GB912422A - Improvements in or relating to electrodes for cleaning weld seams - Google Patents

Abstract

912,422. Arc heating electrodes. SOC. LE CARBONE-LORRAINE. May 19, 1959 [May 21, 1958], No. 16968/59. Drawings to Specification. Class 39 (3). [Also in Group XXII] An arcing electrode for cleaning weld seams comprises a carbon base member having an even number of longitudinal bores symmetrically arranged on either side of a longitudinal median plane and each containing a mixture of from 20 to 50% siliceous and/or alkaline materials and 80 to 50% carbonaceous materials and a binding agent, e.g. of 18% silicon, 12% potassium carbonate and 70% carbon. The base member may consist of 10% amorphous carbon, 30% coke and 60% artificial graphite and may have a rectangular, oval or trapeziumshaped cross-section, the bores being located on the major axis of the rectangle or oval and adjacent the non-parallel edges of the trapezium. The constituent materials of the carbon base member may be bound by tar or resin and the extruded electrode may be baked at high temperature and subsequently graphited before the components of the paste in a suitable binder are injected into the longitudinal bores. The electrode may be coated with silica or silico-alkaline or silico-metallic compounds to render it more resistant to oxidation and may also be coated with a metal, e.g. copper, to ensure good electric connection and metal-carbon heat transfer. The surface of the electrode may be grooved.