Welding of metal structures: technology and features

One of the most commonly used in the production of mass and small-batch products of the joining of parts is welding. With its help it is possible to assemble almost any conjugation of elements - T-wave, angular, end and lapping. With the passage of time, the technological methods by which metal structures are welded are improved, becoming more efficient.

Classical welding methods

Standard methods for welding metal elements involve the use of two main sources of energy: a gas flame or an electric arc.

Gas and arc welding can be automatic, semi-automatic and fully manual. The latter option involves the formation of a welding seam only by the master's own hands. In addition, manual arc welding (RD) welding of metal structures includes manual control of the electrode feed, or filler wire, and the process of welding parts.

Manual mode is most effective only in domestic conditions. When using it, mainly use the technology of submerged arc welding, soldering with a gas welding machine or the classic method of electric arc welding.

At the heart of the first option - automatic welding - lies the process of laying on the seam area without direct human participation. All work is handled by a special mechanism, which is pre-configured. Naturally, this range has a very limited range of functions, but this significantly reduces the cost of finished products, which makes it very popular in large-scale production.

Assembly of metal structures, welding in automatic mode allows to apply contact technology, including heating and pressing of elements, electric welding and other "manual" methods. The only difference is that it's not the master who manages everything, but the specially created and programmed robot.

Semi-automatic mode implies the imposition of a welding seam by a master, however, electrodes or wire are automatically fed into the work area, which significantly increases the productivity of work on the site.

In this mode, virtually any welding technology for metal structures, using non-meltable electrodes, gas fluxes and automated feeding in the heating zone of filler wire. In everyday life and small-scale production of semi-automatic welding of metal structures is the most beneficial and effective option of the technical process.

Technological novelties

In modern welding, not only the flame of superheated gas and the electric arc, but also the thermal effect of friction, laser energy, ultrasound and even the strength of electron beams are used to connect metallic parts.

Simply put, the welding technology itself is constantly being improved. New ways of realizing this technical process are invented regularly. Among the novelties of this kind are the following types of welding: plasma, thermite and electron-beam welding.

By means of the thermite technology, the responsible metal structures are welded, the components of which are melted at the seam during the combustion of the special mixture introduced into the joint site. The termite is also used to remove defects and cracks in already finished metal structures by means of an "inflow" of metal.

Plasma welding is carried out under conditions of transmission through two electrodes of ionized gas. The latter acts as an electric arc, but its efficiency is much higher. Superheated gas is used not only for welding metal, but also for cutting it, so that an automatic and multifunctional welding system can be created around the plasma generator.

With the help of electron-beam technologies, deep seams are welded up to 20 centimeters, while the width of such a seam will not exceed one centimeter. The only drawback of such a generator is that it is possible to work with it only in a complete vacuum. Accordingly, this technology is used only in highly specialized areas.

To assemble small-sized metal structures, it is most effective to use gas or electric arc welding. Semi-automatic device pays off when carrying out works with small-scale objects. Modern welding technologies, respectively, are used only in batch production.

Welding of metal structures: features

The welding technology is applied not only when working with metal, but also with different polymers. The whole process is the heating and deformation of surfaces, which then combine into one.

All welding work consists of two main stages: assembly and connection.

The most laborious and complex is the first stage. The reliability and durability of the design largely depends on compliance with all requirements. More than half of the time is spent on assembling components.

Ensuring the correct assembly of metal structures

High quality, durability and reliability of the final result is ensured by observance of certain requirements.

• When selecting parts, you must strictly adhere to the dimensions of the project.
• Gaps should be of a certain size - as they increase the strength of the finished product will significantly decrease.
• Angles are measured and controlled using special tools. It is important that they fully comply with those specified in the project, otherwise there is a risk of collapse of the entire structure.

Advantages of welding

In addition to the fact that welding of metal structures significantly saves time for all works, and the seam is obtained qualitatively, the process has other characteristics:

• The weight of the finished soldering does not change, because only two basic parts are used, which saves material.
• No restrictions on the thickness of the metal.
• Possibility of control and correction of forms of metal structures.
• Availability of welding equipment.
• The ability to use welding for repair and reconstruction.
• High tightness and durability of joints.

Additional points

To ensure that the resulting design was of high quality and reliable, it is necessary to comply with all technological requirements.

Correctly selected materials, components and equipment make it possible to obtain seams of high quality. Otherwise, the finished structure not only loses its commercial appearance, but also its performance characteristics.

Defects in welding seams

To obtain exact dimensions and simplify the work in the creation of metal structures, a conductor is used. Despite this, RD welding of metal structures, cranes can turn during the process of certain defects - rushes, cracks, burns, porosity, burns, undercut and other.

Causes of defects

Structures are formed on metal structures as a result of the ingress of molten metal. Most often, such a defect is typical for the work on creating horizontal seams. Remove them with a hammer, and then check the product for the presence of impregnations.

The causes of burnout can be poor quality edge processing, increased clearance, low speed of work and low flame power. Eliminate it by cutting and welding the seam.

The most dangerous type of defect is considered to be non-penetration, as it adversely affects the reliability and strength of the weld. Such areas are completely eliminated, metal structures are cleaned and re-welded.