Coating-free weather-resistant steel bridge with a tensile strength of 650mpa submerged arc automatic welding wire and wire rod

Abstract

The invention discloses a wire rod for a submerged arc automatic welding wire with a tensile strength of 650 MPa for a coating-free weathering steel bridge, which belongs to the field of weathering steel welding materials. : 0.12~0.32, Mn: 1.60~2.20, P: ≤0.015, S: ≤0.005, Cr: 0.25~0.55, Ni: 0.6~1.10, Cu: 0.20~0.35, Mo: 0.10~0.40, Ti: 0.02~0.15 , Nb: 0.010~0.025, Ca: 0.005~0.030, Zr: ≤ 0.030, Ce: ≤ 0.025, B ≤ 0.0010, the balance is Fe and other inevitable impurities. Based on the above-mentioned wire rod for submerged arc automatic welding wire, the present invention also provides a submerged arc automatic welding wire with a tensile strength of 650 MPa for a coating-free weathering steel bridge. The welding wire and wire rod of the invention are suitable for the welding of non-painted bridge steel bridges with a tensile strength of 650MPa, wherein the tensile strength of the deposited metal is greater than or equal to 650MPa; the yield strength is greater than or equal to 500MPa; the elongation is greater than or equal to 22%; 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 a submerged arc 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 80J , especially suitable for the welding of large-scale paint-free bridge weathering steel structures. Background technique [0002] In recent years, with the ever-changing development of the transportation industry, bridge construction has gradually accelerated. The planning and construction of long-span steel bridges across rivers and seas has increased, and the construction scale will continue to peak in the next few decades. Especially for the construction of national key projects such as the Sichuan-Tibet Railway. These areas have long been faced with harsh geological conditions such as alpine hypoxia, permafrost, scattered landslides, earthquakes,...

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Problems solved by technology

[0007] The present invention aims to solve the above-mentioned problems such as the poor fluidity of the submerged arc welding weld pool of weathering steel, the high viscosity that easily causes metallurgical quality problems, the increase of alloy elements reduces the welding manufacturability, and the increase of the phase transition temperature increases the weld structure coarsening. A coating-free weather-resistant steel bridge with a tensile strength of 650MPa level submerged arc automatic welding welding wire and wire rod, wherein the tensile strength of the weld deposited metal is ≥650MPa; the yield strength is ≥500MPa; the elongation is ≥22%; the deposited metal -40℃ low-temperature impact energy KV2≥80J, atmospheric corrosion resistance index I is 6.5~7.5, has excellent comprehensive performance, and is suitable for welding of large-scale coating-free bridge weather-resistant steel structures

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