Patent ID: 10898967

Abstract:
The present invention provides a consumable electrode type gas shield arc welding method for performing arc welding of two steel sheets using a welding torch having a consumable electrode. The consumable electrode type gas shield arc welding method includes performing arc welding while a shielding gas having an oxygen potential α which is indicated by the following Expression (1) and ranges from 1.5% to 5% is supplied from the welding torch toward the consumable electrode, and blowing an oxidation promotion gas having an oxygen potential β which is indicated by the following Expression (2) and ranges from 15% to 50% at a flow velocity ranging from 1 to 3 m/sec over a weld bead and a weld toe portion which are formed by arc welding and are in a state of 700° C. or higher, α=100×([V1(O2)]+[V1(CO2)]/5)/([V1(X)]+[V1(O2)]+[V1(CO2)])  Expression (1)β=100×[V2(O2)]/([V2(X)]+[V2(O2)]+[V2(CO2)])  Expression (2)here, [V1(X)] is a mixing ratio (volume %) of an inert gas included in the shielding gas, [V1(O2)] is a mixing ratio (volume %) of oxygen included in the shielding gas, [V1(CO2)] is a mixing ratio (volume %) of carbon dioxide included in the shielding gas, [V2(X)] is a mixing ratio (volume %) of an inert gas included in the oxidation promotion gas, [V2(O2)] is a mixing ratio (volume %) of oxygen included in the oxidation promotion gas, and [V2(CO2)] is a mixing ratio (volume %) of carbon dioxide included in the oxidation promotion gas.