Bottom chord tube manufacturing process of girder of steel tube concrete truss beam bridge

Abstract

The invention provides a bottom chord tube manufacturing process of a girder of a steel tube concrete truss beam bridge. The steel tube manufacturing process includes the following steps: manufacturing a steel plate, and enabling the length of the steel plate to be at least twice the circumference of a single steel tube; manufacturing circular seam grooves on two sides of the steel plate along the rolling direction of the steel plate; adopting an in-plate arc starting rolling process to press head of the steel plate; rolling the plate preliminarily along the rolling direction of the plate to form tube joints having non-closed annular cross sections with openings; manufacturing a straight slit groove at the position of the opening of each tube joint along the axial direction of each tube joint; rolling the tube joints for the final rolling to form straight slits; welding the straight slits of the tube joints formed through the final rolling; connecting at least two tube joints in butt joint mode along the axial direction of the tube joints to form tube sections; and welding a circular seam between at least two tube joints to form a steel tube. By adopting the steel tube manufacturing process, welding quality of weld joints and manufacturing quality of steel tubes are improved.

Description

Technical field [0001] The invention relates to a manufacturing process of steel pipes, in particular to a manufacturing process of the lower chord of the main beam of a steel pipe concrete truss girder bridge. Background technique [0002] Straight seam coiled pipe is generally used for conveying low-pressure fluid due to its production and welding quality limitations, and seamless steel pipes are usually used for important stressed components. The lower chord of the main girder of the steel tube concrete truss girder bridge (for example, Ganhaizi Bridge) is too large to have suitable seamless steel pipes. Therefore, the material is Q345C, the outer diameter is 813mm, and the wall thickness is 18mm~32mm straight seam coiled pipe, which is quite rare in engineering practice. Due to the high level of safety of the bridge, the highest standard in the various specifications was selected as the technical standard for the lower chord, and the first-class qualification requirements of...

AI Technical Summary

Problems solved by technology

[0007] One aspect of the present invention provides a manufacturing process for steel pipes. In the process of steel plate rolling, the arc-starting rolling process within the plate is used to press the head, which solves the problem of forming straight edges at both longitudinal ends of the steel plate when the steel plate is rolled. , to avoid the "peach tip" phenomenon at the pipe joint straight seam joint, thus ensuring the ellipticity of the pipe mouth

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