DUAL-GAS SHIELDING METHOD

摘要

The disclosure of the present applicatîon relates to an improved method of open-arc welding. According to the present method, the outer shield of a double-shield welding system consists of a stream of gas formed in a shield concentric with the inner shield. This method is distinguished by the fact that atmospheric air may be used as the outer shield gas because the outer-shield velocity is so regulated as to prevent the air from being drawn into the weld area. In an alternate embodiment of the same method, the outer-shield gas flow is in a direction opposite that of the inner shield. In this alternate embodiment, in which air is drawn into the welding cup, the velocity at the outer cup is in a range predominantly above the velocity at the inner cup. In the embodiment in which the gas in the outer shield flows in the same direction as that in the inner shield, the outer-shield gas velocity is in a range more nearly approximating the inner-shield gas velocity.