Abstract
The CO2 gas shielded arc welding in welding of the steel is, recentry, being put to practical use. This welding method has some merits and demerits, compared with the other. A demerit of this method is the fact that it tend to produce large amounts of spatter.
We observed the process of metal transference by the high speed motion pictures, and studied on the causes of spatter, then we investigated the ways to eliminate spatter.
The results obtained are as follows:-
(1) The substantial large liquidity of DS-1 electrode wire is a cause for pormoting the spatter. (2) The metal transference is globular type due to the high pressure of gas generated where the carbon dioxide dissociates in the arc colum or its surroundings in the high temperature. At that time, the small particles are apt to be ejected either from the transfering globule or from the molten parts of the electrode tip at the instant when the molten droplet of metal detaches the electrode tip.
(3) If the arc is maintained so short that the electrede tip is inserted into the crater of molten pool of the work but it does not touch the work, the amount of spatter is minimized.
(4) The current density of the electrode should be large then the spatter will be decreased be-cause the molten droplet of metal cannot remain long at the electrode tip by the strong electro-magnetic pinch force and it cannot grow large.
