| 摘要 |
PURPOSE:To prevent discoloration by the effect of the heat generated in the outside surface of a weld zone by shielding the periphery of the weld zone from the atm. in a non-oxidative gas and performing spot welding in said gaseous atmosphere. CONSTITUTION:A blow port 5 for prescribed inert gas or non-oxidative gas 4 is provided near an electrode rod 1 and said gas is ejected therefrom. The gas 4 is otherwise ejected into a toric shape from the periphery of the rod 1. The periphery in the weld zone is covered with a case 6 and the gas 4 is filled therein. Inert gas such as gaseous argon, gaseous helium or a gaseous mixture added with a small amt. of gaseous carbon dioxide to gaseous nitrogen or gaseous argon is used for the inert or non-oxidative gas to be used in this stage.
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