What is welding

Welder HAPPY what is this?

You are probably familiar with the problem of high-quality welding of special types of metal, such as aluminum, copper or non-ferrous metals. With standard electric welding using electrodes, you will not be able to weld a reliable seam, this is due to the characteristics of the metal and its properties. In such cases, experienced craftsmen are looking for another welding method, and welding in an argon environment comes to their rescue.

What is argon welding and what is the principle of operation? What are the pros and cons of this welding method and how to properly weld metal with argon? In this article we will answer all your questions.

general information

Argon-arc welding - what is it? How does argon welding work? This is essentially the same welding as all the others, the only difference is that the process takes place in an argon environment. Argon is a gas stream that is directed into the welding zone during welding.

Below you can see a diagram of welding using argon. Argon, like any other gas, performs a protective function during welding: it prevents metal oxidation, improves the quality of the weld and speeds up work.

Argon for welding, directed into the welding zone, forms a kind of “Dome”, preventing oxygen from negatively affecting the quality of the seam.

Various special metals, such as titanium, can be welded using argon welding. In this work, you can use consumable and non-consumable electrodes and tungsten wire. Tungsten wire is often used when welding dissimilar metals. Welding is carried out both manually and automatically.

Manual argon welding (RAD welding) is the most common and inexpensive type of argon welding. If RAD welding is selected, it is advisable to use a non-consumable electrode.

There is automatic argon welding using a consumable and non-consumable electrode (labeled AADP and AAD, respectively). We will not claim that manual welding is better than automatic welding or vice versa.

Ultimately, each welder decides for himself which method is preferable for him when performing certain jobs.

Equipment

Several types of welding equipment are used for argon welding. This can be a manual method, when the master holds the torch with his own hands and feeds the wire into the welding zone, or an improved manual method, when the wire is fed using a special device.

There is also equipment with which automatic argon arc welding is carried out.

The torch and wire are fed into the welding zone automatically; sometimes the welder does not even need to monitor this process; he can be replaced by a special operator.

Expensive industries can use robotic equipment that does not require human presence. A program is pre-loaded into the machine, according to which the robot performs welding.

Now let's get down to business. We will tell you how to weld with argon welding so that the work turns out to be of high quality and durable.

How to cook in argon

What is needed for proper welding? Of course, a little theory and a lot of practice. We will tell you the theory, but you will have to do the practice yourself. The more you practice, the faster you can start doing serious work. In the meantime, let's find out what the technology of argon arc welding is and what needs to be taken into account so as not to make mistakes.

First of all, you need to thoroughly clean and degrease the joints of the parts to be welded. Even if there is visually no dirt or corrosion, you still need to clean the metal surface. While working, try to shorten the length of the welding arc. The fact is that a long arc forms a wide, shallow seam. The quality of this connection leaves much to be desired.

Therefore, when working with a non-consumable electrode, try to make the arc as short as possible, bringing the rod closer to the metal surface. But this may not be enough to make the seam narrow and deep.

Move the electrode longitudinally without deviating to the side or performing transverse movements.

It is for this reason that the welder must have a “steady hand” when welding with argon, otherwise the slightest deviation can lead to deterioration in the quality of the welded joint.

The filler wire and electrode should only be placed in the welding area. If you constantly move the rod or wire to the side, you will break the protective properties of argon and oxygen will penetrate into the weld pool. The wire should be fed smoothly and evenly, avoiding sudden feeding. Otherwise, the metal will spatter heavily and deteriorate the quality of the weld.

At first, many craftsmen (especially beginners) find it difficult to understand at what speed to feed the wire. Unfortunately, there is no single norm that will solve this problem. Everything is learned with experience, so experiment. The additive wire must be fed at an angle and in front of the rod. These requirements are mandatory. Failure to comply with them leads to the formation of an uneven seam and complicates the welding process.

It is also not recommended to abruptly start or end the welding process, since unnecessary oxygen is guaranteed to enter the welding zone. We recommend feeding argon welding gas into the welding zone for 20 seconds before starting work.

If you don't do this and simply remove the wire and torch, oxygen will enter the welding area.

As you can see, argon welding requires a lot of patience and at least minimal experience. You can evaluate your work using the penetration indicator. Inspect the seam you made: it should not have a round, convex shape.

If the seam looks like this, it means that it is not fused. In this simple way you can check the quality of the seam and evaluate its strength characteristics.

Of course, this method cannot replace full-fledged quality control using instruments, but you will be able to see the shortcomings of your work at the initial stage.

Welding mode setting

Now that we have figured out how argon welding works, let’s take a closer look at choosing a mode. The quality of the welded joint also greatly depends on this. To choose the right mode, you need to practice a lot and carefully study the theory. We've put together some tips for choosing the right welding mode that we hope will help speed up your learning curve.

So, the welding mode is essentially a choice of the polarity and direction of the current. The choice of welding mode depends on the individual characteristics of the metal (or metals) to be welded. If you need to weld steel structures, set the polarity to straight and constant current. If you need to weld aluminum and its alloys, use direct current and reverse polarity.

It is also important to set the current correctly. This parameter is adjusted based on the thickness of the metal, the diameter of the electrode and the polarity you set. All these parameters are interconnected. Many craftsmen learn through practice what current value needs to be set to perform specific tasks. But we recommend that you first use special tables, one of which you can see below.

  Responsibilities of a 5th grade welder

We said earlier that a high-quality seam is obtained if the arc is short. The same applies to arc voltage. By the way, do not forget about gas consumption in an argon environment. If you work in production, then you will need to monitor this indicator. To reduce consumption, it is better to create a laminar gas flow. Laminar flow is when gas moves uniformly and does not mix or pulsate.

Advantages and disadvantages

Pros:

• There is no need to heat the joints very much, so the parts are not deformed under the influence of high temperatures.
• Argon gas for welding is called inert, which means that it is heavier than air, so if the technology is followed, oxygen will not penetrate into the welding zone.
• Arcs have high thermal power, so with proper experience, work can be done quickly and efficiently.
• Despite the many nuances, the welding process is not as complicated as it seems, and it can be learned quickly.
• You can weld metals that cannot be joined with other types of welding.

Minuses:

• It is not recommended to weld outdoors if there is a strong wind outside. Some of the gas evaporates, causing the weld to become of poorer quality. Carry out welding in a closed workshop or garage with forced ventilation.
• At first, it is difficult for beginners to correctly set up the equipment and conduct an arc.
• If you plan to use a high-ampere welding arc, then you need to think in advance about how you will cool the seam.

Instead of a conclusion

Source: https://rem-serv.com/svarschik-rad-chto-eto/

What is welding?

To obtain permanent connections in industry and in the community, a variety of welding methods are widely used. By this action, similar metals and their alloys are connected to each other. Welding is profitable from an economical point of view; welding differs in the highest production and delivery of the best quality material connection.

Welding technology

Welding is a technological process in which tight bonds are formed between machines and molecules into connected parts. In order to provide this kind of connection, the surface of the buildings being treated is first cleaned of contamination, and in addition, the oxide film is removed from the parts.

The surfaces involved in welding are shifted so that the distance between them becomes minimal. Following this, the parts are subjected to powerful local heating or plastic deformation, then the prepared materials merge, creating an inseparable material. At the last moment, the finishing of the weld seam is created.

There are three types of welding: mechanical, thermal and thermomechanical. The mechanical type of welding is performed using pressure energy, for example, processing workpieces by friction, explosion or ultrasound. Heat welding uses heat to melt materials. Thermo-mechanical welding combines the uniqueness of the two types described.

Main types of welding

Arc welding is one of the most famous types of this type of alloy of materials. In this example, welding electrodes are used, fixed in a special holder and moved along the length of the further seam. An electric arc appears in the middle of the electrode rod and the workpiece, the metal becomes liquid and fills the welding seam, solidifying over time.

When resistance welding, the part of the connection of parts that is not considered to be the fusion of workpieces is heated.

In this case, plastic deformation of the metal occurs, which entails the formation of a welding joint. Electric current is used to heat the parts of the joint during resistance welding, which causes heat to occur. At the joints, the metal becomes completely plastic, which simplifies the connection of the surface.

Gas welding has also become widely used in production. At such points where the workpieces need to be welded, they are strongly heated with a gas flame, which has a very high temperature. The edges of the parts are positioned under similar thermal influence.

The filler material enters the resulting gap and serves to form a seam. The advantage of gas welding over arc welding is that the workpiece is heated much more evenly under the influence of the gas flow.

This allows you to use the current welding type to join parts of small width.

Source: https://svarkagid.com/chto-takoe-svarka/

How to properly weld metal

Metal welding allows you to connect various parts and create complex structures. It is used in the construction of bridges, buildings, laying pipelines, and creating complex parts. Parts can be welded together not only at a special enterprise, but also far from cities and power lines.

The method of joining parts by welding is mastered by professionals and amateurs. In garages and sheds, craftsmen bring their ideas to life, repair various mechanisms, and make things useful for the household.

How to cook properly

From the outside, welding work is not difficult. However, experienced metal welders recommend first studying the theory and practicing on unnecessary things, and only then getting to work.

It is not enough to connect 2 pieces of iron together. Such a seam will burst at the first blow. It is important to learn how to weld metal so that it does not lose its characteristics. Only a properly heated bath and the melts of the edges of the parts mixed together can form a strong, hermetic connection.

Work technology

There are about 100 types of metal welding. The technology of electric arc welding with electrodes, wire, and plates is mainly used.

Welding technology involves heating the metal to a liquid state and then mixing it. To connect different parts, molten wire or the electrode itself is used.

Types of Welding Machines

Based on productivity and power, welding machines can be divided into two types: household and industrial.
Parts up to 5–6 mm thick can be welded first. Industrial equipment can operate for a long time without stopping. How to choose the right welding machine?
Lesson 1 Welding of metals occurs by heating to high temperatures. Melting is achieved in various ways. Each of them has its own equipment. It is divided into groups according to the principle of operation:

• transformers;
• inverters;
• rectifiers;
• TIG devices;
• semi-automatic;
• spotters.

In addition, devices are used for gas processing of metal workpieces, cold welding, which creates high pressure, and other types of joining parts.

Transformer

Classic welding machines were the first to be invented. They simply lowered the voltage, leaving it variable. The power transformer reduces the network voltage to no-load values ​​- 50–60V. By setting operating parameters, the following types of equipment are distinguished:

• thyristor - phase adjustment;
• with magnetic dispersion;
• with standard dispersion.

The disadvantage of the device is the unstable arc due to alternating current. Transformers are large in size and have high energy consumption.

Inverters

Inverters create optimal conditions for metal welding. They equalize alternating current and make it high-power, regulated with great precision. Inverters operate from a consumer network of 220V with a frequency of 50 Hz, industrial at 380 V. During the conversion process, the current passes:

• network rectifier;
• a frequency converter;
• high frequency transformer;
• power rectifier.

Inverters are configured to work with forward and reverse current. They work with electrodes of any type, welding high-alloy ferrous and non-ferrous metals. They have protection against power surges. Suitable for training beginners because they have a stable arc.

To work with direct current, rectifiers are also used, which consist of diodes and semiconductors. They convert alternating current into direct current and allow you to regulate its value. They do not have fine tuning.

All other types of welding equipment are various versions of the transformer and inverter.
How to choose a welding inverter for your home. Review from a welder.

Step-by-step instructions for welding work

Before starting welding, it is necessary to check the work site for compliance with safety regulations. There should be no unnecessary objects on the site, especially flammable ones, puddles of water, or spilled oil.

The equipment should be checked for serviceability and connected. The stove must be grounded. A clamp with the corresponding current value is attached to the part. The workpiece is prepared for welding if the following steps are completed:

• joints are cleaned;
• the workpiece is installed on an assembly plate or rack and secured;
• the parts are connected to each other by clamps or clamped in a special device.

You should start cooking after fully preparing the place, equipment and tools.
How to learn to weld metal. Tips for beginners, at the request of subscribers

Tools and protective equipment

In addition to the clamp for the electrodes, the welder should always have a thin metal hammer with him to beat off the slag. The seam is checked for lack of penetration, undercuts, and tops. If necessary, the operating mode can be changed.

Welding is one of the harmful and dangerous jobs. Compliance with safety precautions is especially important for novice workers who do not yet have practical skills. When carrying out welding work, you can get various types of damage: electric shock, burns, eye damage, vapor poisoning when flux burns.

Mandatory protective equipment for a welder when working are:

• mask;
• mittens or gloves;
• pants and jacket;
• work boots;
• tarpaulin.

A mask with dark glass protects the eyes from the blinding light that occurs during welding. Gloves and a suit made of non-flammable materials protect the skin from metal splashes and sparks.

Protective equipment or what do the pros neglect when welding?
Lesson 7 + announcement of the 2nd part of the video course. When working outside an equipped welding station, a worker may need a tarp. He uses it to cover objects that cannot be removed.

For example, a wall and nearby furniture when welding water supply or heating pipes in a house.

Tools and protective equipment

Which electrodes to use

The thickness of the metal and the number of seams applied determine the diameter of the electrode. When welding parts of large thickness, the root seam is laid with a thin electrode of 2–3 mm. In the future, four are used. When the sheet thickness is more than 20, it is possible to use an electrode with a diameter of 6 mm.

For welding structures made of low-alloy steels, coated electrodes of the following grades are used: UONI, OZS, ANO. They are widely used in the creation of building structures, when laying pipelines and welding other parts that have high demands on the strength of joints.

When welding high-alloy and carbon steels, experts recommend using chromium-nickel electrodes grade EA 395.

High-quality welding of non-ferrous metals is carried out using rutile electrodes of the MP 3C series. Tungsten non-consumable grades WC 20 are suitable for joining parts made of non-ferrous metal alloys.

Chromium-nickel and rutile electrodes are recommended for learning the welding process.
They light easily and hold the arc well. How to choose the right electrodes? Lesson 6

Electrodes with rutile and other special coatings are considered universal. They can operate on any current, the seam lies horizontally. Vertical only from bottom to top. Metal spattering is minimal. After them, it’s difficult to switch to UONI and other brands, but only after mastering classic electrodes can you become a welder.

Preparation

Before starting work, you should prepare the metal for welding. The surface of the workpiece must be cleaned of dirt, oils, and rust. Oxide films are removed chemically immediately before welding.

If the seam thickness exceeds 3–5 mm, you should cut the edges on the machine, removing them at an angle of 45⁰.

The parts to be welded are connected using clamps. For mass production, special devices may be used.

Cleaning the joint

Connection

Before work, check the condition of the equipment and grounding. A 0 or a minus is then connected to the part, depending on the type of current being applied. The equipment is connected to the network and modes are configured. After this, the electrode is inserted and the welding machine is turned on.

Welding process

Before cooking, the device is adjusted to the desired operating mode in accordance with the thickness, material of the part and currents recommended for the electrodes. After this, you can proceed directly to welding.

1. Light the arc.
2. Heat the weld pool.
3. Use an electrode to move the molten metal along the seam, ensuring the edges are connected.

During work, you should ensure that the flux does not remain in the seam, but melts and floats up.

What errors might there be?

Incorrectly selected current - if its value is low, the arc will constantly go out and the seam will be interrupted. A high current value leads to penetration, burning through the body of welded metal structures.

The slag output is controlled by the angle of inclination of the electrode and depends on its type. If the bath moves quickly, slag inclusions remain in the seam.

High-alloy steels must be heated before processing, otherwise the edge material will not have time to melt or a transition zone will form.

Welding of non-ferrous metals must be carried out with special electrodes in a shielding gas environment.
The polarity of the current must be straight in order for the metal coated with oxides to melt. 5 main mistakes of a novice welder.

What can be made

Welding is used to connect product elements made using cold forging. The result is openwork fences, uniquely beautiful garden furniture and other metal crafts. Craftsmen turn old bolts and nuts into charming animals and sea monsters.

Source: https://metalloy.ru/obrabotka/svarka/metalla-tehnologiya

What is pressure welding

GOST 2601-24 defines welding as a method of creating permanent joints due to the formation of interatomic bonds between them during heating or plastic deformation. Unlike traditional types, which rely on heating to melt, pressure welding is performed by applying an external force to the joint.

The essence of pressure welding

When two bodies come into contact, mutual diffusion of atoms begins. Under normal conditions, the exchange proceeds very slowly. When pressure welding, this process is accelerated due to the friction of the edges of the parts under the action of the applied load. To create stronger interatomic bonds, the process is carried out with preliminary local heating. The area where diffusion occurs is called the zone of union or connection.

Heating is carried out in furnaces, electric current, induction units, heat from chemical reactions, and an electric arc. Heated pressure welding technology is not identical to traditional types. For example, when joining butt joints, the edges are first melted and then subjected to deformation. The mixture of metal and slag, which is squeezed out after compression, is called gart.

Welding features

In contrast to classical technology, pressure welding has the following advantages:

• cost reduction, since there is no need for consumables (electrodes, fluxes, etc.);
• jointing of workpieces from any metals, even dissimilar ones;
• workpieces made of materials with high ductility (copper, aluminum, lead) can be pressure welded without preheating.

To form a high-quality connection, certain conditions must be met:

1. Cleaning from dirt, rust, degreasing the contact area.
2. Gradually increasing the load so that the contacting layers are first deformed, and then the diffusion process starts. Vibration increases the strength of the seam, as the atoms receive more energy.
3. Maintaining temperature uniformity when working with workpieces made of low-melting materials.

When joining steel elements, chemical elements called intermetallic compounds are formed, which make the seam stronger. They occur if the parts contain chromium, cobalt, molybdenum or tungsten. Nickel does not form intermetallic compounds, so the connection of workpieces made of this metal is fragile.

Types of pressure welding

Methods for welding metals by pressure are divided into 2 groups:

1. Mechanical ones are performed only by applying force. The group includes ultrasonic, friction, explosion, and cold welding.
2. Thermomechanical (combined) methods are performed by a combination of mechanical action and local heating. The group includes contact, diffusion, and gas pressed types of pressure welding.

Contact

When joining using this method, the workpieces are heated with electric current and then compressed. Depending on the methods of execution, resistance welding can be:

• point;
• embossed;
• suture;
• butt.

Source: https://svarkaprosto.ru/tehnologii/chto-takoe-svarka-davleniem

Grandfather's homemade products or what we did during the USSR

Grandfather's homemade products

There were many different circles in the USSR, and the guys were always busy with something. Some people collected boats, others were interested in radio and electronics.

At that time there were no special frills. And after assembling a small detector receiver without batteries, everyone was as happy as children. Today, when the age of technology is raging outside, it is very difficult to surprise with anything.

However, we will try to do this by telling in this article from the construction magazine samastroyka.ru about “grandfather’s” homemade products from the last century.

DIY detector receiver

It used to be very fashionable to collect receivers and catch distant countries. There was even a special direction in this regard, and the more powerful your transceiver was, the cooler and more “pumped” you were.

The boys mainly assembled detector receivers that could work without batteries. Then, when the receiver was assembled, everyone fought in line to listen to the radio station first. Overall, it was an interesting time.

So, the detector receiver works without batteries. Its operation is based on the electromagnetic field created by a radio transmitter. And although such a receiver does not require batteries, its operation requires a long antenna made of copper wire and grounding - a half-meter pin driven into the ground.

Also, to make a detector receiver you will need a carbon speaker and a diode. I’ll tell you how we made detector receivers when we were still boys:

• A piece of 10-15 meters of copper wire was taken from the transformer and tied to something heavy. Then something heavy, for example a nut, flew to the top of the nearest tree. The wire was then stretched to form an antenna for the detector receiver.

• Then a metal pin was driven into the ground, which acted as a ground connection. In simple words, the detector receiver worked from the antenna and ground, without batteries, where the antenna was (+) and ground (-).

• Next, the plus and minus were connected to the carbon speaker (minus through a diode) and, voila, the radio without batteries is ready.

Of course, the detector receiver had its drawbacks. For example, it only picked up powerful radio stations; also, such a receiver was very quiet. However, through simple manipulations and modifications, the power of the speaker could be easily increased.

Phone made from cups

If you are a “dinosaur” from the last century, then probably as a child you assembled a simple intercom from a piece of fishing line or thread and two paper cups. This kind of “telephone” allowed us to communicate with each other at a distance of 20-30 meters.

To make a phone from paper cups you will need to use:

• Two paper cups;
• A long rope, 20-30 meters;
• Matches or toothpicks to which the ends of ropes could be tied.

All you need to do is make two small holes in the bottom of the glasses, strictly in the center. Then, having threaded the ends of the ropes through the holes of the glasses, you will need to attach matches to them. When talking on the phone from cups, it is very important that the rope is kept taut and does not touch anything.

Key from an old chain

Well, the following “grandfather’s” homemade product will certainly be useful to all those craftsmen who do repairs. A key made from an old chain will be a real find in the household, since it is absolutely no worse than a gas or adjustable wrench.

To make it, you will need to take a piece of profile pipe and an old chain from a chainsaw or motor vehicle. Using welding, the chain is welded to the edge of the profile pipe. This completes the key.

The principle of its operation is quite simple: you first wrap a chain around a nut that needs to be unscrewed. By adjusting the length of the chain, you need to achieve its full tension, after which, without pressing too hard on the handle, unscrew the hardware.

Spark plug glass cutter

It’s just as easy to make a glass cutter from an old spark plug. A homemade device will be no worse than a factory glass cutter, and it can be easily used in emergency cases when a normal glass cutter is not at hand.

In order to make a glass cutter, you need to split the spark plug with a hammer and remove the largest piece of insulator. Then, taking a small wooden block, you need to split it into two parts at the very beginning, then put an insulator into the piece of wood and wrap it tightly with tape or tape.

Glue from acetone, polystyrene foam and plexiglass

Previously, when assembling aircraft models, everyone used homemade glue to glue fuselages and other parts of the aircraft. So, we made simple glue from acetone and polystyrene foam, and also used plexiglass. The glue turned out to be of good quality and was well suited for gluing paper, cardboard, veneer, and many other materials.

To prepare it, a solvent was taken, most often No. 647. Then pieces of foam plastic or plexiglass were dropped into the solvent, which immediately dissolved, settling at the bottom of the jar or glass. Then the whole thing was mixed with a wooden stick, and the result was a universal glue, no worse than Moment glue or any other.

Potbelly stove for a garage made from old rims

Well, the next homemade product will prevent you from freezing in a cold garage in winter. To make it you will need 5-6 disks from a car and welding. To make a potbelly stove, the disks are welded to each other, and the topmost one is welded with a piece of metal in which the hole for the chimney is located.

The second disk, cut in half, will serve as a firebox. Here, directly into the disk, pieces of reinforcement are welded, and a metal door is attached. There is nothing complicated about making such a potbelly stove from disks. At the same time, you can use car parts that have been lying around for a long time, and even save money by refusing to buy a potbelly stove for the garage.

Source: https://samastroyka.ru/dedovskie-samodelki.html

Definition and types of welding

The task of connecting two pieces of metal into one whole is physically solved using different methods. It is possible to obtain one part or workpiece from two only under the condition that stable interatomic bonds arise between the surfaces and in the depths of the metal structure. The process [of welding metals] is the creation of conditions under which the connection becomes permanent due to the formation of a weld, a zone of interatomic interaction, which can have different depths and physical properties.

When working with metals and structures made from them, what matters is not just the ability to make two or more pieces into one. The quality, strength and other properties of the connection zone, and therefore the entire part (structure), are influenced by a large number of parameters and conditions. When choosing a method and technology, the following must be taken into account:

• the initial strength of the fragments and the final indicator at the point of contact;
• the ability of metals to weld - not all steels “flow” well when heated, not all metals form a layer that allows creating conditions for mutual penetration;
• the result of local heating - short-term and long-term temperature effects can significantly change the properties of steel, leading to its hardening or tempering;
• depth and ductility of the weld, indicators of fracture strength, tensile and compression, metal fluidity under load.

Additional impacts arise when using technologies that allow foreign inclusions - for example, a fusible electrode or filler wire is introduced into the metal structure as it heats up, oxygen causes rapid oxidation of the aluminum surface with the formation of an oxide film, the argon environment eliminates oxidation and changes in the properties of the contact zone.

IMPORTANT TO KNOW: All about resistance welding - technology and devices

Welding - definition and features

The definition of metal welding indicates the formation of a zone of stable atomic interaction, which is not always associated with heating the material. Industrial and “home” welding with simple devices is in most cases carried out by heating; more complex technologies are based on a sharp change in the fluidity of the metal under high pressure.

If we abandon too complex scientific terms and definitions, we can say this:

welding is a process of structural connection of metal fragments due to melting and mixing of surface layers with the formation of a zone of stable bonds - a weld.

It is worth separately noting that the depth of the surface layer and the area of ​​the contact patch can be different, therefore in practice there is [spot welding], a connection over an area, the formation of a seam filled with metal from an electrode. The ability of the equipment to provide a strong structural connection of large cross-section parts is also of great importance - these are cases when it is not enough to cover the contact area with a continuous closed seam.  

IMPORTANT TO KNOW: Semi-automatic welding technique in a carbon dioxide environment

Types and technologies of metal welding

Depending on the tasks, equipment availability, type of metals and conditions, different types of welding joints can be used.

Electric arc (manual)

Arc welding or electric arc welding is the most common type of joining metals using electrical heating. Applicable to steels and cast iron, a large number of types of non-ferrous metals. The heated metal and the melting electrode form a strong seam, which is the area where the molten metal mixes.

To perform the work, simple devices and accessible electrodes are used. Due to heating and melting, local alloying of steel occurs in the weld zone, which significantly increases its strength. The disadvantages include the likelihood of burning through thin metal, the dependence of quality on the qualifications of the welder, and the relatively low efficiency of the device taking into account the need for electricity.

Gas acetylene welding

Acetylene or [gas welding] is the second most common technology, based on heating the metal with a burning gas mixture with oxygen. High temperatures and fairly slow heating allow the basic properties of metals to be preserved.

This is especially important when working with tool steels, for which tempering is contraindicated, when connecting cast iron parts, and in operations with pipes.

This type of welding allows you to avoid burning through thin metal, but as the thickness increases, productivity decreases due to the duration of heating.

IMPORTANT TO KNOW: Plasma welding technology

Welding in an inert gas environment

[Argon welding] technology is used in cases where it is necessary to prevent oxygen from entering the zone of interaction and heating of the metal. An inert gas is supplied to the heating area under pressure, displacing air and oxygen. When welding aluminum and its alloys, stainless steel, carbon grades, this allows you to avoid oxidation of the metal when heated. The weld pool is reliably protected from oxygen.

Scope of welding technology and the question of choice

In industry, when assembling metal structures, semi-automatic welding technology with wire feed is common. Laser and plasma technologies make it possible to achieve high-quality results in difficult conditions.

In general, technology is selected depending on projected costs and type of metal. At the household level and in workshops, arc and gas methods and semi-automatic devices are most often used.

Car service centers and engine repair companies actively use argon welding to repair cylinder heads.

Source: https://rezhemmetall.ru/opredelenie-i-vidy-svarki.html

⚡ Spot welding machine from an old microwave oven

If you think that only a magician can pull a rabbit out of a hat, you are mistaken. With some skill, anyone can do this. And the ability to transform one object into another is also magic that can be learned.

The main thing is to find a suitable and very experienced mentor. This could be the author of the NRV Wood channel for you. A very inventive master constantly pleases his subscribers with interesting products.

A striking example is the welding machine he made from a microwave oven.

Why you shouldn't throw away your old microwaves

Any modern electrical device is a masterpiece of engineering and the fruit of the labor of many people. In the era of consumerism, all this is of little value, and in the pursuit of new products, people simply throw even functional devices into the trash and rarely bother with the question of whether they can be used in some other way. And it’s completely in vain, because such a decision will help not only save your money, but also enrich your home with interesting and useful things.

In this case, too, the microwave was replaced by a more modern model. And instead of sending this device to rust in a landfill, the master decided to use the spare parts for a good cause

What can be used from a microwave for a new design?

The microwave needs to be disassembled. It's not difficult: the case can be easily removed, revealing all the complex electronic contents. Don’t rush to throw anything away, today you will need a few parts, but the rest will also be useful for other purposes

The spare part you need is a two-turn transformer, which is located in this microwave oven. It must be removed from the housing. The capacitor must be disconnected from the transformer. You may find it useful for many other inventions, but not in this case. So don’t rush to get rid of it either. Another part from the microwave that you will need is a wire for connection.

There is no point in looking for something else. This one is already grounded and made quite well. In addition, it connects perfectly to the transformer.

But remember: do not touch the transformer connected in this way with your hands, you can receive a powerful discharge that can cause irreparable harm to your body

Thus, you only need two parts from the microwave: an electrical cord with a plug and a transformer.

How to assemble a welding machine from a microwave

A standard microwave oven transformer has two windings: primary and secondary. The secondary one is made of thin copper wire, which is not required for the welding machine.

The secondary must be removed, but this must be done very carefully so as not to damage the primary winding. The author first cut off the outer parts of the secondary with a grinder. After cutting, copper remained inside the transformer, which also needs to be removed from the housing. To remove it, you need to drill holes and knock out the remaining wire with a chisel.

In principle, the entire procedure can be done without a grinder and a drill, using only a chisel and a hammer. The place of the secondary winding will be taken by a power cable for welding machines. It should be quite flexible to fit easily into place.

Another important requirement for this part is reliable winding. The most successful option is a KG cable with one core consisting of many copper wires and a thick rubber sheath. Tinned end switches must be installed on the cable. Subsequently, you can use copper electrodes for welding if you prepare a comfortable handle for them. All that remains is to connect the transformer to the power supply and try it in action.

The author conducted an experiment on an ordinary nail. As you can see, the metal melts at the point of contact with the end switches. The welding machine is ready. It will definitely come in handy for various plumbing jobs. It will help heat up metal in a confined space, for example, to remove a nut. The thicker the cable you use, the more powerful the result.

If you add a convenient handle with an electrode to the design, you can use it for spot welding and soldering with brass or copper

And this example is not all that can be used from an old microwave. But you must admit, the idea is quite interesting and visual, especially since the design is primitively simple and can be assembled in literally an hour.

Here is another interesting example of using a microwave oven for other purposes. In it, the author demonstrates a working model of a spot welding unit, which is based on the same transformer:

What do you think about the author's idea? How realistic is it to make such a welding machine with your own hands? Perhaps you have already tried to assemble something similar? Write about it in the comments!

PHOTO: -channel “NRV Wood”

And if you have your own developments, and you did not forget to photograph the process of their creation, then send a photo with a description to our editors, we will be happy to publish your master class!

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Source: https://homius.ru/apparat-dlja-tochechnoj-svarki-iz-staroj-mikrovolnovki.html

Eyes hurt from welding, what to do, folk remedies

Each profession is dangerous in its own way. If we consider welding work, then it must be performed by an experienced specialist, while observing safety precautions. Sometimes even the slightest carelessness can lead to serious consequences.

First of all, your eyes should be protected. If you do not protect them with special glasses, your eyes will hurt after welding. This process cannot be called pleasant, so it must be treated as quickly as possible.

What proven folk or pharmacy remedies should you use if your eyes hurt after welding?

Symptoms

Do your eyes hurt from welding? This is the result of non-compliance with safety regulations. To protect the visual organs from this unpleasant symptom, you must wear a special mask. They are equipped with special glass, which can be used to minimize the impact of welding on the eyes. If you ignore this rule, you can get a retinal burn. Symptoms of the lesion manifest themselves in different ways. It depends on the degree of burns. There are 4 of them in total, and each has its own clinical picture:

1. Mild degree. It is characterized by a slight burning sensation, hyperemia, itching of the eyes, and clouding of the cornea.
2. Average degree. It is accompanied by severe pain, increased sensitivity to light, erosion of the ocular cornea, and the formation of a film on the conjunctiva.
3. Third degree. With such a lesion, severe clouding of the cornea, swelling of the eyelids, deterioration of visual function, and nagging pain develop. A person may also feel the presence of a foreign object in the eye.
4. Last degree. It is accompanied by extremely severe and unpleasant symptoms, as well as severe pain. A person develops complete blindness, discoloration of the cornea, slow death of the conjunctiva, and tissue necrosis. Due to severe pain, it is difficult for a person to open his eyelids.

Eyes after welding may hurt due to the influence of UV rays on the cornea, which are formed during the welding process. The more intense these rays are, the more severely the organ of vision gets burned. With excessive exposure to ultraviolet radiation, a person risks losing his vision completely.

Causes of pain

The principle of the negative impact of welding work on the eyes comes down to the effect of UV rays on the cornea. If you work with a welding machine for a long time without a special mask and glasses, then there is a high probability of developing painful sensations.

First aid

How to help your eyes after welding? First of all, you should not ignore the symptoms that arise. If you help a person in a timely manner, you can not only alleviate his condition, but save his vision.

In addition, first aid to a person who has caught bunnies from welding comes down to the following:

1. To relieve eye pain, a person must be given an anesthetic. Analgin and Ketanov are best suited. In addition, first aid involves the use of anti-inflammatory drugs - Tavegil, Diclofenac.
2. Rinse your eyesight with a large volume of purified water.
3. If small metal particles have entered the eye, you should use a sterile cotton pad or black cloth to remove them. If you cannot cope with this process on your own, then you should consult a doctor, as he has special equipment.
4. Apply a cold compress to the skin of the eyelids. You can use a cold decoction of chamomile for this. In addition to the cooling effect, chamomile will prevent the development of inflammation. The duration of the cold effect is 5-10 minutes.
5. Treat the eyelid skin with antiseptic ointment. Tetracycline ointment has proven itself to be excellent.

As soon as a person has been provided with first aid, an urgent need to visit a doctor for consultation. Examination and timely diagnosis are excellent prevention against various eye complications.

Treatment

Eye treatment for welding can be done using effective pharmaceutical and folk remedies. If your eyes have been burned from welding, it is important to wash them first. You can use either purified water or a weak solution of potassium permanganate. After this, you can use the drops. But let’s dwell on this in more detail.

Drops

When a person has seen enough of welding and his eyes hurt because of it, treatment can be carried out at home. Surgical intervention should be used only if the last stage of the pathology is observed.

Source: https://veltain.ru/glaz-boljat-ot-svarki-chto-delat-narodnye-sredstva/

Variety of welding types

The welding process forms a permanent connection of various parts of any metals due to the formation of new interatomic bonds.

It consists in creating local or widespread heating, plastic deformation, or the simultaneous action of both factors. Modern welding technologies are represented by almost a hundred types of automated and manual welding.

Three main varieties

There are three varieties or types of welding. According to the method of obtaining energy from a compound, it is divided into thermal, thermomechanical and mechanical.

Thermal welding includes processes using an electric arc, gas, plasma and other sources of thermal radiation. It is thanks to him that heating and welding occur.

In thermomechanical types, in addition to thermal energy, pressure is used to obtain an inextricable connection.

Mechanical heat is obtained through friction, pressure, ultrasound or explosion.

The types of welding work are diverse and their classification is made according to different criteria. The classification is based on the method of protecting the weld pool, the continuity of the welding process, the degree of mechanization, and the gases used. In addition, there are technological characteristics that are individual for each type of welding.

Types of welded joints are described in detail in GOST (state standards). In addition, there are a large number of GOSTs describing the types of welding, methods of monitoring welds, and safety measures during welding work.

Thermal welding of materials

Thermal processes are based on the melting of connected parts due to thermal energy. There are several types of thermal welding:

• electric arc (in a protective gas environment, submerged arc and others);
• electroslag;
• electron beam and beam (laser);
• plasma;
• gas;
• termite.

Electric arc welding is the most widely used. But other types are also in demand in various modern areas of production and in everyday life.

Electric arc melting

Electric arc welding works by releasing energy in the arc due to the fact that the resistance of the arc is significantly greater than the resistance of the entire electrical circuit forming a closed loop.

Therefore, almost all the thermal energy is released in the arc, heating it to 4.5-6 thousand degrees and causing the melting of any metal. The arc occurs in the gap between the electrode and the metal being welded, causing them to melt.

When cooled, an unbreakable seam is created, the properties of which are related to the current, the composition of the additive and many other factors.

Arc welding is carried out using consumable and non-consumable rods (electrodes). The equipment uses inverter technology, which makes it possible to create compact, productive devices.

When welding workpieces using an electrode, an arc is ignited between it and the joint surface. This is created due to a short circuit when the rod touches the metal, and its subsequent tearing off at a distance of 3-5 mm.

The arc melts the end of the electrode and the edges of the work being welded. At the arc formation point, a weld pool is created.

To obtain a weld, it is necessary to move the electrode along the joint at a speed sufficient to melt the edges and the electrode, but not sufficient to burn through the parts.

After cooling the metal, a weld is obtained that is comparable in strength to the base. The electrode can be in the form of a separate rod in the coating or a filler wire on the wire feed mechanism.

When welding with a non-consumable rod, an electric arc occurs between it and the edges of the workpieces. The edges and, if necessary, the filler wire melt in the resulting weld pool. The rod can be carbon or tungsten. Non-consumable electrodes are usually used for welding copper, copper alloys (brass, bronze, cupronickel) and refractory metals.

Flux and gas protection

Welding metal under a layer of flux is usually performed automatically or using a semi-automatic process (semi-automatic). In the first case, all processes are automated; in the second, the electrode supply process is carried out automatically, and the movement of the torch is carried out by the welder.

The melt in the weld pool is protected by molten slag from exposure to atmospheric air. Slag is obtained by melting the flux entering the bath. The type of welding using fluxes is very productive, and it also produces a high-quality weld without pores or other defects.

Gas welding protects the welding area from the harmful effects of water vapor, atmospheric oxygen and nitrogen.

This is achieved by supplying a jet of shielding gas through the torch nozzle into the welding zone, which allows atmospheric air to be displaced. Used when using non-consumable and consumable electrodes. The result is a high-quality seam with high labor productivity.

Electroslag

The electroslag type of welding is carried out by fusing the vertical edges of the product with the electrode. When an electric current passes through the varnish, heat is generated. The arc is present only at the initial stage. Subsequently, the metal is melted due to the heat generated by the slag.

Copper sliders are installed on both sides of the gap. They are cooled by supplying water. A tray with flux is installed at the bottom. An arc is ignited between it and the electrode and the wire is fed there.

An electric arc melts the wire and flux, forming a weld pool over which a light liquid slag floats. As the edges and welding wire melt, the sliders move up the joint. The result is a high-quality seam. Thanks to this process, thick metals can be welded in one pass.

Radial

In industry, especially instrument making and electronics, it is necessary to weld very small parts that have special requirements for the welding process. The choice of welding method in this case is small. They can only be dealt with by a powerful light beam, a stream of electrons or plasma.

To obtain an excellent quality seam, a high-energy source is required. This could be a laser or other similar energy source capable of concentrating enormous thermal energy in a small area and for a short time. Electron beam welding uses the energy of electrons accelerated to high speed. In the case of a laser, heating is carried out due to the energy of photons.

Plasma, gas, thermal reaction

The essence of the type of welding using plasma is the formation of a jet of ionized gas, which is a current conductor.

The plasma temperature reaches 30,000 °C, which allows you to melt any metals in the shortest possible time. Plasma energy depends on the welding current, operating voltage, and gas flow. Welding seams are of high quality, thin, without internal stress.

Gas welding is carried out by burning a flammable gas in oxygen and releasing a large amount of heat. This is one of the oldest types of welding.

The temperature of the gas flame is three thousand degrees. Thanks to this, the joints of the welded product melt. The melting process takes a long time, which causes heating of large areas of the surface of the joined products. When cooled, it causes high stress in the seam and the part itself.

Thermite welding uses the heat generated by burning a mixture of aluminum and iron oxides.

Thermo-mechanical welding of materials

Thermo-mechanical welding includes forge, contact and similar types. These methods of welding metal simultaneously use thermal and mechanical energy. This type of technology includes the following:

• blacksmith's;
• contact;
• diffusion;

Forge welding is a method in which the products to be welded are first heated to the required temperature in a forge, and then connected to each other with a hammer. If a press is used instead of a hammer, then this method is called a pressing method.

The contact type has this name due to the fact that welding is carried out at the point of contact of the parts being connected. They are pressed tightly against each other using special electrodes, and then a powerful current is passed through the compression point.

At the point of contact, the greatest resistance is obtained, which causes the main heat to be released at this point. Accordingly, this leads to melting of the metal at the point of contact. Using contact welding, spot or seam welding is obtained.

Resistance welding has become widespread in mechanical engineering, especially in the automotive industry. This is due to the high productivity and cost-effectiveness of this type of welding. It is the easiest to automate and is widely used in robotic systems.

It is impossible not to mention the diffusion type of welding. Its essence lies in the preheating of the workpieces and their subsequent connection using deformation that occurs from mechanical pressure. In this process, atoms diffuse from one part being connected to another and an inextricable connection is obtained.

Mechanical welding of materials

With the mechanical welding method, an inextricable connection is obtained without an external heat source. The joining process occurs under the influence of pressure, friction, explosion or something similar, which forms interatomic bonds between the products being welded.

Friction welding occurs as a result of rapid rotation. The part is pressed so tightly against the other that when it rotates, strong friction occurs and it heats up until it melts. This ensures reliable connection of the workpieces.

If you take two metal plates, clean them of contaminants and press them hard, then at pressures of several tens of thousands of atmospheres, plastic deformation occurs, leading to the formation of interatomic bonds between the two parts. The result is an unbreakable connection. This method is called cold welding.

To create atomic interaction forces, an explosion is sometimes used between two parts. At this moment, the parts to be welded come together so that atomic bonds arise, which ensure a reliable connection of the products.

Another type of welding is ultrasonic. High-frequency waves cause vibrations of atoms in the metal, and they become so strong that they cause atomic interactions. The result is a reliable connection.

Source: https://svaring.com/welding/vidy/raznoobrazie-vidov-svarki

Features of the technology and operating principle of argon arc welding

Inert gases protect permanent joints of steel alloys at the weld creation stage. For non-ferrous metals, argon-arc welding is a reliable joining method. Especially such capricious materials as aluminum and refractory titanium.

Features and principles

Argon welding technology combines the techniques of gas and arc welding. The difference is the non-participation of argon in combustion and melting . Cutting off atmospheric gases with argon as a zoning element from the metallurgical melting site eliminates oxidation of the melt, combustion in an oxygen environment, and eliminates porosity of seam joints.

Argon welding is carried out in 4 classical ways:

• Manual mode with a non-consumable tungsten electrode with filler wire supply - RAD .
• Automated - the burner is fed automatically by the caliper to the welded edges, the electrode is non-consumable - AMA .
• Automatic welding with consumable electrode (wire) - AADP .
• Mechanized consumable electrode welding - MAWP .

Surface deposition of a metal base, classification:

• Automated surfacing: tungsten electrode and additive - AADN .
• Automatic surfacing with consumable electrode - AADPN .
• Mechanized surfacing with fusible electrode – MADPN .

Effect of pure gases on TIG, MAG

The intensity of the process, when refining the conditions for creating a seam: depth, shape, influence of smoke formation, rate of melt deposition, productivity is regulated by an artificial protective environment. The impact on the arc is twofold: the impact is both positive and negative.

Argon (Ar)

The inertness of argon neutralizes the involvement of the atmosphere in oxidative processes . Suppresses the chemical activity of metals. Low thermal conductivity slows down heat transfer to the environment.

A narrow arc column is formed. Accordingly, the penetration profile is V-shaped: deep and narrowed. The tendency for the seam to be convex and undercut at the boundary lines is a consequence of limiting heat transfer to the outer edges. Argon consumption during welding is 7–8 l/min.

The weight of monatomic Ar is greater than that of air, this keeps the cloud in the welding zone. The polarity is predominantly straight - at reverse polarity, the gas generates a flow of current-conducting electrons akin to plasma. In MAG, pure Ar promotes metal jet transport .

Helium (He)

Light helium is the exact opposite of lazy argon. The penetration profile is wide, due to greater heat input, the arc temperature is higher as the current decreases. Without high-frequency excitation, arc ignition is difficult. Successfully used in welding dissimilar metals .

The atomic weight forces the output operating pressure and flow rate of He versus Ar to be increased by 2.5 times: up to 25 l, except for ceiling joints. The cost of unpurified helium is 4 times higher than argon, purified – 8 times. The electrode material in a pure He environment is transferred in large droplets. In a mixture, helium and argon exhibit better properties .

Technology and equipment

The welding process technology is implemented by Tungsten Inert Gas (TIG) machines with mating metal thicknesses of over 2 mm using a consumable electrode in semi-automatic mode. Or a tungsten electrode for thin materials with filler wire - RAD welding.

Equipping the welding station with main and auxiliary equipment:

• Network energy stabilizing device.
• Semiautomatic inverter type, transformer with no-load power interval 60–70 V.
• Power supply voltage contactor.
• Exciter of high-frequency pulses of oscillatory type to overcome ionization and excite the arc without contact with the surface.
• Set of different types of ceramic burners.
• Tungsten electrodes or additive supply mechanism.
• Gas cylinder equipment with reducing devices.
• Individual protection means.

What is argon arc welding in terms of technology recommendations:

• Holding a short arc to form a narrow weld with deep penetration.
• Straightness of the burner feed along the axis of the seam without transverse movement deviations.
• An external sign of lack of fusion is that the convexity of the seam turns into roundness.
• The filler wire is fed towards the movement of the torch evenly, at an angle for easy control of seam formation.
• Butt welds and flanging of small thickness metals are carried out without the use of additives.

Tungsten electrodes

Tolerance to ultra-high temperatures up to 30,000 C while maintaining tip shape and hardness is enhanced by sputtering with rare earth metal oxides. The marking indicates the chemical composition and the size of the rod.

Products of domestic industry do not always coincide with global requirements. International symbols are standardized, generalized, and include alphabetic, digital and color designations:

• W – initial marking symbol, denotes the dominant metal tungsten;
• WP – base without additives, signal color green;
• The second letter means the addition of ligatures per 1000 parts of the base (0.1%);
• Long electrode size (50–175 mm);
• WC – universal electrodes for both types of current;

Purpose of additives:

• Thorium dioxide (WT) – used for non-ferrous alloys, stainless steel, low-alloy carbon steels; the most popular brand on the list, characterized by increased strength;
• Yttrium dioxide (WY) – maximum current values ​​with straight polarity: titanium, copper, argon welding of ferrous metal;
• Zirconium oxide (WZ) – arc stability at alternating current: copper, aluminum, sensitivity to surface cleanliness;
• Lanthanum oxide (WL) – appears in two subcategories with 1.5 and 2% impurity content; the strength characteristics of the rod and the sharpening geometry are maintained at high energy costs at alternating and direct current.

Electrode shaping

Surfacing electrodes with impurities of rare earth metals, depending on the purpose and size of the melting front, are produced in sizes Ø 1–6.4, and have improved properties in terms of:

• conductivity;
• arc formation and arc maintenance;
• refractoriness;
• maintaining a given form.

The configuration of the working end in the form of a sphere, a cone with an angle of 15–1200 affects the quality of the connection when the thickness of the parts changes:

• obtuse angle is beneficial for thin-sheet workpieces, but inconvenient for thick sheets;
• sharpness helps to increase labor productivity;
• best arc stability at 600.

The forming method is important: when sharpening by hand, the transverse removal of metal decentralizes the arc . The intensity of the penetration is concentrated along the side edges. The center lacks heat, the uniformity of the seam is disrupted.

Typical sharpening mistakes:

• An excessively sharp angle is an activation of melting, characteristic exclusively for strengthening the connection of thick-walled parts.
• The degree of penetration is the lowest, when the angle is around 150, the sharp-angled electrode burns out faster.
• Sharpening affects the width of the penetration; if the indicator goes beyond the width of the application, it leads to unplanned consumption of the additive and time.
• Asymmetry of the sharpening angle and other defects lead to uncontrolled displacement and wandering of the arc.

Burner

The burner holds the W-electrode and is a conductor of argon. Tool certification is carried out in accordance with GOST 5.917-71 . The nozzles are divided according to the maximum current and the type of cooling.

Burners up to 200 A are air-cooled, collet chucks are designed for a maximum Ø 3. Powerful ones are cooled by running water. Collets clamp inserts up to Ø 6. Current reaches 500 A.

A torch with a consumable electrode works on the same principle: an arc is supplied between the product and the wire. There is no need for a collet. A narrow thermal effect zone and mechanization of the process when welding aluminum and stainless steel are advantageous .

Using an inverter

The selection of an inverter for operation in an argon environment is determined by the tasks and the material of the welding units. The basic selection element is the maximum current value . The reference point is the tabular values ​​of the grade and thickness of the alloy.

The flexibility and adaptability of inverters turn installations into universal equipment. But the presence of the desired functional settings simplifies the work even for an inexperienced welder:

• Switching from direct current to alternating current is designated TIG AC DC; without this function you will have to refuse to weld aluminum.
• The addition of manual MMA mode, semi-automatic MIG, MAG to TIG expands the range of work to infinity.
• An oscillator that provides non-contact ignition of an arc by increasing the voltage by 10–30 times and the frequency by 30 thousand times.
• Control of the rise and fall of the ampere characteristic.
• Anti-stick electrode and hot start.

Procedures for preparing and carrying out work

Contaminants and traces of rust are removed from the joining surfaces, and degreasing is carried out. Aluminum undergoes mandatory mechanical treatment to destroy the oxide film .

The supply of gas protection is adjusted with a lead time of 10 seconds. before ignition of the arc and a delay in turning off the gas flow at the end of the cycle to protect the seam against oxidative reactions. The electrode is held close to the workpiece without contact. A short arc is the key to quality.

During 10-minute cycles, in accordance with the rated duration of the load, regulated breaks are taken . The nozzle is guided along the longitudinal axis of the seam without transverse vibrations. The weld is completed by smoothly releasing the current with a rheostat to fill the recess of the weld pool crater.

The welder's equipment includes a mask with a light filter, heat-resistant gloves that do not restrict movement, a jacket that is resistant to burning by splashes, and closed shoes.

Modes

Reference tables will tell you how to cook with argon for a beginner when welding at home . The completeness of the data will help you determine the basic settings in advance and adjust the modes.

It remains to ensure that the torch is at an angle of more than 800 relative to the workpiece, the tip of the electrode protrudes from the nozzle by 3–5 mm, and hold it 2–3 mm above the workpiece when the arc is excited.

The current load is determined:

• electrode (wire) diameter;
• metal types and thicknesses;
• polarity.

Ferrous metal is welded with argon with straight polarity . Gas is supplied in a uniform flow without pulsation.

Features of arc ignition

The start of ignition with stable combustion maintenance is facilitated with a constant current of straight polarity . High-density currents with minimal amperage do not contribute to overheating and failure of the electrode.

Changing the polarity is fraught with an increase in arc voltage. The electrode loses its heat resistance, and the arc itself loses its stability. The positive aspect of reverse polarity is that the bombardment of argon particles with positive charges destroys the oxidation of the welded surface.

The flow of electrons causes the electrified gas to become a conductive plasma . For aluminum welding, this aspect is important. The low melting point and fluidity are overcome by lower currents than when welding steel.

Welding copper is complicated by the need for heating, the addition of deoxidizing additives, and fluxes for critical connections . With a non-consumable electrode, straight polarity is used.

Small diameter wire with deoxidizers is fed semi-automatically at high speed. Productive mode with a stable arc and proper penetration is ensured by reverse polarity.

As the feed speed increases, the melting of the wire changes from fine-droplet melting to jet melting. The seam density is satisfactory, spattering is minimal.

Advantages and disadvantages

Advantages of argon welding:

• The low-temperature welding process of aluminum is combined with intense heating of copper and titanium.
• The density and atomic weight of argon provide protection while reducing flow.
• Admissibility of fusion of different metals.
• Ease of mastering the craft.

Minuses:

• Draft and exhaust ventilation increase gas consumption.
• Complexity of equipment and settings.

Source: https://svarka.guru/vidy/thermo/dugovaya/argonovaya.html