電子ビーム溶接におけるハンピングビード形成現象(第1報)
ビーム焦点位置の影響
1982 年 51 巻 3 号 p. 286-291
詳細
1982 年 51 巻 3 号 p. 286-291
The mechanism of humping bead formation in electron beam welding was investigated. In the first part, the process of humping bead formation was clarified by high-speed cine-camera. In the second, the effect of focal position was discussed. The obtained results were as follows.
1) Humping bead was apt to be formed when the focal point was just on or slightly below the weld surface.
2) The reduction of surface bead width was apt to form the humping bead and reduce the pitch of humping bead formation.
3) The formation of nailhead-shaped welds at the focal position above the weld surface prevented to form the humping bead.
4) Nailhead-shaped welds were due to the melting by molten metal flow around the side walls, and to the melting or pre-heating effects by peripheral regions of gaussian distribution type electron beam.
5) The instability of capillary molten metal at the weld surface formed the humping bead.
