from splashes of molten metal and sparks. Also, to a certain extent, the mask protects the respiratory tract. Clear glasses are recommended for use when cutting metal and edge processing. The dark shield of the mask protects the skin from excessive and specific “welding tan”, which can cause skin cancer;
• gloves or mittens with gauntlets (protective elements on the wrists and above). The material of the gloves should be as dense as possible, non-melting (a prerequisite, since heating can be significant), and at the same time soft enough for ease of use. Tight fixation on the hands is undesirable; gloves should fit the hand loosely;
• a jacket or apron made of dense material that is not prone to fire. Can also use overalls or overalls;
• dense shoes that can easily withstand temperature influences. It is important that the shoes do not have open lacing, nails in the soles or other metal elements;
• When working in inconvenient places, with forced laying on the floor or kneeling, knee pads, special stands and mats are used.

According to regulations, welders must also use respirators. However, most often home craftsmen refuse it, citing the inconvenience of the work and its short duration.

Important: people with problems with the respiratory tract (frequent cases of bronchitis or tonsillitis, recent pneumonia, asthma or allergies) must use a respirator while welding!

The material of gloves (mittens, gauntlets) and clothing intended specifically for welders is marked “TR”, the same applies to shoes. It is recommended to manufacture workwear for welders from natural materials (tarpaulin, cotton, genuine leather) with additional impregnation with fire-retardant substances. For everyday use, thick denim or canvas clothing, long aprons and armlets (in the absence of leggings) made of canvas or leather, and leather gloves are suitable. But it is better to purchase specialized mittens or gloves.

What you can work with

Considering the high temperature achieved by using arc welding in an argon environment, the list of metals that can be welded by this method is quite large:

• almost all “ferrous” alloys, from cast iron to structural steels;
• stainless steel (stainless steel);
• alloyed and high-alloyed alloys;
• refractory metals, including titanium and alloys based on them;
• “non-ferrous” metals, including copper, aluminum, alloys based on them.

The temperature and welding conditions are adjusted depending on the material of the parts being joined.

Electrical equipment, light, lighting

0 votes

+

Vote for!

—

Vote against!

Stainless steel, copper, titanium, aluminum, bronze, other non-ferrous metals and alloy steels are all metals whose parts cannot simply be welded together. But in everyday life there are different situations: sometimes you need to weld stainless steel pipes, sometimes you need to weld car parts from aluminum, or you just need to weld a broken leg from a bronze figurine. The metals listed above will require a special approach - argon arc welding, the work of which is not cheap, if not quite “biting” if you order it from a specialist. So the question arises for the owners: is it possible to weld with argon with your own hands and what is needed for this. If you have never welded anything before, then you should absolutely not start with welding non-ferrous metals; this is a painfully labor-intensive and complex process, designed for a certain skill of a specialist and his experience. But if you have experience in conventional arc welding and you are confident in your abilities, then the information from this article is for you.

1. Argon welding: technology and general principles
   Tig welding technology
2. What is needed for argon welding
3. Various argon welding modes
   Features of aluminum welding
4. Features of copper welding
5. Argon arc welding: advantages and disadvantages
6. Argon welding: video instructions

Argon welding: technology and general principles

Argon arc welding is a kind of hybrid of electric welding (arc) and gas welding. It is similar to electric welding technology in that it uses an electric arc, and to gas welding technology in that it uses gas and similar welder work.

The electric arc serves as a source of heating; it melts the edges of the metal, thanks to which welding occurs.

But why do we need argon gas? The fact is that when welding, non-ferrous metals and alloy steels oxidize when interacting with oxygen, or they are negatively affected by other impurities that are in the air, because of this the weld turns out to be fragile, filled with bubbles, and aluminum, for example, generally burns in oxygen. To protect the metal from the effects of various impurities and gases, the inert gas argon is used. This gas is 38% heavier than air, so it easily and quickly displaces oxygen from the welding zone and reliably isolates the working pool from any influence of the atmosphere. It is necessary to start supplying gas to the welding zone 20 seconds before ignition of the arc, and stop 7 - 10 seconds after completion of the work. Argon practically does not react with the metal being welded and other gases in the arc burning area, which is why it is called inert. But there is also some nuance: when welding with reverse polarity, electrons are easily separated from argon atoms, thanks to which the entire argon environment turns into electrically conductive plasma.

Welding with argon can be done with either a consumable electrode or a non-consumable electrode; a tungsten electrode is used as the latter, since this material is extremely refractory. Tungsten is used to make incandescent filaments for lamps. The diameter and material of the electrode completely depends on the metals being fused; these indicators can be easily found in reference books.

There are three types of argon arc welding:

• RAD is manual welding with argon with a non-consumable electrode.
• AMA – automatic argon arc welding using a non-consumable electrode.
• AADP – automatic argon arc welding using a consumable electrode.

If you are looking for a ready-made machine for welding with argon tungsten electrode, look for TIG (Tungsten Inert Gas (Welding)) machines. This is what tungsten welding in an inert gas environment is called.

Tig welding technology

What is an argon welding torch? Its heart is a tungsten non-consumable electrode , which should protrude beyond the burner body by only 2 - 5 mm, no more. The diameter of the electrode is selected according to the tables, based on the parameters of the materials being welded. There is a holder inside the burner into which you can insert and secure an electrode of any required diameter.

A ceramic nozzle is placed around the electrode , from which argon during welding.

For welding, we need a filler wire made of the same material as the parts being welded; its diameter is selected according to the tables.

Let's consider the principle of working with manual argon welding, when both the torch and the filler wire are in the hands of the welder.

Before starting work, the surface of the parts to be welded must be cleaned of oxides, dirt and grease. This can be done mechanically or chemically.

First of all, the so-called “mass” is applied to the part being welded, as in conventional arc welding. If the parts are too small, it can be placed on an iron work table or bathtub. The filler wire is not included in the electrical circuit; it will be supplied separately.

The welder should hold the torch in his right hand and the filler wire in his left hand. The burner should have a button for supplying current and gas; turn on the gas supply 20 seconds in advance. The current strength is selected depending on the materials being welded or based on personal experience through trial and error. We lower the torch with the electrode as close as possible to the surface of the metals being welded, the ideal distance is 2 mm. An electric arc occurs between the tip of the electrode and the metal, it melts the edges of the parts being welded and the filler wire.

How argon welding occurs: photo - example.

Important! The non-consumable tungsten electrode should be kept as close as possible to the surface of the metals being welded in order to create the shortest possible arc. The larger the arc, the shallower the depth of metal penetration and the wider and less aesthetically pleasing the seam. With a large arc, tension increases and the quality of the seam deteriorates.

Slowly moving the torch along the seam, without making transverse movements, the welder should gradually feed the filler wire. The quality and accuracy of the resulting seam will depend on the skill of the craftsman.

Important! Sudden feeding of filler wire results in metal spattering. Therefore, it should be served smoothly and carefully, which can only be achieved with practice. It is best to place the filler wire in front of the torch at an angle to the surface to be welded, without making transverse movements. This will ensure an even and narrow seam.

Please note that ignition of the arc when welding with a non-consumable electrode cannot be done by touching the surface to be welded. And here are the reasons:

• The high ionization potential of argon does not allow the gap between the surfaces to be welded and the electrode to be well ionized due to a spark from contact. When welding with a consumable electrode, the situation is somewhat different: after the electrode touches the surface, iron vapor appears in the welding zone, the ionization potential of which is much (2.5 times) lower than that of argon, this allows the arc to be ignited.
• Due to the electrode touching the surface of the metals being welded, it becomes dirty.

To ignite the arc when welding with argon with a non-consumable tungsten electrode, an oscillator is used, which is connected in parallel to the power source.

The oscillator delivers high-frequency, high-voltage pulses to the electrode, due to which the arc gap is ionized. If the frequency in the network is usually 55 Hz and the voltage is 220 V, then the oscillator converts them and supplies a voltage of 2000 - 6000 V with a frequency of 150 - 500 kHz. This makes it easy to ignite the electrode.

What is needed for argon welding

For argon arc welding, the usual arc welding apparatus is not enough, but it can be upgraded or supplemented with other required elements. Let's look at what we need for welding in argon:

1. Transformer. An ordinary welding transformer is suitable, which is used for arc welding with an open circuit voltage of 60 - 70 V. Of course, its power must correspond to the technological features of the process.
2. A power contactor that will supply welding voltage to the torch.
3. Oscillator. We have already found out why it is needed.
4. A device that will regulate the time of argon blowing. After all, we need to light it in advance, and so that after the welding is completed, the gas is supplied for another 20 seconds. For this delay, we need a regulator.
5. Argon welding torch.
6. An argon cylinder, always with a reducer.
7. Tungsten electrodes, rods of the required diameter.
8. An auxiliary transformer that will be used to power switching devices.
9. Rectifier for powering switching devices with 24 V DC voltage.
10. Electrogas valve (24 V for DC or 220 V for AC).
11. On/off relay for oscillator and contactor.
12. An inductive-capacitive filter, which is necessary to protect the welding transformer from pulses (high voltage) sent by the oscillator.
13. Ammeter for measuring welding current.
14. Car battery (55 – 75 Ah), working or faulty, it doesn’t matter. It is connected in series to the electrical circuit in order to reduce the direct current component, which inevitably appears when welding with alternating current (for more details, see specialized literature).
15. Welding glasses.

All elements of this circuit can be bought on the market and assembled with your own hands, you will get homemade argon welding, moreover, the circuit can be much improved if you have the appropriate knowledge.

TIG devices can also be purchased ready-made; a gas cylinder, a torch, grounding and control buttons for the torch and gas supply can be connected to them. The price of such devices starts from 250 USD.

Various argon welding modes

For better welding of metals, it is necessary to select the correct welding mode.

The polarity and direction of the current should be selected based on the properties of the metals being welded. Basic steels and alloys are welded using direct current of straight polarity. It is better to weld aluminum, beryllium, magnesium and other non-ferrous metals using reverse polarity or alternating current, this promotes faster destruction of the oxide film. During DC welding, there is unequal heat generation at the anode and cathode: 70% at the anode and 30% at the cathode. To minimally heat the electrode and at the same time melt the product well, use straight polarity.

Important! When welding on alternating current, the oscillator, after lighting the arc, goes into stabilizer mode. To prevent deionization of the arc gap during a polarity change and ensure stable arc burning, the oscillator supplies pulses to the arc at the moment of a polarity change.

The welding current is selected depending on the properties of the metals being welded and the size of the parts, as well as the electrodes. You can select the current strength from tables in reference literature, or you can do it experimentally.

Argon consumption directly depends on the supply speed and the speed of the carrying air flows. If welding takes place indoors without drafts, the consumption will be minimal. Welding work in conditions of strong side winds requires increasing the distance between the electrode and the material, since the air flow can carry argon, then the metal surfaces will be unprotected. In such cases, special nozzles (confuser) with fine mesh are used.

oxygen is sometimes added to the gas mixture , about 3–5%. Argon is not able to protect against moisture, dirt and other additives that may appear on the surface of the parts being welded during the melting of the metal. Oxygen reacts with harmful impurities, as a result of which they either burn out or the resulting compounds float to the surface in the weld pool. Using oxygen is a good way to combat weld porosity.

Features of aluminum welding

When aluminum is heated, a refractory film appears on its surface. When welding with reverse polarity or using an alternating current source, this film can be destroyed. When an aluminum part has a positive charge, when welding with reverse polarity, argon ions bombard the surface of the aluminum, destroying the oxide film. In this case, argon no longer acts as just a shielding gas, but is an electrically conductive plasma that simplifies and improves welding work.

During AC welding, a similar process occurs when the aluminum part is the cathode.

Features of copper welding

Copper easily reacts with oxygen to form cuprous oxide. This leads to the seam being uneven and not strong enough. An even bigger problem is that the resulting cuprous oxide reacts with the hydrogen contained in the air, forming water vapor, which tends to escape and forms pores in the seam. That is why it is mandatory to protect the welded area with argon.

Argon arc welding: advantages and disadvantages

Like any process, argon welding has its advantages and disadvantages, which are associated with the technology and the devices used.

The advantages include:

• Protection of the weld seam with argon from environmental influences. This ensures a strong connection, free of pores and impurities.
• The metal heats up little, the heating area is very small, so you can easily weld workpieces of complex design without fear of changing their shape.
• Possibility of welding metals and alloys that cannot be welded otherwise.
• Relatively fast work, thanks to the high-temperature arc.

Flaws:

• Quite complex equipment that requires precise adjustment.
• The relative complexity of welding work, requiring experience and skill.

Argon welding is good because it ensures a high-quality weld with the same penetration depth. This is very important when welding thin metal with access from only one side, for example, fixed butt pipes. By the way, when welding non-ferrous metals of small thickness, filler wire may not be used.

Argon welding: video instructions

What equipment is needed?

Initially, you need to select equipment and consumables for joining metal workpieces. These include argon for welding, which is pumped into gas cylinders, a device that generates welding current, and tungsten or consumable electrodes.

Gas cylinder for argon welding

Types of welding machines

There are 4 types of welding equipment:

1. Automatic - a technology that involves automatic supply of gas, filler wire or tungsten electrode. The equipment is controlled by the operator.
2. Mechanized - implies automatic supply of filler wire. The welder must hold the torch in the desired position.
3. Robotic is modern equipment that operates automatically. Requires initial program setup and algorithm specification.
4. Manual is a classic tool that requires the participation of a welder.

The choice of equipment for argon welding depends on the availability of capabilities and the required performance.

Welders

In stores you can find a number of welding machines that allow you to weld with argon in production or in private workshops. Purchased equipment can be divided into several groups:

• special devices;
• special;
• universal.

Benefits of technology

Argon welding has a number of advantages that allow this technology to be used in many situations where other types of welding are not possible. Among them, the characteristic advantages are:

• eliminating the oxidizing effect of air components on the liquid metal melt due to the protective environment of argon;
• thanks to local thermal power in the working area and correctly selected parameters, high welding speed and high-quality seam are ensured in automatic and semi-automatic mode;
• argon arc welding makes it possible to connect parts made of different metals;
• The welding process can be carried out under visual control.