新シヨッププライマーのガス切断および溶接に与える影響

Abstract

There are two kinds of primer, wash primer for long term exposure and zincrich primer for steel structures including ships and bridges. Protection presents difficulties, for example, rusting in the former; and in the latter when gas cutting and welding operatings are applied, poisonous fume is emitted from the primer. In order to deal with this problem anew primer has been developed which gives a better protec-tion than the wash primer against rusting and to a lesser degree suffers the effects of welding and gas cutting than the zinc-rich primer. However, the effectiveness of the primver must be considered from the following point of view 1) gas cutting 2) shielded arc welding 3) submerged arc welding and 4) stud weldingThese operations are performed frequently in shipbuilding as well as in fabricatin of other steel structures.The purpose of this study has been to ascertain experimentally the effectiveness of the newly developed primer taking into consideration the above four points. Thrungh experimentation the following properties could be immediately ascertained.1) Less poisonous fume of welding and gas cutting on the primer.2) Minor effects of gas cutting and welding.3) Obviously better than wash primer in submerged arc welding and stud weldiing. Effects of the composition in the primver welding and gas cutting were larger in the following order:Zinc dust< Alumimum powder< Red Iron Oxide= Zinc Chromate