CO2 gas shielded welding wire with tensile strength of 650MPa for coating-free weathering steel bridge and wire rod

Abstract

The invention discloses a wire rod for a CO2 gas shielded welding wire with tensile strength of 650MPa for a coating-free weathering steel bridge, and belongs to the field of weathering steel weldingmaterials. The wire rod comprises the following chemical components in percentage by mass: 0.04 to 0.09 percent of C, 0.55 to 0.85 percent of Si, 1.70 to 2.10 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.46 to 0.65 percent of Cr, 1.10 to 1.80 percent of Ni, 0.15 to 0.38 percent of Cu, 0.10 to 0.20 percent of Ti, 0.003 to 0.005 percent of B, less than or equal to 0.015 percent of Al, less than or equal to 0.045 percent of Zr, less than or equal to 0.030 percent of Ce, less than or equal to 0.050 percent of O, less than or equal to 0.070 percent of N, and the balance of Fe and inevitable impurities. The invention also discloses the CO2 gas shielded welding wire with the tensile strength of 650MPa for the coating-free weathering steel bridge, which is prepared by drawing the wire rod. The welding wire is used for welding coating-free weathering steel with the tensile strength of 650MPa, wherein the tensile strength of deposited metalis between 650MPa and 730MPa, and the welding wire has high crack resistance; and the yield strength is more than or equal to 500MPa, the elongation is more than or equal to 23 percent, and the low-temperature impact energy KV2 at the temperature of -40 DEG C is more than or equal to 60J.

Description

technical field [0001] The invention belongs to the field of weather-resistant steel welding materials, in particular to a carbon dioxide gas shielded welding wire and wire rod matched with high-grade weather-resistant steel, the tensile strength of the weld metal is not lower than 650MPa, and the impact energy at -40°C is not lower than 60J, especially suitable for welding of large-scale paint-free bridge weathering steel structures. Background technique [0002] Most of the plateau areas in western my country are nature reserves with light pollution, low humidity, and sparsely populated. Road engineering construction is suitable for the construction of paint-free weather-resistant steel bridges. Compared with Q345qENH~Q420qENH grade weathering steel, high-performance Q500qENH steel is more suitable for constructing super-long-span coating-free weathering steel bridges with high live load in plateau and alpine regions. Gas shielded welding of typical butt welds and fillet ...

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Problems solved by technology

[0008] In order to solve the problems of difficult drawing of gas-shielded welding wire, serious burning loss of alloy elements, poor welding processability, unstable deposited metal strength and impact performance, etc., the invention develops a coating-free weather-resistant steel bridge with tensile strength 650MPa grade CO2 gas shielded welding wire and wire rod, suitable for welding Q500qENH series paint-free weather-resistant bridge steel

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