Differences between ERW and EFW

ERW is the first letter of the abbreviation for Electric resistance welding.

ERW pipe and submerged fox welded pipe welding method is significantly different, using no filler metal pressure welding method, the weld is not filled with other components, relying on the high-frequency current skin effect and proximity effect, so that the plate edge is instantly heated to the welding, the temperature, by the extrusion of the silver extrusion to form the forging organization of the weld. High-quality steel pipe requires the use of weld on-line or off-line heat treatment, so that the weld zone organization refinement, high-quality ERW welded pipe weld can reach the same toughness level with the base material, which is buried fox welding process can not be achieved.

EFW that is, Electric fusion welding Electric fusion welding of the first letter of the acronym

Submerged arc welding (SAW) is a kind of electric fusion welding (EFW), is through one or several self-consumption electrodes and workpieces between the metal heating between the metal in the combination of a process, the arc so that the metal and filler material is fully melted, do not need to be pressurized, the filler metal all from the electrode.

Gas Melt Welding (GMAW) -electric fusion welding (EFW), this process is similar to submerged fox welding, but its protection is from the inert gas, the effect will be better.

Spiral Welding - This is also a type of submerged arc welding with a spiral weld seam.