What shielding gas is used when welding aluminum

Three main methods of welding aluminum

Well-known aluminum is distinguished by such unique properties as lightness, good thermal conductivity and resistance to chemical and mechanical influences. The specific structure of this material is the reason that welding aluminum and its alloys has a number of difficulties that must be taken into account when organizing welding work.

Difficulties of the process

The properties of aluminum should also be taken into account when welding at home, regardless of whether the metal will be welded with a gas torch, inverter or semi-automatic machine.

Problems in alloying this material with other metals (welding aluminum and steel, in particular) are explained by the following reasons:

the difficulty of heat treatment of the workpiece surface, since it is constantly covered with a refractory oxide film, which interferes with the formation of a high-quality seam;
high fluidity of the metal in the molten state, complicating the process of formation of a weld pool from aluminum alloys;
the presence in the structure of the material of hydrogen and silicon, which, when the seam cools, tries to break out and form pores and cracks;
high coefficient of linear expansion of aluminum, which also contributes to the formation of cracks.

To avoid undesirable consequences, certain measures are taken to protect the fusion zone, such as welding in argon, which limits the access of oxygen to the contact point.

In addition to argon, other gases that slow down the oxidation of aluminum and belong to the category of inert (carbon dioxide, for example) can be used for these purposes.

In addition, to compensate for the effect of fluidity of molten metal in a liquid bath, specialists have developed special welding technologies . They involve the use of special pads to remove heat when working with aluminum.

Due to the high thermal conductivity of the material, according to regulatory requirements, aluminum welding must be carried out at high arc discharge current values.

At home, to all the described difficulties is added the difficulty of accurately determining the grade of materials being welded and taking into account the relevant requirements of GOST 14806-80. The latter circumstance significantly complicates the choice of a suitable processing mode, as well as the thermal methods used.

Known methods

Welding of aluminum alloys can be organized in a variety of ways, the choice of which is determined by the working conditions and the characteristics of the workpieces or products being joined. Most often, welding is carried out using the following methods:

welding of aluminum in an inert environment using tungsten-coated electrodes;
semi-automatic welding in a carbon dioxide environment with automatic feeding of welding wire;
simple fusion with electrodes treated with a special composition (MMA).

We recommend that anyone wishing to compare these methods in terms of welding operating parameters familiarize themselves with the table:

It follows from the table that the welding method using tungsten electrodes is called AC TIG (translated into Russian as simply tig).

It has already been noted that in order to obtain a reliable connection of aluminum with other metals, it is important to remember the need to destroy the oxide film that is always present on the surface.

To solve this important problem, the welding process uses direct current, the polarity of which is reversed. This achieves the so-called “cathode” sputtering, under the influence of which the refractory film coating is gradually destroyed. When operating on direct current, the polarity of which does not change, this effect cannot be achieved.

Metal preparation

Regardless of the method in which aluminum workpieces will be welded (using an inverter or a conventional rectifier), their cuts and edges are carefully prepared beforehand.

In this case, firstly, traces of oil, grease and dirt are removed from the surfaces of all welded parts (including filler material). For these purposes, white spirit, gasoline, acetone or any other degreasing liquid from the solvent class can be used.

Secondly, at this stage of work, if necessary, the contact part of the workpieces to be welded is cut. The need for additional processing arises only in cases where welding of aluminum parts with a thickness of no more than 4 millimeters is organized using conventional (uncoated) electrodes.

If it is necessary to weld sheets of aluminum and alloys with a thickness of no more than 1.5 millimeters, their ends must be cut before joining.

Thirdly, immediately before welding, the oxide film present on them is removed from the surfaces being processed. For these purposes, use a simple file or a special metal brush.

Covered electrodes

When carrying out particularly critical welding operations (with workpieces more than 4 millimeters thick), special aluminum electrodes are used to ensure the reliability and strength of the resulting joint.

The disadvantages of this method of joining parts include the relatively high porosity of the weld, as well as the difficulty of separating the slag during operation, which often leads to its corrosion.

Another disadvantage of this process is the strong splashing of molten metal particles during arc welding.

To organize welding work on aluminum, it is advisable to use well-tested brands of electrodes, such as “UANA” and “OZANA”.

These types of rods can be used both for working on pure aluminum and when welding workpieces from its compounds with silicon (AL-4, 9.11).

When using “UANA” and “OZAN”, welding operations on aluminum are carried out using direct current, connected to the circuit in reverse polarity. This fact must be taken into account when choosing equipment for welding in any conditions (industrial or domestic). In this case, experts use a simple calculation, according to which there should be 25–30 amperes of direct current per millimeter of rod diameter.

When inverter welding of parts of significant thickness, preliminary local heating of the workpieces may be required, carried out using a conventional gas torch. This precaution allows us to minimize the risks of deformation and the formation of crystallization cracks in a ready-made aluminum structure.

To all of the above, it should be added that due to the high melting rate of aluminum electrodes, they should be worked with as quickly as possible, thereby ensuring continuity of the welding process. We also draw attention to the fact that when welding aluminum, it is not allowed to produce any transverse oscillatory movements with the electrode.

Using inert gas

According to GOST 7871, when welding aluminum in a shielding gas environment, wire of the appropriate composition, designed specifically for these purposes, must be used. It details the brands of material used, as well as the special conditions for its use during the work process.

This welding is carried out through the use of tungsten electrodes of the appropriate diameter, as well as a special filler wire in the form of rods (the so-called “filler”). Chemically pure helium or argon are used as a protective medium that limits the access of oxygen.

In this case, to facilitate the removal of the oxide film from aluminum, a welding arc is used, formed by an alternating voltage source. Argon consumption, current modes, as well as parameters of electrodes and welding wire are selected according to special tables.

If you have your own consumables, this type of installation operation is quite feasible at home with the possibility of obtaining a high-quality and fairly reliable connection.

It should always be remembered that during welding of aluminum in an inert gas atmosphere, an angle of approximately 70-80 degrees must be maintained between the electrode and the surface of the parts. The welding wire and tungsten electrode are positioned at an angle of 90° relative to each other, and the arc length is maintained within 1.5-2.5 millimeters.

Semi-automatic

Good results when independently welding parts made of aluminum and steel can be achieved using pulse semi-automatic machines. When working with such equipment, the oxide film is broken due to the action of a high-voltage pulse, which also retains particles of molten metal within the weld pool.

The cost of a pulse device is quite high, so private owners often use conventional equipment, converting it into a semi-automatic device.

It should be noted that when working with aluminum in any welding modes, it is necessary to take into account two important points related to the supply of wire to the joint zone.

Firstly, relatively soft wire material when entering the welding zone along the guide sleeve can form loops. To prevent this, the solder is supplied to the work station through a shortened supply channel with a Teflon liner, which significantly reduces the effect of friction.

Secondly, the speed of movement of aluminum wire, the melting threshold of which is below normal, in welding mode without argon should be greater than that of ordinary steel. If this condition is violated, it will melt before reaching the working area.

Source: https://svaring.com/welding/soedinenie/svarka-aljuminija

Welding aluminum semi-automatically with gas (argon) and without

Devices in which a wire acting as an electrode and shielding gas are supplied to a welding gun when a button or trigger is pressed have appeared for quite some time. Their initially high price gradually decreased.

They appeared not only in the arsenal of large enterprises, but also became available to people wishing to purchase such equipment for their own needs.

And yet, despite the significant number of articles and videos posted online, the conditions under which this process takes place remain not very clear to many.

Let's dispel the myths

We will try to clarify a topic that interests many. And to avoid misunderstandings, let’s try, first, to get rid of the speculations and myths that haunt popular technology.

Pure aluminum is almost never used in production because it does not have all the necessary mechanical properties. In most cases, manufacturers have to deal with aluminum alloys or, at a minimum, metal saturated with various additives.
Pure aluminum is toxic, but is not capable of causing harm to humans upon contact, since it is almost instantly covered with an oxide film. Thus, we come into contact with aluminum oxide and the statement that before welding the metal oxides should be removed from its surface loses all meaning. In fact, the surface of the parts to be welded must be cleaned of contamination.
In atmospheric conditions, welding aluminum semi-automatically without gas is impossible. The place where the suture is applied must be protected from the influence of the external environment. Even if the gas is not supplied with the welding wire, it is generated when the flux used is burned, thus providing the necessary protection. There are electrodes with a coating that releases protective gas during combustion, but they are not used in semi-automatic devices.
Mig welding is not the name of the technology, but a term that appeared in our country thanks to the appearance of MIG brand semi-automatic machines on the market. In fact, aluminum welding can be carried out using equipment from any company; fortunately, there is now no shortage of different manufacturers. The main thing is that the device used is of high quality and in good working order. Is it possible to make a semi-automatic welding machine yourself? In principle, yes, but will it be cheaper than the factory one and meet all the necessary requirements?

Facts are stubborn things

Having finished with the myths, let's move on to the real facts that really influence the work with promising, but not very obedient material.

The simplest way to ensure protection of the welded area of the parts from the influence of the external environment is to supply argon under pressure. This noble gas is quite accessible, although it is somewhat more expensive than carbon dioxide used when working with steel. Good results are obtained by using a mixture of argon and helium. Since we have already found out that welding aluminum semi-automatically without argon is impossible, then in the absence of gas we will have to get flux somewhere.
The composition of fluxes for aluminum welding, as a rule, includes salts of alkali and alkaline earth elements and, in small quantities, fluoride components that activate the chemical process. There are many recipes of different compositions, selected depending on the characteristics of the metal with which you have to deal. Thus, AN-A1 and AN-A4 fluxes are well suited for welding widely used aluminum-manganese alloys. When using them, the connecting seam is smooth, uniform and does not contain foreign inclusions.
Even when using shielding gas, the best results can be obtained by treating the surface of the parts to be joined with flux. However, such processing takes some time and slows down the progress of work.
In industrial conditions, it is best to use equipment that uses the principles of pulsed welding for work. It is with its help that the optimal result is achieved. Due to the relative complexity and high cost of such equipment, inverter semiautomatic welding machines are becoming increasingly widespread. Without being too inferior in quality as a connecting seam, they are simpler and can easily be used even at home.
Particular attention should be paid to the quality of the welding wire. Its chemical composition varies and must be selected taking into account the chemical composition used for the manufacture of aluminum alloy parts. Low-quality wire, which does not have a uniform cross-section and has low mechanical properties, makes work difficult and often leads to equipment damage.

Special requirements

The mechanical characteristics of the wire used for aluminum welding force certain requirements to be placed on the design of semi-automatic machines and their operation.

It is unacceptable that the length of the supply hose exceeds three meters, and its protective braiding is prone to twisting or kinking. It is important that the channel through which the wire passes is as smooth as possible, without sharp turns. It is optimal if the supply channel itself is made of Teflon.
The feed mechanism must pull the wire without jerking, providing minimal mechanical impact on its surface. Its components should be inspected promptly for damage and lubricated frequently to ensure free rotation of the rollers.
The best results can be obtained with equipment whose design provides for the possibility of smooth and precise adjustment of all parameters. Everything is important - the current strength, the speed at which the wire is fed, the amount of incoming gas. Since the influence of the external environment can affect the quality of the weld during its formation, stopping the gas supply should not occur simultaneously with turning off the current, but with a delay of about 5 - 7 seconds.

Semi-automatic welding of aluminum requires certain skills and craftsmanship from the specialist involved in it. And although watching a video of how professionals work is not a problem, you should not follow their recommendations recklessly.

This information is best used as a starting point from which you can experiment and gain experience yourself.

This is important because materials that differ in composition and thickness behave differently, as do semi-automatic devices produced by different manufacturers.

Advantages and disadvantages

To summarize, it is worth noting that semi-automatic welding of aluminum is convenient, but still not ideal. It has its advantages and disadvantages.

When assessing the benefits, the following are undoubtedly worth mentioning:

Relatively low cost of the process compared to other technologies. Thanks to this, it is accessible to both large enterprises and private professionals.
Versatility of equipment. It can be used to weld various materials. It is enough to simply replace the gas and wire supplied to the welding gun and make not too complicated adjustments.
Availability of necessary materials. As the technology grew in popularity, there was no shortage of wire, gas and fluxes.
High speed of work execution, preparation for which also does not take much time.

As for the disadvantages, they include:

Mandatory use of shielding gas or fluxes. Without them, the connection quality will be extremely low
The difficulty of selecting welding wire in the absence of information about the composition of the material from which the parts are made.
The speed of the process requires skill from the welder. People with poor reactions may not be able to master aluminum welding with a semi-automatic machine.

You can delve into the features of technology for a very long time, because a lot of serious scientific ponds have been written on this topic. But we hope that the information presented will be enough to evaluate the capabilities of the process at the first stage and decide on the need to use it.

Source: https://svarkalegko.com/tehonology/svarivaem-alyuminij-poluavtomatom.html

Welding aluminum with argon: step-by-step instructions for beginners, video

The most effective way to create a permanent connection of parts made of aluminum and alloys based on this metal, as practice shows, is welding aluminum with argon.

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Any welding technology that involves the use of shielding gas requires the use of special equipment, as well as the welder having the appropriate knowledge, qualifications and experience in performing such work.

In addition, it is necessary to have at least basic knowledge in the field of metallurgy in order to understand what processes take place in the weld pool.

Aluminum argon arc welding process

Applications of TIG aluminum welding

The properties of aluminum and its alloys allow them to be used in almost all industries:

food (tanks, pipelines, etc.);
aviation (light and durable, it is also called volatile material);
automotive (cylinder heads, propellers, etc.)

Healthy! To make the weld seam beautiful and of high quality, tig welding of aluminum with argon is used.

This method is also used when welding joints under ultrasonic and radiographic control. It is impossible to master the method without understanding the characteristics of the material during welding.

Why is aluminum difficult to weld?

Experienced welders know that the Al welding process is one of the most difficult. Working with it requires the worker to have certain skills and, of course, knowledge. In this case, argon welding of aluminum is no exception. Below are some facts that a welder must know:

Oxide film, which is the main “enemy” when welding. Its melting point is more than 2000 C, although aluminum itself begins to melt at 660 C. The oxidation of pure aluminum in air occurs very quickly, forming the same aluminum oxide Al2O3.
It is necessary to clean the metal before welding. This is the key to breaking the oxide layer. Does not change color when heated. It is difficult to monitor the degree of heating of the part, which is why, especially for beginners, burns are observed and molten metal leaks.
It takes a lot of energy. Unlike steels, volatile metal has high thermal conductivity, it is several times higher. Welding aluminum with argon requires a large amount of energy. Moreover, when connecting large parts, it will not be superfluous to preheat it. High thermal conductivity and low melting point can lead to burnout of parts.
The need to fill the crater. And one more technological feature: after the end of the welding process, at the end of the seam, a crater is formed, this happens because the aluminum alloy quickly hardens. To ensure the elimination of this defect, a special mode is provided in welding machines. When welding is completed, increased current flows to the electrode. It is used to break through the oxide film at the beginning of welding, and to weld the crater formed at the end.

We recommend! GOST methods for welding channels together

What needs to be taken into account when carrying out work?

Argon welding is used to join many homogeneous metals and alloys. The principle of operation of this equipment is the formation of an electric arc between a tungsten electrode and a metal surface, which allows the creation of a welding seam. A flow of inert gas is supplied to the surface being treated.

When carrying out work, a number of features should be taken into account:

Formation of an oxide film. The film can be melted at a temperature of 2000 degrees Celsius. At the same time, aluminum melts at 500 degrees. To make a high-quality seam, you must first clean the workpiece from the oxide film. This can be done with a brush or solvent.
Hygroscopicity. Aluminum actively absorbs moisture from the environment. When the workpiece is heated using a welding arc, the material begins to release accumulated moisture. To ensure a better quality weld, welders recommend preheating the workpiece to 150 degrees.
Cleaning the treated surface from air. To do this, you need to set the correct argon flow. If there is not enough gas, the material will foam. The tungsten rod will be damaged. When too much gas comes in, it will prevent the seam from forming. Increased consumption will make the process of joining workpieces more expensive.

When welding with argon, difficulties arise in forming a seam. Beginners often end up with a recess (crankcase). This is due to prolonged heating of the surface. To avoid this problem, you need to set the arc attenuation mode correctly. With a uniform decrease in temperature, you can achieve a high-quality seam without the formation of a crater.

Preparing metal for welding

Without preliminary preparation of the surface of the welded edges, it will be impossible to achieve a high-quality connection.

Mechanical method

The oxide film is cleaned using:

sandpaper;
scraper;
metal wire brushes

It is advisable to use a brush with a stainless steel wire with a maximum diameter of 0.15 mm. When processing with emery, the metal may become contaminated, so the use of the last two methods is most preferable. They are carried out immediately before welding

Important ! Whatever brush you use, make sure it is used exclusively for aluminum.

The reason for this is the possibility of introducing particles of another metal, which in turn significantly reduces the reliability of the welded joint. The use of an attachment for an angle grinder or electric drill is not recommended, as it contributes to the introduction of oxygen into the metal. When strongly pressed, it destroys the structure, leaving pores in the aluminum, which can create additional difficulties during argon welding of aluminum. In industry, special brushes are used for these purposes.

Chemical method

The destruction of the oxide film is achieved by etching for 1 minute with the following composition:

1l. Water
50g. caustic soda
45 g sodium technical fluoride

Then you should rinse the workpieces in running water and light it.

Important! Chemical cleaning allows you to preserve the surface of aluminum and its properties for 3-4 days.

I would like to note that preparation requires not only the metal being welded itself, but also the filler rod in the form of aluminum wire. To obtain good results, it is recommended to perform the following operations:

Solvent washing, no degreasing required;
Etching at a temperature of 60-70 °C in a 15% nm technical sodium solution;
Cold water rinsing;
Drying;
Calcination for 15-30 minutes. temperature 300 °C in atmospheric air

Source: https://instanko.ru/osnastka/svarka-alyuminiya.html

Choosing a welding shielding gas

Shielding gas plays a vital role in the process of creating a high-quality welded joint for the following types of welding:

MIG - Metal Inert Gas. A method of arc welding in a protective atmosphere of inert gas using a consumable electrode in the form of steel or other wire, depending on the type of metal being joined.
MAG - Metal Active Gas. The same method of semi-automatic welding, but in an active gas environment.
TIG - Tungsten Inert Gas. Technology of arc welding in an inert gas environment with a non-consumable electrode.

Why is shielding gas needed in welding?

The weld pool is exposed to the negative influence of oxygen from the atmosphere, which can weaken the corrosion resistance of the weld, reduce its strength and lead to the formation of pores. The gas flow encloses the weld pool in a protective shell, protecting it from harmful external influences of atmospheric air, thereby protecting the solidifying molten weld from oxidation, as well as from impurities and moisture contained in the air.

Types of protective gases.

Inert. A type of gas that does not chemically interact with the heated metal and does not dissolve in it. Designed for welding aluminum, magnesium, titanium and their alloys, which when heated are prone to vigorous interaction with oxygen, nitrogen and hydrogen.

Example: Argon, Helium, Nitrogen (only when welding copper and copper alloys).

Active. They enter into a chemical interaction with the metal being welded and dissolve in it.

Example: Carbon dioxide, Hydrogen, Oxygen, Nitrogen.

Colorless, non-toxic, explosion-proof gas, tasteless and odorless. Typically used for TIG welding of all materials and MIG welding of non-ferrous metals such as aluminum. Argon is chemically inert, which makes it suitable for welding reactive and refractory metals. This gas has low thermal conductivity and ionization potential, resulting in low heat transfer to the outer region of the welding arc. As a result, a narrow arc column is formed, which in turn creates a welding seam profile traditional for welding in pure argon: deep and relatively narrow. Stored and transported in gray cylinders with green inscription.

Lighter than air, odorless, colorless, tasteless, non-toxic. It is a monatomic inert gas. Most often used for TIG welding of non-ferrous metals and for overhead position welding. Has high thermal conductivity and ionization potential. When welding with helium, the profile of the weld is wide, well wetted along the edge and with a fairly high heat input. Due to these features, it is most often used as an additive to argon and is used for welding chemically pure or active metals, aluminum or magnesium alloys, to ensure a large penetration depth. Stored and transported in brown cylinders with white lettering.

Carbon dioxide provides fairly deep penetration, so it is popular when welding thick metal. The disadvantages of welding in a carbon dioxide environment include a less stable welding arc, leading to large spatter formation. It can also only work on a short arc. Typically used for semi-automatic short arc MAG welding and MAG cored wire welding. Stored and transported in black cylinders with yellow inscription.

Welding gases used as components of the welding gas mixture:

Gas mixtures have higher technological performance than pure gases. When using them in the welding process, we get: fine-droplet transfer of liquid metal, the formation of a high-quality seam, and a reduction in losses due to spattering.

Oxygen is a diatomic, active protective gas. Typically used for MIG MAG welding as one of the components of the welding mixture, in a concentration of less than 10%. Oxygen provides a very wide weld profile with shallow penetration and high heat input to the metal surface. Oxygen-argon mixtures have a characteristic weld penetration profile in the form of a “nail head”. Oxygen is also used in ternary mixtures with CO2 and argon, where it provides good wettability and the benefits of jet transfer. Stored and transported in blue cylinders with black lettering.

Hydrogen is a diatomic, active gas. Used when welding austenitic stainless steel to remove oxide and increase heat input. The result is a wide weld seam with increased penetration. The concentration in the welding mixture is usually no more than 10%, and when plasma cutting stainless steel from 30 to 40%. Stored and transported in green cylinders with red inscription.

Nitrogen is used least often for protective purposes of the weld pool. It is mainly used to improve corrosion resistance in duplex steels. Stored and transported in black cylinders with yellow inscription.

Welding gas mixtures:

They differ from chemically pure gases by higher technological indicators. They allow for fine-droplet transfer of liquid metal, form a better-quality seam and reduce losses due to spattering. Using a combination of welding gases, it is possible to increase the productivity of the welding process, increase the penetration depth, stabilize the electric arc, and improve the quality of the welded joint.

	TIG welding	MIG/MAG welding
Welding gas or mixture	steel	stainless steel steel	aluminum	steel	stainless steel steel	aluminum
Argon (Ar)	+	+	+	+
Helium (He)	+
Carbon dioxide (CO2)	+
Ar/CO2 mixture	+	+
Ar/O2 mixture	+	+
Ar/He mixture	+	+	+	+
Ar/CO2/O2 mixture	+
Ar/H2 mixture	+
He/Ar/CO2 mixture	+
Ar/He/CO2 mixture	+	+

The cost of welding gas compared to the overall cost of welding:
Do not underestimate welding gas by focusing solely on the equipment. If you carefully approach the issue of correctly selecting the required shielding gas, this will affect not only the quality of the welded joint and its geometry, but will also help avoid the costs of correcting defects and processing the final seam. Also, the choice of a suitable gas affects the consumption of welding materials by reducing spatter.

Source: https://www.svarbi.ru/articles/vybiraem-svarochnyy-zashchitnyy-gaz/

Welding gas: what it is, where it is used, features of use, pros and cons

Beginning welders usually try to use simple welding methods. Most people use manual arc welding.

For most repair work or the manufacture of simple parts, this is enough. However, sooner or later you will want to try something new and improve your skills.

The next step after manual welding can be welding using semi-automatic equipment. With this method, shielding gas is used to protect the surfaces being welded from oxidation.

Below you will find out which one and how to use it for welding work.

Welding gas

Semi-automatic welding uses inert gases such as argon, helium, carbon dioxide. Less commonly used are hydrogen, nitrogen and oxygen. It is served in cylinders of various sizes.

The most common volume is 40 liters. During welding, the gas forms a protective zone that protects the arc from exposure to the atmosphere, and the welded surfaces from oxidation and pores. When using it, the seam turns out smooth and of high quality.

Experienced welders know the recipes for mixtures, the use of which allows you to take advantage of the advantages of each of the gases that make up the mixture.

Characteristics

Let us dwell in more detail on the various types of gaseous substances used for welding work.

Most often used for these purposes. There is even a separate welding method that uses its name - argon arc. Inert, colorless and odorless, not chemically active towards metals and other substances. Much heavier than air, due to this it creates a reliably protected zone in the welding area.

It comes second in popularity. It is also inert, however, unlike argon, helium is lighter than air. Due to this, much more is consumed.

Considering that its cost is noticeably higher than that of argon, this is a significant drawback. However, this does not prevent its frequent use.

It is especially widely used when working with metals coated with an oxide film. These are metals such as stainless steel, aluminum, etc. When using helium, metals melt evenly, which is especially important when welding parts of large thickness.

In addition to pure helium and argon, mixtures are often used. The most common proportion is 60% helium and 40% argon.

The mixture is quite expensive, but it can be used to qualitatively weld materials with high thermal conductivity. The risk of burning through the metal is greatly reduced.

Colorless, heavier than air. Due to this, the welding area is reliably protected. There are two categories. The first category is recommended for use, however, due to its cost and scarcity, attention is often paid to the second category. The big minus of carbon dioxide of the second category is the presence of water vapor in the composition. When used, may cause the formation of pores in the metal. The problem can be avoided by adding some argon to the carbon dioxide.

It is not used in its pure form, as it causes oxidation of the surface, which negatively affects the quality of the seam. It is usually added to mixtures when it is necessary to obtain a wide and shallow joint.

It is colorless and odorless. Typically used for plasma cutting of stainless steel, achieving very good results. When welding other metals, it can cause the formation of defects, such as cracks. Requires increased attention to compliance with safety regulations due to increased flammability.

Also colorless and odorless, non-flammable. Used in liquid and gaseous form. The scope is also narrow; it is used mainly only when welding copper. When welding other metals, it can negatively affect the strength of the seam.

Choosing gas for welding

To make it easier for you to choose the right gas for welding work, we present you with a correspondence table.

Finally

Develop, experiment, try mixtures with different proportions, and you will see how the quality of the weld improves.

If you don’t want to experiment, use reference materials and select the appropriate gas or mixture for your work. We wish you success in your work!

Source: https://prosvarku.info/rashodnye-materialy/svarochnyj-gaz

Advantages of gas shielded welding

One of the most common and frequently used methods of joining two metals is gas shielded welding. The gas used enters directly into the welding zone, preventing the formation of oxides, that is, it prevents oxygen from entering the seam. Thanks to this welding technique, the connections are sealed and clean and comply with state standards.

Manual welding method

Two types of manual electric arc welding are carried out on semi-automatic machines. It can be local or general in a chamber with controlled atmosphere. The first type is used more often and requires less cost. With local exposure, shielding gas is supplied to the welding area from the torch nozzle.

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This method allows you to weld diverse products of any thickness and complexity, but does not ensure 100% weld quality. Where there is a laminar gas flow, the protection works unambiguously, but where the flow is mixed with other substances, the strength of the seam decreases.

Therefore, the welder’s skills also lie in the correct location of the weld pool so that it is located in the source of the flow.

With increased quality, a special camera is applied to the condition of the seam. It creates excessive pressure. Parts and a welding unit with automatic wire feed are placed there. Under such conditions, they work with metals with increased chemical activity, for example, molybdenum or titanium. Then we can guarantee that the joint will be monolithic and meet the required quality standards.

Welding in shielding gases is performed with consumable and non-consumable electrodes.

Pros and cons of semi-automatic welding

The undeniable advantages of manual local welding include:

the strength of the connection is higher than with conventional electric arc welding;
most gases used for welding are low in cost;
for an experienced welder it will not be difficult to master this welding method;
when using shielding gas, it is possible to connect thick and thin metals;
the process speed is much faster;
there are no difficulties in working with materials such as aluminum, non-ferrous and corrosion-resistant metals,
The welding technology is compatible with mechanical and automatic processes.

Disadvantages exist, like any technological operation:

for work carried out outdoors, an additional purchase of a protective screen is required to prevent air vortices from mixing with the gas stream;
For interior work, powerful ventilation or long-term ventilation is required;
When using argon, you will have to spend money on purchasing it. The price of this gas is an order of magnitude higher than the others.

But these disadvantages do not affect the quality of welding, but only require additional preparation.

What gases are used in welding

To protect products from interaction with air, inert and active gases are used. They are designated as MIG (metal inert gas) and MAG (metal active gas), respectively.

Helium and argon are inert gases; when they interact with metal, they form a kind of shell that prevents air from entering the weld pool. Gases do not react with metal and do not dissolve in it. They have proven themselves in working with aluminum, magnesium and titanium. Using a tungsten electrode, the semi-automatic welding process will be optimal for refractory steels, active metals or for welding critical structures.

Nitrogen, carbon dioxide, hydrogen and oxygen are active gases. Working with carbon dioxide has been widely used due to its low price.

Carbon dioxide welding

Inexpensive to produce, carbon dioxide reliably protects the metal from oxidation and is in greatest demand in semi-automatic welding in protective environments.

Due to a chemical reaction when heated, carbon dioxide breaks down into carbon monoxide and oxygen. As a result, three gases enter the weld pool at once, one of which has a negative effect on the metal. Therefore, silicon and manganese are added to the filler wire. They react earlier than oxygen, resulting in the formation of a protective environment that prevents oxidation.

The combination of silicon and manganese produces a light substance that forms slag, but it is easily cleaned off, but the functions of carbon dioxide are not impaired.

Water in a carbon dioxide cylinder is not acceptable. It is necessary to completely remove the remaining water, otherwise a small amount or remaining moisture will spoil the seam. The joint will be porous.

Welding using nitrogen

Nitrogen does not react with copper, so it is used when welding copper parts and some types of stainless steel. Carbon and graphite electrodes are used; it is not advisable to use an infusible tungsten rod, since there is a possibility of overuse.

The arc voltage should be in the range of 22-30 Volts, the welding current in the range of 150-500 Amps, the approximate gas consumption per minute is 10 liters. The nitrogen in the cylinder is stored under a pressure of 150 atmospheres.

The design of the device is the same as for other types of welding using shielding gases, with the exception of a special holder for carbon wire.

Welding equipment

The main parameters of equipment for welding in shielding gases are the following indicators:

large range of welding current that can be adjusted;
selection of voltage for stable arc burning;
wire dispensing speed;
additive thickness.

In most cases, welding inverters are used that are equipped with a current adjustment function with a large plug. Also, the convenience of work includes automatic wire feeding. If you are working with consumable electrodes, use direct or pulsed current.

There are many modes of semi-automatic welding; depending on the welding elements, all parameters change.

It is necessary to carry out all preparatory work before starting the welding process. Carefully remove edges from grease, paint, varnish, rust and other contaminants. Use metal scrapers, solvents and non-cloth rags.

There is a certain algorithm of actions when working with protective gases. First of all, gas is supplied, then the inverter is turned on, then the filler rod begins to flow and the arc is ignited. And only after all these steps do you begin the welding process.

After the arc goes out, gas is still supplied to the welding area for a few seconds. This is necessary to ensure that all air is removed from the metal area.

Based on the thickness and type of alloy, select the appropriate shielding gas. Argon provides a stable welding arc, and with the help of helium, the weld is welded deeper. Hydrogen is used in welding copper products. Argon is considered a universal gas for welding, but its high cost forces welders to replace it with more affordable gases.

Source: https://svarka-weld.ru/preimushchestva-svarki-v-srede-zashchitnyh-gazov

Gas welding of aluminum

Aluminum is a widely used material in industry, as its properties are quite in demand. This happens mainly due to its lightness, but at the same time, this metal has poor weldability properties, which makes it difficult to work with. Gas welding of aluminum also causes difficulties, as does electric arc welding, which uses a welding transformer.

Gas welding technologies

The main problems arise due to the fact that during welding there is a high risk of defects. The expansion coefficient contributes to non-standard shrinkage, so it is necessary to calculate not only the welding modes, but also the thickness of the seam.

In addition, cracks and pores often form, which require the use of a special protective medium to combat them.

When welding aluminum using gas, it is possible to achieve two goals at once, since the gas exerts both a temperature effect for melting and creates a protective environment from external influences.

Defects in aluminum gas welding

In addition, you have to cope with the increased fluidity properties of the material in the molten state. Gas welding of aluminum helps combat some of these types of problems, but it still has its own characteristics that should be taken into account.

After all, argon welding turns out to be a more effective means, but it does not apply to gas welding, since here the main driving force is the electric arc.

An oxidizing film can be created on aluminum, the melting point of which is above 2 thousand degrees Celsius, while aluminum itself melts at less than 700.

Advantages

Gas welding of aluminum helps to carry out the welding process at lower speeds, which gives a higher level, because the welding speed here is approximately three times less than with electric welding;
Here gas is used as protection against external factors;
There is no need to use electrodes with coating, which often contains hydrogen, which leads to the appearance of stress in the metal;
The quality level of the connection is much higher, even if the work is not carried out by an experienced craftsman;
It is possible to create longer continuous seams thanks to the use of welding wire;
Easier to work with thin workpieces;
The burner flame can be used to heat parts and subsequently cool them.

Flaws

The use of gas is always a more dangerous process for human health and life, since there is a possibility of an explosion;
The preparation process, as well as subsequent cleaning, is longer and less convenient;
The use of gas turns out to be a more expensive procedure than the use of electric welding;
A large amount of equipment is involved.

Materials and tools

The conditions for welding aluminum require the availability of all the necessary tools that will help make this process as high quality as possible. This requires:

A gas torch is the master’s main working tool, which supplies gas to the place where metal is welded. There are several models of burners, but they are all very similar to each other, since they serve to remove gas from two sources and adjust the supply parameters;
Hoses – used to connect the burner to the cylinders. They need to be properly stored and carefully looked after, since if they break down, a dangerous situation can arise.
A pressure gauge is a tool for measuring the pressure in a cylinder, which must be present during the process. This is required to monitor the amount of gas remaining in order to comply with the appropriate regimes.
Gas cylinders - aluminum welding can be carried out using oxygen, as the main substance that sets the combustion temperature, as well as acetylene, propane and other associated gases.
Filler wire is the material that will be supplied as the main substance forming the joint seam. The wire grade is selected according to the grade of aluminum or its alloy. When welding aluminum using gas welding, it is required that the wire material be as identical as possible to the base material on the workpiece. If gas welding of aluminum with a thickness of up to 2 mm is carried out, then the wire should be 1-1.5 mm. If the thickness is up to 5 mm, then the wire diameter should be 1.5-3 mm, and over 5 mm - wire 4 and above.

"Important!

Before each use of gas equipment, you need to make sure that it is working properly.”

Edge preparation

Although welding aluminum with a gas torch is easier than electric, the welding depth suffers as a result, so additional preparation of the edges is required. If the thickness of the workpiece is less than 4 mm, then this procedure is not attractive, since the power of the burner will be quite enough to reach such a depth. Otherwise, it is necessary to give the edges of the parts on the connection side a “V” shape.

Preparation of edges for gas welding of aluminum

The bevel angle can be from 30 to 45 degrees, depending on the thickness, since the higher it is, the larger the angle should be. This will require a larger amount of filler material, but this will make the connection better. Processing takes place using a grinder, a file or other metal-cutting tools.

Step-by-step instruction

First of all, you need to understand the parameters. Aluminum welding parameters, depending on thickness, look like this:

Workpiece thickness, mm	0,5—0,8	1	1,2	1,5-2	3-4
Acetylene torch power, liter/hour	50	75	75-100	150-300	300-500

Welding aluminum with a gas torch begins with preparing the material, since aluminum needs to be cleaned of deposits and degreased, as well as stripped of oxide films and prepared edges;
Then you should lay out flux, which will improve the quality of welding and help fight the oxidative film that very quickly appears on the metal;
Then you can heat the metal so that it does not deform due to sudden temperature changes and the flux melts on it;
Then the direct process of aluminum welding begins, by supplying filler material to the place where the weld bead is formed;
When everything is over, it is advisable to gradually reduce the power of the burner, heating the metal to relieve stress from it;
After cooling, the seam must be processed by chipping away the slag and cleaning it to an aesthetically acceptable appearance.

"Important!

Welding of aluminum structures can occur in different modes, so do not forget to change the settings, as this largely determines the quality of the connection.”

Safety precautions

Gas welding of aluminum and its alloys is an unsafe process, like any work with gas. Before each use of the equipment, you need to make sure that it is intact and carefully monitor the pressure gauge reading.

It is advisable to keep the cylinders themselves as far as possible from the flame source, since welding aluminum with a torch produces an open flame, which can lead to detonation.

You also need to make sure that the hoses are not pinched during operation, which can also cause an accident.

Source: https://svarkaipayka.ru/tehnologia/svarka-alyuminiya/gazovaya-svarka-alyuminiya.html

Selection of welding shielding gas

Welders and welders often overlook the shielding gas they use and its contribution to the welding process.

Shielding gases affect the metal transfer mode, the properties and geometry of the weld, smoke and many other characteristics of the weld.

The correct choice of shielding gas for metal arc welding processes such as TIG welding and semi-automatic MIG MAG welding can dramatically improve weld speed, weld quality and penetration depth.

Clean welding gases

The clean gases used for welding are argon, helium, and carbon dioxide. These gases can have both positive and negative effects on the arc welding process and the appearance of defects in the weld.

Argon 100% argon is commonly used for TIG welding of all materials and MIG welding of non-ferrous metals. Argon is chemically inert, making it suitable for welding reactive and refractory metals. This gas has low thermal conductivity and ionization potential, which results in low heat transfer to the outer region of the welding arc. As a result, a narrow arc column is formed, which in turn creates a welding seam profile traditional for welding in pure argon: deep and relatively narrow.
Helium Helium is also a monatomic inert gas, and is most often used for TIG welding of non-ferrous metals. Unlike argon, helium has high thermal conductivity and ionization potential, which give the opposite effect than when welding in argon. Helium provides a wide weld profile, good edge wetting and higher heat input than pure argon.
Carbon dioxide Carbon dioxide CO2, the active gas, is commonly used for semi-automatic MAG short arc welding and MAG cored wire welding. CO2 is the most common reactive gas used in MAG welding. And the only gas that can be used in its pure form without adding an inert gas. Carbon dioxide is one of the cheapest shielding gases, making it an attractive choice when material costs are a major priority in the welding process. CO2 provides very deep penetration, which is useful for welding thick metal, however, when welding in this gas, the welding arc is less stable, which leads to a lot of spatter. Also, its use is limited to short arc welding and makes jet transfer welding impossible.

Welding gases used as components of the welding gas mixture

Oxygen Oxygen is a diatomic, active shielding gas usually used for MIG MAG welding as one of the components of the welding mixture, in a concentration of less than 10%. Oxygen provides a very wide weld profile with shallow penetration and high heat input to the metal surface. Oxygen-argon mixtures have a characteristic weld penetration profile in the form of a “nail head”. Oxygen is also used in ternary mixtures with CO2 and argon, where it provides good wettability and the benefits of jet transfer.
Hydrogen Hydrogen is a diatomic, active component of the shielding gas, usually used in the welding mixture in a concentration of less than 10%. Hydrogen is used primarily in welding austenitic stainless steel to remove oxide and increase heat input. As with all gases made from diatomic molecules, the result is a wide weld seam on the surface. Penetration is increased. Hydrogen is not suitable for ferritic or martensitic steels due to cracking. Hydrogen can be used in higher concentrations (30 to 40%) for plasma cutting stainless steel - to increase power and reduce slag.
Nitrogen Nitrogen is used least often for protective purposes. It is mainly used to improve corrosion resistance in duplex steels.

THIS IS INTERESTING: How to solder twisted copper wires

Welding gas mixtures

Depending on the welding process and welding materials, many different welding gases and their mixtures are used:

TIG welding	MIG MAG welding
Welding gas or mixture	Steel	Stainless steel	Aluminum	Steel	Stainless steel	Aluminum
Argon (Ar)	X	X	X	X
Helium (He)		X
Carbon dioxide (CO2)	X
Ar/CO2 mixture	X	X
Ar/O2 mixture	X	X
Ar/He mixture	X	X	X	X
Ar/CO2/O2 mixture	X
Ar/H2 mixture	X
Ar/He/CO2 mixture	X	X
He/Ar/CO2 mixture	X

The cost of welding gas against the background of the total cost of welding work

If you look at the distribution diagram of the cost of welding work, you can see that the cost of welding gas is only 2-5% of all welding costs. However, these costs should not be underestimated.

The choice of the correct gas and its quality significantly influence the consumption of welding materials, the geometry of the weld seam and the entire welding process as a whole. The choice of gas also affects the labor expended on correcting defects and processing the weld after welding.

We hope this article was useful to you. On this site you will find many other interesting and useful articles. Thank you

Smart Technics

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Read 62754 times Last modified Friday, 06 December 2013 06:37

Source: http://www.Smart2Tech.ru/vybor-svarochnogo-zashchitnogo-gaza

Which shielding gas to use when welding and cutting: choice and features | Tiberis

Auto repair shop workers, installers and other welding specialists often use natural gas and various gas mixtures during welding. You will learn about what types of gases there are, their features and properties from our article. We will also provide recommendations on the selection and use of one or another shielding gas for different welding methods and depending on the material being welded.

Why are shielding gases needed when welding and cutting?

Shielding gas is an important component that ensures productivity and decent quality of the welding process.

The name of the shielding gas speaks for itself; it is needed to protect the hardening molten weld seam from oxidation, as well as from moisture and impurities in the air that can reduce the resistance of the seam to corrosion processes, lead to the appearance of pores and weaken the strength of the seam, affecting the geometry of the weld connections. In addition, the shielding gas cools the welding gun.

What types of gases are used for welding and cutting: their properties and application features

Inert and active gases, as well as their mixtures, are used as shielding gases used for welding.

1. Inert gases for welding . Inert gases are gases that are not capable of chemical reactions and are practically insoluble in metals. The atoms of such gases are endowed with outer electron shells filled with electrons, which explains their chemical inertness. These include argon, helium and their mixtures.

Argon ( Ar ) is an inert gas that does not enter into chemical reactions with molten metal and other gases in the arc combustion zone.

The advantages of this inert gas include the fact that it is 38% heavier than air; argon displaces it from the welding zone and reliably isolates the weld pool from contact with the atmosphere.

Most often, Ar is used as a shielding gas in the process of argon arc TIG welding and MIG/MAG welding. Examples of metals welded using argon and application features are given below in Table 1.

Argon is in demand as a shielding gas:

in construction and mechanical engineering (when welding parts made of high-alloy steel; rapid cutting of metals, including thick sheets of refractory metals);
in the mining industry and metallurgy (metal smelting; removal of gas inclusions from liquid steel).

Helium ( He ), like Ar, is chemically inert, but differs from it in that it is much lighter than air, which makes protecting the weld pool a more complex process that requires large amounts of shielding gas.

Helium is used as an inert shielding gas during welding of stainless steels, non-ferrous metals and alloys, active and chemically pure materials. It provides increased penetration, and therefore is sometimes used to melt thick metal sheets or obtain a specially shaped weld.

But due to the increased consumption and high cost of helium compared to argon, its scope of application is quite limited.

Helium (He) is used as a shielding gas:

when welding stainless steels, non-ferrous metals and alloys, chemically pure and active materials.

1.1. Inert gas mixtures usually include argon and helium. Having a higher density than helium, such mixtures provide more reliable protection of the weld pool metal from air.

If it is necessary to weld chemically active metals, an inert mixture containing 60-65 vol. is often used. % He, 40-35 vol. %Ar. Inert gas mixtures are noticeably more expensive than pure argon, but provide a more intense release of heat from the electric arc at the welding site. This is significant for semi-automatic welding of metals characterized by high thermal conductivity.

2. Active gases for welding . These are gases that protect welding from air access and at the same time enter into chemical reactions with the metal being welded or physically dissolve in it.

Carbon dioxide ( CO2 ) (carbon dioxide) is a colorless, non-poisonous gas, soluble in water, and heavier than air.

Carbon dioxide gas for welding should not contain mineral oils, glycerin, hydrogen sulfide, hydrochloric, sulfuric and nitric acid, alcohol, ethers, ammonia, organic acids and water. Due to the rarity of grade 1 welding carbon dioxide, grade 2 welding carbon dioxide and food grade carbon dioxide are used for welding.

But, an increased content of water vapor in such carbon dioxide during welding leads to the appearance of pores in the seams and a decrease in the plastic properties of the welded joint.

In the welding process, solid carbon dioxide can also be used, corresponding to GOST 12162-66 of two grades - food grade and technical grade. When welding low-carbon and low-alloy structural steels, a gas mixture of carbon dioxide and oxygen (CO2 + + O2) is also used. Use a mixture that includes 30 vol. % oxygen. The mixture of CO2 + O2 has a more intense oxidizing effect on liquid metal, in contrast to pure carbon dioxide.

Carbon dioxide is used as a protective agent:

in construction and mechanical engineering (electric welding; fine sharpening processes, cold fitting of machine parts)

Oxygen ( O ) is included in the gas mixtures CO2 + O2 and Ar + O2. It is a colorless, odorless gas that supports combustion. In case of cooling to a temperature of -183 degrees. Celsius, oxygen turns into a mobile blue liquid, and at a temperature of -219 degrees.

Celsius freezes. Oxygen guarantees a very wide weld profile, characterized by shallow penetration, and also provides a high heat input to the metal surface.

Oxygen-argon mixtures are distinguished by a special weld penetration profile, reminiscent of a “nail head”.

Oxygen as a protective gas is sometimes necessary:

in construction and mechanical engineering (oxygen-acetylene gas cutting and gas welding of metals, surfacing and spraying of metals, plasma cutting of metals)

Hydrogen ( H ) is colorless, odorless, and flammable. Hydrogen is not suitable for martensitic or ferritic steels due to cracking, but can be used in concentrations of 30 to 40% for plasma cutting stainless steel to increase power and reduce slag.

Hydrogen has found application in atomic hydrogen welding.

Nitrogen ( N ) is a colorless and odorless gas that does not burn and does not support combustion. In accordance with GOST 9293-59, nitrogen comes in four grades: electric vacuum, gaseous gaseous 1st grade, gaseous 2nd grade and liquid. The inclusion of nitrogen in these varieties must be, respectively, no less than vol.%: 99.5; 99.9; 99 and 96. The main impurity in each of them is oxygen.

Nitrogen is most often used as a shielding gas:

2.1. Mixtures of inert and active gases are increasingly used in the process of consumable electrode welding of steels of various classes due to their technological advantages. These include:

high arc stability, favorable character of electrode metal transfer through the arc,
the degree of chemical action on the metal surface of the weld pool is lower when compared with active gases.

The addition of a small amount of oxygen or other oxidizing gas to argon significantly increases the stability of arc combustion and improves the quality of formation of welded joints. Oxygen in the arc atmosphere provides fine-droplet transfer of the electrode metal.

Selecting a gas for a specific type of metal being welded

What gas is used when welding a particular metal is one of the most frequently asked questions for beginners in welding on thematic forums. Examples of the use of various shielding gases and gas mixtures for welding various metals are given in the table.

Metal to be welded	Shielding gas used in welding	Features of the welding process
Carbon steel	75% Ar+25% CO2	High speed of the welding process without burning through metal up to 3 mm thick, minimum deformation and spatter formation
CO2	Deep penetration, high welding speed
Stainless steel	90% He,5% Ar+2.5% CO2	No oxidation of the welded metal and no burn-through, small heat-affected zone,
Low alloy steel	60-70% He+25-35% Ar+4.5% CO2	High impact strength, minimal reactivity,
75% Ar+25% CO2	Sufficient strength, small spatter along the contour of the welded joint, high arc stability.
Aluminum and its alloys	Ar	Stable arc and excellent transfer of electrode material during the welding process of thick parts. up to 25 mm
35% Ar+65% He	Greater heat input compared to welding with pure argon, improved fusion characteristics, used when welding thick metal. 25- 76 mm
25% Ar5% He	Maximum heat input, low porosity, used when welding metal over 76 mm
Magnesium alloys	Ar	Impeccable seam quality (cleanliness)
Stainless steel	Ar-1%O	Improved arc stability, good weld bead fusion, more fluid controllable weld pool, minimal burn-through when welding heavy stainless steels
Ar+2% O	Stable arc, fusion and welding speed than 1% oxygen, used for welding thin stainless steels
Carbon steel	Ar+1-5% O	Improved arc stability, excellent weld bead contour fusion, more fluid controlled weld pool, minimal burn-through, faster welding speed compared to pure argon welding
Ar +3-10%	Beautiful weld seam, welding only with electrode positioning, minimal spatter formation
Low alloy steels	Ar+2% O	Low risk of burn-through, weld strength
Titanium	Ar	Good arc stability
Copper, nickel and their alloys	Ar	It is characterized by good fusion, reduced metal fluidity, and is used for welding thick metal. up to 3 mm
Ar+80-75% He	Characterized by increased heat input
Copper, duplex steel
N	Demanded for protecting the root of the seam. Reduces the formation of oxide films at the root of the weld

By correctly determining the type of shielding gas, you will ensure the efficiency and quality of welding, as well as guarantee an excellent welded joint and penetration depth, increase the reliability of the created seam and the quality of the part. The selection of a suitable shielding gas and its quality significantly influence the consumption of welding consumables, the labor of the welder and the correction of defects and the final processing of the weld joint.

If you have any questions on the topic, we recommend that you find the most up-to-date information on our website, or directly contact Tiberis consultants.

Source: https://www.tiberis.ru/stati/vybor-zashhitnogo-gaza-dlja-svarki

Gas welding of aluminum

Gas welding of aluminum is a widely used process in industrial applications, since aluminum has sought-after properties that are irreplaceable. In general, this process is considered to be correspondingly easy, but the metal has poor weldability properties, which makes it difficult to work with. Gas welding has several negative nuances, just like electric arc welding, which works with a welding transformer.

The main difficulties arise because there is a high chance of marriage. The expansion coefficient contributes to non-standard shrinkage, so it is worth monitoring both the welding modes and the thickness of the seam. Despite this, various microcracks and pores often arise, for the protection of which a special environment is used.

When welding aluminum using gas, two goals can be achieved at once, such as the temperature effect for melting, and the presence of a protective environment from harmful external factors.

Despite all this, we have to contend with the high fluidity properties of aluminum in the molten state. Gas welding helps to cope with such situations, but still it has its own abilities that should not be forgotten.

Argon welding is a very effective method, but it has no relationship with gas welding, since the main source here is an electric arc.

The main problem is removing the oxide film, which melts at a temperature of 2000 degrees, while the melting of aluminum begins at 700.