All kinds of welding seams. All types of welded joints and types of welded seams according to GOST - classification. By spatial position

The quality of the welded joint directly depends on the type of seam selected, the electrode and the mode of operation of the device. To do this, it is recommended to be guided by the current regulations, in particular - GOST 5264-80. It describes in detail the characteristics and types of welded joints and types welds... According to GOST, special requirements are imposed on the performance of work.

Butt

The most popular type of connection, as it is characterized by minimal metal stress, ease of execution and reliability. Depending on the thickness of the edge to be welded, it can be cut at right angles or bevels. It is also permissible to use a one-sided bevel.

Advantages of Butt Welds:

the minimum consumption rate of the base and welding metal;
optimal welding time;
good quality connections.

The latter is achieved only if the technology is followed. The bevel angle can be varied from 45 ° to 60 °. It depends on the thickness of the metal. A similar geometry is used for sheets of 20 mm or more. The characteristics of the material are also taken into account.

Overlapping

The formation of a joint by overlaying sheets on top of each other is relevant for metal thicknesses ranging from 8-12 mm. At the same time, unlike butt welding, there is no need to process the surface - it is enough to cut the workpiece evenly. It is important to correctly calculate the amount of overlap.

Features of lap welded joint:

increased consumption of the main and deposited material;
a seam is formed between the surface of one sheet and the end of another;
field of application - spot, roller and resistance welding.

Before starting work, the sheets must be aligned to ensure a tight hold.

Taurus

This is a T-shaped joint, in which the end of one of the sheets is welded to the plane of the other. For reliability, on the first one you can make one or two-sided bevels. With their help, the volume of the deposited metal is increased. Scope - metal structures of complex shape.

Before starting work, you need to consider the following factors:

The bevel configuration is standard, the angle depends on the thickness of the metal.

Corner

They are used to connect two structural elements at a certain angle. In contrast to the T-joint, the presence of a gap is unacceptable. Reliability is provided by bevels and a large volume of directional metal.

Specificity of fillet welds:

surface preparation is necessary - the formation of bevels of a simple or complex configuration;
for thin-walled workpieces, one-sided connection is allowed;
the geometry of the weld is taken into account.

This method is most often used for the manufacture of tanks or structures similar to them in shape.

Auxiliary welds

In addition to the above-described basic methods of joining steel elements, GOST provides for auxiliary ones. They can be used to form a reliable seam, taking into account the required performance of the product.

Depending on the specifics of the seam, the following methods of forming a welded joint are used:

Slotted. Needed to achieve maximum reliability. In one of the materials, a recess is made for installing another sheet.
End. Belong to the category of side. Sheets are superimposed on each other, seams are made at the ends of the structure.
With overlays. Recommended for structures with complex surface configurations. A special pad is used to ensure the connection of the two components.
With electric rivets. The bonding process is similar to traditional riveting. The difference is that the hole is filled with weld metal.

The choice of one or another weld depends on the end result - the reliability and durability of the connection.

In the process of performing welding work, various are obtained that are capable of joining not only metals, but also other dissimilar materials. Elements docked into an integral knot represent a connection that can be delimited into several sections.

Welding areas

The joint obtained during the welding process is divided into the following zones:

The fusion point is the boundary between the base metal and the metal of the resulting weld. This zone contains grains that differ in their structure from the state of the base metal. This is due to partial melting during the welding process.
The heat-affected area is the zone of the base metal that has not undergone reflow, although its structure has been changed during the heating of the metal.
A weld seam is a section that formed during crystallization in the process of metal cooling.

Types of welding joints

Depending on the location of the joined products relative to each other, the connections are divided into the following types:

Butt. The joining of structural elements is carried out in the same plane with their ends to each other. Depending on the different thicknesses of the parts to be joined, the ends can be vertically displaced relative to each other.
Gusset. In this case, the ends are aligned at an angle. The welding process is carried out on the adjoining edges of the parts.
Lap joint. Weld parts are arranged in parallel with partial overlap.
End connection. The elements to be welded are aligned parallel to each other and docked at the ends.
T-joint. In this case, the end of one part adjoins the side of the other at an angle.

Welding joints also characterize the types of welds, which can be qualified according to some criteria.

Weld seam indicators

There are several parameters by which all the resulting welds can be characterized:

width is the size between the boundaries of the seam, which are drawn by the visible fusion lines;
the root of the seam is its reverse side, which is located in maximum distance from the front;
bulge - is determined in the most convex part of the seam and is indicated by the distance from the plane of the base metal to the border of the largest protrusion;
concavity - this indicator is relevant if it occurs in a welded seam, because, in fact, it is a defect; this parameter is determined in the place where the seam has the greatest deflection - from it to the plane of the base metal, the size of the concavity is measured;
seam leg - it takes place only in the corner and T-joint; this indicator is measured by the smallest distance from the side surface of one welded part to the boundary line of the seam on the surface of the second.

Types of seams by method of execution

Types of welds in spatial position and length

There are such welding positions:

bottom, when the seam being welded is in the lower horizontal plane, that is, at an angle of 0º relative to the ground;
horizontal, the direction of welding is horizontal, and the part can be at an angle from 0º to 60º;
vertical, in this position the surface to be welded is in the plane from 60º to 120º, and welding is carried out in the vertical direction;
ceiling, when the work is carried out at an angle of 120-180º, that is, the welding seams are located above the foreman;
"in a boat", this provision applies only to corner or T-joints, the part is exposed at an angle, and welding is carried out "to the corner".

Breakdown by length:

continuous, this is how almost all seams are performed, but there are exceptions;
intermittent seams, they occur only in fillet joints; double-sided seams of this type can be performed both in a checkerboard pattern and in a chain pattern.

Edge preparation

This design feature it is used when the thickness of the metal used for welding is greater than 7 mm. Bevelling is the removal of metal from edges in a specific shape. This process is carried out in single-pass butt welding. This is necessary in order to obtain the correct weld seam. As for thick material, grooving is necessary in order to melt the initial root pass and then with the following weld beads, evenly filling the cavity, to weld the metal through the entire thickness.

Edging can be done if the metal is at least 3 mm thick. Because a lower value will lead to burn-in. The groove is characterized by the following design parameters: clearance - R; groove angle - α; blunting - with. The location of these parameters is shown in the drawing of the weld.

Edging increases the amount Supplies... Therefore, they try to minimize this value in every possible way. It is subdivided into several types by design:

V-shaped;
X-shaped;
Y-shaped;
U-shaped;
crevice.

Features of grooving

For small thicknesses of the welded material from 3 to 25 mm, a one-sided V-groove is usually used. The bevel can be performed at both ends or at one of them. It is advisable to weld metal with a thickness of 12-60 mm with a double-sided X-shaped groove. Angle α when grooving in X, V shape is 60º, if bevel is performed only on one edge, then the value of α will be 50º. For a thickness of 20-60 mm, the most economical will be the consumption of the deposited metal with a U-shaped groove. The bevel can also be made one at a time or at both ends. The bluntness will be 1–2 mm, and the gap will be 2 mm. For large metal thicknesses (over 60 mm), the most effective method will be slot grooving. It is very important for a welded joint this procedure, it affects several factors of the seam:

Standards and GOSTs

Manual seams and joints in accordance with GOST 5264-80 include types, design dimensions for welding, covered with electrodes in all spatial positions. This does not only include pipelines made of steel.
Welding of steel pipelines. GOST 16037-80 - defines the main types, grooving, structural dimensions for mechanized welding.
from copper and copper-nickel alloys. GOST 16038-80.
Arc welding of aluminum. GOST 14806-80 - shape, dimensions, preparation of edges for manual and mechanized welding of aluminum and its alloys, the process is carried out in a protective environment.
Submerged arc. GOST 8713-79 - Welding seams and joints are performed by automatic or mechanized welding by weight, on a flux cushion. Applies to metal thicknesses from 1.5 to 160 mm.
Welding of aluminum in inert gases. GOST 27580-88 - standard for manual, semi-automatic and It is performed non-consumable electrode in inert gases with filler material and extends to aluminum thickness from 0.8 to 60 mm.

Weld designation

According to regulatory documents the presence of welds is shown on or on general view... Welds are shown with solid lines if they are visible. And if it is the other way around - then by dashed lines. Leaders with one-way arrows are removed from these lines. The symbol of welds is performed on the ledge from the leader. The inscription is made above the shelf if the seam is on the front side. In the opposite case, the designation will be under the shelf. This includes information about the seam in the following sequence:

Auxiliary signs. At the intersection of the leader with the shelf, there may be an icon:

○ - closed seam;

┐ - the seam is welded during installation.

their structural elements and GOST connections.
The name of the seam according to the standard.
Welding method according to normative standards.
The leg is indicated, this item applies only to corner joints.
Seam discontinuity, if any. The step and location of the weld sections is indicated here.
Additional secondary meaning icons. Let's consider them as a separate item.

Auxiliary notation

These marks are also applied to the top of the shelf if the weld is visible in the drawing, and below it when it is invisible:

--- removal of the seam reinforcement;
surface treatment that will provide a smooth transition to the base metal, eliminating sagging and unevenness;
the seam is performed along an open line; this sign applies only to visible welds on the drawing;
the cleanliness of the surface treatment of the welded joint.

To simplify, if all the seams of the structure are made according to the same GOST, have the same grooves and structural dimensions, the designation and welding standard are indicated in the technical requirements. The design may not have all, but a large number of the same seams. Then they are divided into groups and assigned serial numbers in each group separately. One seam shows the full designation. On the rest, only serial numbers are put. The number of groups and the number of seams in each of them must be indicated in the normative documentation.

Welding provides permanent joints of metals by establishing strong interatomic bonds between elements (when they are deformed). Experts know what kind of welding machines are there. The seams obtained with their help are capable of joining identical and dissimilar metals, their alloys, parts with additions (graphite, ceramics, glass), and plastic.

Basis of classification

Experts have developed a classification of welds according to the following principle:

the way of their implementation;
external characteristics;
the number of layers;
location in space;
length;
appointment;
width;
conditions of functioning of welded products.

According to the assessment of the method of execution, welds are one-sided or two-sided. External parameters allow them to be classified into reinforced, flat and weakened, which experts call convex, normal and concave. The first types are able to withstand static loads for a long time, but they are not economical enough. Concave and normal joints withstand dynamic or alternating loads well, since the transition from metal to seams is smooth, and the risk of stress concentration that can destroy them is below 1 indicator.

Welding, taking into account the number of layers, can be single-layer or multi-layer, and according to the number of passes, it can be single-pass and multi-pass. Multilayer solders are used to work with thick metals and their alloys and, if necessary, to reduce the heat affected zone. A pass is called the movement (1 time) of a heat source in the process of surfacing or welding parts in one direction.

A bead is a piece of seam metal that can be welded in a single pass. The weld layer is a metal junction with several beads located at the same level of the cross-section. Focusing on their position in space, the seams are subdivided into lower, horizontal, vertical, "boat", semi-horizontal, semi-vertical, ceiling, semi-ceiling. The characteristic of discontinuity or continuity indicates length. The first types are used for butt seams.

Classification principles

Solid joints can be short, medium and long. Allocate sealed, strong and tight seams (according to their purpose). Width helps to categorize them into the following types:

broadened, which are made with transverse, oscillatory movements of the electrode;
thread, the width of which may slightly exceed or coincide with the diameter of the electrode.

The conditions in which the welded products will be used in the future assume that the joints can be working and non-working. The former carry loads well, while the others are used to join parts of a welded product. Welded joints are classified into transverse (in which the direction is perpendicular to the weld axis), longitudinal (in a direction parallel to the axis), oblique (with a direction placed at an angle to the axis) and combined (the use of transverse and longitudinal seams).

The method of holding the hot metal allows you to subdivide into created:

on the remaining and on removable steel supports;
without additional linings, pillows;
lined with flux-copper, copper, asbestos or ceramics;
on gas and flux cushions.

The material that is used in the process of welding elements is classified into compounds of non-ferrous metals, steel (alloyed or carbon), vinyl plastic and bimetals.

Depending on the location of the parts of the products that are to be welded relative to each other, there are joints at right angles, at an obtuse or acute angle and located in the same plane.

Permanent joints that arise when using welding are:

angular;
butt;
T-shaped;
overlap or end.

Corner views are used during construction work. They involve a reliable connection of elements that are located in relation to each other at a certain angle and are welded at the junction of the edges.

Butt types have found application in the welding of tanks or pipelines. With their help, parts are welded with ends that are located on the same surface or in the same plane. The thickness of the surfaces does not have to be the same.

Overlapping types are used in the manufacture metal containers, v construction works and when welding tanks. This type assumes that one element is superimposed on another, located in a similar plane, partially overlapping each other.

Welding is one of the main methods of fastening two elements together, and welding seams are the zones that connect two metal workpieces to each other. Such adhesions are obtained during the melting and subsequent cooling of the steel.

A good welder should know the types of welded joints and be able to apply all types of seams. . Without these skills, it is impossible to make a high-quality and durable structure.

Joint types

Weld seams are divided into 5 variations:

overlapping;
parallel;
butt;
corner;
t - shaped.

Overlapping is often used to create cylindrical tanks that are planned to be operated in a horizontal or vertical position. The welded elements overlap, but do not overlap completely. The result is a structure that looks like a step. Welding seams are applied on the end sides of the parts .

Parallel deposition methods are used to increase the strength of the structure. Both components are tightly attached to each other and are sealed by welding from the side of the ribs. With this technique, you can strengthen structures, the appearance of which will be subject to strong mechanical stress. However, this technology is prohibited to use in the repair of moving mechanisms.

The butt version is the most popular. The parts to be welded must be in the same plane, one opposite the other. This joint is used to hold water pipes, chimneys, storage facilities or steel columns together. Also, this system is used in mechanical engineering, in the manufacture of air and water transport, at military plants. Yes, and the creation of such a "gluing" requires a minimum of money and time.

Fillet welds work well for joining multiple workpieces that need to be positioned at right angles. The workpiece is made as follows: parts are installed at an angle of 90 ° (in the form of the "G" symbol), and a weld is applied at the junction of the edges . This welding is common both in industry and in private households. And with its help, you can make strong supports or boilers.

The T-weld or T-weld is unlike the others as the finished part will look like a “T”. It will be difficult for an inexperienced person to create this, since it is important to take into account the limitations related to the holding of the electrode in the process (it is recommended to adhere to an angle of 60 °). In this case, the thickness of the sheets to be joined may differ. Also, more wire will be required for execution, and elements welded with the T-method may come out with defects.

Technique of work

The movement of the rod along a solid line will not be enough for a good weld , and to become a master of your craft, you need to understand the technique of using the apparatus. The main features of the technology are constant control of the gap between the components. If the distance is too small, then the steel will not heat up well, which will negatively affect its strength. Both the speed of the tripod guidance and the basic soldering procedure should be monitored. The main thing is that the molten metal is evenly distributed over the groove.

How to apply a suture correctly :

Cook in a circular or zigzag motion. The trajectory should be maintained throughout the entire adhesion.
Keep the handle at the correct angle. The sharper the slope, the shallower the steaming depth.
Control the pace of movement of the electrode. It all depends on the voltage of the apparatus. A high current allows the holder to move at a higher speed, and the seams will ultimately be thinner.
Choose the adhesion layers wisely. Several rows can be made in the butt joints, however, this technique is more often used to make a T-welded seam.

Taking these rules into account will help to achieve the desired result, and the specialist will accurately produce any type of weld.

Application methods

Application methods include:

Horizontal type. According to the rules, you can apply a seam both from right to left, and in reverse side... It is important to observe an acceptable angle of inclination here, since excess molten metal will flow out. If a person has few skills, then the entire procedure can be performed in 2-3 passes.
Vertical type. The work surface can be located in the ceiling or wall areas. Welding joints can also be made in two ways: from top to bottom and from bottom to top. However, it is better to choose the first option, since the heat from the arc contributes to the high heating of the alloy.
Ceiling type. The whole process must be carried out very quickly, while maintaining a stable pace of the rod. Also, to preserve the alloy in the seam, you will need to make rotational movements. It should be noted that the current version is the most difficult, and you should start working after gaining the necessary experience.

From the first time it is difficult to understand what the varieties are and to study all the technologies. But regular practice will make any newcomer a real professional.

Greetings, dear readers. In today's article we will tell you about the main types welded joints and seams... Many experts in welding production call these joints welded, some - welding, although this does not change the meaning.

In this article, they will also be mentioned differently, depending on the turn of speech, but remember: welded and welded in relation to joints and seams are the same thing.

Welded joints and seams are classified according to several criteria

There are a number of types of welds depending on the of the kind connections:

- butt joint seam
- T-joint seam
- lap joint seam
- fillet joint

Butt joint

A butt joint is a connection of two sheets or pipes with their end surfaces. This connection is the most common, due to the lower consumption of metal and less time for welding.

The butt connection can be, depending on the location of the seam:

- One-sided
- Bilateral

For preparation of a joint for welding, depending on the thickness of the products to be welded:

- No bevel edges
- Bevelled

A one-sided connection without beveling of the edges allows welding of sheets up to 4 mm thick (with the exception of the Laser Hybrid Weld process). It is recommended to perform a double-sided connection without beveling the edges when welding thicknesses up to 8 mm. In both cases, to ensure high-quality penetration, it is necessary to make a small gap when joining the sheets for welding, about 1 - 2 mm.

It is recommended to bevel the edges with a one-sided welded joint at thicknesses from 4 to 25 mm. The most popular is the V-type bevel joint. Less popular, but one-sided and U-bevels are also used. To prevent the possibility of burn-through, a slight blunting of the edges is done in all cases.

For thicknesses of 12 mm and more, when welding on both sides, it is recommended to make an X-groove, which has a number of advantages over a V-groove. These advantages consist in reducing the volume of metal required to fill the groove (by almost 2 times), and, accordingly, increasing the welding speed and saving welding consumables.

T-joint

A T-joint is two sheets when a "T" joint is formed between them. As in the case of butt joints, depending on the thickness of the metal, welding is performed on one or both sides, with or without grooves. The main types of T-welded joints are shown in the figure.

1. When welding a T-joint of thinner metal with a thicker one, it is necessary that the angle of inclination of the electrode or welding torch is about 60 ° to the thicker metal. As shown below:

2. Welding of a T-joint (and a corner joint to the same extent) can be greatly simplified by positioning it for welding "in a boat". This allows welding to be carried out predominantly in the lower position, increasing the welding speed and reducing the likelihood of undercuts, which are a very common defect in a T-welded joint, along with lack of fusion. In some cases, a single pass will not be enough, therefore, the burner vibration is required for the filling joints.
Boat welding is also used in automatic and robotic welding, where the product is turned by means of a special tilting device to the position required for welding.

3. Currently, there are special welding processes for increased penetration. Using them, you can achieve one-sided welding of a sufficiently thick metal with guaranteed penetration and the formation of a reverse bead on the other side. More details about the Rapid Weld welding process are available. You can learn about welding equipment for one-side welding of a T-seam with a reverse bead of a bead in the section

Lap joint

This type of connection is recommended for welding sheets up to 10 mm thick, and sheets must be welded on both sides. This is done due to the fact that there is no possibility of moisture getting between them. Since there are two welds in this connection, the time for welding and consumable consumables increases accordingly.

Gusset

A fillet weld is a type of connection between two metal sheets located at right angles or at a different angle to each other. These connections can also be chamfered or not, depending on the thickness. Sometimes the corner joint is also welded from the inside.

Classification on other grounds

Welded joints and seams are also classified according to other criteria.

Types of joints according to the degree of convexity:

- normal
- convex
- concave

The bulge of the seam depends on both the welding consumables used and the welding conditions. For example, with a long arc, the seam is shallow and wide, and, conversely, with a short arc, the seam is narrower and more convex. The weld speed and groove width also affect the degree of convexity.

Types of connections by position in space:

- bottom
- horizontal
- vertical
- ceiling

The most optimal for welding is the lower seam position. Therefore, when designing the product and drawing up the technology of the welding process, this should be taken into account. Welding in the down position contributes to high productivity, is the simplest process to obtain a quality weld.

The horizontal and vertical position of the welded joint requires advanced qualifications from the welder, and the overhead one is the most laborious and unsafe.

Types of welded joints by degree of length:

- solid (continuous)
- intermittent

Discontinuous welds are used in joints where tightness is not required.

Hope, this information by types of welds and joints will be useful to you and will help you to increase the quality and productivity of your welded structures in the design. It will also help to make the welding process itself safe and the most optimal. Thank you for your attention, read other articles as well.