High precision cold drawn precision pipe technology and its application

High precision cold drawn precision tube is a new type of high-tech energy-saving products. In recent years, the use of this technology in the production of precision steel tube has been widely used in domestic hydraulic, pneumatic cylinder, coal mine bracket (pillar), oil pump pipe, jack and other manufacturing areas. Application of high precision cold drawn precision steel tube to save steel, improve the machining efficiency, save energy and reduce the hydraulic cylinder, cylinder processing equipment investment has important significance.

Cold drawn method: production of high precision cold drawn precision tube � � compared with traditional cutting technology, the hydraulic cylinder has the following characteristics: (1) high efficiency: with the traditional method to produce a 420 mm inner diameter, 12 meters long cylinder should be 154 hours, with cold drawn method production only 4 minutes. (2) high functions: due to the effect of rolling pressure head and the guide of the boring, in the process of cutting, the blank pipe due to the weight of the deflection, the rolling head deviate and boring cutter, cause waste. Functions only around 60%, and with cold drawn method production, functions can reach more than 95%. (3) high utilization rate of metal: made of traditional method of boring cylinder body, metal utilization only 50-70%. When using a method of drawing production, metal not only by cutting the end of the iron, it can get 30% extension of metal utilization rate can reach 95%. (4) can improve the mechanical properties of the finished tube metal: production by drawing method, make blank gets more than 30% of the plastic deformation, due to work hardening has greatly improve the strength of the finished tube metal limit. Generally in the finished tube layer strength limit increase of 60%. High precision cold drawn 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 of design of mould drawing, produce high precision tube. The dimensional accuracy of H10 ~ H8, straightness of 0.35 ~ 0.5 mm/m, the surface roughness Ra1.6-0.4.

Production process is as follows: feed, appearance inspection, mechanical cleaning, mechanical cleaning, annealing, straightening, tube processing, pickling, neutralizing - water - scale change - saponification - drawing - check - cut to length, honing, end processing, straightening, assembly, testing, packing

High precision cold drawn precision pipe application:  (1) engineering hydraulic machinery, such as hydraulic truck crane, excavator, bulldozer, forklift, etc. (2) in the coal mine hydraulic support: at present the national production has 48 downhole hydraulic support of the enterprise, the high precision cold drawn pipe, the total demand of about 1.2 million meters.  (3) hydropower station gate crane machine, template, especially in the Yangtze river three gorges project is a big demand in the next decade.  (4) construction machinery: the work high above the lifting machinery, general building construction repair is also inseparable from the hydraulic machinery.  petroleum geology pipe (5) : oil fields all over the country each year need to pump more than 30000 units, annual consumption and high precision tube more than 20-40 meters, also can use this technology finishing all kinds of drill pipe.  (6) arms industry: military departments now use guns tube spinning method processing, spinning method is low productivity and high cost, production is more appropriate in cold drawing way. (7) bearing industry: currently, the production of the rolling bearing race, with round steel as raw material, the slice through stamping. Large bearing race will be hollowed to make solid bar, metal utilization rate of less than 40%, an urgent need to high-precision, bearing steel thick wall pipe. Drive shaft, automobile industry (8) : 95 6000 tons of precision tube, axle tube 10000 tons and a variety of pipeline, etc.  (9) aviation industry: aluminum alloy aircraft landing gear and thick wall steel pipe, etc.  (10) jack: jack manufacturing in China has considerable strength, good prospects to earn foreign exchange through exports. Our production enterprises at present more than one thousand catties DingGang using solid bar processing, low production efficiency, high material waste, urgent demand for high precision cold drawn pipe.  (11) other areas: all kinds of printing roller, roller roller tube, stainless steel pipe, aluminum pipe, copper pipe, special pipe and the inner and outer pipe, and so on can be produced by this technology.