This way you can connect manually, semi-automatically or automatically at different spatial positions of various metals and alloys with a thickness of tenths to tens of millimeters.
Summary of the procedure. When welding arc zone through a nozzle 2 shielding gas is fed continuously 3 (see Fig.). Heat of the arc melts the base metal 4 and, if performed welding consumable electrode is melted and welded. The molten metal weld pool, crystallizing to form a seam. When welding electrode consumable electrode is not melted, but its consumption is caused by evaporating the metal or partial melting at higher allowable current sva-rochnom. Education seam occurs due to the melting edges of the base metal or additionally injected filler metal. As the shielding gas used inert (argon and helium) and active (carbon dioxide, hydrogen, oxygen and nitrogen) gases and their mixtures (Ar + He, Ar + CO2, Ar + O2, CO2, O2 +, etc.). With respect to the electrode shielding gas can be supplied centrally or laterally (Fig. 37). Side of the gas is supplied at high speed welding consumable electrode, when the central safety security protection is violated because of the blowing gas fixed air. Drafts or wind during welding, blowing a stream of inert gas, can dramatically reduce the quality of the weld or connection. In some cases, especially when welding with tungsten electrode to produce the necessary technological properties of the arc, as well as to save scarce and expensive inert gas protection used by two concentric gas flows. Property ID shielding gases have a great influence on the technological properties of the arc and the weld shape. For example, compared with argon helium has a higher ionization potential and high thermal conductivity at temperatures of the plasma. Therefore, the arc in helium, a "soft". Under equal conditions the arc in helium has a higher voltage, and the resulting joint has a smaller depth of penetration and a large width. Therefore, the helium should be used when welding sheet metal. In addition, it is lighter than air and argon, which requires a good defense for the fusion of its high flow rate (1.5-3 times). Carbon dioxide is the influence on the shape of the seam occupies an intermediate position. wide range of shielding gases are used which have significantly different thermal properties, makes great technological capabilities of this method both in terms of weld metal (almost all), and their thicknesses (from 0.1 mm to tens of millimeters). Welding can be performed using as a non-consumable (carbon, tungsten) or consumable electrode.
Compared with other methods of welding in protective gases has several advantages: high quality welds on a variety of metals and alloys of varying thickness, the ability to weld in different positions, the possibility of visual observation of the formation of the joint, which is especially important for semi-automatic welding, the lack of filling operations and cleaning of flux and slag removal, high performance and ease of mechanization and automation, low cost of using active shielding gas.
The disadvantages of the method of the comparison with the submerged arc welding is the need for protective measures against the light and heat radiation of the arc.
See also:
Manual Arc Welding
Introduction to Arc Welding
Creating and maintaining an arc
Ways to improve performance
Technique of upper and horizontal joints
Technique of the lower seam
Pipe Welding Technique
The Method
Arc Welding in Protective Gases
Electrodes for Manual Arc Welding
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