Welding definition and preparation before welding work:
The Welding Wires  is performed by heating, pressing, or a combination of both, with or without a filling material, so that the two workpieces generated between atoms binding processing and joins. Welding wide range of applications, both for the metal, can also be used for the nonmetal.
By heat or pressure or a combination of both, and with or without a filling material, so that a the weldment achieve the combination of a method called welding.
Welding can not only solve a variety of steel connections, but also can solve the connection of aluminum, copper, and other non-ferrous and special metal materials such as titanium, zirconium, and thus has been widely used in machinery manufacturing, shipbuilding, ocean development, automotive manufacturing, petrochemical, such as space technology, atomic energy, electricity, electronics, and construction sectors. According to the statistics of the industrial countries, only a year after the welding process used steel accounted for about 45% of the total production of steel.
Welding preparation before work:
1, check the assembly gap and bevel angle. The open groove edge of the weldment object In order to ensure sufficiently the entire thickness of penetration, to form a secure joint welding process applied in the weldment. Correct machining of the groove, which is a necessary condition to ensure the quality of the welding.
Clean up the surface of the groove. In order to ensure the weld quality, welding ago must the groove surface oil, paint, rust and other impurities cleaned, the scope of welds on both sides of each 2030mm must make the groove surface of metallic luster.
3, Welding Rod, flux required to drying, heat; wire need to go to the oil, rust; shielding gas should be kept dry.
4 Select the welding machine and its polarity; provisions of the welding specifications; determine the welding sequence.
5, with the relative positions between the tack welding method of fixing weldment prevent weldment is deformed in the welding process, the welding operation can be normal.
6, in order to prevent weld metal and heat affected zone cracks To weldments preheating slowly and evenly cooling after the welding, the weldment.
7, after assembly, coping joint inspection qualified before welding.
Analysis of the Welding Technology