| 摘要 |
PURPOSE:To perform preheating and melting of a weld zone continuously and to form a deposited part of high quality free from blowholes in a TIG welding method using two pieces of non-consumable electrodes by setting the distance between two pieces of electrodes adequately. CONSTITUTION:To weld a base metals 19 to be welded with a torch nozzle 20 provided with two pieces of non-consumable electrodes 13A, 13B made of tungsten, the distance between both electrodes 13A and 13B is set at 5-15mm.. The weld zone of the base metal 19 is preheated with the arc 18A of the preceding side electrode 13A, following to which the preheating part is melted with the arc 18B of the succeeding side electrode 13B, whereby a deposited part 21 is formed. Since the distance between both electrodes is adequate, the inflow of the combustion gas produced during preheating into the shielding gas around the electrode 13B and consequent formation of blowholes in the part 21 are obviated, and the part 21 of superior quality without degradation in preheating effect is obtained. |
