CO2 gas protection flux-cored wire for matching welding of low-alloy steel with strength of 490 MPa

The invention relates to a CO2 gas protection flux-cored wire for matching welding of low-alloy steel with the strength of 490 MPa. The CO2 gas protection flux-cored wire is made of a steel belt and flux-cored powder, wherein the flux-cored powder comprises the following components in parts by weight: 4-10 parts of sintering powder, 0.1-0.7 part of Fe3O4, 0-1.0 part of TiO2, 0.1-0.5 part of Al, 0-0.4 part of Ti, 0.1-0.5 part of Si, 2.0-2.5 parts of Mn and 1.0-2.0 parts of Fe. The CO2 gas protection flux-cored wire has the beneficial effects that the mechanical property of the weld metal of the produced flux-cored wire can meet the technical index requirements; the moisture absorption capability of the produced flux-cored wire is greatly improved, so that the pore resistance of the flux-cored wire is enhanced, and i.e., no pore is generated in welding after the unpacked CO2 gas protection flux-cored wire is placed for seven days under the environment with 80% relative moisture.