| 20090236320 | METHOD FOR TANDEM GAS METAL ARC WELDING, AND WELDING TORCH AND WELDING APPARATUS USED THEREFOR - The present invention provides a method for tandem gas metal arc welding using a leading electrode and a trailing electrode, wherein a shielding gas for the leading electrode is a two-component mixed gas containing argon and carbon dioxide, or a three-component mixed gas containing argon, carbon dioxide, and oxygen; a shielding gas for the trailing electrode is argon, a two-component mixed gas containing argon and carbon dioxide, a two-component mixed gas containing argon and oxygen, or a three-component mixed gas containing argon, carbon dioxide, and oxygen; and the concentration of carbon dioxide in the shielding gas for the trailing electrode is lower than the concentration of carbon dioxide in the shielding gas for the leading electrode. | 09-24-2009 |
