High-weather-resistance gas protection welding wire with excellent weldability

Abstract

The invention discloses a high-weather-resistance gas protection welding wire with excellent weldability. The high-weather-resistance gas protection welding wire comprises the following components in percentage by mass: C less than 0.02%, 0.75-1.30% of Mn, 0.20-0.40% of Si, P not more than 0.015%, 0.016-0.030% of S, 2.2-4.0% of Ni, 0.80-1.20% of Cr, 0.10-0.30% of Cu, 0.005-0.020% of Ti, and the balance of iron and inevitable impurities; and Ti and S elements are reasonably matched in a stated range. The welding wire is suitable for welding of such steel structures as bridges, building structures and railway trucks with higher atmospheric corrosion resisting requirements. The welding wire adopts 100% of CO2 or Ar+20% of Co2 as protection gas for welding, is excellent in welding line surface and section forming, is excellent in comprehensive performance of welding line metal, reaches the welding line tensile strength of not less than 650 MPa, and reaches -40 DEG C impact power of not less than 100 J.

Description

technical field [0001] The invention belongs to the field of welding materials, and in particular relates to a highly weather-resistant gas-shielded welding wire with excellent weldability. Background technique [0002] Due to the influence of environmental climate and other factors, the steel structure exposed to the air is easy to corrode, which affects the safety and maintenance of the steel structure. In the late 1980s, some steel enterprises developed the first generation of weathering steels (such as SPA-H and Q345GNHL for containers, 09CuPTiRe for railway vehicles, etc.). In 2003, domestic steel enterprises developed the second-generation weathering steel Q450, which upgraded the yield strength from the first-generation 345MPa to 450MPa, which has better corrosion resistance, avoids coating pollution, and reduces maintenance costs for steel structures. In the past few years, the large-scale new products manufactured by the railway wagon factory are C70 open car, P70 ...

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Problems solved by technology

[0003] In order to adapt to the welding of weather-resistant steel, the supporting weather-resistant gas-shielded welding wire has also been developed accordingly. For example, the weather-resistant gas-shielded welding wire disclosed in CN1611321A can meet the performance requirements of 550MPa-level welding wire through argon-rich gas shielded welding, and it has certain weather resistance. It meets the requirements for welding the second-generation weather-resistant steel Q450NQR1, but cannot adapt to the high weather resistance of the third-generation weather-resistant S450EW; the 650MPa-level weather-resistant gas-shielded welding wire disclosed in CN102756219A solves the new high-corrosion-resistant weather-resistant steel series for the third-generation railway vehicles However, due to its high Ni, Cr, Cu content and high proportion of Ti element, the welding process is poor, mainly in: the molten metal is not easy to spread during welding, the weld bead is towering, and the shape is poor. In order to ensure the mechanical properties of the weld, argon-rich gas protection is used for welding. When this welding process is matched with welding, the weld finger-shaped penetration is prominent, which is easy to cause defects such as slag inclusions and cracks.

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