Submerged arc welding can be used to a larger current

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. Therefore, it is particularly suitable for large parts of the straight seam welding of girth. And most mechanized welding. Submerged arc welding has been widely used in carbon steel, low alloy steel and stainless steel welding. As the slag cooling can reduce the connection speed, so some high-strength structural steel, high carbon steel, also can be used submerged arc welding. This is a non-melting polar gas shielded arc welding is the use of tungsten arc between the workpiece and the metal melt and form a weld. Tungsten welding process does not melt, only play the role of the electrode. At the same time sent from the torch nozzle for the protection of argon or helium. Also needed to add another metal. Internationally known as TIG welding. Gas tungsten arc welding as well to control the heat input, so it is connecting sheet metal and welding backing and a great way.
All other welding methods can be used for fusion welding of metals and alloys can be welded with the electron beam. Demand high-quality product is mainly used for welding. Can solve the dissimilar metal, easily oxidized metals and refractory metal welding. But not suitable for high-volume products. Laser welding is the use of high-power coherent monochromatic light from the sub-stream focused laser beam as heat source for welding. This welding method usually has a continuous power laser welding and pulse-power laser welding. Advantages of laser welding is not in a vacuum, the disadvantage is that penetration electron beam welding as strong. Laser welding can perform precise energy control, which allows precision welding of micro devices. It can be applied to many metals, particularly difficult to solve some of the weld metal and dissimilar metal welding. Brazing is a chemical reaction heat energy can also be an indirect heat. It is the use of lower melting point than the melting point of the welded materials for low-metal brazing, after heating the solder melts, the solder materials by capillary action into the joint space within the contact surface, wetting the surface of the metal being welded, the liquid and inter-diffusion between the solid phase and the formation of brazed joints. Therefore, brazing is a solid phase and liquid phase welding method. Brazing heating temperature is low, the base metal does not melt, but also without pressure. However, before welding must take certain measures to clear the welding surface of the oil, dust, oxide film. This is a good wettability to the workpiece, an important guarantee to ensure joint quality. Solder liquidus above 450 ℃ and the humidity is lower than the melting point of base metal, called brazing; less than 450 ℃, known as soft soldering.