The small-diameter welded pipe is also called a small-diameter welded steel pipe, and is a steel pipe which is formed by welding a steel plate or a strip steel after being crimped. The small-diameter welded pipe has simple production process, high production efficiency, many varieties and specifications, and low equipment, but the general strength is lower than that of seamless steel pipe
. Since the 1930s, with the rapid development of high-quality strip continuous rolling production and the advancement of welding and inspection technology, the quality of welds has been continuously improved, and the specifications of small-diameter welded pipes have been increasing, and they have been replaced in more and more fields. Seamless steel pipe. Welded steel pipes are divided into straight welded pipes and spiral welded pipes in the form of welds.
The billet used is steel plate or strip steel, which is divided into furnace welded pipe, electric welding (resistance welded) pipe and automatic arc welded pipe due to different welding processes. Due to the different welding forms, it is divided into straight seam welded pipe and spiral welded pipe. Because of its shape, it is divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes.
The small-diameter welded pipe has a simple production process, high production efficiency, low cost and rapid development. The strength of the spiral welded pipe is generally higher than that of the straight welded pipe. It is possible to produce a welded pipe with a larger diameter by using a narrow blank, and it is also possible to produce a welded pipe having a different pipe diameter with a blank of the same width. However, compared with the straight pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is low. Therefore, most of the smaller diameter welded pipes are straight seam welded, and the large diameter welded pipes are mostly spiral welded.
Supplement: The small-diameter welded pipe is welded with strip steel, so it has no high seamless steel pipe in its original position.
The difference between small diameter welded pipe and stainless steel pipe
1. The former is a steel pipe made by welding a steel plate or a strip steel after being crimped. The latter is made by ingoting a steel ingot or a solid tube blank, and then making it by hot rolling, cold rolling or cold drawing.
2. The strength of the small diameter welded pipe is lower than that of the stainless steel pipe. The production process is simple, the production efficiency is high, the variety specifications and specifications, and the equipment cost are small. As the quality of the weld seam is continuously improved, the variety specifications of the small-diameter welded pipe are increasing, and the stainless steel pipe is replaced in many fields.
3. The blank used for the small-diameter welded pipe is steel plate or strip steel, and the narrow billet is produced.
4. Small-diameter welded pipes are mainly used for oil and natural gas transmission pipelines. The stainless steel tube has a hollow section and is light in weight. It is an economical section steel and is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile drive shafts, bicycle frames, and steel scaffolding used in construction.
5. The rolling direction of the small-diameter welded pipe vertical coil is not the direction of the vertical steel pipe axis, and the rolling direction of the stainless steel pipe is perpendicular to the axial direction of the steel pipe. The crack resistance of the small-diameter welded pipe material is better than that of the stainless steel pipe.