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

Abstract

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.

Description

technical field [0001] The invention relates to welding materials, in particular to a CO2 used for supporting welding of low-alloy steel with a strength of 490MPa. 2 Gas shielded flux cored wire Background technique [0002] In recent years, in the field of shipbuilding, CO 2 Gas shielded automatic and semi-automatic welding. The application of flux-cored wire greatly improves production efficiency, greatly reduces welding deformation, shortens construction period and reduces production cost. However, in energy construction, especially power station construction projects, CO 2 The gas-shielded all-position titanium-type flux-cored wire does not meet its technical requirements, mainly in the following aspects: 1) The mechanical properties do not match the technical requirements of low-alloy steel welded joints used in power stations: such as CO 2 The deposited metal strength of the gas-shielded all-position titanium flux-cored wire is generally at the marine 3y level, tha...

AI Technical Summary

Problems solved by technology

However, in energy construction, especially power station construction projects, CO 2 The gas-shielded all-position titanium-type flux-cored wire does not meet its technical requirements, mainly in the following aspects: 1) The mechanical properties do not match the technical requirements of low-alloy steel welded joints used in power stations: such as CO 2 The deposited metal strength of the gas-shielded all-position titanium-type flux-cored wire is generally at the marine 3y level, that is, the tensile strength is ≥490MPa, and the Charpy impact absorption energy at -20°C is ≥47J

The low-alloy steel (such as 16Mn steel) with a tensile strength ≥ 490MPa for power stations requires that the Charpy impact absorption energy of the weld at -30°C ≥ 27J (toughness does not match); the low-alloy steel with a tensile strength ≥ 590MPa for power stations Steel (such as 6062 steel) requires that the Charpy impact absorption energy of the weld at -20 ° C is ≥ 47J (strength does not match); 2) Poor porosity resistance, etc.

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