GB791347A - Improvements in or relating to electric arc welding - Google Patents

Abstract

791,347. Welding by fusion; making electrodes; bending. BRITISH OXYGEN CO., Ltd. June 6,1956 [June 13, 1955], No. 17022/55. Classes 83 (2) and 83 (4). In gas shielded arc welding of a ferrous workpiece using a consumable-ferrous electrode, the shielding gas contains 80-100 per cent carbon dioxide and powdered deoxidants: are fed to the arc. The powdered deoxidants may be contained in a tubular electrode or may be fed from a hopper positioned ahead of the arc. The powder may include fluxes, binders, arc stabilizing agents and alloying agents. A specified powder composition is 0-20 per cent rutile, 1-6 per cent, manganese or ferromanganese, 1-3 per cent silicon or ferro-silicon, 0-2 per cent aluminium, 0-2 per cent titanium, 0-2 per cent zirconium and 65-95 per cent iron. For welding with alternating current, the powder may also contain 0.2-2 per cent mischmetal or 1-2 per cent zirconia. Other possible constituents are alkaline earth and rare earth metals and metal oxides, such as cerium lanthanum, barium and strontium, thorium, thoria, nickel, chromium, molybdenum, vanadium, mobium and ferro tetraium. The shielding gas may be carbon dioxide with 5-10 per cent oxygen or any mixture of carbon dioxide with up to 50 per cent of argon, helium or oxygen. The electrode is of soft iron or mild steel strip or wire. Where the powder is contained in the electrode the electrode is made by forming a groove in the strip, depositing the powder from a hopper and closing the strip by rolling: Alternatively the electrode is made from two strips 23, 20a, Fig. 2, by shaping by rolls 25, 22, respectively, to the grooved and flanged forms shown in Fig. 3, filling the groove formed in the strip 20a with powder from a hopper 13 and bringing the strips together between rolls 27 which bend the flanges of the strip 23 over the edges of the strip 20a as shown in Fig. 4.