Steel pipes are divided into seamless steel pipes and welded steel pipes. The production process of seamless steel pipe is to thread a solid billet or ingot into a hollow capillary tube, which is then rolled into a pipe of the required size. The different piercing and rolling methods used constitute different methods of producing seamless steel pipes. The production process of welded steel pipe is to bend the tube blank (steel plate or strip) into a tubular shape, and then weld the gap to form a steel pipe. Due to the different forming and welding methods used, different methods of producing welded steel pipes are formed.
Seamless steel pipes are mainly produced by hot rolling. The extrusion method is mainly used to produce hard-to-pierce low-plastic high-alloy steel pipes or special-shaped steel pipes and composite metal pipes. Cold rolling and cold drawing methods can continue to process hot rolled pipes into small diameter and thin wall pipes. Welded steel pipe has simple process, high production efficiency, low cost, and the product variety is expanding day by day.
