What is automatic welding

Automatic and semi-automatic submerged arc welding of pipes

Engineers have long thought about welding automation, which would help speed up many work in production. One of the invented options is automatic submerged arc welding. This method was introduced into industry in 1939 thanks to the developments of academician E.O. Paton. and his team at the Electric Welding Institute. How is submerged arc welding performed? What are its advantages? What kind of automatic welding equipment is used?

The essence of the process and options

Automatic submerged arc welding, called in the international SAW system, is based on the burning of an electric arc that melts the edges of the metal. To do this, a wire (GOST 16130-72 or with other compositions) is fed into the welding zone, and an arc is excited between the tip of which and the product.

The welding tractor, in parallel with this, supplies a special powder to the joint zone - flux, which covers the molten part of the seam, protecting it from the effects of external gases.

Additionally, the flux layer promotes better fusion of alloying elements into the seam structure and reduces metal spattering.

The melting end of the wire is held by the head of the welding machine at a certain distance from the product. The welding machine can work stationary when it is used to weld pipes that rotate on rollers driven by a gearbox. Or the head of the device can move along a given path, thanks to the presence of a template corresponding to the shape of the connection.

The installation operator only sets the welding modes and starts the process. Automatic submerged arc welding technology requires human control over the work and adjustment of modes, as well as periodic assessment of the quality of the result. Models called welding tractors move independently on their own chassis along the welding line.

All the main components of such a machine move with it.

According to GOST 8713-79, the following types of work that a welding machine can perform are distinguished:

• weld products by weight, without supports for the reverse side of the seam;
• on a special copper lining that protects against leaks and sagging;
• on a cushion of powder;
• on a copper slide that accompanies the movement of the apparatus head.

In some cases, it is necessary to apply a preliminary root seam along which the welding tractor will carry out its work. In other technologies, it is necessary to produce welding seams on the reverse side of the product.

Application of welding method

Automatic arc welding complies with the parameters of GOST 8713-79. Due to its high operating speed, it is successfully used for applying smooth seams in a longitudinal position.

To ensure direct movement of the head, the welding machine is equipped with templates, along the edge of which the electrode wire moves and the arc burns. This method quickly joins thick sheets of iron used for industrial structures.

Curly movements of the head of the apparatus are also possible. To do this, install the appropriate template.

Welding tractors for submerged arc welding are capable of performing all seams specified by GOST 11533-75. They are well suited for butt, lap, corner and T joints. The weld is smooth and well-melted, without excessive consumption of filler material.

Where it is necessary to lay a pipeline, automatic welding of circumferential seams is especially successfully used. The essence of the method is to rotate the product under the stationary head of the welding machine. Thanks to the increased current, work is carried out faster than in manual mode. The seams are of high quality.

Automatic pipe welding can be carried out over a large area, connecting sections into one line. The size of such blanks reaches 25 meters. Large connections are also possible, but this depends on the possibility of transporting the pipe to the installation site. Additionally, tractors or railway equipment are used.

Using a crane, the pipes are laid into the main, and the final butt weld is performed by a welder manually. This significantly speeds up the process of laying pipelines.

Advantages of the automatic method

A welding machine operating in automatic mode has a number of advantages over other types of welding. Namely:

• high productivity of work due to increased current strength and speed of welding, which can exceed other methods by 15 times;
• good connection quality due to the stability of the additive supply and the constant speed of passage of the entire line;
• deep penetration;
• working with large diameter pipes;
• using fewer welders for the same amount of work;
• more favorable working conditions for the welder and less harm to health, due to the distance from the source of radiation and smoke.

Fast modes of automatic submerged arc welding are also achieved through the use of powder, which is supplied to the arc combustion zone from a special hopper through a tube. The amount of rash is regulated by the opening width of the damper. Externally, the flux looks like round light balls, finely granulated. Fluxing the welding area has the following advantages:

• eliminates splashing of the metal of the weld pool and filler element;
• gives stability to the arc;
• delays the cooling process of the weld, which improves its physical properties;
• protects the weld pool from the interaction of molten metal with oxygen;
• deoxidizes the metal and helps the alloying elements to be fused better.

The welding tractor melts part of the powder with an electric arc from the wire, as a result of which a small crust forms on the surface of the joint. The other part of the powder remains in the form of granules. After completing the seam, it is necessary to remove the slag layer with a hammer and a metal brush. The cleaned product is ready for painting or treatment with anti-corrosion compounds.

Types of automatic welding

An automatic welding machine that creates an arc by supplying current to a wire and protects the weld pool with a layer of flux can have several designs. These can be machines with a movable head that perform straight or patterned seam lines. For pipelines, fixed heads are used, under which the product rotates on rollers.

Tractors themselves drive over the product, transporting the apparatus and at the same time carrying out welding. All models use a consumable electrode (wire GOST 16130-72). Subsequently, after the introduction of these methods into industry, other devices were developed to automate welding work.

Some operating principles of such installations are similar, while others are fundamentally different.

In an argon environment

One of the varieties is automatic argon arc welding with a non-consumable electrode. The latter is a tungsten rod with some additives.

An electric arc is excited between it and the product, and the argon composition of the gas mixture supplied through the nozzle of the apparatus head prevents carbon from escaping through the surface of the weld. Thanks to this, the connection is strong and smooth.

Welding in a shielding gas environment can be performed by a stationary head of the device, under which the product is rotated, or by a moving part along the connection line. The argon-arc method is actively used when working with stainless pipes and containers.

Cored wire

Another option is automatic cored wire welding. The device supplies the consumable electrode to the welding zone along rollers. The voltage at the end of the wire creates an arc. But to protect the molten metal, it is not the powder from the hopper that is used, but the flux located in the wire itself.

For this purpose, the latter is made in a tubular shape and placed in reels. Such consumables are more expensive, but facilitate preparation for the welding process. The welding machine does not require loading flux into the hopper. The weld bead, as in the case of bulk powder, needs to be cleaned.

The devices can work moving on the product itself or stationary, with the parts being welded scrolling underneath them.

Plasma welding

Automatic plasma welding has been developed to quickly join alloy steels. In such devices, an electric arc burns between two electrodes in the torch head. Argon or helium, supplied under high pressure and swirled by a swirler, promotes ionization of the arc flame and increases its temperature.

Plasma welding is installed on brackets that can rotate along an axis. The distance from the center to the head can be changed, which makes this equipment convenient for automatic circular seams of container bottoms.

Depending on the thickness of the metal and the required seam height, the device can be equipped with an additional block for feeding filler wire.

In addition to the above units, there are semi-automatic versions where the welder needs to direct the welding head or control the movement of the tractor. Automatic and semi-automatic welding are in demand not only in large enterprises, but also in small firms. After all, in this way you can significantly increase productivity and profitability. Some craftsmen were able to make a homemade device based on a semi-automatic device, which is capable of moving along a given trajectory.

Modes and Features

Automatic welding occurs at high currents. This ensures high speed and efficiency of the process. The recommended settings are:

Wire diameter, mm	Current strength, A
2	200-300
3	350-500
4	400-700
5	500-1000

In addition, for each type of work when using automatic welding on a pipeline, a technological map is drawn up, which indicates the entire range of efforts and resources to connect one kilometer of pipe.

These include: labor intensity (the presence of a certain number of people and days to complete), production per shift, the need for a crane (the number of machines per shift), the consumption of energy resources (current and fuel), specific requirements for the assembly and welding of products, safety precautions.

Thanks to the automation of the welding process, the completion of many works has been accelerated. These machines facilitate the installation of pipelines and other structures. And the high quality of the seams allows them to be used on critical joints.

Source: https://svarkalegko.com/tehonology/avtomaticheskaya-svarka.html

Features of the automatic welding machine: device, types of devices, advantages

With the advent of welding machines, it has become possible to perform reliable connections of metal products with minimal time and labor. But over time, the understanding came that they were not ideal either. More advanced equipment was required to perform specific tasks more efficiently. This led to the creation of a new type of device - automatic welding machines. They made it possible to fully automate the workflow.

Thanks to these devices, the participation of the welder is reduced to monitoring the quality of the welded joint, while processes such as: supplying electrodes, maintaining the burning of the welding arc, starting and ending the work process are performed by welding equipment.

In fact, a person has turned into an operator who is only required to install the machine and the parts to be connected in the required position, and then control the welding process using the control panel. Automatic welding machines have radically changed the way the work process can take place and have helped to achieve a significant reduction in worker labor costs.

An automatic welding machine is usually called a device that monitors the quality of the connection and, due to this, allows one to significantly reduce labor costs..

Modern automatic welding machines are divided into three main types:

• suspended stationary machine;
• mobile machine;
• welding tractor.

Hanging stationary

A special feature of the suspended stationary machine is that it is installed in a pre-selected location and remains stationary throughout the entire process . Most often, welding equipment of this type is used for welding pipes.

During this work, special mechanical devices are additionally used that ensure uninterrupted rotation, while the head of the suspended stationary apparatus remains motionless during the entire process. The operator’s role here comes down to monitoring the operation of the equipment, carried out using a special remote control.

Mobile self-propelled

The mobile machine is equipped with a self-propelled trolley, which allows it to be transported to any necessary place. Equipment of this type is most actively used when carrying out work on creating straight seams of considerable length.

Welding tractor

It differs from the two types discussed above in that it is capable of independently moving not only along the path intended for it, but also along the surface of the structure that needs to be welded . The installation procedure takes very little time, so such equipment is used mainly in situations where it is necessary to perform a fairly large amount of work on connecting parts.

Classification of equipment by characteristics

According to their purpose, automatic welding machines can be divided into two main types - specialized and universal. They differ from each other by a certain set of characteristics that characterize their useful performance qualities :

• Depending on the possibility of movement, welding equipment can be divided into self-propelled and non-self-propelled. The latter are also known as pendants.
• Automatic welding devices can also be divided according to the type of electrodes used. Universal devices support work with any type, including non-consumable ones made of tungsten. Specialized devices can only work with a certain type of consumable material.
• By type of electrode melting: wire, piece and strip.
• According to the method of protecting the area where welding is performed: flux, a protective gas environment, and a combined method involving the simultaneous use of flux and a gas environment.
• According to the type of supported operating current. Automatic welding installations can operate with direct or alternating current. There are also special designs, the operation of which is possible with both types of voltage.
• According to the method of feeding filler wire: manually adjustable and adjustable taking into account the voltage with which the electric arc is supplied.
• According to the method of making a welded joint: free and forced technology.
• By type of welding current setting: smooth, stepped and combined.

In cases where an automatic welding machine is required to effectively connect metal products, most often welding is performed not using electrodes, but using a special filler wire, which is wound on a special reel . This material is located in the feeding mechanism and is fed, if necessary, into the area of ​​the seam being created due to the roller system. An automatic feeding method is also possible if there is an electric motor.

The mechanism in which the filler wire is located ensures its movement and straightening, after which it enters the mouthpiece, and from there to the welding arc.

There is also a special contact in the mouthpiece that conducts electric current. It is in constant interaction with the filler wire, thereby creating a welding arc. The contact itself and the arc are located at a short distance from each other. Because of this, the movement of the filler wire resembles the technology of working with a short electrode, when the latter remains the same length throughout the entire process.

The welding zone has a fairly large area, especially if Leister brand machines are used.

As a result, even when working with high-density electric current, the latter can be directed to melt the metal without worrying about overheating the wire or equipment.

Leister automatic welding machines are able to ensure a uniform flow of wire, thanks to a reliable feeder. This eliminates the need for the operator to make allowances for the arc, which tends to change its length.

Of the solutions offered on the market today, quite interesting are the machines from the Twinnie T company, which differ from competitors in their ability to ignite the arc independently, without interacting with the workpieces being connected.

If the technological requirements for carrying out work using an automatic machine are met, then it is possible to solve the following problems:

1. Fine-tune the filler wire feed speed based on the operating voltage of the arc and its size. The filler material will be fed into the welding zone at the same rate at which it melts, provided that the welding arc has normal operating parameters. Likewise, if the arc size decreases, the wire will also decrease, maintaining arc voltage stability.
2. If, due to the circumstances that have arisen, the length of the arc becomes longer, the wire will automatically begin to feed at an increased speed, which will allow the size of the arc and its voltage to be adjusted to standard values. In other words, the machine will maintain optimal operating parameters of the arc throughout the entire welding process and adjust them to normal values ​​without additional consumption of filler wire.
3. When using an automatic welding machine, operation can be normalized after a short circuit. If the described phenomenon leads to an unexpected loss of voltage, the wire immediately moves back, moving away from the structure being welded. In other words, thanks to the machine, the direction of its movement instantly changes.
4. But as soon as the energy supply is resumed, the wire again begins to move towards the elements being connected and, in order to reduce the idle arc voltage, short-circuits at the moment it touches the structures being welded. At the same time, the welding arc lights up. If this does not happen, the wire moves again into the welding zone. Then it takes its original position, after which the arc restores its normal operating parameters.

Thus, thanks to the automatic welding machine, it is possible to ensure the stability of the operating parameters of the arc throughout the entire working process, which is an almost impossible task when carrying out work manually.

Advantages and disadvantages

If we compare the workflow using an automatic machine and welding carried out manually, the first can have the following advantages::

• High labor productivity. Using an automatic welding machine, you can not only connect metal structures of considerable thickness, but also create small seams when you have to perform large-volume work of the same type. In both cases, this equipment provides a significant increase in labor productivity, which cannot be achieved with manual welding, since there is no need to waste time replacing burnt electrodes.
• Eliminating the possibility of human factor influence. Since a person practically does not take part in the welding process, this makes it possible to create a seam that is even along the entire length and uniform in thickness. When welding manually, there is always a risk that the hand will tremble. This will never happen with an automatic machine, since it maintains stable parameters of the welding process throughout the entire welding process. The quality of work cannot be affected by the operator’s condition (not only psychological, but also physical).
• Ability to carry out work in hard-to-reach places. Each person has certain dimensions, so for comfortable welding work he needs a certain area. In the case of an automatic welding machine, it becomes possible to perform welding in conditions where a person not only does not experience inconvenience, but even if he wanted to, could not spoil the quality of the connection.
• Automatic adjustment. A distinctive feature of modern automatic welding machines is the ability to adjust the wire feed in the event of an increase or decrease in the arc length, as well as restore operation after technical failures without consequences for the quality of the seam. Welding carried out using an automatic device guarantees a high quality weld, which is not affected by any external environmental changes.
• Economical. When carrying out work using an automatic machine, a reduction in the consumption of materials used is ensured, since the machine is initially configured to receive them in such quantities as to ensure high-quality connection of parts, preventing them from being wasted into useless waste or splashing.

As for the disadvantages that the technology of joining parts using automatic devices has, the main thing is the occurrence of additional time costs for preparation for the work process.

Before starting work, it is necessary to set up the equipment for welding: install it permanently with the setting of the supply of welded elements or lay a rail track.

This technology also does not allow changing the quality of the seam during the work process, since all characteristics are controlled by an automatic device without the possibility of adjusting them.

The automatic welding machine has become a new stage in the development of equipment used for welding work. Their main advantage is that they made it possible to almost completely automate the work process, minimizing human participation in it .

These devices allow you to maintain stable welding performance throughout the entire time, which is the key to obtaining a high-quality connection of parts. The equipment is not exposed to environmental factors, which can happen at any time to a person who is capable of making a serious mistake. And this ultimately can have an extremely negative impact on the quality of the weld being created.

Source: https://tokar.guru/svarka/svarochnyy-avtomat-vidy-i-preimuschestva-apparatov.html

Automatic welding

Almost every person at least roughly knows what welding is. However, in most cases, the image of a person in a welding mask and with tools in his hands appears in his head.

However, manual welding is not everything; modern technologies make it possible to fully automate the welding process. The use of automatic welding occurs in various industries.

This method is valued for its simplicity, speed of work, high quality of the result and long service life of the seam. Most often, to achieve the best quality of the seam, flux is used .

Automatic flux welding is, in most opinions, the best type of automatic welding. This is the reason for its popularity in various industries. Also, the concept of automatic submerged arc welding is often called submerged arc welding.

The whole process goes as follows. Under the influence of electric current, the arc heats up to high temperatures, as a result of which it begins to burn. The flame is directed to the place where the welding electrode is located and melts it. The electrodes are located at the site of the future weld, it is located between the ends of the two parts being welded, at a distance of 5 to 20 millimeters.

The welding flame must be directed strictly to the location of the future weld; programming of actions is used; if automatic aiming is not possible, in this case the welding arc is directed mechanically.

The flame heats the metal, and with it the flux, which, when melted, forms a strong elastic film, its task is to create a barrier from air.

Pros and cons of submerged arc welding

Any process always has its advantages and disadvantages. Automatic submerged arc welding is no exception. A distinctive feature of this welding method is its high efficiency; the fact is that the amount of flux required for an excellent final result is very small. Consequently, automatic submerged arc welding allows you to significantly save material, and this will have absolutely no effect on the quality of the seam.

The special design of the welding machine allows saving flux, which provides excellent traction for adhesion even of high-density materials. The seam is also covered with a thin layer of slag, which also has a positive effect on the physical characteristics of the joint. This is why automatic and semi-automatic submerged arc welding is very often used for welding pipes.

Advantages of using automatic welding:

• high level of productivity, relative to alternative welding methods;
• the electrode is used almost completely, its losses are less than 2% of the original volume;
• no splashes are generated during the welding process;
• the joint is protected by an elastic layer, so gases present in the atmosphere will not affect the quality of the seam;
• During automatic welding, virtually no oxides are formed;
• the seam is obtained with a fine-grained structure, this is achieved by uniform heating throughout the entire process;
• due to the fact that flux is used to adhere materials, there is no need to use additional protective devices;
• After the process is completed, the metal cools down quite quickly.

A person who has never encountered automatic welding may think that there are only advantages to using it. However, it is not. This method has several disadvantages:

• High financial costs. Creating the entire process and purchasing the necessary equipment is very expensive. In this regard, the use of this welding method is advisable only in industrial conditions; in everyday life it is better to use conventional manual welding.
• The material that needs to be joined is quite difficult to fix in the desired position, this is due to the technological features of the method.
• Automatic welding has a negative impact on the human body.
• A large percentage of work performed requires specialized equipment, which, as a rule, is available only in production.

Based on the above information, it can be understood that this welding method is used mainly only in various industrial enterprises; using this method in everyday life is associated with certain difficulties . This joining method allows you to weld both homogeneous and dissimilar metals; the thickness of the material being welded can take values ​​from 1 to 150 mm.

What is needed to ensure the automatic welding process?

To weld metals, specialized equipment called a welding machine is used. At the moment, there are a large number of its modifications, each of them differs from each other in technical characteristics and each is better than the other for performing certain operations.

For example, there are modifications of an automatic welding machine, the device of which implements a constant supply of welding wire. Welding using such a unit allows you to increase the level of productivity to the maximum level, because with its help you can very quickly create a homogeneous mass and create a high-quality connection.

There are also modifications that can fully automatically adjust absolutely all parameters without exception. Many people consider units of this type to be the best, but this is not so, everything is due to the complexity of the technical setup of the device.

A large number of programs require configuration, and only after its completion the device will be able to carry out its activities without the additional participation of anyone or anything.

Therefore, this modification of the welding machine is used only by professionals; it will be very difficult for amateurs and beginners to understand all the intricacies of the settings.

Any welding heads are equipped with a recovery mode; it is performed if they rotate uniformly and the arc length changes its size. The entire process is dependent on the melting of the electrodes, which occurs due to automatic adjustment of the arc length.

It is important to know: an increase in the size of the gap directly leads to an increased supply of voltage, this affects the change in the current required to perform welding.

The automatic welding machine has another feature. When the welding arc changes its size, the current level and melting rate increase. Naturally, an ordinary household outlet will not work; to perform this function, you need to use an element with a rigid current-voltage characteristic.

 And if the level of electrode feeding speed under the welding arc is reduced, then welding heads equipped with an automatic voltage regulator will affect the size of the arc. In any case, the voltage level will rise back, but for this to happen, you need to use a battery with a decreasing current-voltage characteristic.

All welding machines differ not only in their technical parameters, but also in their settings. For various modifications it can vary significantly. To put it in simple terms, a person has to independently change the current and voltage supplied to the arc.

In units that operate at a constant feed speed, it is necessary to select a voltage and current value suitable for welding any type of material. The arc voltage setting is determined experimentally.

Finally

Any modification of an automatic welding machine has its own unique design. Previously, it was believed that the type of construction was created by the manufacturer, but over time, GOST welding standards were created that must be followed. Their creation made it possible to make the design of welding machines from different manufacturers similar to each other.

Source: https://svarkagid.com/avtomaticheskaja-svarka/

Types of automatic and semi-automatic welding machines

Electric arc welding is considered the most common method of producing permanent joints of metal parts. It is widely used in industrial production, construction and repair work.

Unlike soldering and gluing, where the filler material is not mixed with the base material, the use of an electric arc leads to melting of both the electrode and the parts being connected.

The physical processes and chemical transformations occurring at this time make it possible to obtain a seam with high mechanical characteristics.

Equipment for welding work is constantly being improved, and today there are a huge number of its modifications on the market. The greatest interest is generated by devices that fall into the categories of automatic and semi-automatic. Despite the similarity of names, they have a number of fundamental differences in design and welding technology.

Design of a semi-automatic device

The device is a modular design consisting of a power source, a feed mechanism and a burner. Devices for welding in a shielding gas atmosphere are equipped with cylinders.

There are a number of high-performance refrigerated models that connect to a mains or water tank. Semi-automatic devices are lightweight and highly mobile. They can be carried or transported on a chassis to the work site.

The devices are used for installation of engineering systems, during repairs in existing production and workshops.

There are also semi-automatic machines of a stationary design - welding stations. They are used in the serial production of metal structures, when most of the seams are short in length (up to 0.8 m).

Semiautomatic welding machine Aotai MIG 500

The main design difference between a semi-automatic and an automatic is the presence of a burner, which is usually made in the form of a pistol grip. Joining her: power and control cables; gas and water hoses; sleeve with metal cord for wire feeding.

Semi-automatic welding technology

The molten metal of the electrode and the parts to be connected needs protection from atmospheric oxygen. There are two technologies to avoid their intense oxidation and burnout of alloying additives.

• Welding in shielding gases. The technology involves the use of solid wire, as well as argon or carbon dioxide. Gases are supplied through the nozzle under slight excess pressure, allowing air to be displaced.
• Flux cored wire welding. Flux-containing filler materials eliminate the need for a protective atmosphere. When melting flux-cored wire, slag and gases are formed, which protect the weld pool from oxidation.

Semi-automatic welding process

The tasks of the operator of a semi-automatic installation include selecting the operating mode of the device (setting the current strength, choosing the polarity) in accordance with the diameter of the electrode and the material, activating the burner and performing the required number of passes along the seam. The wire feed speed (maintaining a constant arc length) is adjusted in automatic mode.

Many modern devices have additional functions that make the welder’s work easier: increasing the voltage when igniting the arc, the ability to switch from direct current to alternating current or pulsed current for joining parts made of non-ferrous metals. Some models can be converted to non-consumable electrode welding or conventional manual welding.

Electronically controlled semi-automatic machines have a built-in memory for saving settings. To switch to another mode, the operator only needs to select the appropriate program number.

Designs of automatic welding machines

Welding machines represent a whole class of high-tech equipment. They are most often used in production settings. The machines independently supply filler materials and move the welding head along the seam. The variety of designs of such devices is due to differences in production technologies.

Scheme of organization of welding work on the UAST-1 installation during pipeline construction

Depending on the method of movement, machines are of the following types.

• Hanging. The operator places the welding head and the part in the desired spatial position. In this case, the latter moves. Such machines allow you to produce seams of almost any configuration.
• Self-propelled. Such machines are installed on a special trolley. their feature is the ability to move both the head and the part during the welding process.
• Welding tractors. The lightest and most mobile machines equipped with a chassis. During welding, the tractor moves along special rails or the part itself. The main advantage of such a machine is the ability to work with long parts. Theoretically, the tractor is capable of making an endless straight seam.

Automatic welding machines are used in the production of pipes, vessels and large-diameter containers, construction and industrial metal structures. There are specialized machines for welding certain parts. Many manufacturers equip their machines with replaceable equipment that allows them to expand the scope of application. For example, copying devices allow welding of parts of complex shapes.

Structurally, single- and multi-electrode machines are distinguished. The latter are characterized by higher productivity. Some machines can be combined into production lines with a single control.

Automatic welding technologies

The choice of technology depends on the specifics of the parts being connected. The following types are most widespread.

• In a protective gas environment. To obtain a weld of the required quality, argon, helium, and various mixtures can be used.
• Submerged arc welding. One of the most productive technologies used in large-scale mechanical engineering and metallurgical production. The machine uses solid wire and bulk flux as filler materials.
• Electroslag welding. Heat for melting the base and filler metals is released when current passes through a layer of liquid slag. This welding ensures minimal dissolution of hydrogen in the metal and ensures high impact strength of the joint.

The machines can be configured for any type of filler metal transfer into the weld pool, including jet transfer. If a short circuit occurs, the device restores the welding arc without operator intervention.

ADS-1 device for automatic welding with solid wire in CO2 shielding gas

Advantages and disadvantages of semi-automatic welding

The advantages of welding in semi-automatic mode include the following.

• Possibility of joining thin sheet materials. By selecting the operating mode of the device and the diameter of the wire, we achieve minimal thermal loads and reduce the warping effect.
• The quality of the seam does not depend on its length. If necessary, parts can be joined by spot welding.
• Variety of materials. The semi-automatic machine is capable of working with both structural carbon steels and many high-alloy tool steels. By changing the type of current and polarity, you can set the modes for welding non-ferrous metals, including those with high chemical activity.
• Ease of setup. The operator can quickly set the required mode, which is very convenient when performing small jobs.

Such devices also have a number of disadvantages that limit their use.

• Inability to work with large diameter wire due to its high rigidity.
• Difficulties in carrying out welding activities outdoors. To prevent the wind from blowing away the protective atmosphere, it is necessary to increase the consumption of inert gas.
• Intensive metal spattering at currents above 500 A.
• High intensity of radiation from the arc.
• The need to refill cylinders.

Advantages and disadvantages of using automatic machines

The advantages of automatic welding machines are clearly evident in intensive operation modes.

• High performance. The installations are capable of working with tape and wire of large sections. Their productivity allows welding of parts with a thickness of more than 100 mm. They are also effective if it is necessary to produce a large number of short seams in mass production.
• The influence of the human factor is excluded. The operation of the machine does not depend on the physical and psychological state of the operator. If the adjustment is made in accordance with the technology, the seam will be even in length and thickness.
• Work in hard-to-reach places. The designs of the devices allow welding to be carried out in places where a person cannot physically be present. Some installations are designed specifically for such specific operations.
• Ease of adjustment. Modern machines are equipped with electronic controls and built-in memory. For each new product, welding parameters are adjusted once. Subsequently, presets can be loaded from memory.
• Operator safety. Modern installations are equipped with forced smoke removal systems and other protective equipment. Due to the absence of exposure to harmful and dangerous factors, the risk of occupational diseases is reduced.

The main disadvantages of automatic machines are the high cost and costs of organizing the process. Some items and parts to be welded may require lifting equipment to install. To obtain a high-quality seam, the initial setting of the mode must be done carefully: the operator must have the appropriate qualifications.

To receive additional information about welding equipment and professional recommendations for selection, contact a representative of TSK LLC by phone. We are ready to create a welding production project, provide its support, as well as supply it with equipment and materials.

Source: https://www.tck-spb.ru/articles/svarochnye-avtomaty

What is the difference between an automatic welding machine and a semi-automatic machine?

For experienced welders and beginners in this business, there is a huge selection of welding equipment. It differs in technological processes, in the set of additional tools, in dimensions and functionality.

If a novice master can still find the differences between a transformer and an inverter, then he will most likely think about automatic and semi-automatic welding. This article will help you understand all the nuances of these processes and understand where you need to use this or that welding.

We will also make a comparison between these devices, pay attention to the differences and note the advantages of the machines.

What is a welding machine

One variation of the welding process is automatic welding. The device is configured in such a way that human participation is not required, everything happens automatically, and the welder is called the machine operator. His responsibilities include choosing the correct welding mode and setting the necessary settings.

An automatic welding machine can withstand heavy loads, but the quality of the seam is affected not by its performance, but by the knowledge and skills of the specialist operating this machine. The unit performs several operations simultaneously:

• ignites an arc;
• automatically creates an even seam;
• protects the welding area from oxides (flux machines);
• continuously and evenly feeds the welding rod into the pool area.

Advantages of automatic welding machine

The automatic welding machine has a number of advantages over other welding machines. It is an undeniable fact that the welding process is carried out without human intervention. This is a robot capable of working day and night according to a given algorithm, performing kilometers of seams with the same result. Even the most qualified and experienced craftsman is not able to perform such work with consistent quality.

This machine makes no difference what operation to perform and what types of seams to make. The machine does not require rest.

It happens that the settings of the machine are not suitable for the work being performed. Such an incident is corrected in a matter of minutes, and if a person who is dizzy or has an attack of toothache works with incorrect settings, then the entire batch of products may not pass quality control and will be written off as defective.

If the electricity goes out, the machine is programmed so that after being connected to the network, it independently updates the settings according to the specified parameters and continues to work with the same speed and quality. In this case, operator assistance is not required. Hard-to-reach welding places that are inconvenient for a human position can also be performed by an automatic machine.

Automatic devices are very economical in terms of consumables, so it is impossible to encounter the problem of excessive wire consumption or lack of protective gas.

In hazardous production conditions that may threaten human health, automatic installations are always used. The entire process occurs only by machine and does not allow human participation.

What is the difference between a semi-automatic and an automatic?

In automatic mode, the main task falls on the shoulders of the operator. Only it sets the settings and turns on the Start button. The operation of the automatic machine depends on his knowledge. The person participates in the process indirectly, he is not present during the operations, does not operate the torch and does not monitor the retention of the arc.

In semi-automatic mode, the person himself is both an adjuster and a performer. His tasks include: setting up the device, adjusting it, lighting the arc, holding it, making a seam. The technology involves the use of all materials, as with the previous method: flux, filler wire, shielding gas. Only uniform wire feeding remains automatic. That's just the similarity with a machine gun.

Why use a semi-automatic when there is an automatic?

Inexperienced welders, having read all the praises of automatic welding, often ask this question. At first glance, the automatic has an overwhelming number of advantages in comparison with the semi-automatic. It uses additional materials sparingly, is stable and denies human participation, but everything is relative.

Most industries use semi-automatic welding. Only large large-scale enterprises use machines, where the machine works almost non-stop. And such companies can be counted on one hand. Automatic installations themselves are expensive equipment. The average entrepreneur would rather hire a first-class specialist than spend money on a machine, because a downtime machine will bring more losses than monthly expenses on paying a specialist.

Therefore the question remains unanswered. It is necessary to build on the assigned tasks. For small volumes, semi-automatic welding will be the optimal solution, but when expanding production, plans do not always coincide with reality.

You should also be aware that only a specialist with knowledge of all the intricacies of welding should set up a welding machine. The machine executes given commands and does not understand emergency situations. A semi-automatic is much more mobile than an automatic and much lower in cost. It is transported on a specially designed gurney, and the machine is a stationary installation.

The technology of the welding process is the same in both cases, in one without the participation of people, in the other with the presence of a welder.

Conclusion

Now you know all the differences between automatic and semi-automatic welding, where it is necessary to use one or another technology, why a semi-automatic method is more appropriate and why fully automatic units are used. The two processes have many common points. But the difference is only in the presence or absence of a person.

Source: https://svarka-weld.ru/otlichiya-avtomaticheskoj-i-poluavtomaticheskoj-svarki

Features and benefits of automatic arc welding technology

Welding is the most reliable type of permanent connections between metal and plastic parts. Arc welding of ferrous and non-ferrous metals in cramped conditions and environments harmful to health is carried out using automated welding complexes. Automatic arc welding: what is it, where is it used, what types are there, what features may be encountered - this article will answer these questions.

Areas of use

In home workshops, due to the high cost of equipment and materials, automatic welding is rarely used. But in production conditions, where payback is ensured by large volumes of work, automatic machines are used for:

• work with non-ferrous and ferrous metals in various combinations;
• connections of workpieces with a thickness of 1.5 to 200 mm;
• assemblies of especially critical products - housings of nuclear and chemical reactors, pressure vessels and others;
• welding of internal seams of pipelines and containers.

Advantages

Manual and automatic welding use similar welding technologies. The automatic welding method has the following advantages:

• increased productivity, speed is several times higher;
• high stability of seam parameters;
• possibility of deep penetration;
• assembly of vessels and pipes, including large ones;
• a significant reduction in both overall labor intensity and the need for highly qualified welders;
• significant improvement in working conditions and production safety.

Certain advantages come from the use of fluxes, both powdered and supplied from a storage tank through a hose, and those included in the welding wire. These include:

• prevents splashes from the weld pool;
• stabilizes the parameters of the electric arc;
• slows down the cooling of the weld material, improving its properties;
• protects the melt from the effects of oxygen, nitrogen and water vapor contained in the air;
• promotes deoxidation of the weld material and integration of alloying additives into it.

Flux powder is not completely used during welding. Modern tractors clean off and collect the remaining powder along with scale . On older models, this is done manually after the seam has cooled, before applying protective paint coatings.

Varieties

Several types of automatic welding technology are used. On some units, the manipulator moves the head, on others, used for connecting pipes, the head is stationary, and the workpiece rotates. Self-propelled chassis move tractors along a predetermined path inside or outside the parts being connected. In addition to kinematic schemes, methods of creating a protective atmosphere around the welded zone also differ.

Tools to Ensure

An automatic welding machine is a complete technological complex that carries out most of the technological operations to create a welded joint.

However, it should be understood that they cannot always perform most of the preparatory and final operations, such as:

• mechanical cleaning of the seam area;
• degreasing;
• descaling;
• surface preparation and application of protective coatings.

In most cases, this work is carried out, as before, manually. They require angle grinders, wire brushes, solvent sprayers and rags. Only the most modern tractor models are capable of pre-cleaning the seam area.

An automatic electric arc welding machine involves software control of both welding modes and the supply of the workpiece (or the movement of the tractor along it). Therefore, an important component of modern machines is the processor unit containing control programs . The program is generated in a post-processor based on data from a three-dimensional model of the product loaded from a parametric modeling application.

The creation, testing and debugging of such a program requires the working time of highly qualified specialists, therefore the economic efficiency of automatic welding is achieved in two cases:

• production of a series of products;
• production of unique, but very important structures (aerospace industry, nuclear energy, etc.).

It is more efficient to make a single product or a small series of ordinary parts using semi-automatic welding. In this case, the welder moves the head along the weld line manually, and the modes, wire supply and shielding gas are controlled by mechanisms.

Device design

The main design elements of an automatic welding machine, common to all varieties, are as follows:

• power source: powerful inverter unit, which allows you to receive welding current of the required voltage, strength and polarity;
• welding head, fixed on the machine or on a manipulator, either fixed infusible electrodes or a mechanism for feeding welding (filler) wire, as well as nozzles for supplying shielding gas are attached to it;
• workpiece feed mechanism for stationary machines;
• self-propelled chassis for tractors;
• storage location for gas supplies and wiring;
• control system containing a program for controlling welding modes and movement.

Depending on the technology used and the type of workpieces being welded, automatic machines can be equipped with additional equipment:

• inertial positioning system for orientation inside extended structures;
• CCTV cameras for visual control by the operator of the welding progress;
• systems for preparing the joint area for welding and seam cleaning mechanisms.

Based on the requirements of a specific technology, significant changes can be made to the design of the device, including changing the length and degrees of freedom of the manipulators, equipping the chassis with magnetic fasteners, specific settings of welding modes, and others.

Some of them can be performed at the production site by service departments. Major changes to the design require intervention from the manufacturer.

Advantages

The main advantages include the following factors:

• The creation of a large volume of identical work requires less human labor;
• The welding speed becomes more accurate;
• All products will be made almost identically, so that defects due to human negligence are excluded;
• The regimes are strictly followed in all cases;
• Serial production becomes more economically profitable.

Flaws

Automatic welding of pipes and other products is a very peculiar matter, so there are not only positive aspects, but also negative ones:

• For small-scale work, this method turns out to be completely useless, since it is very expensive and requires lengthy preparation;
• The equipment is highly expensive, which makes it inaccessible even for some enterprises, not to mention individuals;
• The equipment takes up a lot of space, while manual devices and semi-automatic devices are more compact;
• Automation is difficult to maintain and repair;
• Operating the machine requires special training that differs from that required for standard welding.

Source: https://svarkaipayka.ru/tehnologia/termicheskaya/avtomaticheskaya-svarka.html

Features of the automatic welding machine: device, types of devices, advantages - Machine

Welding wire with flux, in accordance with GOST 8713 of 1979, is intended for permanent connection of parts made of steel and alloys with the inclusion of an iron-nickel base. Using this type of welding work, you can perform joints of any complexity.

Training a specialist for semi-automatic submerged arc welding does not require a lot of time and money. The flux itself is a granular powder that, when burned, creates a protective layer of gas and slag.

Effect of protective coating

Electric arc welding under a layer of protective powder is a simple, but high-quality and reliable connection of various metal structures and parts.

The peculiarity of submerged arc welding lies in the connection of molten metal of two parts under a layer of special granular powder. At high temperatures of the electric arc, the metal and flux melt.

The film formed when the granules melt protects the weld pool from exposure to oxygen and the environment and prevents metal from splashing.

A thin layer of slag appears on the seam, which allows the welded joint to cool evenly. The crust is easily removed from the surface of the seam. It is necessary to perform removal for visual control of welding quality.

To remove slag, just hit it lightly with a hammer and it will crumble. Before this, it is necessary to remove the remaining flux from the parts; it can be used at the next joint.

Working methods

To make a connection using submerged arc welding, two methods are most common.

Connection using semi-automatic welding. To ensure optimal feed speed of flux-cored wire, the welder selects the appropriate operating mode on the machine, taking into account the thickness of the metal and the type of connection.

The arc is directed manually. At the same time, the wire feed speed, current strength and angle of inclination of the holder are the main factors affecting the quality of the work performed.

The automatic (robotic) welding scheme is designed for connecting butt and corner parts. In this case, the machine sets the direction of arc movement, wire feed speed and carriage travel. Such a device produces a high-quality seam at high welding speed.

One of the varieties of the automatic method allows you to weld with two electrodes at once - this is the tandem method. In this case, the electrodes run parallel to each other and are in the same plane, which makes it possible to increase the weld pool when the electric arc is instantly excited. The flux protects the seam from oxygen and ensures uniform cooling .

Types of fluxes

Each substance included in the flux is intended for welding certain metals and alloys. When choosing a brand of flux, it is taken into account whether the steel to be welded is high-alloy or high-carbon, or whether non-ferrous metals, alloys, and so on will be welded.

According to the production method, fluxes are divided into two types:

• unfused (baked and ceramic) – granules with alloying additives that ensure high quality welded joints;
• fused - with inclusions of glass or pumice.

Baked and ceramic fluxes are made by grinding a base material and combining the solution with liquid glass. They are used to add alloying additives to the weld body. Fused fluxes are made by sintering base materials.

Fluxes for seam protection are produced separately for electric and gas welding. They differ in chemical composition. Granules, which contain a certain amount of fluorides and chlorides, are intended for electric arc welding with remelting of slags with active metals. These are salt granules.

The combination of saline and oxide solutions allows the use of mixed fluxes for weld penetration of alloy steel. Oxide flux is intended for joining structural steels with a high fluorine content.

Welding wire classification

Semi-automatic welding is performed with flux-cored wire without gas to improve the quality of joining parts. The mechanical performance of the welding joint depends on the type of rods and chemical composition.

Important. Steel wire for submerged arc welding must comply with GOST 2246 of 1970 and be used depending on the material of the parts.

Wire is made from three types of steel:

• alloyed;
• highly alloyed;
• structural, low-carbon.

The cross-section of the cores, depending on the thickness of the metal, is made with a diameter of no more than 12 mm. Supplied in coils no more than 80 m long. At the request of customers, winding on cassettes or reels is possible.

Steel wire should be stored in dry rooms. When rust forms, the coils are treated with gasoline or kerosene.

For welding aluminum parts, the wire is made in accordance with GOSTs 7871 and 16130. For this purpose, copper-plated wires are produced and most often used, which do not require processing during welding.

Features and Benefits

The advantages of semi-automatic and automatic welding under a protective layer of flux allow this type of permanent connection to occupy one of the leading places.

High level of performance

According to this characteristic, the advantage over manual welding is at least 6 times, some experts believe that it is much more. But this is not the limit; by increasing the operating coefficient of the welding machine, the amount of labor productivity increases. Another reason for achieving such results is the use of high current values ​​during welding.

A dense layer of flux material does not allow the metal to spread, while good weld formation occurs. At higher current values, this equipment can reliably provide penetration of even thick metal without extensive cutting of edges. Therefore, productivity increases even more. The time required to clean up splashes and heavy metal spreading is reduced.

Improved seam quality

The quality of the connection increases due to the fact that the molten metal is not exposed to oxygen and other atmospheric substances.

There is a wide choice of welding wire material available. By using the brand that is best suited for welding, you can obtain a weld with a homogeneous composition.

It becomes possible to give the seam an excellent shape, with the required seam leg. Thanks to the protective film that forms when the flux burns, there are no undercuts, lack of penetration, pores or cracks in the seams. Finally, there is no need to replace electrodes, so the seam is smooth and without tears.

Economical consumption of materials and improved working conditions for the welder

When welding with submerged arcs, wire consumption is reduced by up to 35%, when compared with welding with electrodes. The material is not wasted in the form of cinders and metal spattering.

With this method, carbon monoxide is released in smaller quantities; the specialist’s eyes and face are not exposed to strong ultraviolet radiation, as with electric welding.

Equipment

We produce 2 types of equipment for submerged arc welding of parts. In the first type, welding wire with a thickness of no more than 3 mm is used.

The design principle of such a welding machine involves self-adjustment of the arc (voltage on it), while the wire is fed at a constant speed.

The second type is equipment in which the current is automatically adjusted depending on the feed speed of the welding wires. The diameter of the electrode wire for such equipment starts from 3 mm.

We produce semi-automatic welding machines and devices for automatic welding. They produce universal machines that can be used for welding with flux-cored wire, submerged arc welding, MIG, as well as electric arc gouging. The current reaches values ​​of 300-1500 A.

Modern automatic models are equipped with a mechanism that allows you to collect unmelted flux and send it back to the loading container. There is a seam proportionality control function.

Self-propelled vehicles (tractors, suspended heads) are common in industry, allowing automatic welding of voluminous and extended structures. If the welding machine is equipped with a laser, this makes it possible to monitor the position of the electrode. Moreover, the screen can be installed at a distance of about 20 meters.

Application area

It is necessary to understand where submerged arc welding is used, which is rightfully considered one of the main methods for obtaining a permanent connection. Welding is performed in the lower position, for connecting parts end-to-end, overlapping, for corner connection methods.

Previously, the method was used only for welding metal structures made of structural steels. With the development of new technologies, it became possible to weld all types of steel and nickel alloys. For this purpose, a wire suitable in its composition is used.

Titanium and its alloys, copper and copper-based alloys, aluminum alloys and pure metal - these materials are successfully and reliably joined using submerged arc welding.

Using the submerged arc method, complex building structures, bridges, pipes, tanks, sea and river vessels are welded. It is economically profitable to use this method for sheets with a thickness of 6 mm or more.

It is important to choose the right operating mode, wire material and type of flux . The seam will be able to withstand large temperature changes and exposure to aggressive environments. A joint made by a professional will withstand very high pressure and will be reliable in conditions of complete vacuum.

Source: https://regionvtormet.ru/okrashivanie/osobennosti-svarochnogo-avtomata-ustrojstvo-vidy-apparatov-preimushhestva.html