Monolithic Welding Joint

Metal structures are used in all industries, but, unfortunately, not every product can be cast in an oven or in a mold. A ready-made parts are not always convenient to join rivets or carving. It is for such cases that welding (or welding joint) is needed - the process of reliable joining of metal products, which is based on interatomic connections. Classifications and varieties of welding are very many, but the main ones are three of them, which can be separated into separate large groups. This is a mechanical method, thermal and complex - thermomechanical. Mechanical welding is distinguished by the connection of parts under pressure or explosion, ultrasound, friction. Thermal welding is a plasma method, electric arc, laser, electron beam and the like.

Characteristic features of surfacing and thermal welding

Almost every kind of thermal welding involves the use of a special wire. In arc welding, the welding wire is included in the electrode, in all other cases the wire is present as a separate element fed to the welding location. It can have a different diameter and material - each weld metal needs its own wire with special technical characteristics that meet the requirements of welded joints.

Repair or restoration of parts worn out during operation can be carried out by a method of surfacing - by applying to a lost or pressed part of a new metal layer. Usually the same metal is used for surfacing, but this condition is not necessary. Sometimes, in order to improve the mechanical properties and performance characteristics for welding, another wire with a different chemical composition is taken. For example, in a bucket of excavators, the teeth are made of a stronger metal with a high carbon content.

Welding connection: marking of welding wire

The marking makes it easy to determine which wire to use for a particular type of welding work. The first digit denotes a diameter, and the letters designate the type of metal (alloying element). The letters "Sv" mean "welding wire", and the figures following them represent a carbon fraction of 0.01 percent. The letter following the figure is the percentage of the alloying element in the wire. Alloying elements are designated as: A - nitrogen, B - niobium, B - tungsten, G - manganese, D - copper, K - cobalt, M - molybdenum, H - nickel, P - phosphorus, C - silicon, T - titanium, Vanadium, X - chromium, U - aluminum. Then there is a figure for the percentage of this element in the wire. However, when the percentage is less than one, the figure is not put. For example, the welding wire is 08g2s, where the carbon content is 0.08%, almost 2% of manganese and less than 1% of silicon.