INVESTIGATION INTO THE EFFECT OF PULSED GAS GMAW ON FILLET WELDS

摘要

Alternating shielding gas GMAW is a new technology that supplies two different shielding gases viz. Argon and CO{sub}2 in the weld zone alternatively instead of the current method of using premixed shielding gas. The goal of this new gas pulsing method is to create a superior method of protection for the molten weld pool. This new technology is found to give better weld quality and higher efficiency. The improved weld quality is attributed to the periodically varying weld-pool dynamics caused by the alternating shielding gases. Argon and CO{sub}2 have been used as the alternating shielding gases for the study on carbon steel. ARCWISE method, which involves depositing a series of welds of constant volume at a constant arc length over a range of welding parameters, has been made use of to select the optimum welding conditions that maximizes welding productivity and weld quality. Alternating shielding gas or Pulsed Gas GMA welding is found to produce fillet welds of quality matching or even better than that of GMA welding with 80%Argon+20% CO{sub}2 premixed gas. The argon gas consumption is also reduced by 30% in pulsed gas GMAW.