TIG 필러와이어의 아크쪽 비표면적이 용융효율과 입열량에 미치는 영향

Abstract

TIG welding has an advantage of securing excellent welding quality in most of materials. Though it is widely used in modern industries, there is a problem of relatively low weld productivity. It is necessary to increase current and welding rate in order to increase productivity of TIG welding, but use of large current causes severe pressing of molten pool surface due to strong arc force. Welding defects such as undercut, humping bead, and separated bead occur to bring limitation in application of high rate welding. There had been many previous attempts to increase productivity of TIG welding such as use of stranded wire made of narrow wires under 0.2mm diameter and supply of filling materials to molten pool after heating to melting point. However, fundamental problem is that the cross section of wire is round. S. M. Cho et al. announced that melting efficiency of deposition metal can be increased by enlarging specific surface area of arc against filler volume. Accordingly, a strip with rectangular cross section was made to obtain high melting efficiency of deposition metal. In this study, weldability and deposition metal melting efficiency of 3.3 x 1.6 rectangular strip with identical cross sectional area as existing Ø2.6 round wire were comparatively reviewed. Heat input per 1g of deposition metal for each strip with identical cross sectional area was compared while increasing specific surface area of arc.