The difference between ERW and EFW

ERW is the acronym of resistance welding. The welding method of ERW welded pipe is obviously different from that of submerged arc welded pipe. The unfilled metal is used for pressure welding, and other components are not filled in the weld. The skin effect and proximity effect of high-frequency current make the instantaneous plate edge heated to the welding temperature, which is extruded by the extrusion roller to form the weld. High quality steel pipe needs online or offline heat treatment on the weld line and refining the weld area. The weld of ERW welded pipe with high quality can reach the same toughness level as the base metal, which is an achievement that can not be achieved by submerged arc welding process. EFW is the first letter of saw - electric welding (EFW). It is through the combination process of one or more consumable electrodes and the metal heating the workpiece to the metal between the metal, the metal arc and the filler material are completely melted, without pressure, and all the hard metal parts are filled from the electrode. GMAW - electric fusion welding (EFW), similar to submerged arc welding, differs in that it is protected by inert gas and works better. Spiral welding - this is also a submerged arc welding, with spiral welding.