Pre-bending process for longitudinal submerged arc welding pipe production line

Abstract

The invention discloses a pre-bending process for a longitudinal submerged arc welding pipe production line. According to the process, operation is carried out on a longitudinal steel pipe welding pre-bending device; the longitudinal steel pipe welding pre-bending device comprises conveying roll tables which are arranged in parallel, a sucker hoisting conveyor is arranged at the upstream of the conveying roll tables, and a steel pipe pre-bending forming machine is arranged at the downstream of the conveying roll tables; the sucker hoisting conveyor comprises a hoisting cross beam and a vacuum sucker; and the steel pipe pre-bending forming machine comprises a pre-bent upper mold, a pre-bent lower mold and a pre-bent fixture. The process comprises the following steps: a feeding step in which the upper surface of a pre-bent steel plate is sucked by the vacuum sucker to move toward the downstream of the conveying roll tables; a bending step in which the pre-bent upper mold and the pre-bent lower mold of the steel pipe pre-bending forming machine make forward motion; and a resetting step. Relative sliding and friction between the pre-bent steel plate and conveying equipment can be reduced in the pre-bent steel plate feeding process, scratches generated on the surface of the pre-bent steel plate can be avoided, and the anti-rust and anti-corrosion capability of a longitudinal steel pipe can be improved.

Description

technical field [0001] The invention relates to a pre-bending process of a straight seam submerged arc welded steel pipe production line, belonging to the technical field of straight seam welded pipes. Background technique [0002] Steel pipes made of hot-rolled or cold-rolled steel plates or steel strips coiled and welded. Among them, the steel pipes obtained by straight seam welding on welding equipment are straight seam welded pipes, and the welds of the straight seam welded pipes are in a straight line. Longitudinal welded pipes are widely used in water supply engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction; for liquid transportation: water supply and drainage; for gas transportation: gas, steam, liquefied petroleum gas; as structural Uses: as piling pipes and bridges; pipes for wharves, roads, building structures, etc. [0003] The main production process of large-diameter straight seam we...

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