The bearing capacity of the welded pipe is related to two points, one is the mechanical properties of steel, which is often said yield point, tensile strength, elongation and impact toughness, and the other is related to the geometric characteristics of its cross-section. Ordinary circular longitudinal welded pipe resistance to local buckling the strongest, so it is to withstand radial internal pressure and radial external pressure of the best components.
In the same steel, the same area and the same support conditions, the rectangular bearing capacity of straight pipe under eccentric compression, circular and square steel pipe bearing capacity of the strongest axis, but the square and rectangular straight seam pipe in the subject nodular resistance to local buckling than circular pipe. Seamless steel pipe and straight seam welded pipe compared to the former production process is complex, high quality and expensive, less used in engineering, the latter more applications.
Straight seam steel pipe currently made of steel can be structurally combined with the advantages of the two, can make the straight seam steel pipe in the lateral compression state, its compressive strength can be doubled, at the same time due to the existence of straight seam pipe, improve the rigidity of steel pipe, the two play a role together, thus greatly improving the carrying capacity.
