Ads
related to: low frequency resistance welding
Search results
Results From The WOW.Com Content Network
Low-frequency electric resistance weld, LF-ERW is Electric resistance welded (ERW) pipe manufactured by cold-forming a sheet of steel into a cylindrical shape. Current is then passed between the two edges of the steel to heat the steel to a point at which the edges are forced together to form a bond without the use of welding filler material.
Low-frequency electric resistance welding (LF-ERW) is an obsolete method of welding seams in oil and gas pipelines.It was phased out in the 1970s but as of 2015 some pipelines built with this method remained in service.
Iron rods work well for direct-current (DC) welding but it is difficult to use them at frequencies much higher than 60 Hz. At a few kilohertz, an iron welding rod would glow red hot as current flows through the greatly increased AC resistance resulting from skin effect, with relatively little power remaining for the arc itself.
This is a list of welding processes, separated into their respective categories. The associated N reference numbers (second column) are specified in ISO 4063 (in the European Union published as EN ISO 4063 ). [ 1 ]
Competing welding processes such as resistance welding and oxyfuel welding were developed during this time as well; [32] but both, especially the latter, faced stiff competition from arc welding especially after metal coverings (known as flux) for the electrode, to stabilize the arc and shield the base material from impurities, continued to be ...
Laser welding; Thermite; Induction. Low frequency (50–450 Hz) High frequency (induction resistance; 200–450 kHz) Others Heated metal plate; Solvent; Dielectric;