What is argon welding used for? Why is it simply irreplaceable in certain situations? Answering these questions is not so difficult. The fact is that some metals, such as aluminum, copper or titanium, simply cannot be joined with an ideal seam using standard methods. And here argon welding comes to the rescue.
This technology is not something super complicated, but it has its own characteristics. The quality of work largely depends on the equipment available, the welding method, etc. Only under specific conditions can a reliable and almost imperceptible seam be obtained – this is a priority for any production.
Argon welding technology
Argon welding combines the features of gas and electric arc. From the gas to the technological process, a number of techniques have been taken for creating an integral connection and the use of gas, and from the electric arc, the use of an electric arc.
The electric arc during combustion creates a high temperature, due to which the edges of the parts melt together with additives, resulting in a seam. Argon, namely this gas used in this case, protects the melt from oxygen. But more on that later.
There are a number of features inherent in the welding of most non-ferrous metals, as well as their alloys and alloy steels. They consist in the interaction of molten metals with the air surrounding them: oxygen and its impurities. Being in the molten state, metals begin to actively oxidize.
This interaction has a bad effect on the properties of the welded joint. As a result of the appearance of air bubbles in the molten metal, pores are formed inside the seam. This leads to a decrease in bond strength. In the process of melting, aluminum, under the direct influence of oxygen, begins to burn.
Therefore, it is necessary to protect the weld from the influence of the air on the joined alloy steels and non-ferrous metals. The use of argon as a protective gas is considered optimal, since it effectively protects metals during welding.
Due to the fact that argon is 38% heavier than air, it easily displaces it from the weld pool, protecting the seam. It does not react with metals in the molten state and with other gases in the melt zone. In the case of reverse polarity welding with argon protection, we must not forget that the gaseous medium is easily transformed into a plasma conducting current. This is due to the flow of electrons that are separated from the argon atoms.
Work in an argon medium can occur using two types of electrodes: melting and non-melting. The latter are tungsten rods, which are known to be quite refractory. In order to choose the appropriate diameter of such electrodes, you need to look into a special guide. Most often, the choice depends on the material of the workpieces.
2 main methods of argon welding
The type of welding is selected depending on the material with which to work. A qualitative result can only be obtained by choosing the optimal welding method in each case.
The most popular argon welding. It is performed manually using piece electrodes.
Main features of argon welding:
- High speed of work.
- Relatively low welding temperature.
- Lack of filler material.
- Neat and thin enough seam.
The second most common is argon arc welding. It is widely used in industry. It is carried out both by manual and automatic methods using tungsten piece electrodes and filler wire. Specialists consider this welding more complicated and time-consuming than argon. However, this method also has its advantages:
- Sufficiently high labor productivity, which is difficult to achieve with manual welding.
- The ability to weld materials such as carbon and alloy steel.
- High quality seam.
However, the choice of the connection method depends not only on the equipment, but also on the welding material. In most cases, these methods are interchangeable. Most often, they prefer argon-arc welding. When choosing equipment for welding, it is worthwhile to dwell on units with alternating and direct current, despite their high cost, but they can be used when working with almost any metal.
Argon arc welding gives a high-quality result, but in this case, work requires good equipment, high-quality consumables and highly qualified personnel.
Types of equipment for argon arc welding
There are several types of argon welding, which depend on the level of mechanization of the process:
For each welding method, certain equipment is necessary, respectively, and the cost of work varies.
In the manual welding method, non-consumable tungsten electrodes are used, the wire is supplied by the master himself, the torch for argon-arc welding moves.
The mechanized method is characterized by the filing of filler rods in automatic mode, while the master himself holds the burner.
Automated welding is completely under the control of the operator – wire feed and torch movement are automatic.
The robotic process eliminates the presence of the operator.
8 rules of argon arc welding
To carry out argon welding, it is necessary to purchase the following equipment: an inverter or a welding transformer, a container with argon, a torch, filler wire or rods. There are a number of rules necessary to perform this type of welding:
- Workpieces (or the welding zone itself) must be cleaned of any kind of contaminants and then degreased.
- Gas supply starts 20 seconds before operation and stops 10 seconds after its completion.
- The arc should be made as small as possible, since with increasing distance of the burner from the surface of the workpiece, the heating zone expands, the melt of the product deepens.
- An even and beautiful seam can be obtained by performing the movement of the burner along the axis of the connection, without departing from it.
- The additive (wire or bar) is fed strictly in front of the burner without any transverse movements. Thus, the seam is narrow.
- The additive and electrode must always be in a protective gas atmosphere.
- Movements should be performed smoothly to avoid splashing of metal and sparks.
- The seam ends with a crater, which is poured when using reduced current. It is impossible to abruptly divert the burner and break the arc, this negatively affects the protection of the connection.
The process of learning argon welding is simple. But patience and practice are required to make smooth, quality joints.
Advantages and disadvantages of argon welding
Argon welding has both pros and cons that must be considered when choosing this method. Its advantages are:
- The lack of deformation of the workpieces due to the high temperature, since it is not necessary to significantly warm up the edges of the parts.
- Argon is an inert gas, therefore, it is heavier than air. This means that oxygen cannot penetrate into the weld pool.
- The arc has a large thermal power, welding occurs at high speed and good quality, if the master has sufficient qualifications.
- Despite some features of argon welding, this process is simple, it is easy to learn.
- Argon welding can connect metals that cannot be combined otherwise.
The disadvantage of argon welding is the impossibility of conducting it in the open air in the presence of strong wind. Argon is carried by the wind, therefore, it does not protect the seam well, so the latter can be of poor quality. In enclosed spaces, welding should only be carried out using forced ventilation. In addition, if it is necessary to use a high-ampere welding arc, it is necessary to decide in advance how the seam will be cooled during work.
Applications for argon welding
What is argon welding used for? It is necessary in cases where welding seams must be performed flawlessly. Especially often with its help difficult to weld materials and workpieces with thin walls are connected. This type of welding is in demand in aircraft and rocket science, the automotive industry. Through this connection, important components are made of aluminum and its alloys.
Most often, argon arc welding is used when working with aluminum, which is difficult to weld, often cracks, and gives strong shrinkage. In addition, in the molten state, this metal is easily oxidized, becoming covered by a refractory film, which prevents the formation of a seam. And only welding in an argon environment will help to obtain high-quality seams.
Such welding is especially in demand at automobile service stations, where using this method of connection the period of operation of parts is significantly extended.
Why use argon welding at car service stations? It can be used in the repair of radiators, various parts of gearboxes, tubes from air conditioners and other elements made of aluminum and its alloys. Soldering and plasma spraying, as well as other welding methods, could not be used for such work, since the parts have technical features.
Argon welding can also be used when working with other materials, such as titanium, copper, duralumin, silumin, cast iron and other ferrous and non-ferrous metals.
Each of the materials has chemical characteristics and nuances of “behavior” during heating, and the master must know them in order to prevent mistakes
When creating forged products, for example, gates, fences, chandeliers, railings, furniture, argon welding is also used. Complex connections of such products are quite difficult to process, and this welding method simplifies the work process, giving the products a beautiful appearance without finishing.
The seams obtained by argon arc welding are almost invisible. This is important not only for obtaining an aesthetically attractive appearance, but also for the strength of the entire structure.
Savings are another reason for using argon welding. Moreover, you can save not only money, but also effort and nerves.
A high-quality result of the work is achieved using argon with various additives. The optimal composition of consumables is well known to professional welders, so they perform their work most efficiently and with high quality.
Argon Arc Welding Safety
When using liquefied gases, it is necessary to strictly observe safety rules. Let’s name its main requirements when using argon:
- It is not allowed to carry out welding near flammable substances.
- it is necessary to remove all foreign objects.
- only certified materials and serviceable equipment should be used.
- Before starting work, it is necessary to undergo preliminary training, to obtain basic theoretical knowledge.
- during the work it is obligatory to use a mask or goggles, preferably “chameleons”.
Despite the fact that argon is harmless enough for the human body, it is better not to inhale it, since it is lighter than oxygen, and therefore simply pushes it. After argon enters the lungs, a person begins to choke. Welding should be carried out in a room with good natural ventilation, otherwise, for the instant removal of combustion products, care must be taken to ensure high-quality constant ventilation.