Flux copper gasket method submerged arc welding technology of Q420 high-strength steel thick plate

Abstract

The invention provides a flux copper gasket method submerged arc welding technology of a Q420 high-strength steel thick plate. The technology is characterized by comprising the following steps that aY-shaped welding groove is machined in a welding position of the to-be-welded Q420 high-strength steel thick plate; a tack weld is welded; a run-on plate and a run-off plate are welded at the two endsof the Y-shaped welding groove respectively; step type restraining weld joints are welded at the two ends of the welding groove; slag and impurities on the surface of a copper gasket are removed, then back flux is spread on the copper gasket, and then the copper gasket is tightly attached to the back surface of the welding groove after the copper gasket is aligned to the center of the welding groove; a proper welding material and suitable electrode welding parameters are selected for welding; and after welding is completed, gouging cleaning is conducted on non-welded defects at the restraining weld joints of the arcing end and the arc extinguishing end, and the gouged groove is subjected to repair welding. The technology can effectively solve the problem that the mechanical property of awelding joint of the Q420 high-strength steel thick plate is severely weakened under a large-heat input welding technology, and application of the flux copper gasket method submerged arc welding efficient welding technology on the Q420 high-strength steel thick plate can be realized.

Description

technical field [0001] The invention relates to a welding process for high-strength steel thick plates, in particular to a flux copper lining method submerged arc welding process for Q420 high-strength steel thick plates. Background technique [0002] With the improvement of technical indicators and service life requirements of bridges, tunnels and other buildings, the load-bearing reinforced concrete structure has been gradually replaced by the design structure of high-strength structural steel, and the steel used in the design is also developing in the direction of high-strength and large-thickness . Q420 is a low-alloy high-strength structural steel with a yield strength level greater than or equal to 420MPa. It has been applied to steel box girder structures, truss structures of bridge buildings, and steel shell structures of tunnel buildings. [0003] In the welding of Q420 high-strength steel plate, the welding methods of manual electrode arc welding, semi-automatic c...

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Problems solved by technology

[0006] Aiming at the deficiencies of the prior art, the present invention proposes a flux-copper-lined submerged arc welding process for Q420 high-strength steel thick plates, which effectively solves the problem of welding crack defects and weakening of welded joints under conditions of large heat input welding and high-speed welding The problem of mechanical properties

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