Abstract
The carbon dioxide gas dissociates, 2CO2_??_2CO+O2, and possesses oxidizing effect on the molten metal at high temperature. Therefore it was supposed that the filler wire used by our now welding process, described fully in report 1, has to contain much deoxidizers to gain a sound weld free from porosity.
This is a report on preliminary research to take aim at these proper contents of deoxidizers in filler wire. And it was recognized that if a filler metal or a base metal contains proper contents of deoxidizers, the carbon dioxide gas shielded metal-arc welding of steels gives a excellent weld free from porosity. Manganese, silicon, titanium and aluminum are useful as such deoxidizers. Moreover silicon and titanium are effective to improve the appearance of bead.
Contents of the diffusible hydrogen contained in joints by carbon dioxide gas shielded metal-arc welding are very small compared with those of joints obtained by coated electrodes.
