Welding with polar gas shield
Conventional gas shielded welding (GMAW) has evolved over the past few decades and has been used for more than two-thirds of welding tasks. The flexibility, operability and applicability of GMAW in both manual and automatic applications make it a suitable metal bonding process. Polar GMAW process is an efficient welding process developed by German researchers since 2001. It USES a flat electrode with rectangular cross section to replace the conventional GMAW cylindrical wire for welding, and its welding speed and deposition efficiency are close to that of double wire welding.
Working principle of GMAW with pole
The technological conditions of polar GMAW are basically the same as those of traditional GMAW. Typical strip wire is 4mm 0.5mm, which is roughly the same as the cross-sectional area of common wire with a diameter of 1.6mm. The difference is that the girth is 9mm, compared to 5mm for a regular wire, which increases the surface area of the wire by about 45%.
Due to the so-called skin effect, the current is concentrated in the thin layer on the outside of the wire; The closer to the wire surface, the higher the current density, and the smaller the actual current inside the wire. As the surface area of the wire increases, more current can be transmitted with less resistance, which helps to speed up welding by changing the shape of the wire.
In polar GMAW, an arc covers the entire width and completely fuses along that width. Depending on the orientation of the strip wire and the weld, it may produce a wide shallow pool or a narrow deep pool. When the strip welding wire is perpendicular to the direction of welding seam, a wide and shallow weld pool can be obtained, and the gap has strong caulking ability, which greatly reduces the assembly requirements of welding parts, especially suitable for high-speed thin plate welding. When the strip wire is parallel to the direction of the weld, a narrow and deep weld pool is produced, which can improve the welding speed and depth. Different welding pool can be produced by changing the direction of strip welding wire and welding seam.
A foreign company has produced commercial MAG welding system, including special power supply, welding gun and wire feeding system. Due to the large welding current of polar MAG welding and the high thermal stress in the welding process, the gas nozzle of the welding gun should be directly cooled by circulating water, as shown in FIG. 2.
Fill material and shielding gas
Strip wire is usually rolled from round wire. This technology makes the sharp edges of the wire round and helps to increase the service life of the special-shaped contact tip and the guide wire hose. The shielding gas is the same as that of ordinary wire.
The practical application
Typical applications of GMAW include construction machinery, steel structure engineering, pressure vessels, vehicles and ship construction. The technology is used for continuous, automated welding of semi-finished products such as pipes, profiles and steel bars, as well as for the manufacture of parts such as axles, body parts and rims.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods