Product Code: ICAL07_606

Laser-Arc Hybrid Welding for the Cover Plate of ITER TF Coil
Authors:
Katsunori Shiihara, Toshiba Corporation; Yokohama Japan
Y. Makino, Toshiba Corporation; Yokohama Japan
T. Ogawa, Toshiba Corporation; Yokohama Japan
S. Asai, Toshiba Corporation; Yokohama Japan
T. Kanahara, Toshiba Corporation; Yokohama Japan
I. Senda, Toshiba Corporation; Yokohama Japan
K. Okuno, Japan Atomic Energy Agency; Ibaraki Japan
N. Koizumi, Japan Atomic Energy Agency; Ibaraki Japan
K. Matsui, Japan Atomic Energy Agency; Ibaraki Japan
Presented at ICALEO 2007

A laser-arc hybrid welding combining the laser beam and arc is used as the process of high efficiency manufacturing in the heavy industrial fields. Especially, it is important to have wide tolerance for gap of weld groove. On the other hand, ITER TF Coil is on large scale and we must set superconductive insulator under 200 degrees during welding, and so it is necessary to have low heat input and less deformation welding. Therefore Toshiba has been developing the laser-arc hybrid welding combining the 5kW fiber laser and the converged TIG arc for the cover plate with twin beam. The twin beam welding head can irradiate the laser beam divided by the half mirror on both grooves of a cover plate. TF coil model to scale of 1/8 was welded using the welding head, and it checked that good welding could be performed to gap width of 0.8mm by welding speed 1200 mm/min. Subsequently, it was confirmed that the laser-arc hybrid welding were so effective as manufacturing process of ITER TF Coil, after controlling the good welding conditions of laser and arc parameters.