How are welds divided according to the type of welded joint?

Types of welded joints

Currently, welding has become one of the most popular technological processes for connecting various parts and structural elements. The process is so technologically advanced that it is sometimes difficult to make a complete classification of all types of such a process. They are classified into two groups: the weld itself and preparatory work (edge ​​preparation).

Types of welded joints

What are the types of welding seams and connections classification?

All types of welded joints are classified according to the following criteria.

By method of execution

According to the method of execution, the technological process is carried out as follows:

• high temperature melting;
• through pressure.

Melting creates conditions for improving atomic-molecular bonds due to high temperature and the introduction of additional metal.

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The second method differs from the previous one in that plastic deformation of elements under strong pressure occurs near the welded zone. This helps improve the quality of the final result.

Welding methods

The heating itself is carried out using various types of technical techniques:

• creating an electric arc;
• formation of a flame using an oxygen gas mixture;
• high frequency current;
• using a laser beam.

To protect the area adjacent to the joint, various methods are used: work in special baths, an environment of inert gases. According to experts, the types of welds have more than 70 well-developed methods, called welding.

This parameter is defined as the cross-sectional profile of the resulting joint. Its shape depends on the loads that will be applied to the finished structure. The following types of seams are distinguished according to the degree of convexity:

• convex (with varying degrees of geometric roundness);
• normal (the seam is triangular in shape, the leg of the triangle is equal to the thickness of the sheet being welded);
• concave (the leg of the triangular joint is less than the thickness of the sheet by approximately 0.8);
• For fillet welds, special profiles are used (they deviate from the rule of creating an isosceles triangle and create a figure that has individual parameters).

Schematic illustration of a convex seam

By position in space

Two types of relative positions of various elements are considered:

• position of parts during the welding operation;
• the position of the weld itself relative to the future structure.

In the first case, the following types of position are distinguished:

• lower;
• vertical;
• ceiling;
• horizontal position of the seam on a vertical plane;
• fillet weld (in professional literature you can find the term “boat welding”).

Classification of seams by position in space

In the second case, there are two main types relative to the surface of the part:

• one-sided (it is performed only on one side of the welded structure);
• double-sided (in this case, welding is performed on both sides).

By length

The total length of the contact segment is considered. The quality of work performed along the entire length determines the reliability of the resulting element. Welds are divided into three categories:

• short seams (length does not exceed 250 millimeters);
• medium category (length increases from 250 mm to 1 meter);
• long seams (their length exceeds one meter).

Weld seams by length

The position of the parts being welded relative to each other divides all seams into main types:

• butt-welded metal sheets (they are called butt-welded);
• tee (after welding, tee seams are formed);
• angular (one element is welded to another at a certain angle);
• before welding, one part of the sheet is placed on another (lap type);
• welding two products end to end;
• the action is performed in such a way that the cross section forms a figure resembling a cross;
• free combination of several elements in an established order;
• welding using cutting technology (slot type).

Types of welded joints by location

In the direction of the acting force and the vector of action of external forces

When carrying out welding work, special attention is paid to assessing the direction of the acting force and the vector of action of external forces applied to the resulting structure. Knowledge of these parameters allows one to assess the reliability of the weld. They are considered as the following types of welding joints:

• longitudinal or flank directions (the vector of forces is directed parallel to the line of the formed connection);
• transverse or frontal (the vector of the acting forces makes a right angle relative to the longitudinal line);
• combined directions (the angle is in the range from 0 to 90°, but perpendicular to the axis);
• oblique (the angle of inclination changes along the axis of the resulting connection).

Flank seam

Types of welds according to the shape of the products being welded

In many ways, the quality of welding depends on the correct approach to assessing the geometric shape of the parts being welded. It should be understood that the types of welds are assessed by the shape of the products being welded. There is no exact division between them. The weld is divided into two large categories. Obtained on flat surfaces and spherical surfaces. The types of seams also depend on the thickness of the working material and the length of the joint itself.

The weld will be of high quality after carefully carried out preparatory work. They are necessary before welding structures whose element thickness exceeds 5 millimeters. For one-sided welding. The preparatory operation is called edge cutting. The rules and quality of such work are determined by GOST requirements. Removal of contamination from the entire edge should be carried out at a distance of at least 20 millimeters from the future welding site.

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Download GOST 5264-80

The main types of this operation are:

• through careful cutting;
• without preliminary cutting;
• the so-called flanging.

Edge preparation and parameters

The flanging is made one-sided for corner joints, double-sided for butt joints.

Preparation is carried out manually (using a file, sandpaper, metal brush) or using electric tools (drills equipped with the necessary attachments, grinders, factory equipment).

For metal with a thickness ranging from 3 mm to 26 mm, a V-shaped single-sided or double-sided type of edge bevel is used. For metal with a thickness of 12 to 60 mm, an X-shaped type of bevel is made.

Edge preparation procedure

A procedure has been established for preparing the material for subsequent work with any type of welded joints. It includes the following items:

• cleaning the edge of the metal (any dirt, deposits, corrosion are removed);
• removing the necessary chamfers (this operation depends on the method used for welding);
• preparation of the gap (size, quality must correspond to a certain type).

Cleaning the edge of the metal

Edge Preparation Options

To properly complete the preparation, you must adhere to the following parameters:

• edge cutting angle;
• the size of the interval between the edges forming reliable contact;
• the degree of dulling of the edge of the workpiece.

Source: https://stankiexpert.ru/spravochnik/svarka/tipy-svarnykh-soedinenii.html

Classification of welds | Metal welding

Welds are divided according to the type of welded joint and the geometric outline of the weld section into butt and corner (Fig. 12). The butt weld is characterized by width e and reinforcement q, penetration depth A, gap b; corner - leg K.

Butt welds are used to make butt joints. Fillet welds are used in lap, tee and corner joints. The cross-sectional dimensions of the seams are established by GOST 5264-80.

External surface shape

Depending on the shape of the outer surface, butt seams can be flat or convex. Fillet welds can also be made concave. Welded joints with convex seams perform better under static loads than joints with flat or concave seams. However, seams with too much convexity

Rice. 12. Geometric parameters of welds

Rice. 14. Classification of welds by length (a), relation to the direction of acting forces (b), shape of the outer surface (c)

Rice. 13. Basic welding provisions and their designations

due to the large amount of deposited metal, they are uneconomical. Butt joints with flat seams and corner, tee and lap joints with concave seams perform better under dynamic or alternating loads than connections with convex seams.

This is explained by the fact that with flat and concave welds there are no sharp transitions from the base to the deposited metal, in which there is a stress concentration and from which the destruction of the joint can begin.

In accordance with the standard, seam convexity during bottom welding is allowed up to 2 mm and no more than 3 mm for seams made in other positions. Concavity is allowed in all cases no more than 3 mm.

By position

According to GOST 11969 - 79, seams are divided according to position: boat - L, bottom - N, semi-horizontal - Pg, horizontal - G, semi-vertical - Pv, vertical - V, semi-ceiling - Pp, ceiling - P (Fig. 13) .

Welding the bottom seams is the most convenient and can be easily mechanized. The most complex and difficult is the ceiling seam, the execution of which requires special training. Making horizontal and vertical seams is somewhat more difficult than the bottom ones, but easier than the ceiling ones.

Vertical, horizontal and ceiling seams are used in most cases in the construction and installation of large structures and much less often in factory conditions, where with the help of devices it is possible to almost completely weld the structure only in the lower position.

Many highly qualified welders perform vertical welds with better quality than lower ones, since in this case contaminants are more easily removed from the weld pool and the weld metal becomes cleaner, denser and stronger.

In the direction of current efforts

In relation to the direction of the acting forces, the seams are divided into flank (longitudinal, lateral), the axes of which are parallel to the direction of the force; frontal (transverse), the axes of which are perpendicular to the direction of force; combined and oblique (Fig. 14).

By length

Based on their length, seams are distinguished between continuous and intermittent. The interrupted seam can be valued or staggered.

A chain weld is a double-sided intermittent seam of a T-joint, in which welding areas and gaps are located on both sides of the wall, one against the other (Fig. 14, a). A checkerboard seam is a double-sided intermittent T-joint seam.

In which the gaps on one side of the wall are located opposite the welded sections of the seam on the other side. The distance from the beginning of the welded section of the seam to the beginning of the next section is called the seam pitch.

According to working conditions

According to operating conditions, seams are divided into working seams, which absorb external loads, and connecting seams (connecting seams), intended only for fastening parts of the product. Bonding seams are often called non-working seams.

Source: http://www.svarkametallov.ru/content/klassifikaciya-svarnyh-shvov

Welds: classification, types of welding joints - Ice advice

MiscellaneousWelding seams

A weld is a section where two parts are joined into a single whole due to the melting of the metal under the influence of high temperature and its further crystallization. Today, more than 100 types of connections are distinguished. They are all divided according to special parameters and divided into various groups and subgroups, and therefore there are many classifications of welds.

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According to the type of welded joint

The classification of welds according to the type of welded joint is divided into butt and corner. The master decides which connection to make in a given situation, based on the position of the parts in space.

• Corner welds are made when the workpieces are at an angle to each other.
• Welding of butt joints is formed as a result of the adjacency of two parts or parts with their ends facing each other, which are located on the same plane. The track itself can be of three types - concave, convex or flat. The latter is used most often, since it does not have a particularly pronounced transition at the junction of parts, which looks more natural in comparison with the other two types. This method is most often used when electric arc welding at low currents, so as not to scorch the workpiece. For example, sheet steel is an ideal material for butt welding applications.
• Slotted (electric rivet) is made in the hole that is on the part and is made in the form of spot rivets. That is, in this case, a weld pool and a seam are not formed as a result, and the parts are soldered in small sections through grooves in the workpiece.

At the place of welding

The classification of welded joints and seams in this category depends on the position of the welded parts in space.

For example, if you need to repair a part of some kind of structure that cannot be removed and put down, but it is located at some distance from the floor, then the master will carry out the work using a ceiling, bottom, horizontal or vertical connection, starting from the placement of this part.

• Horizontal are welds that extend from left to right (or vice versa) on a vertical part. To prevent the mass of metal from flowing down, it is necessary to correctly select the speed of movement of the electrode or torch and the current strength (this is selected for each case individually, based on the type of welding, the characteristics of the parts and the skill of the specialist).
• The vertical method of producing butt welds is carried out on vertically positioned workpieces, with the seams being made from top to bottom (or vice versa). The complexity of this process lies in the fact that the force of gravity of the Earth is triggered and the molten metal mass flows down all the time, which spoils both the quality and appearance of the part. Such connections are recommended to be carried out in extreme cases and only to those craftsmen who already have a certain theoretical and practical knowledge for working with such paths. More information about vertical seam technology can be found here.
• Ceiling is a position in which the part is located above the master’s head, which greatly complicates the process. When making ceiling welds, you must strictly follow safety rules and welding technology, because in this case the danger lies in the flow of molten metal.
• Lower welding methods are performed when the part is located below in relation to the master. This is the most convenient connection method, since the metal does not spread to the sides or down, but flows into the crater. In addition, gases and slags freely escape to the surface. A butt welded joint in the lower position is performed by forming beads throughout the entire joint of the parts. At the same time, the welding technology is simple - it is enough to move the electrode or torch straight or in a zigzag to create a reliable and aesthetically attractive path.

By configuration

This category of butt welds is used in manual arc welding with an electrode. This includes three types of welds - straight, curved and annular (spiral). They are produced regardless of the position of the work product. All types of seams of this classification require both butt and lap welded joints.

According to execution technology

Depending on the technology used for fastening, there are four main types:

• The underwelding, where - the smaller part of the double-sided seam, is performed in advance to prevent burn-throughs during subsequent welding;
• a tack weld allows you to fix parts that are already positioned for welding;
• a temporary seam is necessary to hold the workpieces together for a while, and upon completion of the work it is removed.
• installation weld, used during installation of various structures.

In relation to the direction of current efforts

Butt welding contains another important classification, depending on the relationship to the direction of force:

• Longitudinal method of creating a joint (flank), in which the force acts parallel to the axis of the track;
• Transverse method (frontal) of the weld, in which its axis is perpendicular (90 degrees) to the axis of force;
• A combined welding connection includes both flank and transverse types;
• Oblique, in which the axis of the seam is located at an angle to the direction of the acting forces.

According to the shape of the outer surface

According to the shape of the clutch surface, they are divided into three main types:

• Convex (reinforced) are multi-layer seams used in clutches under static loads, but increased influx leads to excessive consumption of electrode metal and therefore an economic justification is required for its use.
• Concave (loose) methods are used to hold thin metal together.
• Normal or flat are relevant for dynamic loads, since they do not have a special difference between the track and the base metal.

By type of welding

The classification of welds by type of welding is divided depending on the type of impact of the welding machine. For example, when working in an environment of argon or other protective gas, the connection will be nothing other than “gas”; when working with an electrode, it will be “electric arc”. The most basic types are the following seams:

• manual arc welding - butt or lap joints are made manually using an electrode. Thus, it is possible to fasten almost any metal with a thickness from 0.1 to 100 mm in any position;
• automatic welding, which is carried out when working with a device - a transformer, rectifier or inverter;
• welding in inert gas. Such butt, corner and lap joints are considered the most durable, since welding occurs in an environment of inert gases, which protect it from oxidation. The big advantage of such fastening is the aesthetic appearance and the absence of waste and slag;
• gas welding - the track is formed under the influence of temperature, which is created due to the combustion of the working gas emanating from the torch;
• solder connections that are made using a soldering iron.

In addition to those described, there are many more methods for connecting parts, both conventional and non-standard, which are used for welding parts in hard-to-reach places. For example, seams can be single-layer (a) or multi-layer (b, c), in which several rollers are applied, located at the same level of the cross-section of the seam.

Types of welded joints. Calculation of connections under the action of axial forces

/ Design of steel structures / Welded joints / Types of welded joints. Calculation of connections under the action of axial forces

Welded joints differ in their design as follows:

butt connections;

lap joints;

end-to-end connections (in a tee or in a corner).

The names of seams and types of welded joints are given in the table Type of welded joints.

Classification of seams by position in space

The welds used to make connections are divided according to a number of characteristics, namely:

• according to position in space - lower, vertical, horizontal and ceiling;
• according to the design of the seam - butt and corner; Fillet welds, according to their location to the current forces, are divided into flank and frontal (end);
• by type of processing (cutting) of sheet edges - into V-shaped (denoted by the Latin letter V), X (X)-shaped, K-shaped (table Classification of seams by type of edge processing);
• by length - continuous and intermittent;
• according to the number of layers applied during welding - single-layer and multi-layer;
• by purpose - for working (transmitting forces) and constructive, non-binding.

Symbols for seams and their sizes used in the drawings are given in the table Symbols for welds.

Source: https://LEDsovet.ru/svarnye-shvy-klassifikaciia-tipy-svarochnyh-soedinenii/

Classification of welds and joints

The effectiveness and quality of work depends on the availability of the necessary tools, materials and skills. Success in any business, no matter what direction it is, is also significantly influenced by knowledge of theory. Welding work is considered to be one of the most common.

This type of activity requires material, equipment, work experience, as well as theoretical knowledge. Having mastered the necessary information, a person gets an idea of ​​​​what a seam is, what classification of welds exists and how to choose the best option for adhesion of various metal products.

What is a weld seam?

During welding, three metal sections are involved in the process: two pieces of iron are fastened together using the third, which acts as an electrode. At the point where metal parts are connected to each other, a thermal process occurs, forming a seam. Thus, a seam is a part of a metal structure resulting from the action of fused and hardened iron.

Any metal can be joined by welding. They have their own structural features, according to which a certain type of fastening is selected. Classification of welds is made depending on the type of adhesion, material and other parameters. Each connection has its own instructions and execution order.

There is a classification of welds by length. Depending on the size, welding seams are:

• Short. The size does not exceed 30 cm. Such a seam appears as a result of welding performed in one direction from the very beginning to the end.
• Average. The length of the seam is from 30 cm to 1 meter. These seams are welded from the middle to the edges. The reverse-step method is ideal for them. Its essence lies in the fact that the entire seam is divided into several sections, which are alternately processed by welding. Each of these segments has a length from 10 to 30 cm.
• Long (over one meter). They are welded in the same way as the middle seams, with the only difference being that the number of sections here will be greater.

Types of welded joints

Welds are also classified according to the type of fastening. There are four types of connections:

• butt;
• T-bar;
• overlap;
• corner.

The most common type

During butt bonding, the thickness of the product is taken into account. This allows you to save a significant amount of material.

Butt clutch is considered the most popular. This is due to the fact that this welding process is the fastest and most economical.

T-welding. Features and Recommendations

This type of clutch is characterized by a T-shaped connection of metal products. As in butt coupling, special attention is paid to the thickness of the metal, depending on which the seams can be single-sided or double-sided.

When using this type of clutch, you must adhere to the following recommendations:

• When performing T-welding when joining two products of different thicknesses, it is necessary to hold the welding torch at an angle of 60 degrees in relation to the thicker product.
• Welding work can be made easier if the structure is placed “in a boat”. This position of the workpiece will eliminate undercuts and missing undercooked areas, which are considered the most common defects for this type of adhesion.
• If one pass of the welding torch turns out to be ineffective, since defective areas may remain, they should be welded by oscillating the welding electrodes.
• In a T-joint, you can limit yourself to one-sided welding. To do this, you need to use Oineo Tronic Pulse welding equipment, which allows for RW welding.

Overlap welding

The principle of this type of connection is the double-sided welding of products whose thickness is no more than 1 cm. This welding is used in cases where it is necessary to prevent moisture from entering the gap between steel sheets. As a result of this work, two seams are formed. This type of welded joint is considered long-lasting and is not economical, since more materials are required for the job.

Angular grip

This type of welding is used to connect metal products in a position perpendicular to each other. Depending on the thickness of the sheets, fillet welding is characterized by the presence or absence of beveled edges. If necessary, this type of connection is made from the inside of the product.

Weld shapes

The classification of welds according to the shape of the outer surface defines three types:

• Flat. They are effective under dynamic and alternating loads, since these seams (as well as concave ones) do not have a stress concentration that can cause sudden changes and destroy the welding bond.
• Concave. A weld concavity not exceeding 0.3 cm is considered acceptable. Otherwise, the concavity of the weld is considered excessive and is regarded as a defect. The level of concavity is measured in the area where there is the greatest deflection.
• Convex seams. They arise as a result of the accumulation of a large amount of frozen metal and are considered uneconomical. But at the same time, a welded joint that produces a convex seam is more effective under static load than a connection with a flat or concave weld. The convexity index is the distance from the surface of the base metal to the point of greatest protrusion. Convexities not exceeding 0.2 cm for bottom welds and not more than 0.3 cm for welds performed in other positions are considered standard.

Classification of welds by position in space

According to the criterion of placement in space, there are four types of seams, each of which has its own characteristics and recommendations for welding:

• Bottom seams. In technical terms, they are considered the simplest. Welding of the lower seams is carried out on a flat surface in a position from below. This process is characterized by high efficiency and quality. This is due to more comfortable conditions for the welder. The molten metal is directed by its weight into the weld pool located in a horizontal position. It is easy to follow the welding of the bottom seams. The work is done quickly.
• Horizontal seams. A little more difficult to weld. The problem is that the melted metal, under the influence of its weight, flows to the lower edges. This may result in undercuts at the top edge.
• Vertical seams. They are the result of connections of metal products placed in a vertical plane.
• Ceiling seams. This welding is considered the most difficult and responsible. Characterized by minimal comfort. During the welding process, the release of slag and gases becomes more difficult. Not everyone can handle this task; a lot of experience is required, since it is not easy to keep slag falling on your face during work. It is important to maintain the quality and strength of the connection.

How are welds and connections designated?

Classification and designation of welds is made using special icons, lines and callouts. They are placed on the assembly drawing and on the structure itself. The classification of welded joints and seams is indicated, according to the regulatory document, using special lines, which can be solid or dashed. Continuous welds indicate visible welds, dashed welds indicate invisible ones.

Seam symbols are placed on the shelf from the leader (if the seam is located on the front part). Or, conversely, under the shelf if the seam is placed on the reverse side. Using icons, the classification of welds, their discontinuity, and the placement of segments for welding are indicated.

Next to the main icons there are additional ones. They contain supporting information:

• about removing the weld reinforcement;
• about surface treatment for a smooth transition to the base metal and to prevent sagging and unevenness;
• about the line along which the seam is made (is it closed).

For identical designs and products of the same GOST, standard symbols and technical requirements are provided. If the design has identical seams, then it is better to give them serial numbers and divide them into groups, which are also assigned numbers for convenience. All information about the number of groups and seams must be indicated in the regulatory document.

Seam position

Welds are classified based on the position of the weld. They are:

• One-sided. They are formed by welding sheets whose thickness does not exceed 0.4 cm.
• Double sided. They occur when welding metal sheets 0.8 cm thick on both sides. For each connection case, it is recommended to leave 2 mm gaps to ensure quality adhesion.

Possible flaws

Defects during welding can occur due to excessive current and arc voltage. This may also be the result of improper manipulation of the electrodes. Classification of weld defects according to their location:

• Internal. To identify them, a technique is used that consists of control: not destroying the structure, destroying it completely or partially.
• External. They are easily identified during external examination.

Due to a violation of the welding regime caused by a lack of necessary experience, insufficient preparatory work, or incorrect measurements, defects are divided into:

• Lack of penetration. Manifests itself in the local absence of fusion between the connected elements. The defect leads to an increase in stress concentration and a decrease in the weld cross-section. A design with such a flaw is characterized by reduced strength and reliability. Lack of penetration can be caused by either insufficient current or fast welding.
• Undercut The defect consists of a local decrease in the thickness of the base metal. This problem is observed near the boundaries of welds.
• Burnout. The flaw looks like a cavity in the weld. It occurs due to leakage of molten metal from the weld pool. A burn-through is an unacceptable defect and needs to be corrected urgently.
• Unsealed crater or depression. Occurs due to arc breaks while approaching the end of the seam.
• Influx. The defect manifests itself in the flow of weld metal onto the base metal without fusion.

The causes of defects can be very different, but they are equally capable of reducing adhesive strength, operational reliability, accuracy and spoiling the appearance of the product.

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Welded joints

What is welding?

Welding is a method of forming a permanent connection of metal parts by heating them until they melt and reach a plastic state, followed by squeezing the parts being welded or without it.

What is a weld called?

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A weld is a metal that has hardened after welding and connects the welded parts.

How are welds divided depending on the location of the parts being welded?

Depending on the location of the parts to be welded, welds are divided into butt, lap, tee, corner, with flanged edges, etc. Moreover, butt joints are made without bevels of the edges of the parts being welded and with bevels, which can be V-shaped, X-shaped, etc., since the shape of the bevel depends on the thickness of the metal being welded and the welding method.

How are welds (joints) divided according to their position in space?
According to their position in space, welds (joints) are divided into lower, horizontal, vertical and ceiling, and in relation to the forces acting on the seam - flank, frontal (or end), combined, etc.

How is the solidity of the welded joint ensured?

The solidity of the welded joint is ensured due to the molecular interaction of the surface layers of the metal parts being connected. To connect two parts into one, you need to bring their surfaces closer together so that adhesion forces arise between molecules located in the boundary layer, which have free bonds.

This possibility can only exist if the distance between the surfaces of the parts is no more than 0.4 nanometers.

It is not yet possible to achieve such rapprochement mechanically, since even with the most careful processing of surfaces, irregularities remain on them, so the contact of the surfaces will not be continuous, but only at individual points.

In addition, molecules located in the boundary parts of the part trap foreign microparticles from the environment, which leads to the formation of oxide and organic films on the surfaces, weakening the free adhesion forces of the surfaces.

When welding parts or assemblies, these surface irregularities are eliminated, and the contaminants covering them are removed, as a result of which the smallest distance between the surfaces is achieved and physical contact is established between them over the entire area.

What welding methods are there?

Depending on the method of obtaining a welded joint, there are three main methods: fusion welding, pressure welding, fusion and pressure welding. Based on the type of energy consumed to create a welded joint, a distinction is made between electrical, mechanical and chemical.

How is fusion welding performed?

Fusion welding is carried out by heating the edges of parts installed close to each other with some gap between them to a molten state and joining them in liquid form.

Moreover, of the numerous varieties of fusion welding, the most widely used so far are electric arc welding, electroslag and gas welding.

In turn, metal arc welding is carried out manually and automatically (automatic submerged arc welding with a metal electrode).

How is electric arc welding performed manually?

Manual arc welding is performed by passing an electric current through an electric arc that occurs between the part being welded, connected to one of the poles of a DC or AC power source, and an electrode connected to the second pole of the same source.

The arc current, depending on the type and mode of welding, can be from tens to hundreds of amperes, and the temperature of the welding arc reaches 6000 °C or more. In this case, the molten metal of the parts being connected and the additional metal (electrode), melting spontaneously, without any pressure on them, merge into a common so-called weld pool.

As the electrode moves along the part being welded, the weld pool solidifies, forming crystals - an ordered system of atoms and molecules. The crystallized metal connects the parts into a single whole.

During welding, liquid metal intensively interacts with nitrogen and oxygen in the air, which reduces the strength of the weld and leads to the formation of defects. In order to isolate the weld zone from the surrounding air, and sometimes to add a substance to the weld that improves its quality, the surface of the electrodes is coated with a special composition.

How is automatic electric arc welding performed using a metal electrode using flux?

Automatic electric arc welding with a submerged metal electrode is carried out by a welding unit automatically, while the arc burns under a layer of flux in a liquid bubble of molten slag, which completely protects the molten material; bath from exposure to air.

You perform welding with an electric current of up to 3000 A, and the current density of a welding wire with a diameter of 1.2–5 mm is several times higher than in an electrode for manual electric arc welding.

This welding method is more economical compared to manual arc welding for continuous straight and circular seams of considerable length, especially in mass production.

How is electroslag welding with a metal electrode carried out?

Electroslag welding with a metal electrode is carried out by heat generated when an electric current passes through the slag bath from the electrode to the product.

What advantages do welded connections have over riveted ones?

Welded joints have the following advantages compared to rivet joints: they provide significant savings in metal and significantly reduce the labor intensity of their manufacture, since during welding operations such labor-intensive work as making rivets, marking and punching or drilling holes for rivets and chasing seams is eliminated. In addition, welding work is now in many cases carried out by automatic machines, which sharply reduce the labor intensity of welding work.

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