the interaction with the surrounding gas

Most of the arc is burning between electrode and workpiece arc as heat source. In the formation of joints, may or may not use filler metal. Electrode is used in the welding process the welding wire melts, the melting polar arc called, such as arc welding, submerged arc welding, gas shielded arc welding, tubular wire arc welding, etc.; electrode is used in the welding process does not melt The carbide or tungsten rods, called non-melting polar arc, such as TIG welding, plasma arc welding and so on. Arc welding is arc welding method of early development is still the most widely used as a welding method. It is coated with a coating of the external electrodes and filler metal for welding, arc welding is the welding tip and the surface between the combustion. Coating in the arc under the action of one hand, can produce hot gas to protect the arc, on the other hand can produce slag covering the weld pool surface, the molten metal to prevent the interaction with the surrounding gas.  laser pointer of super high quality is of the higher cost and expense.
Slag is the more important physical and chemical reactions produce molten metal or alloy elements added to improve the weld metal properties. Arc welding equipment is simple, lightweight, flexible operation. Can be applied to maintenance and assembly welding seam in short, in particular, can be used for difficult to reach parts of the welding. Arc welding with the electrode applied with the corresponding most industrial carbon steel, stainless steel, cast iron, copper, aluminum, nickel and their alloys. Submerged arc welding is a continuous feed, as when the wire electrode and filler metal. Welding, the welding area covered with a layer of granular flux, under the burning arc in the flux layer, the wire tip and base metal partial melting to form a weld. Under the action of heat in the arc, on the part of the flux and molten slag metallurgical reactions occur with the liquid metal. Slag floating on the surface of the metal pool, on the one hand to protect the weld metal, to prevent air pollution, and physical and chemical reactions produce molten metal, weld metal of extreme and improve performance; the other hand, can make the weld metal slow Coolers. Submerged arc welding can be used to a larger current. Compared with manual arc welding, its biggest advantage is that the weld quality, high welding speed. The machining process of laser pointer is important to enhance quality of laser pointer .