Welded pipe production process flow:
Welded pipe, also known as welded steel pipe, is a steel pipe made by using welding technology to roll a steel plate or strip into a tube shape, and then flatten, curl, weld, and level it.
Generally, the production process of welded pipes is divided into three processes: hot rolling, cold rolling and cold drawing. Among them, hot-rolled welded pipes are made of hot-rolled steel strips welded at high temperatures, and cold-rolled welded pipes are made of cold-rolled steel strips welded at room temperature. Cold drawn welded pipes are made by cold drawing process after welding.
Welded pipe materials and characteristics:
The raw materials of welded pipes are mostly black steel plates (black steel pipes), whose main components are carbon and manganese. During the welding process, the composition of the welded joint changes, and chemical reactions occur between carbon and other elements. Therefore, welded areas are generally more susceptible to corrosion than non-welded areas.
Welded pipes are widely used because of their light weight, low price, high strength and easy processing. However, due to changes in welding processes and the influence of pipe composition, the physical properties of welded pipes sometimes have certain deficiencies.
Welded pipes can be made by either hot rolling or cold rolling.
Hot rolling is rolling above the metal recrystallization temperature, while cold rolling is rolling below the metal recrystallization temperature. The outer wall of the welded pipe is generally produced by hot rolling, and the inner wall is generally produced by cold rolling to ensure smoothness and no seams.
The main difference between hot rolling and cold rolling is that hot rolling has a slow forming speed and low output, but the toughness and plasticity of the rolled steel are better; while cold rolling has a fast forming speed and high output, but the hardness and strength of the rolled steel will decrease. has seen an increase.
