The difference between ERW and EFW

ERW is the first letter of resistance welding Electric resistance welding abbreviation ERW pipe and submerged arc welding pipe welding methods are significantly different, the use of unfilled metal pressure welding, the weld is not filled with other components, by high-frequency current The skin effect and the proximity effect, so that the instant plate edge heated to the welding temperature, squeezed by the extrusion roller forging the formation of the weld. High-quality steel pipe requires weld line on-line or off-line heat treatment, the weld zone refinement, high-quality ERW welded pipe weld can reach the same level of toughness with the base metal, which is submerged arc welding process can not be achieved. EFW is the first letter of electric fusion welding SAW - electric welding (EFW), is through one or more consumable electrodes and the workpiece is heated to the metal between the metal Between the combination of a process, the arc of the metal and filler material to fully melt, do not need to pressure, fill the metal part of all hard work from the electrode. GMAW - A type of electric fusion welding (EFW) that is similar to submerged arc welding except that it is protected by an inert gas and works better. Spiral welding --- This is also a kind of submerged arc welding, with a spiral weld.