advantages and defects of welded steel pipe

There are the advantages and defects of welded steel pipe:

Steel pipe according to the rolling process can be divided into hot rolled steel pipe and cold rolled steel pipe; According to the steel tube is there a seam can be divided into seamless steel pipe and welded steel pipe, which are commonly used welded steel pipe; According to the weld steel pipe can be divided into high frequency welded pipe, straight seam submerged arc welding pipe, three kinds of spiral submerged arc welding pipe, etc.

A, high frequency welding steel pipe:

High frequency welding tube shape, uniform wall thickness, welding of inside and outside the burr by corresponding tool, leveling online through strict control of welding quality of nondestructive testing (NDT) methods, a high degree of automation, low production cost. And relatively thin wall thickness and pipe diameter is relatively small, the wall thickness is generally not more than 12 mm, tube diameter is generally not more than 610 mm, the steel structure especially suitable for making GuanYan in frame structure.

Second, the straight seam submerged arc welding pipe:

Straight seam submerged arc welding pipe using double-sided submerged arc welding welding process, welding in static conditions, high quality weld, short, low rates of potential defects. Good steel pipe through the hole diameter, tube size precision, wide range of steel tube wall thickness and pipe diameter range, a high degree of automation. Compared with seamless steel tube, the production cost is low, suitable for buildings, Bridges, DAMS and offshore steel structure bearing with columns, such as wind and earthquake resistant of large span structure and require electricity tower mast structure.

Three, spiral submerged arc welding pipe:

Are distributed in spiral submerged arc welding pipe weld spiral weld, especially under dynamic condition, when welding the weld it left cooling molding, easy to produce welding hot crack. Crack parallel to the direction of the weld and the axis and pipes with a certain Angle. This Angle just consistent with the shear Angle, so its bending, tensile, compressive and torsional properties is much less than the straight seam submerged arc welding pipe, at the same time limit due to the welding position, the saddle and fish ridge shape weld affect beautiful.

In addition, the mother spiral welded pipe in the construction process the curve of the node weld split the spiral seam, generate a large welding stress. Thus greatly weaken the component of safety performance, so should strengthen the nondestructive test of spiral welded pipe welding seam, ensure the welding quality, otherwise in the steel structure of the important occasions unfavorable use spiral submerged arc welding pipe.