What is hot rolled steel pipe? What is a cold drawn steel tube?
Hot rolling is relative to cold rolling, cold rolling is performed under recrystallization temperature, while hot rolling is rolling above recrystallization temperature.
Overview of two processesHot-rolled (extrusion seamless pipe): billet, heating, perforation, three roll cross rolling, rolling or extrusion, tube to tube diameter (or reducing) - cooling - tube, straightening, pressure test (or testing), marking and warehousing.Cold drawing (rolling) seamless steel pipe: round tube to heating to perforation, annealing, pickling, leading to oil (copper), multi pass drawing (Leng Zha), the blank pipe, heat treatment, straightening, pressure test (testing), marking and warehousing.
General use seamless steel tube: is with 10, 20, 30, 35, 45# and other high-quality carbon steel, 16Mn, 5MnV and other low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB and other alloy steel hot-rolled or cold rolled. Seamless tubes made of low carbon steel, such as 10, 20, are mainly used for fluid delivery pipelines. 45. Seamless tubes made of medium carbon steel such as 40Cr, used for the manufacture of mechanical parts, such as parts of automobiles and tractors. General use of seamless steel pipe to ensure the strength and flattening test. Hot rolled steel tubes are delivered in hot rolling or heat treated conditions. Cold rolled in heat treated state.
Seamless steel pipe, hot-rolled and cold-rolled (DIAL) seamless steel pipe two categories.Hot rolled steel tubes are divided into ordinary steel tubes, low and medium pressure boiler tubes, high pressure boiler tubes, alloy steel pipes, stainless steel pipes, oil cracking pipes, geological steel pipes and other steel pipes, etc..Cold rolled seamless steel pipe (DIAL) in general, steel pipe for low and medium pressure boiler tube, high-pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, oil cracking tube and other steel tube, including carbon thin-walled steel, alloy thin-walled steel, stainless steel, thin steel tube. The outer diameter of hot-rolled seamless tube is generally greater than 32mm, the wall thickness is 2.5-75mm. The outer diameter of cold-rolled seamless steel tube can reach 6mm, the wall thickness can be up to 0.25mm, the outer diameter of thin-wall pipe can be 5mm, the wall thickness is less than 0.25mm, and cold rolling has higher precision than hot rolling dimension.
