The electric arc is a stable discharge in a strongly ionized gap. The strength of the current flowing through it, depends on the potential difference at its ends and from its linear dimensions. Since the heat is entirely determined by welding current, to ensure the desired mode of operation with sufficient accuracy to maintain its value. The thicker and deeper weld, the more current is required, and vice versa. Sometimes regulate its current value, and sometimes, by contrast, is rigidly fixed.
The main problem is relevant for all methods of welding – arc stability. At the time of ignition and extinction often have defects in the seam. Make a "burning" maximum sustainable – the most important task that solve a variety of ways. Of course, when applied to the electrodes of alternating current is difficult to achieve good results, even resorting to all sorts of "tricks". Almost All materials are better than "cooked" the dc, with the exception of only aluminum and its alloys. Oxide film on the surface prevents the formation of a lasting connection and effectively destroyed only when "Variable" exposure. Plays an important role and a protective environment in which the welding process.
Its specially created and maintained in the workspace. With various methods for protecting the environment impose different tasks: stabilization of the arc, the protection of the metal, changing its physical properties (eg doping). Stick electrode Allows you to create a protective environment without any additional hardware. Necessary for gas emitted during the evaporation coating, or powder flux.