The difference between hot rolled steel pipe and cold rolled steel pipe

Steel pipe as an important part of steel products, due to its manufacturing process and the shape of the billet used is divided into seamless steel pipe (round billet) and welded steel pipe (plate, strip billet) two categories.

1, cold rolled forming steel allows the cross-section of local buckling, so that you can take full advantage of the bar buckling after the bearing capacity; and hot rolled steel does not allow the cross-section of local buckling.

2, hot rolled steel and cold rolled steel residual stresses arising from different reasons, so the distribution of the cross-section is also very different. Cold-formed thin-walled steel cross-section of the residual stress distribution is bending type, while the hot-rolled steel or welded steel cross-section of the residual stress distribution is thin film type.

Two kinds of steel pipe in the finished product is not much difference, generally are manufactured in accordance with the standard. Mechanical properties are not what kind of difference exists in most of the processing technology is different, as well as the final out of different precision, generally speaking, cold-drawn dimensional accuracy and surface finish is higher.

Welded steel pipe, also known as welded pipe, is made of steel plate or steel strip welded steel pipe after roll forming. Welded steel pipe production process is simple, high production efficiency, more varieties and specifications, less capital for equipment, but the general strength is lower than seamless steel pipe.

Welded steel pipe according to the form of weld seam is divided into straight seam welded pipe and spiral welded pipe. Spiral welded pipe strength is generally higher than the straight seam welded pipe, can use a narrower bad material to produce a larger diameter of the welded pipe, but also with the same width of the bad material to produce a different diameter of the welded pipe. However, compared with the same length of straight seam pipe, the length of the welded seam increases by 30-100%, and the production speed is lower. Therefore, the smaller diameter welded pipe is mostly used straight seam welding, large diameter welded pipe is mostly used spiral welded pipe.