Inert gas-shielded arc welding torch with water-cooled non-consumable electrode and method of welding therewith

摘要

769,879. Welding by fusion. UNION CARBIDE & CARBON CORPORATION. June 20, 1955 [Aug. 9, 1954; Sept. 27, 1954], No. 17828/55. Class 83 (4). [Also in Group XI] In order to minimize electrode wear in gasshielded arc welding using alternating current or reverse polarity direct current, cooling fluid is passed through a passage extending within the electrode to the vicinity of the arcing tip. The electrode may be of copper or an alloy thereof and the arcing tip may be of the same material or gold or silver or an alloy thereof or tungsten. Shielding gas constituents may be argon, helium, oxygen, carbon dioxide, nitrogen and additives such as silicon tetrachloride. Aluminium, steel, stainless steel and copper containing 3 per cent silicon are examples of workpieces. Mild steel and aluminium were welded using a shielding gas containing 93.1 per cent argon, 4.9 per cent oxygen and 2 per cent nitrogen. To weld aluminium, argon containing 0.1-5 per cent (preferably 0.1-0.4 per cent) oxygen was used. Other shielding gases referred to are argon, helium, carbon dioxide and mixtures of argon with 5 per cent or 50 per cent carbon dioxide, argon with 50 per cent helium and 5 per cent oxygen and argon with helium and carbon dioxide. A welding torch consists of a hollow body B into which is threaded a copper tube E. A hollow conical copper arcing tip 40 is threaded into the lower end of the tube E and is surrounded by a watercooled gas nozzle N secured to the lower end of the body B. Shielding gas is passed through grooves 22 in the body B to the nozzle N. A further tube 38 extending through the tube 36 serves to convey cooling water to the hollow tip 40. The cooling water outlet 14 communicates with the hollow tip via the space between the tubes 36 and 38. In a modification, the electrode is formed as a welded unit consisting of concentric copper tubes and a copper or tungsten arcing tip welded thereto.