For the joining of the 316LN stainless steel Vacuum Vessel sectors, the Narrow Gap TIG Welding process is the present reference, representing a low industrial capability with 0,6 kG/h mass deposition rate and welding travel speed in the range of  0,1 m/min and requiring a highly trained team of welders.
An alternate process has been developed for enhancing this performance, while conforming to the required RCCM-R code requirements: Hybrid welding, which combines the MIG/MAG process and the laser process with the potential for high quality of welds and high productivity rate: 6 kG/h mass deposition rate and welding travel speed in the range of more than 1 m/min. Due to this combination, the hybrid process has to deal with several major operating parameters corresponding to the respective processes (power, welding speed, wire speed, focus) plus the relative location of each source. It requires low qualification level welders and this process is fully automatic (robotic carrier, in line controller, repair sequences).
Results, performances, relevant scale level are discussed for application to ITER manufacturing. The potential mismatch and positioning defects will be analysed, including NDT possibilities. Conclusions will clarify the opportunities for use. Application fields are discussed, adhering to the ITER schedule.

Présentation par Philippe Aubert / CEA et Fabrice Scandella / INSTITUT DE SOUDURE