GB774866A - Gas shielded arc cutting - Google Patents

Abstract

774,866. Cutting by fusion. AIR REDUCTION CO., Inc. Nov. 15, 1955 [Nov. 15, 1954], No. 32681/55. Class 83 (4). A method of cutting metals by a gas shielded electric arc comprises supplying to the arc a substance comprising a metal selected from the group consisting of: the alkali metals (lithium, sodium, potassium, rubidium, cesium, francium); the alkaline earth metals (calcium, barium, strontium, radium); lanthanum and the lanthanum series rare earth metals (cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutecium); actinium and the actinium series rare earth metals (thorium, protactinium, uranium, neptunium, plutonium, americium, curium); scandium and yttrium. The substance may be added to the electrode of to the shielding gas, as described in Specifications 731,836 and 738,284, and may be in elemental or metallic form or as compounds such as oxides, carbonates, borates, phosphates, nitrates, silicates or halides. Mixtures of two or more elements and/or their compounds may be used. Specific examples of the compounds used are cesium nitrate, rubidium carbonate, cesiumrubidium chloride, barium oxide or carbonate, barium-strontium mixtures in the form of oxides or carbonates, potassium carbonate. For cutting a plate 11, the electrode 14 is fed to a cutting head 13, supported on a motorized carriage 12, from a supply reel 19. The arc current which may be alternating or straight polarity direct current, is supplied from a welding machine 21 and the shielding gas, preferably argon, which may contain minor amounts of active gases, is fed from a cylinder 24 through valve 26, pressure regulator 27, flow meter 28 and flexible tube 29. During cutting the end of the electrode is maintained in the kerf whereby the molten metal projected from the end of the electrode will fall clear of the kerf. A ferrous electrode wire is used for cutting copper or aluminium base workpieces.