Welding method for Q420qENH coating-free weathering steel for steel bridge

Abstract

A welding method of Q420qENH coating-free weather-resistant steel for steel bridges, the Q420qENH coating-free weather-resistant steel has an atmospheric corrosion resistance index I≥6.5, a welding sensitivity index Pcm≤0.23, and when the welded joint form is a butt weld, The combined welding process of solid wire gas-shielded welding for backing and submerged arc automatic welding for filling and covering is adopted; when the welding joint form is T-shaped penetration fillet weld, the gas-shielded welding process of flux-cored welding wire is adopted; the welding joint form is single-sided bridge deck When welding double-sided formed joint welds, a combined welding process of solid wire gas shielded welding for bottoming and submerged arc automatic welding for filling and covering is used. The atmospheric corrosion resistance index I of the welding wire in the present invention is ≥ 6.5, and the relative corrosion rate of the deposited metal is ≤ 8%, which ensures that the welding seam matches the composition of the steel plate, and solves the weather resistance of the welding seam of the coating-free weather-resistant steel. Coating the weather-resistant steel bridge solved the technical bottleneck.

Description

technical field [0001] The invention belongs to the field of welding technology, in particular to a welding method for Q420qENH coating-free weathering steel used for steel bridges. Background technique [0002] In recent years, due to its superior atmospheric corrosion resistance, weathering steel has been more and more widely used in steel bridges. However, although the whole bridge steel is made of weathering steel in practical applications, heavy anti-corrosion coating is used after the bridge is completed. The system does not give full play to the advantages of weathering steel. The main reason is that the welding consumables used for the connection welds of weathering steel are still selected according to the welding consumable indexes (ReL, Rm, A, AKv) of ordinary bridge steel, without considering the corrosion resistance of the welding seam, which hinders the construction of weathering steel bridges. Paint-free (bare) application. Therefore, the weather resistance ...

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Problems solved by technology

The main reason is that the welding consumables used for the connection welds of weathering steel are still selected according to the welding consumable indexes (ReL, Rm, A, AKv) of ordinary bridge steel, without considering the corrosion resistance of the welding seam, which hinders the construction of weathering steel bridges. Paint-free (bare) application

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