Patent ID: 9266197
Filing Date: 2016-02-23
CPC Classification: B23K

Claim Text:
1. In a tandem gas-shielded arc welding method which comprises welding with a leading electrode and a trailing electrode while injecting a shielding gas to the weld area, the improvement comprising: using a solid wire as the leading electrode and carbon dioxide as a shielding gas for the leading electrode; using a solid wire or a flux-cored wire as the trailing electrode and using an argon-carbon dioxide gas mixture containing at least 60% by volume of argon gas as a shielding gas for the trailing electrode; making both the leading electrode and the trailing electrode have a reverse polarity; adjusting a welding current I (amps), a welding voltage V (volts), a wire feed speed W adjusting a welding current I (amps) and a welding voltage V (volts) in the welding conditions for the trailing electrode to satisfy relationships represented by Expression (3) in (amps·volts)/(m