Analysis of Welding Phenomena and Effect of Short Circuit Current Rise Slope in the High Speed $CO_2$ Welding of Steel Sheets

$CO_2$박판 고속용접에서 용접현상 분석과 전류상승기울기의 영향

  • Kim, Young-Sam (Advanced Welding & Joining Technology Team, KITECH) ;
  • Ryoo, Hoi-Soo (Advanced Welding & Joining Technology Team, KITECH) ;
  • Kim, Hee-Jin (Advanced Welding & Joining Technology Team, KITECH)
  • Published : 2005.10.01

Abstract

In high speed $CO_2$ welding, it has been blown to produce no sound bead with undercut or humping bead. In this study welding phenomena through synchronized high speed camera and output welding voltage and current waveform has been analyzed. For the purpose to improve a welding bead, effect of short circuit current rise slope has been examined. With commercial power source it was produced no sound bead by instantaneous short circuit, long arc period and stubbing at welding speed 2.5mm/min Humping bead or undercut were showed by instantaneous short circuit and long arc period. Also, the weld bead was not formed during the long short circuit period after stubbing start and long arc extinguishment period after wire sticking by failure of arc regeneration, because the droplet was not transferred to weld pool. With increasing short circuit current rise slope the frequency of stubbing was decreased and the normal short circuit rate was increased. A control of short circuit current rise slope was effective factor in high speed welding.

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