Characterization of the behaviour of the electric arc during VAR of a Ti alloy

International Symposium on Liquid Metal Processing & Casting 2015

材料科学;金属工艺学

Chapelle, P.^1 ; Noël, C.^1 ; Risacher, A.^1 ; Jourdan, J.^1 ; Jourdan, J.^2 ; Jardy, A.^1

Institut Jean Lamour - UMR 7198 CNRS, Université de Lorraine, Laboratory of Excellence DAMAS, Nancy Cedex

54011, France^1

Timet Savoie, Avenue Paul Girod, Ugine

73400, France^2

关键词: Arc structures;    Direct observations;    High speed framing cameras;    Interelectrode gaps;    Interelectrode plasma;    Liquid metal drops;    Operating regimes;    Vacuum arc remelting;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/143/1/012011/pdf
DOI  :  10.1088/1757-899X/143/1/012011

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

In this paper, we report experimental results based on the direct observation of the electric arc behaviour during vacuum arc remelting of a Ti alloy. These results were obtained in a specifically instrumented industrial furnace using high speed framing camera and optical emission spectroscopy, for a current density level of the order of 10 A/cm2and a gap length of a few centimetres. It was observed that the arc exhibits a similar operating regime to that described in the literature for the case of Inconel 718 and Zr alloy electrodes. The arc structure corresponds essentially to that of a diffuse metal vapor arc with separate and rapidly moving cathode spots. Several critical parameters of the cathode spots, including their current, size and velocity, and of the interelectrode plasma were evaluated. Also, the interactions between the arc operation and the transfer of metal drops in the interelectrode gap were investigated. Three modes of transfer of the liquid metal drops in the interelectrode gap have been identified depending on the gap length: drop falling, drip short and drop erosion induced by the cathode spots.