How to butt weld a profile pipe

Principles of welding profile pipes

Welding machines are used in many cases. They are used during the laying of water pipes and sewer systems. Welding is also widely used in domestic conditions, when it is necessary to create a structure for a canopy, roof, or eliminate defects in the design of a car. In each of these options, a welding machine can solve the problem quickly and efficiently.

Welding a profile pipe with your own hands

Of particular importance in the use of welding are profile pipes, which often have to be connected using it. In most cases, this type of pipe is made of either stainless or carbon steel. Such metal products have several advantages in their application:

1. Large selection of types, shapes and sizes;
2. The mass of both a single pipe and entire structures is not large. This allows you to connect them in complex configurations without creating a significant load on the load-bearing elements;
3. You can select several standard types at once. This allows you to independently install the structure in the future.

The most important thing when independently fastening a profile pipe is the correct temperature. The fact is that the temperature conditions determine the quality with which the products will be welded. This indicator depends on the wall thickness of the workpiece. It should also be remembered that when making an end connection, the corners of the elements being welded have a high voltage.

How to weld a profile pipe using manual arc welding?

The characteristics and simplicity of using the metal of a profile pipe allows you to connect it to each other in a variety of ways - a joint, a T-type method, and also an overlap. The lower position of the seams is a priority when welding metal profile elements.

The welding mode is determined by the following criteria:

• Electrode movement speed;
• Arc voltage;
• Polarity (assuming constant current);
• Current strength.

The last of these criteria is determined by the cross-sectional value of the electrode used. Welding of a profile pipe will be performed correctly and reliably only in one case - if it is possible to achieve the maximum current allowed for the metal. When welding using the butt welding method, the arc should be drawn so that the edges melt and the metal itself does not sag as a result.

Machines for welding profile pipes

You can connect metal pipes using two main types of devices:

• Arc welding;
• Gas welding.

Each of them has its own advantages and disadvantages. It is generally accepted that gas welding is more universal in its application. It can handle a wide variety of tasks and different types of metal. But not everyone can afford this type of welding machine.

The more common type is conventional arc welding. Therefore, all that is required for successful fastening of profile pipes:

1. take into account the wall thickness of the product;
2. select the optimal electrode diameter;
3. set the correct voltage on the device.

What electrodes should be used to weld a profile pipe?

Since standard structural steel is used for the manufacture of profile pipes, you can use the standard, most common electrodes. For example, the OMA-2 brand is ideal for this purpose. The products of this brand include titanium concentrate and ferromanganese.

Application of various electrodes:

Also, many experienced welders recommend using electrodes marked on the MT-2 packaging. They are usually used together with welding rectifiers. The main criterion for selection is a stable arc and uniform consumption of filler materials.

Welding a profile pipe: rules for forming a reliable connection

The basic rule for using arc welding is to correctly connect the elements and carefully fix them using the spot method. When all the products are in place and pressed tightly against each other, you just need to weld several points around the entire perimeter so that the structure does not fall apart.

After this, you can start scalding all the parts. The weld line is drawn smoothly. The filler material must be applied evenly. When using conventional electrodes, beginners can arc from side to side within a small range. Not all professionals use this approach, but for beginners the method is quite suitable.

The most important thing during this process is to form a neat roll from the material being processed. A straight weld line will be formed.

How to weld a profile pipe - your secrets

The first piece of advice would be to thoroughly clean the surfaces and, most importantly, to make a perfectly even cut of both sides that will be joined.

Experts with many years of experience always advise beginners to adhere to several basic points. Their effectiveness has been repeatedly applied in practice.

So, the main points of the connection, known only to the “experienced”:

• The main problem with inexperienced welders is that they forget to check the correctness of the entire structure. Always control the geometry of the metal. They often start to twist during welding. This is especially true for profile pipes.
• The quality of the seam and its reliability directly depend on the speed with which the elements are welded. The speed should be such that the specialist has time to fasten the products before the heated edge cools down.
• For profile pipes, propane-butane and acetylene torches are not used. Their temperature is too high.

We perform arc welding

Initially, you should bring the products into a specially prepared room. All ends of the pipes that will be connected are degreased. The chamfer remover is used only if the thickness of the profile pipe is more than 4 mm. After using this device, you can make a seam in several layers. It will be quite durable.

If the pipe thickness is less, one welding seam will be enough. All parts must be secured in a table specially designed for this purpose. If it is not there, then use the help of one or more people. Welding of the profile pipe will be carried out efficiently.

A certain thickness of the material, brand and cross-sectional thickness of the electrode sets the voltage with which the welding process must be performed.

The slag should be knocked down from time to time to avoid premature corrosion.

Electrode position options

We perform gas welding

After preparing and degreasing the surfaces, apply flux paste. It will prevent oxide from forming. It is important to adhere to a certain bevel angle of the edges. It is usually 30˚.

How to weld a profile pipe correctly? The answer is simple - by feeding the additive evenly from start to finish in front of the flame. The burner will gently melt materials and connect pipes.

Gas welding has a distinctive feature. If the wall thickness exceeds 6 mm, the burner is moved from side to side. Thus, the level of acetylene consumption is reduced. And the parts are more firmly attached to each other.

Horizontal gas seam:

Electrode welding and its features

The main aspects of using arc welding are the correct current mode. The location of the seams is determined by the position of the electrodes during the welding process. In this case, it is necessary to tilt the electrode slightly towards the seam.

With constant practice, you can achieve excellent results and learn how to create one of three main types of seams:

1. Short;
2. Average;
3. Long.

Source: https://viascio.ru/materialy/printsipy-svarivaniya-profilnyh-trub

How to properly weld profile pipes with your own hands?

Metal structures are made from profile pipes, which are used in various spheres of human life. These can be fences, garage frames, greenhouses. The most reliable way to connect metal parts is welding. Having learned how to weld profile pipes, you can easily make metal structures with your own hands.

Welding profile pipes with argon

Characteristics of profile pipes

Frames from profile pipes are manufactured at various enterprises and workshops. Such products have a number of advantages:

• low price;
• resistance to water;
• no deformation at low or high temperatures.

Profile tubes are made of low-alloy or carbon steel. The cross-section can be square, oval, rectangular, triangular, or complex in shape. The more stiffening ribs, the stronger the parts.

Welding methods

There are certain features that are important to consider before starting welding work:

1. If the diameter of the tube is large, before creating the main seam, the parts to be joined are grabbed at separate points.
2. Carry out work at such a speed that the metal melts, but does not spread.
3. To connect two small-diameter tubes, they are first fixed opposite each other in a vice. The suture is applied without interruption.
4. If the wall thickness of the products is more than 4 mm, chamfer is removed from the connected ends. For this purpose, a special tool is used - a chamfer remover.

When welding, it is important to ensure that molten drops of metal and slag do not get inside the tubes. In place of frozen drops, plaque and debris will accumulate, which will lead to rapid wear of the part.

Contact

An inverter machine is used for contact welding. During the working process, current is passed through the parts, and the master presses the connection with an electrode. The metal melts and a strong seam is formed. Welding of profile pipes with an inverter is used for the manufacture of industrial metal structures.

Electric arc

This welding technology is used to connect parts in hard-to-reach places. To make a strong seam you will need a welding machine and electrodes. Step-by-step instructions for performing the work:

1. Touch the electrode to a metal surface. Wait for the arc to appear and move the tip of the electrode a few millimeters away from the workpiece.
2. Make smooth movements at the joint area so that the metal melts evenly.
3. Don't take breaks. Delays are allowed only for changing electrodes.

When the seam is almost finished, you need to hold the consumable for two seconds at the end point to prevent cracks from appearing.

Electric arc welding of profile pipe

Gas

Before starting work, you need to prepare the following tools:

• reducer for gas cylinder;
• cylinders with oxygen, acetylene;
• gas burner;
• flux powder, filler material;
• several hoses for connecting equipment.

Using this equipment, you can make a strong connection between parts with medium to large wall thickness. Step-by-step instruction:

1. Use a grinder to cut the pipes.
2. Coat the sections with flux.
3. Direct the flame to the area to be joined.
4. Slowly feed the filler material into the heated area.

When the work is completed, you need to clean the finished seam from slag and coat it with an anti-corrosion compound.

Selecting the welding mode and type of electrodes

To weld a profile pipe, you need to properly configure the equipment and select electrodes. The optimal current for melting thin-walled metal is 60 A. This figure can be increased only for thick-walled parts.

There are several types of electrodes:

• MR-3S;
• OZS-12;
• ANO-4;
• UONI-13/55.

Before purchasing, it is advisable to consult with the seller or familiar welders.

Welding Recommendations

When welding pipes with your own hands, you need to follow several rules:

1. To make an even cut, you need to use a grinder with an appropriate disk. Unevenness can be corrected with a file or sandpaper.
2. Scale and rust are removed with a grinding machine.
3. Check the dimensions of the elements. To do this, you need to put them together on a workbench.

When welding is completed, you need to let the seams cool and clean them of slag.

How to weld thin pipes?

Thin-walled products should be welded with one seam, without additional points. To do this, you need to fasten two parts opposite each other at a distance of 2-3 mm and start doing work.

Right angle connection

Not many novice welders know how to weld a profile pipe at 90 degrees. First you need to cut the tubes evenly. Next, the parts are clamped in a vice at the desired angle. Spot rough welding is carried out along the contour of the future seam. Next, you need to check the dimensions so that the angle remains in its original position. After this, weld the parts along the intended contour using a continuous seam.

Right angle welding

Possible mistakes

Sometimes when heated, the profile is burned through. To avoid this, you need to perform a number of actions:

1. Insert a metal block into the pipe that fits the size of the hole.
2. Do not stop the electrode in one place.
3. Reduce output current power.
4. Carry out preliminary spot welding, then connect them with a continuous seam.

You can practice working on rough parts in advance.

Various metal structures are made from profile pipes. To make them yourself, you need to master the workflow using a welding machine. Having familiarized yourself with the nuances, you can make a strong connection without much difficulty.

How to weld a profile pipe without burning it:
HOW TO WELD A PROFILE PIPE AND NOT BURN IT!

How to weld a 1.5 mm profile pipe:
How to weld a 1.5 mm profile pipe

Source: https://trubyda.ru/svarka/profilnyh-trub

How to weld profile pipes efficiently and correctly - recommendations from experts

Welding is a method of connecting parts, which makes it possible to create a structure of the most complex configuration - at any angle and inclination.

Profile pipes are often used to create frames for greenhouses, fences and other fences, gazebos, etc. All metal pipes are connected using various types of welding; when choosing, you need to take into account the wall thickness.

Features and characteristics of profile pipes

Profile pipes are used for the construction of structures for various purposes and are used in furniture production.

The use of metal is justified by low financial costs, the ability of products to retain their shape at high water temperatures and fairly simple installation.

Most often, profile pipes are made from carbon and low-alloy steels. The strength and smoothness of the material, both outside and inside, ensures comfortable operation and durability of the entire created system.

The profile cross-section can be rectangular, square, polyhedron or oval, which provides a high margin of strength against fracture and bending. But precisely because of the cross-sectional features, welding of profile pipes has certain nuances.

Types of welding work for connecting profile pipes

Both the welding method and the features of the preparatory stage of work depend on the wall thickness:

1. For pipes with a wall thickness of 4 mm and above, the ends of the products are processed with a bevel remover - at an angle from 25 to 50 degrees. This will make it possible in the future to create several layers of welding, which ensures reliability and strength of the seam.
2. Thin pipes are welded with one seam. To make it perfect, rigid fixation of the product is recommended. The clamps are removed only after the seam has completely cooled.
3. With a large diameter and thickness, the sections are first grabbed along the contact line and only then the main welding is performed.
4. The speed of work must correspond to the melting of metal without spreading.

Note! During operation, it is important to ensure that slag and drops do not fall into the hole. Liquid metal can get into the inside of the pipe, which will reduce its throughput; plaque will accumulate here, which will inevitably lead to corrosion.

The following types of welding work are used for welding profile pipes:

• contact welding;
• electric arc;
• gas.

Arc welding

The peculiarity of this type of welding work is that it makes it possible to connect pipes even in hard-to-reach places. Performed using a welding machine and electrodes.

When burning, the element begins to melt, melting and enveloping the sections of the joints.

Sequence of work:

1. After the electrode comes into contact with the surface, as soon as the arc appears, the tool is quickly retracted a few millimeters above the cut.
2. The movements are made smoothly along the line of contact, without gaps, so that the metal has time to melt, but does not drip down.
3. The technology provides for constant burning; breaks are allowed only to change the electrode.
4. At the end point, the arc is held for a couple of seconds to prevent the occurrence of cracks or delamination.

For household, that is, low-power, electric welding machines, it is enough to have a connection to single-phase wiring.

The welding transformer is capable of converting alternating current from the house network into direct current, which is necessary for welding. However, the equipment is not able to maintain a constant or stable arc, so a rectifier is often purchased for it.

For beginners, it is most convenient to perform arc welding using an inverter, because in this case a change in the pulse mode is provided, which prevents sticking of the electrode, this ensures a constant current strength, which stabilizes the length of the electric arc.

Arc welding makes it possible to connect pipes in different ways: overlapping, butt welding, at an angle, with a T-weld. In this case, the quality of the connection depends entirely on the choice of electrode.

Selecting Electrodes

For profile pipes, electrodes are used that have characteristics corresponding to metals or alloys, as well as the thickness of the products. The strength and quality of the seam depends on correctly selected parameters.

There are two main types of electrodes: consumable and non-consumable, for which they are additionally used with an additive of tin or brass wire with the addition of phosphates.

The diameter of the electrode is always selected in accordance with the thickness of the pipe walls and their diameter.

The electrode must always be less than or equal to the thickness of the profile:

• consumable diameter 1.5 mm is suitable for products up to 2 mm thick;
• 2 mm – for pipes with a thickness of 2 to 3 mm;
• 4 mm - for wall thicknesses from 4 to 6 mm.

Important! At high current values, the arc appears at close distances of the electrode from the surface. Without the skill of determining the arc length and the necessary dexterity, you can easily burn through thin metal.

Gas welding

Used in cases where it is not possible to connect welding equipment to electricity. The method is not unreasonably considered expensive: it is necessary to purchase cylinders with acetylene and oxygen. Work experience is also required.

Gas welding is suitable for connecting pipes with medium or thick walls. Thin products cannot be processed - they melt, deforming the metal, and the seam cannot be made without gaps.

To carry out the work you must have:

• a cylinder with acetylene (butane or propane) and oxygen;
• gearbox,
• gas burner and a set of tips for it;
• additives;
• flux powder;
• hoses of the required length to supply gas to the welding site.

Before welding, the prepared sections are coated with flux. The connection is made using filler wire. According to the technology, it is recommended to connect thin-walled pipes from right to left, with the introduction of an additive following the burner flame. For more than 5 mm - from left to right and the filler material is laid in front of the burner.

After finishing the work and cooling the seams, they are cleaned and coated with an anti-corrosion compound.

contact welding

The resistance welding method requires the use of special equipment. In the process of joining pipes, an electric current is passed through the pressure of the electrodes on the metal surface, as a result of which the metal is deformed and a very strong seam is formed. Such welding is carried out to connect structures of industrial facilities.

Recommendations for welding profile pipes

Experts recommend following the rules when performing welding work when installing structures from profile pipes to create better connections:

• It is better to cut metal with a saw designed specifically for this purpose, so that the cut is smooth without grooves or protrusions. All distortions must be smoothed out before welding begins.
• The metal should not be covered with scale or rust. The surface must be clean and smooth. The work is carried out using a grinding machine or metal brushes.
• Before assembling individual elements, it is recommended to lay out the entire structure and check all main and auxiliary parts for compatibility and dimensions.
• After completing the welding work using fasteners, the seams are allowed to cool and only then removed from their fixation.

How to connect a profile pipe at right angles

First of all, the pipes must be cut correctly and the sections prepared for work. For reliability, all structural elements are fixed so that the pipes do not move under their own weight. Angles, scarves or magnetic squares are used as auxiliary devices for establishing accuracy.

The welding itself is carried out in two stages. First, a rough connection is made, the necessary linear values ​​and the position of the vertical element are checked. After cooling, the finishing seam is made.

Source: https://InfoTruby.ru/soedinenie/svarka-profilnyh-trub

Welding a profile pipe: which electrodes and inverter to weld thin-walled frames

Profile pipes are widely used in the manufacture of lightweight metal structures, for example, frames of greenhouses and greenhouses, supports for fences and fences for private houses, etc.

A special feature of rolled pipe is considered to be a square or rectangular cross-section, so welding of a profile pipe is characterized by certain features, without taking into account which it will not be possible to obtain a truly high-quality welding joint.

Features of welding profile pipes

A profile pipe is a special type of rolled metal product made from carbon or stainless steel by casting a steel pipe with a round cross-section and its subsequent molding.

The cross-section of the material can vary from 10x10 to 500x400 mm, which allows you to select the current option taking into account the specific load on the metal structure. The thickness of the tube walls, depending on the parameters of its cross-section, varies in the range of 1-22 mm.

Rolled pipe is a special type of construction metal, which is relevant for the construction of light metal structures.

Main advantages of the material:

• low weight, which reduces labor costs when installing a metal structure;
• wide variety of sizes;
• standard sizes according to the type of pipes, which facilitates their end joining during welding;
• uniform wall thickness, even smooth surface of profiled products outside and inside.

Welding with special equipment and an electrode is the most popular type of heat treatment of rolled metal on the domestic market.

Welding profile pipes allows you to create frames for polycarbonate greenhouses, supports for fences for household purposes, gates for garages and private cottages, communication systems of various types and purposes.

But it is important to perform welding operations taking into account the characteristics of this material; without knowledge of how to properly create welds on rolled metal, you should not expect excellent results.

Generalized about welding of profile pipe

Here is some general information that a craftsman must understand when working with rolled pipe:

• under the influence of high temperature, pipes with a profile section are more deformed than round products;
• when the metal melts, the internal space of the rolled pipe may fill and overlap; if the hollowness of the product is extremely necessary, it is important to control the absence of metal droplets inside the pipe;
• When end-connecting rolled metal with a profile section, due to uneven heating or improper formation of the rollers, high stress may appear at the corners of the product.

The thickness of the walls of rolled metal varies over a fairly wide range of values, but it is the welding of thin-walled pipes that requires the master to have certain knowledge and skills.

Methods for welding profile pipes.

Working with thin metal is not as simple as welding thick-walled pipes with an inverter, since a number of important points must be taken into account when working:

• to create welded joints on rolled metal, a current of 10 to 60 A is required;
• electrodes for welding thin-walled profiles should have a diameter of 0.5-2 mm, but no more;
• the seam is performed in one pass;
• the quality of the connection is largely determined by the speed of welding;
• The craftsman must have time to weld the profile until the working edges have cooled down.

If you carefully study the described recommendations, welding a gate with your own hands from a profile pipe will not be difficult even for an inexperienced craftsman. If you perform such work without knowledge of the specifics of rolled metal, the structures will not be reliable, strong and durable.

It is equally important when working with profile pipes not to make a mistake with the choice of electrode, since the operational parameters of the weld depend on this.

The welder must pay special attention to the cross-section of the welding wire: an excessively thin electrode will cause instability in the arc, and an electrode with a large cross-section can burn through a thin-walled product.

The diameter of the welded wire must be selected taking into account the wall thickness of the rolled metal:

• if the cross-section of a rolled metal pipe does not exceed 2 mm, an electrode with a diameter of 1.5 mm is relevant;
• a profile pipe with a cross-section of 2-3 mm is welded with an electrode with a diameter of 2 mm;
• rolled metal with a cross section of 4-6 mm requires the use of welded wire with a diameter of 4 mm.

Welding of a truss or other kind of structures made of a metal profile can be carried out in different ways, but the most popular of them are the following options:

We'll talk about this in more detail below.

We weld pipes with an electric arc unit

Do-it-yourself welding of square pipes with electric arc equipment is not considered a complex technology. This type of welding is easy to perform even for a craftsman with minimal experience in welding operations, which is why this method of joining rolled metal is very popular among welders.

The electric arc unit allows you to easily weld products in hard-to-reach places.

Features of welding profile pipes.

Do-it-yourself electric arc welding of trusses from a profile pipe requires a welding machine and electrodes, as well as protective clothing and special fasteners for profiles.

The technology can be implemented in different ways:

• making butt connections;
• organization of overlapping welds;
• tee seams;
• connections made at a convenient angle.

The production of various types of metal structures from profile pipes should be organized in special premises. For example, welding sliding gates should be performed in a workshop or a spacious garage adapted for this work.

The ends of the pipes to be welded should be cleaned and degreased before starting work to ensure maximum tenacity to the edges of the products.

If the thickness of the walls of the metal profile exceeds 4 mm, the edge should be prepared using a chamfer. This will allow you to form a seam in several layers and make the joint more durable and reliable.

Rolled metal with a smaller thickness is welded in one seam. In this case, it is important to fix the parts on a special table. A pipe with a smaller wall thickness must be welded in one seam, also securing the parts on a special table.

If the rolled metal has a cross-section of more than 10x10 mm, experts recommend applying spot tacks in some places and only then welding. The speed of the electrode is selected based on the melting rate of the metal, but it must not be allowed to flow into the internal lumen of the product.

Assembly diagram for the joint of profile pipes.

Excessively slow electrode advance speed leads to burn-through when welding thin-walled metal. The electrode is moved in a herringbone pattern or from side to side.

The mode of arc welding of profile pipes completely depends on the type and strength of current, the diameter of the welded wire, as well as the selected polarity. In this case, the current strength is selected within the range of 20-90 A, taking into account the cross-section of the welded electrode.

If profiled pipes are welded with a small cross-section electrode, direct current with reverse polarity will be required. When making a weld, slag forms on the surface, which must be periodically knocked off.

It should also be taken into account that the weld seam, cleaned after cooling, will be more reliable if it is treated with special anti-corrosion agents.

The problematic issue is that a weld heated to a high temperature becomes covered with rust much faster, losing its strength characteristics. Treatment with an anti-corrosion compound will not take much time, but will significantly extend the service life of a metal structure made from a profile pipe.

Pipe welding with gas equipment

Gas welding of profiled metal products is less commonly used by craftsmen than electric arc welding, since this method is characterized by high costs, increased danger due to the use of acetylene gas, and the need for special training of the welder to perform these operations in practice.

But if it is not possible to connect the welding equipment to electricity, a gas unit must be used to weld thin-walled pipes.

Preparation and welding of pipes according to the template.

There are two technologies for using gas welding equipment:

1. The master must move the additive from left to right behind the burner, which is why this technology is called right-handed.
   The advantages of this method are good heating of the welding zone and excellent visibility of the working area, which allows you to achieve high productivity and reduce gas consumption. But the right technology is used only for profile pipes with a wall thickness of at least 5 mm.
2. The left method involves the movement of the burner from right to left and is relevant for thin-walled metal profiles.
   In this case, the wire is moved in front of the burner.

Gas welding is performed in stages.

At the initial stage of work, it is necessary to prepare the following materials:

• cylinders with acetylene and oxygen;
• gearbox;
• additive;
• gas burner and tips for it;
• hoses providing gas supply to the place where metal is welded;
• flux.

Using gas welding to connect profile pipes.

At the next stage of work, you need to degrease the prepared metal parts and fix them on a special table. The edge of the product is treated with flux in the form of a paste to prevent the formation of oxide during the welding process.

Experts insist that the bevel angle of the edge must be 30 degrees in order to be able to organize several high-quality rows of welds.

The flame supply is provided by a mixture of acetylene and oxygen. Filler material is fed between the metal pipes to be welded in front of the burner flame. Due to the high temperature of the flame, the metal of the profile pipe and the additive will begin to melt, as a result of which a high-quality weld is formed.

In this case, the burner must be moved from right to left. When butt welding pipelines with thick walls, the rod must be fed behind the torch flame, and the torch itself must be moved from left to right.

It is important to select the correct size electrodes for welding a profile pipe in order to perform welding operations as efficiently as possible.

Let's sum it up

To create structures like greenhouse frames, garage doors or private houses from rolled metal, it is important to know what electrodes should be used to weld a profile pipe, choose the welding method that is most suitable for the working conditions and become familiar with the nuances of working with such material.

Follow the rules for working with rolled metal to obtain the best weldability of the metal and the most durable and strong welds.

Source: https://tutsvarka.ru/vidy/svarka-profilnoj-truby

Which electrodes should be used to weld a 2 mm profile pipe, professional advice

Profile pipes of square or rectangular cross-section with a wall of 2 mm are in good demand among the population; in everyday life, they are used to make various types of building structures (gazebos, greenhouses), organize fences, make frames for canopies and canopies. The main method of connecting them is electric arc welding, and if the homeowner has purchased a welding machine and does not have experience in carrying out welding work, he will immediately be faced with the question of what electrodes to use to weld a 2 mm profile pipe.

In addition to the selection of suitable electrodes, the quality of welding profile pipes largely depends on adherence to technology, selection of the correct operating modes of the device, knowledge of basic techniques and methods that facilitate the performance of electric welding work by a beginner.

Fig.1 Application of structures made of rolled profiles

What is a profile pipe

A profile pipe is a rolled product with a square or rectangular cross-section with a wall thickness of 0.8 to 14 mm, the width of its edge varies from 10 to 140 mm, and the length can reach 14 m.

The usual material for its manufacture is structural steel of grades St2, St 4, St10, St45; there is a stainless steel profile on the market.

The industry produces hot-rolled and cold-deformed square and rectangular profiles; the products can be seamless (made from hot-deformed and cold-deformed round pipes using the molding method) or have an electric welded seam when manufactured from rolled sheets.

The use of profile pipes in households has the following advantages:

• Thanks to the angular stiffeners, the pipes have high mechanical strength with low metal consumption.
• The rectangular or square shape makes pipelines easier to transport and store, while they take up less space than round bars.
• Rectangular cross-section, in contrast to round steel, gives an advantage to profile pipes when used as frames on which various parts are attached.
• The use of low-carbon structural steels as manufacturing materials makes them easier to weld by any method.

Fig.2 Appearance of profile products

• Another advantage of low-carbon steels is their low hardness and high ductility (compared to high-carbon and alloy steels) - this allows the material to be cut, processed and deformed with hand and power tools using inexpensive consumables.
• In accordance with the standard (GOST 8639-82), the industry produces profile pipes with a wall thickness of 2 mm. with an external edge size from 20 to 60 mm. – this makes its weight convenient for work and independent installation of volumetric structures by one person.
• Welding profile pipes is the most convenient of all types - they have the same cross-section and thickness along the entire length, a smooth and even surface.

Methods for welding profile pipes

To weld metal profiles at home, you can use several methods that differ in their cost. When performing welding work, the following difficulties arise:

• When a separate section of the edges is heated, the workpieces being welded change their location.
• End connections create high stress points at the corners.
• A thin-walled profile often burns out when welded by an inexperienced welder.

Rice. 3 Devices for resistance spot welding

How to weld profile pipes with your own hands: what electrodes, how to weld thin-walled ones

Profile pipe is a material for small work or small structures inside the yard. It is most often used to assemble greenhouses, make frames, fences and much more with your own hands.

It is not immediately clear how to weld profile pipes professionally. To understand the process, let's look at the variations of working with the profile.

How to weld profile pipes correctly?

For various types of structures, the following types of profiles are used:

There are others, but these are some of the popular ones. After all, there are also differences in cross-section.

Another thing is more important - the profile pipe is produced from carbon and low-alloy steel. It is not difficult to connect this material; there are the following technologies for welding a profile pipe:

• Electric arc.
• Gas welding of profile material.
• Contact.
• Inverter.

Each of them has its own characteristics. We read about this below.

Welding methods and methods

All known methods and devices for profile welding today. Let's list them by popularity.

Inverter

An improved type of electric arc welding. Just as reliable, simple and independent for private construction. The inverter device is convenient in everyday life and at work. The benefit is obvious: compact, light weight, affordable price.

It is important to understand that for beginners this is the most correct way. Because there is a pulse mode.

An inverter machine can weld profiles of any thickness. Welding of thin-walled profiles with an inverter is carried out at 50 A. By increasing the voltage, you can work with classic thickness.

Welding is carried out by exciting an electric arc and contacting the workpiece with an electrode. The consumable (electrode) begins to burn and covers the cleaned base. What’s interesting is that the electrode contains a composition that, when heated, prevents contact between atmospheric air and the working surface.

Visible advantages of the inverter:

1. No electrode sticking.
2. The constant current of the device maintains the stability of the arc, hence the quality of the seam. The product looks high quality without additional processing.
3. Contact welding provides a reliable connection that is resistant to stress.

Questions for professionals

It is worth noting that it is not prohibited to weld the profile at any desired (comfortable) angle. Also for profiled pipes there is an overlap connection, a joint to a joint, or a T-joint.

The formation of the seam is more important, and experienced welders recommend creating seams from the bottom position. When there are inconvenient areas, horizontal, vertical and ceiling positions are used.

Which electrodes are best for cooking?

Considering the grade of steel, in order to successfully weld a profile pipe with electrodes, we give preference to:

• AHO-4. One of the most common due to its versatility. No need to ignite, suitable for different types of equipment.
• MP-3С. For ideal seam quality and appearance.
• UONI-13/55. For professional welders.
• OZS-12. Optimal connecting seam. Lack of resistance to wet weather.

Which mode should I use?

We study the welding process. When setting the mode for manual welding equipment, we focus on the current strength. This is the most important indicator. It strictly corresponds to the diameters of the electrodes. And the electrode (electrode thickness), in turn, is selected to match the thickness of the profile wall.

Table with indicators to select the electrode diameter:

Butt welding

Otherwise called T-bar. Simple in appearance, but to perform it requires training. Butt welding requires:

1. Performing clamps at each corner of the section. Then it is necessary to correct the joining of the section, welding along the entire plane of the frame.
2. A thin profile is cooked in one go, a thick one will require several stages.
3. The arc is fed so that there is no metal subsidence. So that the edges have time to melt.
4. It should be completed with a reference to the edge. It necessarily coincides with the original one, which overlaps.

Welding a thin profile pipe

It is difficult to weld a thin pipe. For a thin profile pipe (its walls are 2-3 mm), it is more correct to choose an electrode of similar thickness with a diameter of 2-3 mm. If you have no experience, then it is not advisable to spoil the material.

It is better to entrust it to a qualified welder. He will set the required current strength and take suitable electrodes (ANO21 or MP3S).

For your information! It is optimal to connect a 2 mm profile with an inverter to avoid burn-through.

How to weld profile pipes at 90 degrees?

Before work, read the rules:

• We cut the blanks.
• We work on a flat plane (concrete).
• Temporarily fix the angle. Magnets and scarves will do.
• We cook steel in stages. From the very beginning, rough welding, then checking the geometry. Then there is the finishing high-quality seam.

When welding, the pipe ignites, what should I do?

To get the job done without this incident, we follow the rules:

1. Spot welding over short sections.
2. To avoid overheating, you can insert a massive metal block with a cross-section. It must be adjusted to the internal dimensions of the tube blank.
3. Reduce the distance between each edge.
4. Set the lowest output current mode.
5. Moving the electrode itself is faster.

welding lesson

How to properly and quickly weld a profile in various ways:

Joint welding. Let's watch the video instructions for a master without experience:

How much does it cost to hire a welder?

We focus on cost on the central region of the Russian Federation. It is important to understand that the work of a hired welder is measured in different quantities. Focus on:

• Centimeters (from 20 rubles per unit).
• Joints (from 150 rubles per joint).
• High cost for complex (inconvenient) designs. Gates and fences are already in linear meters (from 600 per linear meter).
• Hot welding method.

On any of the sites the price is always approximate. Discuss specific actions at the site. After which they issue an invoice. The welder not only makes the weld, but also the preparation. And this is a labor-intensive process.

Results

Theoretically, we delved into the essence of the seemingly simple work of welding corrugated pipes at home. We came to the conclusion that it is better to choose budget equipment, universal electrodes, for connecting with your own hands. It is important to practice on small useless sections before starting work. And only then start creating the design.

Source: https://vseotrube.ru/montazh-i-remont/kak-svarivat-profil

Welding a profile pipe: rules for forming a reliable

04/24/2017Pipes

Welding profile pipes with your own hands is a much more difficult task than it might seem at first glance. In fact, in addition, a person who is fluent in a welding machine will have to try very hard to get a reliable design that matches the given dimensions. What can we say about beginners who are just mastering this technology?

But it is still possible to cope with such a task, and apart from practice (nowhere without it!) fundamental theoretical training is needed to ensure an acceptable result.

Pros of a profile pipe

The advantages of profiled steel products as raw materials for welded structures are completely obvious:

• Firstly, pipes are manufactured to standard sizes , which greatly facilitates their alignment, especially when connecting at the end.
• A large assortment of sections allows you to select parts for any design . So if we want, for example, to weld a gate from profile pipes, we can easily find elements for the posts, the frame, and the filling.
• Another plus is the uniform thickness of the metal . This is extremely important when welding, because it largely determines the reliability of the seam.
• Finally, it is very ergonomic that we will have to work with an already leveled edge and fairly smooth surfaces . When producing profile pipes, there are fairly strict tolerances, and in most cases deviations do not exceed fractions of a millimeter.

Note! All these advantages are characteristic primarily of products that were produced in a factory in accordance with GOST and according to the established range. A homemade profile pipe (for example, rolled from a round billet) in most cases has much larger deviations in size, and therefore behaves unpredictably during installation.

Main difficulties

But the process of welding square and rectangular pipes includes many nuances:

• Firstly, when the product is heated, its configuration changes, usually much more strongly than that of a round pipe. Quite often this leads to the fact that the entire structure is deformed, and the direction and degree of deformation is determined by the placement and number of welds.
• Secondly, with end connections, areas of increased stress are likely to form at the corners. This is due to the difficulty of forming rolls of molten metal in these areas and uneven heating.
• In addition, this installation technique can lead to partial blocking of the pipe lumen with hot and then frozen metal. If it is fundamentally important for you that the parts remain hollow, consider this possibility.

Naturally, these difficulties in most cases do not stop real masters. So, after carefully studying the technology and practicing skills in practice, it is possible to cook the profile with a bang.

Preparation of structures

The success of the event greatly depends on how well we prepare for it. Eg.

Before welding a gate from a profile pipe, it is worth performing the following operations:

• First, we select parts with the required length and cross-section. Cutting to size should be done using a metal saw rather than a welding machine - this way the edges will be smoother, and in the future it will be much easier for us to work with them.

• Then we smooth out all the pipes. In most cases, it is in areas with curvature that the part begins to “lead” when heated.
• Then we clean the areas to be joined from rust, sanding them until they shine with either an iron brush or a grinding machine.
• If necessary, smooth the edges so that when combining two elements the gap is minimal. The more carefully this operation is carried out, the less force we will actually spend during welding.
• Then we place all the elements in the position in which they will be in the finished structure. When performing welding work, it is necessary to additionally fix the mounted parts so that they do not deform or move relative to each other. The fixation should be removed only after the weld has cooled.

Arc welding

So, the parts are ready for work, it is possible to start their installation. And here two methods can be used: electric or gas welding. Below we will look at both of them in detail.

For electric arc welding, we need a welding machine. The price of similar devices is quite enormous, so it is worth buying it only when you plan to work with metal more or less systematically. For one-time work, you need to rent a device, especially since in most cases there are enough opportunities for this.

The next point is the selection of the electrode and operating mode. Here the following table will come to the rescue:

Pipe wall thickness, mm	Electrode diameter, mm	Current on the device, A
2 or less	1,5 – 1,6	up to 50
2 — 3	2	40 – 80
2 — 3	2,5	60 — 100
3 — 4	3	80 — 100
4 — 6	4	120 — 200
6 — 8	5	175 — 250
10 – 24	5 – 6	220 — 300
up to 50	up to 8	300 — 400

Advice! These values ​​are a recommendation, therefore, before starting work, you should perform test welding on small sections of pipe in order to check the quality of the seam taken.

We do the connection process like this:

• We fix the parts on a welding table or on auxiliary devices.
• We do spot welding in several places, “grabbing” the pipes to each other. In most cases, fixation at four to five points on all edges of the pipe is sufficient.

• Once the tack is completed, we check the position of the parts. If necessary, correct the positioning with hammer blows.
• Then we begin to weld the joints of the pipes being connected, forming a bead of molten metal on each, which will then take the form of a weld.
• At the same time, we conduct the arc in such a way that the edges of the pipes have time to melt, but the metal itself does not sink into the cavity of the product.

• We weld thick-walled pipes in a couple of steps, slowly connecting all layers of metal. Along with this, we make any next pass in the direction opposite to the previous one: this way we will ensure that the optimal structure of the metal is secured.

Advice! At the end of each operation, we control the geometry of the product: long pipes in most cases begin to “lead” just after welding of long seams is completed, at a time when huge areas of stress are formed on the surface of the metal.

At the end of the work, let the structure cool, and then proceed to clean up the weld. In the future, these areas require the highest quality protection against corrosion, because metal exposed to high temperatures rusts much faster.

Conclusion

It goes without saying that a sufficiently detailed answer to the question of how to weld a profile pipe is not enough for the successful application of knowledge in practice. In order for the result to be at least satisfactory, it is worth carefully studying the video in this article, and then trying out the techniques presented there on small examples, under the guidance of a skilled mentor. This is the only way you can master this installation technology at a sufficiently large level.

Source: https://uchebniksantehnika.ru/truby/svarka-profilnoi-truby-pravila-formirovaniia-nadezhnogo.html

How to weld profile pipes efficiently and correctly - recommendations from experts - Prof Pipes

Many structures in the country are made from profile pipes. The choice of this material is due to durability, ease of installation, and lightness of the finished structure. To give the product additional strength, the structural elements are connected to each other by a weld. Do-it-yourself welding of a profile pipe can be done using several methods.

Assembling a structure consisting of profile pipes

Preparing for work

The connection of profile pipes without welding is mainly carried out using specialized clamps and bolts. Over time, the fasteners weaken, so when caring for the product, it is necessary to constantly check the strength of the structure. To reduce operational problems, welding is used to assemble the structure.

To obtain a strong weld, the surface of the pipe must be prepared. For this:

• pipe sections are cut to the required length;

Using a grinder to cut pipes

• if it is necessary to connect elements at an angle, then the pipes are carefully adjusted to each other so that there are as few gaps as possible. This will increase the quality of the weld and, as a result, the reliability of the finished product;
• the places where the weld is supposed to be located are cleaned of rust, burrs and other foreign deposits. Any inclusion negatively affects the strength of the seam. Cleaning can be done with a simple metal brush or specialized equipment, for example, a grinding machine.

Surface preparation before welding

Welding technique

Welding of a frame from a profile pipe can be carried out by any of the following types:

Welding profile pipe

The so-called profile pipe has become quite widespread in various areas. It is used in construction and the creation of metal structures, laying pipelines, and manufacturing decorative products (including furniture). All applications require welding of the profile pipe. A feature of this process is the difference in the cross-sectional shape and the steel used for their manufacture.

Welding methods and methods

All profile pipes are made of steel, which is used for the manufacture of similar products with a round cross-section. The same connection technologies apply to them. The following types of welding are considered the most common:

• electric arc (consumable or non-consumable electrode);
• gas.

These two methods are implemented using different welding machines.

Welding with inverter

This electric welding machine got its name due to the process of converting a standard alternating voltage of 220 V with a frequency of 50 Hz into direct current voltage. Welding a profile pipe with an inverter is considered the simplest and most reliable way to connect two workpieces. The main advantages of the unit used are:

• well-developed methodology for carrying out work;
• suitable for beginner welders;
• prevents sticking of electrodes;
• provides high quality arc;
• it is possible to obtain good seam quality;
• all elements of the welding machine are available for use even in a home workshop;
• Wide range of applications for welding metal structures.

It is used for the production of a frame from profile pipes with a thickness of 2 mm. Using this method, you can obtain a base for greenhouses or furniture from a profile pipe. The elements to be welded can be workpieces of any length. The inverter allows you to weld workpieces from various grades of metal using appropriate electrodes.

Depending on the wall thickness and pipe profile size, inverter devices are selected that can provide the required process mode. The use of inverter units is used for laying pipelines both indoors and outdoors. Thanks to the versatility of inverter machines, welding can be done at any desired angle.

One of the optimal modes is considered to be working at an angle of 90 degrees. In this case, it is necessary to use tools and devices that ensure that the angle remains vertical throughout the entire period of work.

To obtain a profile of a given design using a 2 mm pipe, it is necessary to work carefully with the electrode to prevent damage to the edge of the workpiece and, especially, burn-through.

Selecting welding modes

The quality of the expected seam largely depends on the correct setting of the mode parameters. Its choice requires clarification of the following parameters:

• what electrodes are planned to be used for work (their characteristics and diameter);
• values ​​of parameters of the supplied current (including its type: direct or alternating);
• welding arc voltage;
• speed of the process;
• the number of passes required to fill the seam.

In many ways, the quality of the connection depends on how these parameters are selected. Depending on the grade of metal from which the pipe is made and the thickness of its walls, they choose which electrodes to make the connection with. If you choose the right welding mode, the seam will be good and reliable.

Selecting electrodes for welding profile pipes

The quality of the work performed and the reliability of the resulting connection largely depend on the correct choice of electrodes for welding profile pipes. For welding profile pipes, professionals recommend the following electrodes:

• ANO-4 (distinguished by their versatility, which allows them to be used in various units);
• UONI-13/55 (mainly used by professional welders with high skills, including profile pipes);
• MP-3S (provide the highest quality seam);
• in some cases, OZS-12 electrodes can be used (they provide acceptable weld quality, but have poor resistance to high humidity).

The variety of shapes and materials of profile pipes requires a careful approach to choosing which electrodes to weld the profile pipe with. When choosing electrodes, you should use existing reference information and recommendations of experienced welders.

Profile pipe welding technology

The most widely used technologies are: electric arc, gas and resistance welding. This is possible due to the fact that almost every workpiece is made of low-alloy or carbon steel. Each of these technologies involves the use of appropriate equipment and connection methods and allows you to obtain a reliable seam and create a new profile structural element.

Welding a profile pipe at 90 degrees

Many designs require connecting parts at right angles. This task is easily solved if you follow simple recommendations developed by experienced welders:

• Welding a profile pipe at 90 degrees begins with precise marking of the cut angles;
• make a precise cut (it can be done on a flat surface with the workpiece fixed);
• use ready-made templates and professional squares;
• divide the welding process into several stages (first perform rough welding, then check and make sure how accurately the given angle is maintained, then perform finishing welding).

Following these tips will allow you to get a right angle.

How to avoid burning a pipe while welding

This negative phenomenon occurs when working with thin-walled workpieces, the thickness of which does not exceed two millimeters. To prevent this, it is necessary to use thin electrodes. In addition, when setting welding modes, the current value should be reduced to minimum values. Inexperienced welders need to study the developed instructions for working with thin-walled products.

Source: https://stankiexpert.ru/spravochnik/svarka/svarka-profilnojj-truby.html