Argon welding for beginners: technology, equipment

2024 Author: Aaron Duncan | [email protected]. Last modified: 2023-12-16 03:30

The most common and reliable way of joining various metal parts is welding. But there are a number of metals that are very difficult to combine in the usual way. To create a strong one-piece contact of metals such as titanium, aluminum, stainless steel and many others, argon welding is used. For beginners, the technology is somewhat difficult.

Features of argon welding

Connection of metal surfaces occurs in the zone of action of argon. The use of an inert gas in the welding of metals is a kind of protective barrier against the oxidation process, which occurs as a result of interaction with oxygen in the surrounding air. It is easier to say that the inert gas covers the place of welding from the penetration of oxygen into the area of the parts to be joined.

All argon welding technology involves manual, semi-automatic and automatic work. It is from the methods of welding and the type of electrode used that the qualification of the modes of the welding process occurs.

Tungsten wire is used as a non-consumable electrode, which guarantees a reliable connection of metals.

Techniquemaking a connection

Knowing the basic rules of work will make welding with argon much easier, and lessons for beginners will help to achieve a good quality weld.

Some practical tips from experienced welders:

1. The quality of the connection of parts is significantly reduced by a long arc. The longer it is, the wider the seam will be and the shallower the melting depth. A non-consumable electrode must be placed in close proximity to the joint of the products.
2. To create a deep and narrow seam, you need to achieve longitudinal movement of the torch and electrode. Even small deviations significantly impair welding. When welding with argon, special attention and accuracy must be observed.
3. To prevent nitrogen and oxygen from penetrating into the welding zone, the electrode and additive must be in this zone, but under a layer of argon.
4. Feeding wire is a tricky operation, as the jerks cause the metal to splatter. The input of this component is uniform and smooth.
5. If the weld turns out to be convex and rounded, then this indicates a low melting of the metal, which indicates a low quality of argon welding.
6. To create a small seam and its smooth surface, the filler wire must be led in front of the burner and at an angle to the plane of the metal. This condition will allow you to reliably control the entire process of welding with argon.
7. To prevent nitrogen and oxygen from penetrating into the area where the parts are joined, the welding process cannot be read and finished with sudden movements. Work should be started 15–20 seconds after gas supply, and finished beforeburner shutdown.
8. It is necessary to complete the work by reducing the current strength with a rheostat included in the argon welding machine. If you simply take the torch to the side, you can open the access of oxygen and nitrogen to the welding zone.

The main requirement before work is high-quality cleaning and degreasing of the mating surfaces of the product.

The advantages of using this type of welding

Given that argon welding is an effective method of joining metals, difficult to other types of joining, the advantages of its use are based precisely on this property. These include:

1. Small heating temperature of the joined surface, which allows you to keep the shape and dimensions of the part.
2. Inert gas is denser and heavier than air, so it can protect the weld well.
3. The rather high power of the thermal arc contributes to the short-term nature of argon welding.
4. The ability to focus the weld allows you to work in hard-to-reach places.
5. Welding thin parts is easy due to the not very high temperature in the melting zone of the metal.

Disadvantages of argon welding

Like any other connection, argon welding has some disadvantages that must be considered when doing the job. The main disadvantages of such a connection:

1. The presence of a draft significantly reduces the protection of the place of soldering, so it is recommended to carry out work in closedpremises. Only in this case, you need to take care of good general ventilation of the object.
2. If it is necessary to obtain a high-ampere arc, it is necessary to ensure cooling of the connected products.
3. The equipment belongs to the category of complex fixtures, so argon welding for beginners is a difficult process. Only an experienced welder can make the correct setting of the modes.

Argon connection modes

In order for welding to take place with high quality, you need to choose the right optimal mode of operation. Such an action, as a rule, is only possible for specialists with extensive practical experience.

Conditions for the correct choice of welding mode:

1. The direction and polarity of the current directly depend on the properties of the metals being joined.
2. The current strength is determined based on three main characteristics, namely the polarity, the diameter of the electrode used, the thickness and type of material. It is in choosing this parameter that you will need your own experience as a welder.
3. The uniformity of the flow of inert gas affects the consumption of argon. The flow when welding aluminum with argon should be without pulsations.

Composition of equipment

Before you understand the principle of operation of the device, you need to familiarize yourself with the main components of the equipment. For high-quality welding you will need:

1. Welding machine of any type with idling 60-70 volts.
2. Power contactor transmitting voltage to the head fromwelding machine.
3. Oscillator. This is a device that converts standard voltage into 2000-3000V at 150-500kHz, making it easier to start the arc.
4. Ceramic burner.
5. A device designed for blowing with argon.
6. Inert gas tank.
7. Fixing wire and non-consumable electrode.

How the device works

After preliminary cleaning of the surfaces to be joined and setting the desired welding mode, we take the wire in the left hand, and in the right torch. Using the gas supply button, which is located on the torch handle, we supply gas to the welding zone.

The electrode must be inserted into the burner so that it protrudes by about 5 mm. We bring the torch up to a distance of 2 mm from the welding surface. Then we turn on the unit and apply voltage to the electrode until an arc occurs. Argon at this time enters the welding zone.

With the other hand, the welder guides the filler wire into the gap, which melts, forming a joint of metals. Moving gradually along the seam, we completely weld the two parts.

Difficulties in aluminum welding

Aluminum is considered the most widely used material in the industry. Welding it is of great difficulty due to the oxide film, in which the melting is higher than that of the metal. Before you start welding aluminum with argon, you must carefully study all the nuances of the joining process:

1. The main mistake of beginner welders is poor-quality preliminarymetal cleaning. A good metal bond is out of the question if there is dirt, dust or grease on the surface.
2. The low melting point of aluminum and its high thermal conductivity requires a lot of energy from inert gas welding.
3. Aluminum melts at a low temperature, in order to avoid damage to the material, you need to set the correct mode on the inverter.
4. Aluminum welding machine must have a special function that, before welding, it supplies an increased current to melt the film, and at the end to completely weld the crater.

Metal Surface Cleaning

The main condition for high-quality argon welding is a good preliminary cleaning of the metal surface.

Purification is carried out in two ways:

1. The method of chemical treatment contributes to the destruction of the oxide layer on the metal due to the action of a special solution. You can prepare such a composition yourself, for which you need to dissolve 50 grams of technical sodium and 45 grams of sodium fluoride in one liter of water. Next, you need to stir this mass until a solution is obtained. The surface is treated with this composition, after which it is washed off with running water.
2. Mechanical cleaning method involves processing the part with an iron brush or sandpaper. At the same time, it is necessary to ensure that there are no inclusions of other metal on the surface of the cleaning tool, particles of which can significantly impair the final result of the work.

Features of stainless steel welding

Stainless steel is a metal that has high anti-corrosion resistance and great strength, widely used in all weather conditions. The special properties of this metal require special technologies for processing the product. It is the welding of stainless steel with argon that makes it possible to achieve a good quality of the connection of such products.

The main problem when working with stainless steel is its cracking. In addition, there are other features:

1. Due to the low thermal conductivity of stainless steel during the welding process, the temperature in the melting zone must be high, which creates a great risk of burning through the metal. To avoid such a nuisance, it is required to choose a lower current strength than that of ordinary steel.
2. Stainless steel has a high linear expansion, so when welding, there is a large casting shrinkage, which can lead to cracking of the metal. To avoid this, you need to create a larger gap between the parts of the product.
3. Since stainless steel has a high electrical resistance, the electrode gets very hot during welding, which also negatively affects the quality of the connection.

When welding discs with argon, it must be taken into account that the wrong temperature of the welding mode can lead to the loss of the anti-corrosion properties of stainless steel.

Connecting with a semi-automatic machine

The semi-automatic argon welding process significantly increases productivity. Technology of application of welding in semi-automaticmode allows you to get reliable and visually attractive welds.

The main nuance of semi-automatic welding is the need to use nickel as part of the welding wire. If it becomes necessary to weld the pipe with argon, then with a large thickness of the part, carbon dioxide is also added to the protective composition, which improves the miscibility of the welding edges.

The semi-automatic welding process can be carried out using several technologies:

• pulse mode;
• jet transfer;
• short arc.

Safety

When welding in an argon environment, you must follow the rules for safe work. Basically, they are not much different from the rules that must be observed during conventional welding, but there are some nuances:

1. It is important to check gas cylinders for tightness, as the gas in them is under pressure.
2. Don't let the argon leak, because this gas is heavier than air and has no smell. Therefore, its gradual accumulation can lead to suffocation.
3. Work in a protective mask, special shoes and clothes.
4. Strictly follow the rules of electrical safety. Unit equipment must be properly grounded.
5. Special attention should be paid to combating the likelihood of a fire. All flammable objects must be removed from the welding area.
6. It is necessary to prohibit the presence of strangers in the welding area.

Remember thatargon welding allows you to get a high-quality connection of metals, which cannot be done in other ways. A novice welder will have to put in a lot of effort and patience to master all the ways of argon welding.