Seamless steel pipe production methods is broadly divided into cross rolling and extrusion method. Former method is to use oblique roll bad perforated tube, and then rolling it extends. This method of production speed, but higher on the tube workability
stainless steel fitting requirements, mainly for the production of carbon steel and low alloy steel pipes. After the rule is puncher billet or ingot will be perforated, and then into a pipe extruder, this method is lower than the efficiency of cross rolling method is suitable for the production of high-strength steel pipe.
Cross rolling method and extrusion billet or ingot must first heating, production of hot-rolled steel tube called. Produced by thermal processing of the cold pipe may sometimes be needed then. Cold working in two ways: one is the method of drawing, the pipe is drawn through a die to extubation, the steel pipe is tapered, elongated; Another method is to cold rolling, it is the brother of the invention Mengneisiman The cold rolling mill used in the method. A seamless steel tube cold working of steel can be improved dimensional accuracy and finish machining, and the like to improve the mechanical properties of the material. Hot-rolled and cold drawn thermal processing is cold. The main difference: in the hot rolling temperature above the recrystallization rolling, cold rolling at a temperature below the recrystallization rolling cold rolling and sometimes there will be heated, but the temperature is relatively low, as it will produce cold rolled after processing. hardening, if required for the molding material is relatively high, but also for annealing of cold-rolled and hot-rolled plates or profiles generally, and wire drawing is generally cylindrical cross-section. Another hot-rolled sheet is generally higher alloy content, high strength steel, and cold-rolled carbon steel is a low alloy by cold rolling can improve strength, ensure the surface quality of the material. Cold drawn seamless steel pipe and hot-rolled seamless steel tubes of different distinction and plate. Seamless steel pipe manufacturing process is different because it is divided into hot-rolled (extrusion) Seamless two seamless and cold drawn (rolled).
Cold drawn (rolled) pipe is divided into two circular pipe and shaped tube: cold drawn steel tubes generally require multiple drawing between each drawing must be appropriate to stress annealing, to ensure a smooth next drawing proceed. From the appearance of cold-rolled seamless steel tubes tend to be small-diameter, hot-rolled seamless steel tubes tend to be large diameter. Accuracy than hot-rolled seamless steel cold-rolled seamless steel pipe, hot-rolled seamless steel pipe price is also higher than. Generally smaller diameter cold drawn seamless tubes, mostly in 108mm or less, especially precision cold drawn seamless pipe diameter is very high, cold drawn seamless pipe lengths are generally shorter than hot-rolled seamless pipe. Cold drawn seamless pipe wall thickness aspect than hot-rolled seamless uniform.
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