CO2, arc welding: An efficient and practical welding technology

CO2, arc welding: An efficient and practical welding technology
CO2, arc welding (also known as carbon dioxide gas shielded welding) is a fusion welding process that uses CO2 gas as the protective medium and the heat of the electric arc to melt the welding wire and the base material. With features such as low cost, high efficiency and wide applicability, it has become one of the mainstream welding methods in fields such as steel structures, ships, vehicles and construction machinery, especially occupying an important position in the welding of medium and heavy carbon steel plates
Basic principle
Arc welding under gas protection, CO2, the core of arc welding is to generate high temperature (up to 5000-6000 ° C) through arc discharge, which melts the end of the welding wire and the base material to form a molten pool. At the same time, CO2 gas is used to isolate the air to prevent the oxidation of the molten pool metal. Its working principle can be divided into three key links
Arc formation
The welding machine outputs direct current (usually in reverse polarity connection, that is, the welding wire is connected to the positive terminal and the workpiece to the negative terminal). After the welding wire, as an electrode, comes into contact with the workpiece and short-circuits to start the arc, or directly starts the arc through high-frequency pulses. The high temperature of the arc melts the end of the welding wire, forming droplets that transition into the molten pool.
Gas protection
CO2 with a purity of ≥99.5% is ejected from the nozzle of the welding torch, forming a protective layer around the arc to isolate harmful gases such as oxygen and hydrogen in the air. If these gases invade the molten pool, they will cause metal oxidation (generating oxides such as FeO) and hydrogenation (forming pores), thereby reducing the mechanical properties of the weld seam.
Wire transfer
The welding wire is fed into the molten pool at a constant speed through the wire feeding mechanism (such as the wire pushing type or the wire drawing type). The molten welding wire metal fuses with the base metal and forms a dense weld seam after cooling.
The welded boom produced by Tai 'an Xutai Machinery Co., Ltd. is mainly used for carbon dioxide gas shielded welding, and the welded boom is used
Realize continuous welding