溶接衛生に関する研究 : (その8)周囲気体が低水素系溶接フュームの成分に与える影響

概要

論文の詳細を見る
Welding fumes were generated from several kinds of low hydrogen type electrodes which changed the atmosphere with use of various gases, such air, Ar, CO_2 and N_2, and were collected in water with an impinger. These fumes were analyzed by X-ray refractometry and chemical analysis, and pH of their collecting water was measured. Based on these results, this paper discusses the mechanism of scattering K and Na in fumes from low hydrogen welding which are considered to be the sources of respiratory tract irritation. All sample fumes from low hydrogen welding in several atmospheric conditions contained fluorite (CaF_2). The pH of water in which all sample fumes were collected remarkably elevated. Chemical composition ratios of both K_2O and Na_2O in all sample fumes were larger than those in coating materials. The sample fumes from welding in each of both N_2 and CO_2 atmosphere showed higher ratios of K_2O and Na_2O than those in Ar. The conclusions obtained from the discussion are as follows: The potential gradient of the arc becomes larger during welding in the atmosphere with use of N_2 or CO_2 because the dissociation voltage of N_2 and CO_2 is very low. Furthermore, fluorite (CaF_2) makes the slag more fluid. Then, K and Na become easily dispersed from the arc column of low hydrogen welding.
社団法人日本産業衛生学会の論文
1986-05-20