Gas shield welding method for high-crack-arrest-toughness steel with yield strength of 460 MPa

The invention discloses a gas shield welding method for steel with yield strength of 460MPa and high crack arrest toughness, which comprises the following steps: (1) welding a base material with yield strength of more than or equal to 460MPa and tensile strength of more than or equal to 570MPa, and setting proper chemical components and weight percentage of the base material; (2) selecting a gas shield welding wire with the diameter of 1.2 mm as a welding material, and setting proper chemical components and weight percentage of the gas shield welding wire; (3) groove parameters are set, preheating is not conducted before welding, the interlayer temperature is smaller than or equal to 100 DEG C, and back gouging is avoided on the back face; gas shield welding is adopted, shielding gas is pure CO2, corresponding gas flow, welding current, arc voltage, welding speed and welding heat input parameters are set, and a welded joint is obtained. The method has the advantages that a welded joint has good comprehensive