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Title: The basics of semiautomatic welding

Journal Article · · Welding Journal (Miami); (United States)
OSTI ID:6274520
 [1];  [2]
  1. Esab Group, Florence, SC (United States)
  2. Esab Group, Hanover, PA (United States)

By definition, gas metal arc welding (GMAW) and flux cored arc welding (FCAW) are semiautomatic processes in which a consumable electrode is fed into a weld at a controlled rate, while in most cases a continuous blanket of gas shields the weld zone from contamination by the atmosphere. Semiautomatic welding includes five distinctive techniques or process variations, known as short circuiting, spray transfer, pulsed spray, gas shielded flux cored, and self-shielded flux cored welding. Short circuiting welding operates on generally lower arc voltages and amperages than spray transfer. This process pinpoints the arc heat and produces a small fast-freezing weld pool. The spray transfer process provides an intensely hot, higher voltage arc and high deposition rates. The pulsed spray mode of metal transfer uses two weld current levels: low background and pulse peak. Droplet transfer usually occurs during the pulse peak portion of the cycle. The low current background allows reduced heat input and improved weld pool control. Flux cored welding transfers metal in a manner similar to spray transfer, but with larger droplets. The higher weld currents usable with flux cored welding result in higher deposition rates and deeper penetration. Self-shielded flux cored welding is similar to gas-shielded flux cored welding except that its weld shielding mechanism is self-contained in the wire. As a result, it can be used outdoors with less need for wind breaks.

OSTI ID:
6274520
Journal Information:
Welding Journal (Miami); (United States), Vol. 72:8; ISSN 0043-2296
Country of Publication:
United States
Language:
English