The University of Osaka · 공학
Shinichi Tashiro 교수의 연구실은 아크 용접 공정에서 발생하는 금속 연마물(흄) 형성 메커니즘과 아크 플라즈마의 물리적 특성 변화를 수치 해석과 실험을 융합하여 연구합니다. 주로 TIG 및 GMAW 용접에서 금속 증기의 영향이 아크의 열 흐름, 전류 밀도 분포 및 금속 이송 거동에 미치는 영향을 분석하며, 고온·고속 조건에서의 플라즈마 거동을 CFD 및 자기유체역학 모델을 활용해 정량적으로 규명하고자 합니다. 특히, 용접 품질 향상과 안전성 확보를 위한 기초 과학적 이해를 목표로 합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
In order to clarify the fume formation mechanism in arc welding, a quantitative investigation based on the knowledge of interaction among the electrode, arc and weld pool is indispensable. A fume formation model consisting of a heterogeneous condensation model, a homogeneous nucleation model and a coagulation model has been developed and coupled with the GTA or GMA welding model. A series of processes from evaporation of metal vapour to fume formation from the metal vapour was totally investigat
The energy source characteristics of gas tungsten arc (GTA) strongly depend on the physical property of arc plasma. In welding processes, it has been experimentally confirmed that metal vapour evaporated from a high temperature weld pool drastically changes the property of arc plasma and decreases its temperature. However, the effect of metal vapour on the characteristics of heat flux into a base metal is still not clear owing to the difficulty in experimental studies of arc plasma. In the prese
Abstract The metal transfer behavior is one of the most pivotal links of gas metal arc welding (GMAW) for improving the welding quality. Arc impacts the current path and heat input on the droplet surface, in reverse, the metal droplet detachment makes the arc to flicker. It is hard to make the metal transfer process clear with only experimental methods since the limited measuring space and high temperature in the welding region. In this work, with the help of computational fluid dynamics softwar
The effect of flux ratio on metal transfer behavior during metal-cored arc welding was elucidated through investigation using a standard solid wire and three metal-cored wires with flux mass ratios of (2-2) 10%, 15%, and 20%. Investigation was performed using a shadowgraph technique based on images recorded with a high-speed camera equipped with back-laser illumination. We observed that the droplet transfer frequency increased with both the welding current and flux ratio, with the effect of flux
Energy source properties of electric arcs strongly depend on physical properties of the arc plasma. In a welding process, it has been experimentally confirmed that an admixture of metal vapor diffused from a high temperature weld pool drastically changes the properties of arc plasma and lowers its temperature. However, the effect of the admixture on heat input characteristics to a base metal is not clear due to the difficulty of the experimental study. In this paper, energy source properties of
