High speed resistance seam welding of uncoated and coated steels
A comparison is made of conventional wide seam welding with narrow wheel and wire seam welding techniques, using either an AC or DC secondary current and a range of uncoated and coated mild steels. Results indicate welding speeds up to 16m/min can be attained with narrow seam and mash welding of uncoated steels. As the welding speed increases, the available current range between weld formation and weld splash decreases, decreasing the available range for satisfactory welding: The maximum speed depends on the welding conditions, steel thickness and the type of seam welding process used. A basic model of weld formation is developed showing that weld growth is governed by the distribution of resistance in the weld zone and corresponding variation in current density in this zone. Increased welding speed is achieved by use of increased electrode force levels and/or use of larger diameter electrodes, and improved cooling of the welding seam surface by more efficient water cooling and/or electrode extension system. The use of a two stage process of a low heat weld to initiate bonding followed by a high heat stage ensures acceptable weld quality.
Bibliographic Reference: EUR 11550 EN (1988)
Record Number: 198910029 / Last updated on: 1994-12-01
Original language: en
Available languages: en