Observation of the electric arc behaviour in VAR
Résumé
This study investigates, at different scales, the electric arc during Vacuum Arc Remelting of metallic alloys. First observations – very short timescale – were obtained in a specifically instrumented industrial furnace using high speed framing camera and optical emission spectroscopy, during the remelting of Ti alloys. Also, the interactions between the arc and the transfer of metal drops in the interelectrode gap were investigated. A second set of experiments – large timescale – consisted in characterizing the dynamics of the arc during actual heats under various operating conditions. Measurements of the luminosity recorded during actual Zr or Ni-based remeltings indicate that a periodic asymmetric behaviour takes place. The influence of such a behaviour on the electrode melting and ingot growing processes was simulated and some results are presented and discussed.
Domaines
Sciences de l'ingénieur [physics]
Origine : Fichiers produits par l'(les) auteur(s)