Argon-enriched gas shielded welding wire and wire rod with tensile strength 650mpa grade for coating-free weather-resistant steel bridge

Abstract

The invention discloses a wire rod for a coating-free weather-resistant steel bridge with a tensile strength of 650MPa grade argon-enriched gas shielded welding wire. The chemical composition includes: C: 0.05-0.09, Si: 0.27-0.50, Mn: 1.65~2.00, P≤0.015, S≤0.005, Cr: 0.35~0.65, Ni: 0.65~0.90, Cu: 0.15~0.30, Mo: 0.08~0.20, Ti: 0.04~0.09, Ca: 0.010~0.030, V: ≤0.030, Nb: ≤0.020, Zr: ≤0.030, Ce: ≤0.020, O: ≤0.005, N: ≤0.007, the balance is Fe and unavoidable impurities. The invention also discloses an argon-enriched gas-shielded welding wire with a tensile strength of 650MPa for a coating-free weather-resistant steel bridge. The welding wire of the present invention is suitable for argon-rich shielded welding of coating-free bridge steel with a tensile strength of 650MPa, wherein the tensile strength of the deposited metal is ≥650MPa; the yield strength is ≥500MPa; the elongation is ≥23%; the deposited metal-40 ℃ low temperature impact energy KV2≥80J.

Description

technical field [0001] The invention belongs to the field of weather-resistant steel welding materials, in particular to an argon-rich 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 low In 80J, it is especially suitable for the welding of large-scale paint-free bridge weathering steel structures. Background technique [0002] At present, my country is vigorously promoting the construction of Sichuan-Tibet railways and highways. As a key channel and control project for crossing canyon waters in this harsh area, long-span steel structure bridges have attracted widespread attention for their design, construction and application. The Sichuan-Tibet Plateau is located in an alpine, high-altitude, and high-intensity area with diverse and complex geological conditions. The design and construction of bridges must meet the requirements of larg...

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Problems solved by technology

[0008] In order to solve the problems of difficult argon-rich shielded welding operation, metallurgical quality problems, the increase of alloy elements in weathering steel, the increase of phase transition temperature, and the coarsening of weld seam structure, etc., the invention develops a coating-free weathering steel bridge Protect the welding wire and wire rod with argon-rich gas with a tensile strength of 650MPa, in which the tensile strength of the deposited metal is ≥650MPa; the yield strength is ≥500MPa; the elongation is ≥23%; Atmospheric corrosion index I is 6.5-7.5, with excellent comprehensive performance, suitable for structural design and welding manufacture of paint-free steel bridges with a tensile strength of 650MPa

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