The production process of hot-rolled seamless steel pipe is to perforate and roll a solid tube billet (or steel ingot) into a steel pipe with the required shape, size and performance. The whole process has three main deformation processes: 1) Perforation - piercing and rolling a solid billet (ingot) into a hollow rough tube; 2) Tube rolling - rolling the rough tube into a rough tube close to the required size; 3) Fixed diameter reduction - rolling the rough tube without a mandrel into a finished tube with the required dimensional accuracy and true roundness. In production, different types of tube rolling mills are selected according to different conditions such as product variety, specification and production capacity. Since different types of tube rolling mills have different kinematic conditions, stress state conditions, pass deformation, total deformation and productivity when rolling tubes, it must be equipped with perforators and other equipment for the previous and next processes that match the deformation and productivity. In this way, different tube rolling mills constitute different tube rolling mill units. The production method of hot-rolled seamless steel pipes is classified by the type of tube rolling mill in the unit.
The production method of welded steel pipe is to bend the tube billet (steel plate or steel strip) into the required cross-sectional shape by various forming methods, and then weld the weld seam by different welding methods. Forming and welding are its basic processes, and the production method of welded pipe is classified according to the characteristics of these two processes. Continuous straight seam welding mainly uses two methods: ERW and high-frequency welding; UOE method is the main method for producing large-diameter straight seam electric welding, which is non-continuous; there is also spiral welding, which is mainly used to produce large-mouth machine pipes when the width of steel plates was limited.
There are three cold processing methods for steel pipes: cold rolling, cold drawing and cold spinning. Cold spinning is essentially cold rolling. The specifications of cold rolling mills and cold spinning machines are expressed by their product specifications and rolling mill types; the specifications of cold drawing machines are expressed by their allowable rated drawing force.
A53 Black Steel Pipe
