HIGH SPEED GAS CHAMBER TYPE GAS SHIELD ARC WELDING METHOD AND HIGH-SPEED GAS INJECTION NOZZLE

摘要

PROBLEM TO BE SOLVED: To provide high reliability gas shield and windsbreaking for an arc column part and a welding metal part simultaneously in a gas shield arc welding, concerning the gas shield arc welding method and a high-speed injection nozzle capable of obtaining a sound welding quality by intercepting penetration of the atmosphere into a molten metal under welding in TIG welding, GMA welding, etc. SOLUTION: A compressed air 10 is injected from an almost 0.2-0.5 mm narrow gas discharge port 12 of a high speed gas injection nozzle 9, which is disposed at the position separated from a welding base metal 13, and provided integrally with or independently from a welding torch so as to shield the periphery of a welding part under welding entirely or locally to form a thin-layered and high-speed air curtain 11. The position of the high-speed gas injection nozzle 9 sets up the optimal air discharge angle and the standoff distance such that the shield for the molten metal is not inhibited by direct penetration of the air into the shield gas area 6.