溶接母材表面の仕上げに関する研究 １ ブラシ掛けによる研磨力と研磨痕の検討

Abstract

In the arc welding, spatters are frequently bonded to the surface of base metal. Therefore, to keep the quality of the weld products, the weld metal surfaces were usually brushed with bevel type or cup type wire brushes. Since the spatters cannot be removed completely under a certain brushing condition, it is very important how to finish the surface of base metal.This study tries to show the brushing conditions under which spatters can be removed completely. As the first step to find the proper condition, we made a brushing apparatus that can control the pushing force of the wire brush, and measured the force (we call it the brushing force) in the steel plate. The brushing force is determined by the two forces. One (Fy) is from the direction of brushing and the other (Fx) is perpendicular to the brush.In brushing the metal, the pushing force was set at 9.8 N, 19.6 N, or 29.4 N and the angle of the brush and workpiece was 15, 20, 25 or 30 degrees. The metals we used were two types of SS400. One had the scale and the other had no scale, which had been removed by the surface grinder.When the steel plate is brushed, various kinds of brushed traces appeared on its surface. The brushed traces were examined through a metallographical microscope and we showed the relations between the brushed traces and the brushing conditions. We also examined the brushing force when a tiny part of the surface (8.04 mm2 in size) was brushed (we call it the local brushing force), so that we could show the relations between the brushed traces and local brushing forces.