Abstract
In the field welding with the ordinary CO2 arc welding torch, the limit of wind speed which can be obtained satisfactory welds is considered to about 2 m/sec. Several investigators have examined to increased effect of protective gas shield, but welds obtained with these torchs have such drawbacks as low reliability of mechanical properties and necessity of large flow-rate shielding gas. Authors therefore carried out to fundamental study of automatic CO2 arc welding in field using three type wire brush nozzles which were obtained good results to applied under water wet MIG/CO2 Welding. Observation of condition make raid white smoke wind into the wire brush nozzles and the mechanical tests of welds which are obtained under a artificial condition were carried out and both results were evaluated to lead the conclusions.
(1) The observation of white smoke wind was severe than the mechanical testings of welds to know the effect of the wind.
(2) In CO2 arc welding without the wire brush nozzles, satisfactory welds were not obtained over wind velocity of about 3 m/sec under a flow rate of 25 1/min shielding CO2 gas.
(3) With a medium mesh type wire brush nozzle, satisfactory results were obtained under the same flow rate of shielding gas, even at a wind velocity of about 10 m/sec.
