抄録
A CO2-O2 arc-welding process, in which a new gas-shielded metal-arc welding processis, employed, invented by Prof. H. Sekiguchi has come to be applied for practical purposes. Experiments in a small cabin were made to analyse the atomospheric condition by using this welding process. The results of this method were compared with that of the manual welding with covered electrodes. They are summerized as follows. 1) Temperature rising and decrease of humidity were more remarkable in comparison with the welding with covered electrodes. 2) Carbon dioxide increase seen in this method was not so great, though it was much more than on the welding with covered electrodes. This seems to come about by natural ventilation caused by the effect of rising temperature. 3) Carbon monoxide increase was not very much, but it is more than by the other welding process. 4) The production of ultra violet radiation was less than in the case of other welding. 5) The production of ozone and nitrogen dioxide were so slight that they would not cause the poisoning. 6) Quantity of dust produced was consider-ablly large, but less than in the case of the welding with covered electrodes. In using CO2-O2 arc-welding process in a small room, one must pay attention to good ventilation of the room, but as this welding process is usually used in a large room with good natural ventilation, there are very few hygienic problems with regard to this welding process.
