Main uses and production process of seamless steel pipe

Former method is to use a bad oblique rolls perforated tube, and then rolling it extends. This method of producing fast, but higher on the tube workability requirements, mainly for the production of carbon steel and low alloy steel pipe. After the rule is perforated tube or ingot perforation machine, extruder and then extruded into pipe, 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 drawing method, 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 rolling and hot drawing is cold working, 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, however. relatively low temperature, because it will produce cold rolled after 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 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 several drawing between each drawing must be appropriate to stress annealing, to ensure a smooth next drawing get on. From the appearance of cold-rolled seamless steel tubes tend to be small-diameter, hot-rolled seamless steel tubes often 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.It is the difference between the production of hot-rolled and cold-drawing process, the hot rolling is processed at high temperatures, will not change the properties of the metal structure, drawing at a high temperature to round perforations, and then the cold drawing machine extubation, in no tempering state, this process will affect the crystal structure of the metal. In general, the ratio of hot rolling cold rolling to better mechanical properties, heat-treated steel, and its tensile strength, yield strength, ductility and toughness are improved, in addition, a heat treatment to eliminate residual stress, which may be cold-rolled because the steel yield inhomogeneous deformation occurs in the process, will produce residual stress, a large impact on the stability of the residual stress.