高速度写真によるMIG熔接現象に関する研究(第1報)

Abstract

We have investigated phenomena of the argon gas metal arc welding of aluminum by the high speed motion pictures.We have photographed the welding arc by the method similar to that of Dr. T. Okamoto and Dr. K. Ando, that is, we have photographed the welding arc as a shade, made by lightening of an intense carbon arc from the backside.In the clear pictures obtained, some effect of current density, wire speed, welding speed, and characteristics of the welder upon the phenomena are remarked.The results obtained are as follows:(1) The comparatively large particles and compararively small particles of molten metal transfer, one by one, from the wire tip to the base metal. Then particles more than one do not transfer at a time.The small particles are made in some circumstances at separation of the large particles from the molten parts of wire tip.(2) In the drooping characteristics of the welder, the size of particles is scarcely affected by current density in the region of our experiment. But in the rising characteristics, it tends to be smaller than in the droopng characteristics.(3) As a matter of course, the speed of growth of particles become large as the current density is large, and accordingly, times of the transference of particles increase.(4) Although the current density is large, there are scarcely the chance of short circuit and arc is peaceful when the gap between the wire tip and the base metal is long and the welding speed is proper.If the gap is short or the welding speed is too fast, arc, molten pool of the base metal and molten parts of the wire tip are agitated violently, and the spattering of small particles repeats frequently.In the rising characteristics, the agitation of arc, molten pool, molten parts seems to be stronger than in the drooping characteristics.