Welding types of welded joints and seams. Welding seams: types of seams and joints

Welding still remains one of the most popular methods for producing permanent structures from metals and polymers. This popularity also determines the variety of welded joints, which are similar in some ways, but fundamentally different in others. In this article we will look at all the main types of thermal welding joints.

So, what are the types of welded joints? The types of welding joints are as follows:

Butt

The most widely used variety, which can be single- or double-sided, with a removable or non-removable lining or without it at all. A butt welding joint can be used to connect parts with a flange, with a locking edge, as well as with a variety of bevels: two- and one-sided, symmetrical and asymmetrical, broken and curved.

Angular

As the name itself makes clear, this connection welds corner structures. Besides, Using corner joints, it welds structural elements in hard-to-reach places. This type of connection is used in the following cases:

• Bevels (one-sided or two-sided) are available at the edges of the two parts being connected;
• The edges of the parts being connected do not have bevels;
• There is a flange at one edge.

In other cases, a corner connection cannot be used, since due to the complexity of the edges, the quality of the connection deteriorates sharply.

Tavrovoe

It is used for welding T-shaped structures, as well as for parts that are connected at a slight angle to each other. This connection is compatible with the following types edges:

• There is no bevel;
• The edge can have symmetrical or asymmetrical one- and two-sided bevels;
• The edge has a curved one- or two-sided bevel located in the same plane.

The small number of edges to which a T-joint is applicable is explained by the complex geometry of the parts being connected.

Overlapping

This type of welding connects the ends of parts or structural elements. Overlap welding work is carried out only with edges without bevels.

End

A rather rare type of connection, since it involves welding one part to the end of another. Therefore, often the main types of welding joints do not include the end joint as a separate item, but combine it with an overlap joint.

Classifications of seams

Also types welded joints differ in the seam obtained as a result of welding. Current standards imply several classifications:

By spatial location

According to their location, welds can be:

• Bottom, if their angle relative to the horizontal does not exceed 60 degrees;
• Vertical, if their angle relative to the horizontal is in the range of 60-120 degrees;
• Ceiling, if their angle relative to the horizontal is in the range of 120-180 degrees.

By their continuity

Welds can be continuous (without breaks) or intermittent (there are breaks). The latter are most typical for corner and T-joints.

According to the nature of the ruptures, intermittent seams are divided into:

• Chain - uniform breaks, like cells in a chain;
• Chess - tears move small seams relative to each other, like white squares on a chessboard;
• Dotted seams - similar to checkerboard seams, only the seams do not look like lines, but in the form of single dots.

Note that continuous seams are more reliable and more resistant to corrosive destruction, but they are often impossible to use for technological reasons.

By type of welded joint

Welded joints also differ from each other in the resulting seam:

• Butt joint is obtained by joining parts of the same name;
• Corner is formed not only when welding parts with corners, but also during T- and butt welding;
• It is obtained through T-welding and overlapping joints of parts whose thickness does not exceed 1 cm;
• Electric riveting is obtained by welding T-joints and overlaps. The technology for making these seams is as follows. Metal parts whose thickness does not exceed 3 mm are cooked without pre-treatment, since the electric arc pierces them through. If the thickness of the parts being welded exceeds 3 mm, then one part is drilled and the second is tacked through it by welding;
• End welds are obtained by welding parts at their ends.

According to the nature of the profile section

This classification indicates the cross-sectional shape of the weld in section:

• Convex ones protrude in a semicircle above the surface of the connected parts;
• Concave form a small depression relative to the surface of the connected parts;
• Normal are one line with the surface;
• Special. They are formed when parts are joined at an angle or a tee. IN cross section they look like an equilateral triangle.

The internal cross-section determines the performance characteristics of welded joints. For example, a convex section gives good resistance to static loads; such seams are considered reinforced. While concave ones, on the contrary, are considered weakened, they are better able to withstand dynamic and multidirectional loads. The performance characteristics of normal welds are similar to those of concave welds. Special seams cope well with variable loads.

They also reduce the stress that occurs in welded parts during their daily use.

According to the technology of welding work

• Here, welds are classified according to the path of the electrode during welding:
• Longitudinal is formed when the electrode moves along the joint of the parts being connected;
• Transverse is obtained when the electrode moves across the joint of the parts being connected;
• An oblique is formed when the electrode moves at a certain angle relative to the extreme points of its trajectory;

Combined is formed by alternately using the three above mentioned seams.

By number of layers

The specified welding work is carried out in one or several layers (passes). With one pass, a bead of molten metal is formed. Rollers can be performed at the same or at different levels. In the first case, one layer will consist of several rollers. The bead farthest from the facing level is called the root of the seam.

Multi-layer and multi-pass welded joints are used when welding thick-walled elements or to avoid thermal deformation in the structure of a steel alloy. To avoid thermal deformation and burn-through, a weld seam is often used. Facing is used to improve appearance

welded joint of structural elements welded to each other.

Results of violation of welding technology

• If the welding technology is violated at the joint, the following may occur: Burns (undercuts) are zones of critical heating of the metal, in which, under the influence high temperatures
• various chemical reactions began (crystalline corrosion, etc.);
• Lack of penetration - zones in which the temperature was insufficient for mutual penetration of the edges into each other and the formation of a single monolithic structure;
• Non-fusion - the edges being joined have not heated to the melting temperature and have not fused to each other; Slag clogging - points of concentration of slag substances that have penetrated into from low-quality electrodes into the weld pool and, upon solidification, forming foreign crystalline inclusions;
• Pores appear due to spattering metal due to sudden peak temperatures in the weld pool;
• Cracks appear due to poor-quality joining of two types of steel that have different melting points;
• Microcavities arise due to uneven heating and cooling of the metal.

Quality Control Technologies

All types of welded joints must be checked. Depending on the requirements for the quality of work, the following quality control technologies are performed:

• Visual inspection allows you to determine only visible quality defects (slag inclusions, cracks, burns, etc.);
• Length and width measurements indicate consistency of the result obtained technical specifications and GOST;
• Checking tightness using crimp testing. Used in the manufacture of various containers;
• Special instrumentation establishes the characteristics of the internal structure of the resulting welded joint;
• Laboratory studies make it possible to determine the behavior of a welded structure under the influence of various loads and chemicals.

A welded joint is a connection of two or more elements obtained by welding.

The welded joint (Fig. 2) consists of: a weld that has a cast structure and is formed as a result of crystallization of the weld pool, a fusion zone, a heat-affected zone - a section of the base metal that has not been subjected to melting, where structural and phase changes and parts have occurred as a result of heating base metal.

Rice. 2. Welded joint diagram

1 – weld, 2 – fusion zone, 3 – heat-affected zone, 4 – base metal

There are 5 types of welded joints (Fig. 3) - butt, corner, T, lap and end.

Rice. 3. Types of welded joints: a – butt, b – lap, c – end, d – corner,

d – tee

The most typical and preferred butt joints, but the heat of the energy source is not always enough to melt the entire thickness, therefore, for parts with a thickness of more than 4 mm, special edge preparation is used (Fig. 4)

Rice. 4. Examples (a-g) of edge preparation

The structural elements of edge preparation are as follows:

S – thickness of connected elements;

C – blunting of edges (usually 1-2mm);

β – for bevel from 25 to 45˚;

α – cutting angle, equal to 2 β;

B – gap, depends on the thickness and welding method;

R – Curvature radius for shaped edge cutting.

Classification of welds.

All welds are classified according to the following criteria:

1. According to the type of welded joint: butt joints, formed by butt joints and corner joints - T-joints, lap joints, corner joints.

2. By position relative to the current force - flank, frontal and oblique.

3. By position in space (Fig. 5)

Rice. 5. Basic spatial positions of welding:

1 – bottom, 2 – vertical or horizontal, 3 – ceiling

4. By external form(Fig. 6) – into convex, normal and concave.

Fig.6. Shape of welds: a – normal, b – convex, c – concave

5. By length (Fig. 7) – into continuous and intermittent, which are divided into chain and chess.

Rice. 7. Classification of welds by length.

The ultimate goal of any welder is to obtain a high-quality weld. The strength and durability of the connection of parts depends on this. For successful work it is important to make the connection correctly; select the current strength, the angle of the electrode; have a good command of the seam technique. The result proper operation there will be reliable welding of metal parts.

Welding seams classified according to several criteria. The types and types of welding joints must be considered sequentially, delving into the intricacies of the process. The seam is affected by the location, direction and trajectory of the electrode.

After fixing the selected electrode in the clamp, setting the current, connecting the polarity, the welding process begins.

Each master has his own preferred angle of the electrode. Many consider the optimal value to be 70° from the horizontal surface.

An angle of 20° is formed from the vertical axis. Some work at a maximum angle of 60°. In general, most training guidelines include a range of 30° to 60° from the vertical axis.

In certain situations, when welding in hard-to-reach places, it is necessary to orient the electrode strictly perpendicular to the surface of the material being welded.

You can also move the electrode in different ways, in opposite directions: away from you or towards you.

If the material requires deep heating, then the electrode is directed towards itself. Following him in the direction of the welder is the working area. The resulting slag covers the fusion site.

If the work does not involve strong heating, then the electrode is moved away from you. The welding zone “crawls” behind it. The depth of heating with this type of weld is minimal. The direction is clear.

Trajectory of movement

The trajectory of the electrode has a particular influence on the seam. In any case, it has an oscillatory character. Otherwise, it will not be possible to sew the two surfaces together.

Oscillations can be similar to zigzags with different steps between the sharp corners of the trajectory. They can be smooth, resembling movement in an offset figure eight. The path can be similar to a herringbone or a capital letter Z with monograms at the top and bottom.

An ideal seam has a constant height, width, uniform appearance without defects in the form of craters, undercuts, pores, or lack of penetration. The name of the possible flaws speaks for itself. Having mastered your skills well, you can successfully apply any seam and weld a variety of metal parts.

Standards and the concept of leg

The weld begins to form in the working area when the metals are molten, and is finally formed after solidification.

The existing classification groups seams according to various criteria: the type of connection of parts, the resulting shape of the seam, its length, the number of layers, orientation in space.

The types of possible welded joints are shown in the standard for manual and arc welding GOST 5264. Connections made by arc welding in a shielding gas atmosphere are standardized by the GOST 14771 document.

GOSTs have a designation for each welded joint, as well as a table containing the main characteristics, in particular the values ​​of the leg of the weld.

It’s quite easy to understand what a leg is by looking at the drawing of the parts being connected. This is the side of a speculative isosceles triangle maximum dimensions, which will fit in the cross section of the seam. A correctly calculated leg value guarantees the strength of the connection.

For parts of uneven thickness, the cross-sectional area of ​​the part in its thinnest part is taken as a basis. You should not try to unduly increase the leg. This can lead to deformation of the welded structure. In addition, the consumption of materials will increase.

Checking leg dimensions is carried out using universal reference templates presented in specialized literature.

Types of connections

Depending on the relative position of the parts, welding joints occur:

• end-to-end;
• overlap;
• in an angular way;
• in a tee way.

When butt welding, the ends of two parts located in the same plane are welded. The joint can be made with a flange, without a bevel, or with a bevel. The shape of the bevel may resemble the letters X, K, V.

In some cases, welding is done with an overlap, then one part is partially mounted on another, located parallel. The combined part is an overlap. Welding is done without bevel on both sides.

Often there is a need to make a welded corner. This connection is referred to as the corner type. It is always done on both sides and may not have bevels or have a bevel on one edge.

If the welded parts result in the letter T, then a T-joint has been made. Sometimes parts welded with a T-seam form an acute angle.

In any case, one part is welded to the side of the other. Welding is carried out on both sides without a bevel or with bevels on each side.

Shape and extent

The shape of the seam can be convex, even (flat). Sometimes it becomes necessary to make a concave shape. Convex joints are designed for increased load.

The concave areas of the alloys withstand dynamic loads well. Flat seams, which are made most often, are characterized by versatility.

The length of the seams is continuous, without intervals between the fused joints. Sometimes interrupted stitches are sufficient.

An interesting industrial variation of the intermittent seam is the joint formed by resistance seam welding. It is done on special equipment equipped with rotating disk electrodes.

They are often called rollers, and this type of welding is called roller welding. Continuous connections can also be made using such equipment. The resulting seam is very strong and absolutely airtight. The method is used on an industrial scale for the manufacture of pipes, containers, and sealed modules.

Layers and spatial arrangement

A metal seam can consist of a bead made in one pass. In this case it is called single-layer. If the parts being welded are thick, several passes are performed, as a result of which beads are sequentially formed one on top of the other. This welding joint is called multilayer.

Considering the variety of production situations in which welding occurs, it is clear that the seams are oriented differently in each specific case. There are lower, upper (ceiling) seams, vertical and horizontal.

Vertical seams are usually welded from bottom to top. The trajectory of moving the electrode along a crescent, herringbone or zigzag is used. It is more convenient for novice welders to move the crescent.

When welding horizontally, several passes are made from the bottom edge of the parts being joined to the top edge.

In the lower position, butt welding is carried out or by any angular method. Good result gives welding at an angle of 45 °, “in a boat”, which can be symmetrical and asymmetrical. When welding in hard-to-reach places, it is better to use an asymmetrical “boat”.

The most difficult thing to do is weld in the ceiling position. This requires experience. The problem is that the melt tries to drain out of the work area. To prevent this from happening, welding is carried out with a short arc, the current strength is reduced by 15-20% compared to normal values.

If the thickness of the metal at the welding site exceeds 8 mm, then several passes must be performed. The diameter of the first pass should be 4 mm, subsequent ones - 5 mm.

Depending on the orientation of the seam, select the appropriate position of the electrode. To make horizontal, vertical, ceiling connections, and weld non-rotating pipe joints, the electrode is directed at an angle forward.

When welding corner and butt joints, the electrode is directed at an angle backwards. Hard-to-reach places are welded with an electrode at a right angle.

Weld joint processing

When welding, slag is formed. If slag inclusions get into the weld, its quality deteriorates. All slag deposits must be cleaned off.

If welding is performed in several passes, then the seams are cleaned after each welding stage. In this case, any methods are used. First, the welded parts are hammered and cleaned with a stiff brush.

Then a rough cleaning is carried out. Small parts are cleaned with special knives or grinding wheels. Large blanks are cleaned on machines. At the final stage, the welded joint is polished.

Often a fiber wheel of a grinding machine is used for this. There are other ways to polish welded joints.

Welding is constantly evolving. New materials are appearing and technology is improving. It is necessary to follow the news in welding to learn a lot of new and interesting things.

A weld is a line of molten metal at the edges of two joining structures, resulting from the action of an electric arc on the steel. The type and configuration of seams is selected for each case individually; its choice depends on factors such as the power of the equipment used, thickness and chemical composition welded alloys. This type of seam also occurs during welding. polypropylene pipes soldering iron.

This article discusses the types of welds and the technology for their implementation. We will study vertical, horizontal and ceiling seams, and also learn how to clean them and check for defects.

1 Classification of welds

Classification of seams into varieties is carried out according to many factors, the main of which is the type of connection. According to this parameter, seams are divided into:

• butt seam;
• overlap seam;
• tee seam.

Let's consider each of the presented options in more detail.

1.1 Butt connection

This method connection is used when welding the end parts of pipes, square profiles and sheet metal. The connecting parts are placed so that there is a gap of 1.5-2 mm between their edges (it is advisable to fix the parts with clamps). When working with sheet metal whose thickness does not exceed 4 mm, the seam is laid only on one side; in sheets of 4-12 mm it can be either double or single, with a thickness of 12 mm or more - only double.

If the wall thickness of the parts is 4-12 mm, mechanical cleaning of the edges and sealing of the edges using one of the following methods is necessary. It is recommended to connect particularly thick metal (from 12 mm) using X-shaped stripping; other options are unprofitable here due to the need for large quantities metal to fill the resulting seam, which increases the consumption of electrodes.

However, in some cases, the welder may decide to weld thick metal in one seam, which requires filling it in several passes. Seams of this configuration are called multilayer; the technology for welding multilayer seams is shown in the image.

1.2

The lap joint is used exclusively when welding sheet metal 4-8 mm thick, while the plate is welded on both sides, which eliminates the possibility of moisture getting between the sheets and their subsequent corrosion.

The technology for making such a seam is extremely demanding in terms of maintaining the correct angle of inclination of the electrode, which should vary in the range of 15-40 degrees. In case of deviation from the norm, the metal filling the seam will move from the joint line, which will significantly reduce the strength of the connection.

1.3 T-seam

The T-joint is made in the shape of the letter “T”; it can be made on both sides and on one side. The number of seams and the need for cutting the end part of the part depends on its thickness:

• up to 4 mm - one-sided seam without cutting the ends;
• 4-8 mm - double, without cutting;
• 4-12 mm - single with one-sided cutting;
• more than 12 mm - double-sided, double cut.

One type of T-joint is a fillet weld, used to connect two sheets of metal that are perpendicular or inclined towards each other.

2 Types of seams according to spatial position

In addition to classification by type of connection, seams are divided into varieties depending on the position in space according to which they are:

• vertical;
• horizontal;
• ceiling

The problem with making vertical seams is the sliding of the molten metal downwards, which occurs due to gravity. Here it is necessary to use a short arc - keep the end of the electrode as close to the metal as possible. Welding vertical seams requires preliminary work - stripping and cutting, which are selected based on the type of joint and the thickness of the metal. After preparation, the parts are fixed in the required position and a rough connection is made with transverse “clamps” that prevent the workpieces from moving.

Welding a vertical seam can be done both top-down and bottom-up; in terms of ease of operation, the latter option is preferable. The electrode must be held perpendicular to the parts being joined; it is permissible to rest it on the edges of the weld crater. The movement of the electrode is selected based on the required thickness of the seam; the strongest joint is achieved when the electrode is moved transversely from side to side and with loop-shaped oscillation.

On vertical planes, horizontal type seams are laid out from left to right or from right to left. Welding horizontal seams is complicated by the pool flowing down, which requires maintaining a significant angle of inclination of the electrode - from 80 to 90 0. To prevent an influx of metal in such positions, it is necessary to move the electrode without transverse vibrations, using narrow rollers.

The speed of movement of the electrode is selected so that the center of the arc passes along the upper boundary of the seam, and the lower contour of the molten pool does not reach the upper end of the previous roller. Particular attention here must be paid to the upper edge, which is most susceptible to the formation of various defects. Before starting welding of the last bead, it is necessary to clean the formed seam from slag and carbon deposits.

The most difficult to perform are the ceiling seams. Since in this spatial position the molten pool is held solely by the surface tension of the metal, the seam itself must be made as narrow as possible. The standard width of the roller is no more than twice the width of the electrodes used, and in this case it is necessary to use electrodes with a diameter of up to 4 mm.

When laying a seam, the electrode must be held at an angle of 90 to 130 0 to the planes being connected. The roller is formed by oscillatory movements of the electrode from edge to edge, while in the extreme lateral position the electrode is delayed, which avoids undercuts. Please note that welders without experience are not recommended to tackle ceiling seams.

2.1 Technology for welding ceiling seams (video)

2.2 Cleaning and checking defects

After the formation of a seam, slag, drops of molten steel and scale remain on the surface of the connected parts, while the seam itself may have a convex shape and protrude above the plane of the metal. These shortcomings can be eliminated by cleaning, which is carried out in stages.

Initially, you need to remove scale and slag using a hammer and chisel, then use a grinder equipped with an abrasive disc or a grinder to level the connected planes. The grain size of the abrasive wheel is selected based on the required smoothness of the surface.

Weld defects, often encountered by inexperienced specialists, are usually the result of uneven movement of the electrode or incorrectly chosen strength and current value. Some defects are critical, some can be corrected - in any case, monitoring the seam for their presence is mandatory.

Let's look at what defects exist and how they are checked:

Defects can also form in the form of cracks that appear during the cooling stage of the metal. Cracks come in two configurations - directed across or along the seam. Depending on the time of formation, cracks are classified into hot and cold, the latter appearing after the joint has hardened due to excessive loads that a particular type of seam cannot withstand.

Cold cracks are a critical defect that can lead to complete failure of the joint. If they form, it is necessary to re-weld the damaged areas; if there are too many of them, the seam must be cut off and re-made.

Welded metal joints are among the main methods of fastening structures used in everyday life and production. This is a very reliable method of obtaining a single design, which is also relatively cheap.

Bonds of this type are formed by melting the metal in the area of ​​the connection and its subsequent crystallization as it cools. Their quality depends on the right choice operating mode of the electric welding machine, electrode, seam penetration. This is regulated by current regulations and standards. They indicate all types of welds, as well as types of joints and their characteristics.

Numerous metals have their own welding characteristics, different work conditions, and requirements for fastening. For them, appropriate types of electric welded connections are used. When welding metal elements, the main types of electric welding fasteners are used, which are discussed below.

Classification

Welding joints are divided into several varieties, depending on their characteristics. The classification of welds covers the entire range of their uses. According to external parameters they are:

• convex type (with reinforcement);
• concave (weakened design);
• flat type (normal).

According to the type of execution, they are found in one-sided, as well as double-sided, according to the number of passes with the electrode: single-pass, double-pass. In addition, there are single-layer and double-layer welding methods.

According to their length, suture fastenings are:

• single-sided with intermittent pitch;
• solid one-sided;
• spot (for contact electric welding);
• chain double-sided;
• double-sided checkerboard pattern.

Separation by spatial location:

• horizontal, lower;
• vertical, ceiling;
• into a boat;
• semi-horizontal design;
• semi-ceiling type;
• semi-vertical.

According to the force vector:

• longitudinal (flank) – the force has a vector parallel to the penetration;
• transverse - the force acts perpendicularly;
• combined - a type of frontal, as well as flank;
• oblique - the impact occurs at an angle.

According to their purpose and function, electric welding penetrations can be durable, as well as durable and tight, hermetically sealed. Based on their width, they are distinguished into thread type, which does not exceed the diameter of the electric welding electrode rod, and widened, performed using oscillatory movements when welding in the transverse direction.

To simplify the understanding of the classification and application of certain varieties, a special table has been compiled.

All types of seams have strict designations according to GOST. The drawings use special icons that contain complete information about the type of fastening and its method of execution. For those who are thinking of seriously engaging in welding work at a professional level, they should additionally study the drawing symbols of welded fasteners.

Types of welds

Depending on the material used, thickness, and design features are used Various types welds. To do this, you need to undergo the necessary theoretical training. This will allow you to better understand the specifics of welding parts and avoid defects in work. Novice welders often do not sufficiently weld the joint areas, which affects the weak mechanical resistance of the joints. By choosing the right operating modes and types of welding, you can obtain welding seams of sufficient strength and quality. Welder training consists not only of practical training, but also of theoretical training with the study of requirements, standards and regulations, as well as including the types of welding joints and equipment used. Knowledge of the principles of using certain electric welding fasteners, the techniques for producing them, the joints will be very strong and durable.

Butt

This connection option is the most used among other types of welding seams. This butt welding is used on end sections, pipes or sheet metal structures. To obtain it, a minimum amount of time, material and effort is spent. These butt joints have some seam features. On thin sheet metal, welding is carried out without bevel of edges.

Products with large thickness of joint sections require preliminary preparation joints, which consists in beveling them to increase the depth of welding penetration. This is necessary when the thickness of metal products is over 8 mm and up to 12 mm. Thicker sections must be joined by double-sided welding with preliminary bevel of the edges. Butt welding is most often performed on products in a horizontal plane.

T-bar

These types of electric welding connections are made like a regular letter “T”. They connect objects of the same or different thickness, which determines the width of the weld seam. In addition, these types are used single- or double-sided, which is influenced by the characteristics of the fastening. When working with metal elements of varying thickness, the electrode is held in an inclined position at an angle of about 60 degrees. The welding process can be greatly simplified by using tacks, as well as boat welding. This method significantly reduces the occurrence of undercuts. The T-weld is applied in one welding pass. In addition to manual arc welding, automatic electric welding machines are widely used for this type.

Overlapping

This method is used for welding sheet metal with a thickness of up to 12 mm. The areas to be joined are overlapped and welded along the joints on both sides. Do not allow moisture to enter the interior of the structure being welded. To strengthen the bond, full welding is performed around the perimeter.

With this welding, the formation of a connecting joint occurs between the end of one product and the surface of another. With this type of welding seams and connections, the consumption of materials increases, which must be taken into account in advance. Before starting work, you should align the sheet structures and ensure that they are pressed well together.

Corner

These connections include fastenings of elements made at a certain angle to each other. They are characterized by the use of preliminary bevels to ensure the best weld penetration. This will increase the depth of the welding joint, which will increase the reliability of the structure. To enhance strength, double-sided welding of metal products is used, while gaps in the joined edges are not allowed. These types of electric welds are characterized by increased use volume of deposited metal.

Ceiling

Welding with a ceiling seam, the seam of which is located above the welder, is one of the most difficult types of electric welding work. It is applied by intermittent welding at a low electric current. Vertical and ceiling connections are very difficult, so not all welders can perform them with sufficient quality. They are used in places where it is not possible to change the position of the structures being welded. These are pipes, various metal structures, as well as ceiling beams and channels at construction sites. The specifics of making ceiling seams, the video of which will explain the nuances, can be mastered through constant practice.

Weld geometry

Having studied numerous types and methods of obtaining joints by welding, it is necessary to familiarize yourself with the geometry of the joints, which photos of welding seams will help with.

The main parameters of a seam joint include its width - e, welding thickness - c, convexity - q, gap - b, welding depth - h, and the thickness of the material being welded - S.

For corner joints, the following designations are used: convexity - q, thickness - a, leg - k and design height - p.

Various methods of applying welds, their numerous types, as well as the parameters of the prepared edges affect the volume of use of the deposited and base metals. Its quantity may differ markedly when any calculated values ​​change.

Types of welding joints are characterized by a shape coefficient, which is calculated by the ratio of the width to the thickness of the seam joint. For butt fastenings, this parameter is in the range of 1.2-2 (limit values ​​0.8-4). The convexity coefficient is calculated by the ratio of width to convexity, the value of which should be from 0.8 to 4.

Welding metal materials at an angle relative to each other requires precise adherence to the geometry of the seam. The reliability of the connection, as well as its durability of use, directly depends on the quality of welding and compliance with the required parameters.

Types of control

The further operation of the structure depends on the high-quality execution of electric welded fastening. Various defects significantly reduce the strength and reduce the period of use of the product. To prevent marriage, as well as to prevent emergency situations Various types of weld inspection are used. These include an external inspection, which can visually determine violations, their types, as well as the use of special equipment to determine hidden defects in welds.

Control methods are divided into non-destructible and destructible. When using the first method, the strength of the welded joint is determined without changing its appearance or parameters. Destructible methods are used for mass production of structures using the same type of electric welding work. This provides an opportunity with high accuracy identify internal violations of welding bonds.

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