Union melt welding wire with tensile strength of 650 MPa grade for coating-free weathering steel bridge and steel wire rod

Abstract

The invention discloses a steel wire rod for a union melt welding wire with tensile strength of 650 MPa grade for a coating-free weathering steel bridge, and belongs to the field of weathering steel welding materials. The steel wire rod is prepared from chemical composition in percentage by mass: 0.04-0.09% of C, 0.12-0.32% of Si, 1.60-2.20% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.25-0.55% of Cr, 0.6-1.10% of Ni, 0.20-0.35% of Cu, 0.10-0.40% of Mo, 0.02-0.15% of Ti, 0.010-0.025% of Nb, 0.005-0.030% of Ca, less than or equal to 0.030% of Zr, less than or equal to 0.025% of Ce, less than or equal to 0.0010% of B and the balance of Fe and other unavoidable impurities. Based on the steel wire rod for the union melt welding wire, the invention further provides the union melt welding wire with the tensile strength of 650MPa grade for the coating-free weathering steel bridge. The welding wire and the steel wire rod are suitable for the welding of the coating-free steel bridge with tensile strength of 650 MPa, wherein the tensile strength of deposited metal is greater than or equal to 650 MPa; the yield strength is greater than or equal to 500 MPa; the elongation is greater than or equal to 22%; and the low-temperature impact energy KV2 of the deposited metal at -40 DEG C is greater than or equal to 80 J.

Description

Technical field [0001] The invention belongs to the field of weathering steel welding materials, and specifically relates to a submerged arc welding wire and wire rod matched with high-grade weathering steel. The tensile strength of the weld metal is not less than 650MPa and the impact energy at -40°C is not less than 80J , Especially suitable for welding of large-scale coating-free bridge weathering steel structure. Background technique [0002] In recent years, with the rapid development of the transportation industry, bridge construction has shown a gradual acceleration mode, and the planning and construction of large-span steel bridges across rivers and seas have increased. In the context of my country's steady promotion of "regional coordinated development" and other strategic backgrounds, its 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 fac...

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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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