Brief introduction of technology and equipment of cold drawn steel pipe Project Profile high precision cold drawn precision steel pipe is a new type of High-tech energy-saving products. In recent years, the use of this technology to produce precision steel pipe has been widely used in domestic hydraulic, pneumatic cylinder, coal downhole stent (pillar), oil pump pipe, Jack and other manufacturing areas. The popularization and application of high precision cold drawn precision steel pipe is important for saving steel, improving working efficiency, saving energy, reducing investment of hydraulic cylinder and cylinder processing equipment. The technology in November 1991 through the metallurgy, Anhui Province, the organization of scientific and technical experts, December 1992 through the organization of Jiangsu province, experts identified by the Scientific Commission. The technology is included in the National Science and Technical Commission (93) Guo No. 500, the national scientific and technological achievements of the Project Guide, the number is i4-1-4-21. The so-called high precision cold drawing pipe refers to the internal and external diameter dimension precision (tolerance range) strict, internal and external surface finish, roundness, straightness, good thickness uniformity of precision steel pipe. After slightly Gar grinding, the product can be used directly as hydraulic and pneumatic cylinder body tube. and the traditional hydraulic, pneumatic cylinder cylinder tube production process, is the use of hot-rolled seamless steel tubes, boring-rolling joint cutting process, the production process, a large number of metals are cut into chips wasted, but also consumes a lot of electricity. With the development of China's industrial technology, hydraulic cylinder technology has been widely used, according to incomplete statistics, the country each year needs a variety of hydraulic cylinder about 3.8 million meters, the use of old technology to produce hydraulic cylinder, has been difficult to adapt to the needs of production and development. The use of new technology, cold drawing way to produce high-precision cold drawing pipe-hydraulic cylinder and the traditional cutting process comparison, has the following characteristics: (1) High production efficiency: the traditional method of production of an inner diameter of 420 mm, 12 meters long cylinder need 154 hours, the production of cold drawing is only 4 minutes. (2) The high rate of authenticity: because of the boring rolling head and the guiding role, in the cutting process, the blank pipe due to the weight of the deflection, resulting in rolling head and boring knife deviation, resulting in waste products. The genuine rate can reach only about 60%, and use cold drawing method production, the authentic rate can reach more than 95%. (3) Metal utilization ratio: using the traditional boring method to make cylinder, metal utilization only 50-70%. When produced by drawing method, the metal is not only cut to the end of iron, but can get 30% elongation, and the metal utilization can reach 95%. (4) Can improve the mechanical properties of finished pipe metal: By drawing method production, so that the blanks get more than 30% of plastic deformation, due to the processing hardening of the finished pipe metal strength limit greatly improved. Generally in the finished pipe layer strength limit up to 60%. High-precision cold drawing pipe is made of seamless hot-rolled steel pipe, straight seam welded pipe as blank, after chemical treatment on the special cold drawing machine, through the special deformation principle design of the die for drawing, production of high-precision tube. Its dimension accuracy reaches H10~h8, straightness reaches 0.35~0.5mm/m, surface roughness reaches ra1.6-0.4. Production process flow is as follows: feeding--appearance inspection--mechanical cleaning--mechanical cleaning--annealing--straightening--tube-head processing-pickling-neutralization-washing--scaling--saponification--pull--check--cut fixed ruler-honing--end processing-straightening--assembly--Test pressure--packing Technical specifications The main technical specifications of the high precision cold drawing pipe produced by the technology have met or partially exceeded the requirements of national standard GB8713--88 and International Standard iso4394/i-1980 (E). 2 industry Demand (1) engineering hydraulic machinery: such as hydraulic car crane, excavators, bulldozers, forklifts and so on. (2) coal mine under the hydraulic support: At present, the national production of downhole hydraulic support enterprises have 48, high-precision cold drawing pipe total demand of about 1.2 million meters. (3) Hydropower station Gate hoist, formwork machine, especially the Three Gorges project in the next 10 years of great demand. (4) Construction Machinery: Aerial work lifting machinery, general construction repair can not be separated from hydraulic machinery. (5) Petroleum Geology Pipe: The National oil field each year needs to pump more than 30,000 units, the annual consumption of high-precision pipe more than 20-40 million meters, in addition to this technology can be used to complete all kinds of drill pipe. (6) Ordnance Industry: The Military department now uses spinning method to process the gun tube, the spinning method has low production rate and high cost, so it is more suitable to produce by cold drawing method. (7) Bearing industry: the current rolling bearing seat ring production, to round steel as raw material, after slicing and pressing into. Large bearing housings also hollowed out solid rods to make, metal utilization less than 40%, the urgent need for high-precision, bearing steel thick-walled pipe. (8) Automotive industry: 95 transmission shaft with precision tube 6000 tons, half axle casing 10,000 tons and a variety of pipelines. (9) Aviation industry: aluminum alloy aircraft landing gear pipe and thick-walled steel pipe. (10) Jack Industry: China's Jack Manufacturing has a considerable strength, the prospect of export earnings. At present, most of the jack cylinder using solid rod processing, low production efficiency, high material waste, the demand for high precision cold drawing pipe. (11) Other fields: all kinds of printing and dyeing rollers, roller rollers with tubes, stainless steel tubes, aluminum tubes, copper tubes, irregular tubes and internal and external composite pipe and so on can be used in this technology production.