溶接の高速化は，中大型構造物生産ラインの稼働率向上及び溶接ロボットの投資効果を高める上で，重要な要素技術である．しかし溶接の高速化に伴いアーク現象や溶融池挙動は急激に不安定となり，アンダカット等の溶接欠陥が発生し，従来のすみ肉溶接法では1.5m/min程度が限界である．本研究では，高速化に必要な要因として溶着量の確保，アーク圧力の分散及び溶融金属流れ制御を考え，これを具体化した高速オシレートアーク適用の１プールタンデムすみ肉溶接法を開発した．本溶接法での溶融池挙動を明らかにして，適正溶接条件を見いだし，溶接速度２～2.5m/minの従来にない高速溶接を可能にした．本溶接法は，すみ肉溶接の高速化に有効である．

The welding process is an important manufacturing technique for large steel structures such as ships? Bridges and boilers and recently? Welding automation and improving its efficiency have been vigorously advanced to elevate productivity and improve the working environment? This is particularity true of horizontal fillet welding? Which is a welding process universally applied to all structures? In this paper? In order to improve the performance of horizontal fillet welding? A“one pool-tandem welding process with a high speed oscillating arc”has been developed? In this new process? A bead formation with an equal leg length of 5 mm is made possible without producing undercuts and humping beads even at a welding speed of 2.5 m/min by selecting the optimum welding conditions? This welding process is effective in speeding up horizontal fillet welding?