Cold expansion of straight seam steel pipe
Cold expansion of straight seam steel pipe has the following purposes:
(1) Improve LSAW steel pipe and pipe end the geometric dimensional accuracy, so that the diameter of the steel tube and pipe end, roundness, and the diameter of the pipe ends Poor meet the standard requirements, facilitate field welding construction.
(2) Reduce inhomogeneous deformation of LSAW steel pipe forming and welding process, to reduce the residual stress of forming and welding of tube, and improve its distribution, improve the overall mechanical properties of the steel pipe.
(3) Steel Pipe overall performance of a comprehensive and effective inspection.
(4) Cold expansion also improve LSAW the tube straightness role, especially for the smaller diameter LSAW pipe straight is more obvious.
Straight seam submerged arc welded pipe cold flaring, steel tube and pipe end diameter will increase by about one percent difference in diameter of the diameter, roundness, and the pipe ends are greatly improved, also have greatly improved the straightness of the steel pipe, steel pipe a length of about 0.5% reduction in wall thickness decreases by about 0.8%. Fully develop LSAW process should consider these changes, to determine the pipe plate width, length and thickness, and the pipe diameter in front of the enlarged diameter, in order to avoid the enlarged diameter steel pipe geometry reach the final requirements caused by substandard.