Welding technology. Permanent connection

Approximation to the desired range of parts hinder the surface roughness, as well as being on her dirt and oxide films. To overcome the influence of their need to expend energy that is transferred during welding work piece by two physical processes: heat and pressure.

Education weld

Figure. The relationships between temperature and pressure at which the possible formation of weld

The figure shows a graph showing the relation between temperature and pressure at which the possible formation of a welded joint (the exact numerical values ​​depend on the characteristics of welded metal). Range of ratios is large enough. Metal may be from outside does not heat up and create a zone of high pressure welding (point A). In this case the activation surfaces of welded parts and weld formation occur due to significant plastic deformation. Under this scheme, compounds are formed by cold welding, explosion welding. If the metal is heated to a certain temperature, to form a welded connection, you can use a lower pressure (point B). To this point, for example, corresponds to the friction welding in which heat is released due to friction during the rotation of one of the parts and while squeezing them. With further increase in temperature compression load of parts required for welding, continues to decline. For example, at relatively low pressures and heating temperature Tn = 0.7 Tm by diffusion welding (point C).

When heating the metal to the melting temperature (point D) to get the weld to apply pressure is not necessary. The molten liquid metal spreads over the surface of activated heating the solid metal, wets it and come on far enough to establish common bonds. After cooling, the permanent connection is formed.

Thus, all welding methods can be divided into two groups: pressure welding and welding fusion. For welding pressure (region I in the figure) is characterized by a compression force of welded parts, which provides the plastic deformation of metal in the welding area. Fusion welding (region II in the figure) is made without pressure, and heating of the metal is above its melting temperature.

Welding pressure can be connected in metals, plastics, glass, ceramics (eg, diffusion welding). Fusion welding is commonly used for metal compounds.

Welding work in sterile conditions.

Welding works produced in the LHC, held in absolute sterility. Under the control of numerous experts and tested on the new equipment, in strict compliance with all technical standards. Difficulties faced, I want to share with you.
Welding equipment encountered during different from the equipment with which we work every day. Cumbersome equipment is more than compensated for customization. The basic amount of the work undertaken was carried argon welding. My view of this process the future.

Underwater and dry welding is applicable for installation of heating systems.

Advantages of dry welding pipe during installation is: We often weld heating systems, in which the pressure continues to flow large amounts of water at this time often experience comes in handy underwater welding.
In the absence of welding work in a dry place such as "welding heating pipe burst point and all the basement to the ceiling filled with water" in this case the repair is carried out with the use of underwater welding welder-diver.
Wet welding consumable electrode has been, is and will be the main process for the repair of underwater steel structures.

Technology of fusion welding

Arc welding electric, and so we ended up with a theory, now for the practice.

Electric technology although it looks simple and quick, are not, monotonous and complex processes in execution. Perhaps you will say that electric welding quick way of welding, but to set a really fast machine but the process of electric welding in front of a very, very much like I said complex. I consider it my duty to tell that electric welding requires a tremendous amount of energy.

The process of arc welding.

Welding constructions took place in Almaty, the design of such a canopy you zadodite question how to make the most inexpensive canopy. So the most expensive of any load-bearing elements is kanstruktsii Output-bearing beams menishe than the cheaper will cost you a shed.