【正文】 e is not stable enough, the deviation of the carbon has a number of worldclass production line, but the variety and quality of the product has not yet reached world class highquality alloy steel wire, pure steel wire, free cutting steel wire rod imports also there are many problems of the variety and quality, such as spring steel alloy, stainless steel a year to the operating rate of highline calendar and production of advanced countries in the machine production line, generally the larger the gap, resulting in low yield in the calendar of the operating rate and the machine because In addition to the lack of billet supply, mainly for production preparation and replacement size used for longer working hours, low life expectancy of equipment, spare parts and lack of reserves, equipment maintenance, testing means are inadequate, resulting in downtime and maintenance and long working line in hot charging rate, fuel consumption, electricity consumption in advanced countries than there are also a quality of the main issues。1)automatic monitoring device inaccurate, and the rolling temperature is uneven, adjustments are not timely or improper causes the product size is )due to the roller ring breaking, rolling groove wear or blank surface defects and other reasons caused by the product surface )Due to the the the billet subcutaneous bubbles serious or rolling groove is badly worn resulting in rolling convex part of the Roll caused by the product surface )Due to the quality of the roll surface hardness different or the spinning temperature is too high, the cooling rate is too slow, wire rod surface by severe oxidation or billet is heated properly, part or all of the serious decarburization causes the hemp side of the surface of the line used for the production of advanced technology and development trends billet hot delivery and hot charging process In order to further energy conservation, some highwire factory uses a billet hot charging process, further reducing fuel consumption and improve the heating quality, reduce metal charging temperature is generally at about 600 ℃, Germany BSW plant reached 650 ℃ ~ 920 ℃.Defectfree billet hot charging requirements, more billet defect site, it would be inappropriate to use the hot furnace The furnace is to ensure product quality, yield, and reduce the energy consumption of key , the furnace furnace selection and level of equipment, should match the scale and rolling line of the workshop process equipment and equipment highspeed wire rod mill, the rolling speed is high and needs to reduce its open rolling temperature controlled , the heating temperature, bining with the rolling mill, rolling speed and controlled rolling and cooling no head rolling Without a head rolling is one of the latest technology applications in the field of small bar and wire rod point is that just left the furnace and billet head welded to the rear of the former a billet without a head rolling, thereby eliminating the tensionfree section of the head and tail, in particular, to reduce the intermediate cutting head and bite into the accident, and improve the finished product rate and the metal yield, enhance the production efficiency of the the subvolumes in the set rolls, wire sub reel weight can be selected according to user factory in Japan39。s NKK Corporation Tokyo Steel wire rod and bar mill has endless rolling this are also a factory test welding without a head rolling, welding quality is not satisfactory, resulting in a greater loss coarse, medium rolling mill group of flat / vertical layout Crude Rolling short, the whole rolling site using a threeroll mill rolling, and subsequent rolling the stiffness is not conducive to the production of high precision a full level of rough rolling, intermediate rolling to singleline layout, mill on the flat / vertical alternate installation, the rolling, twisting road, reducing rolling to reverse the result of surface and internal defects and waste, and can choose to use the high stiffness mill, suitable for the production of highgrade prefinishing mill “microtwist mill” Prefinishing mill in the past as a separate drive / vertical alternating arrangement cantilever rack with or without arch cantilever mill small size, specifically to install the hard roll rings, but the poor mill mill is the high rigidity of the Short Stress mill roll can only use the hard steel roller, wear this end the new High Line will be the finishing mill group drive to extend the concept prefinishing is one of the latest progress of the highspeed wire rod is prefinishing four to large cantilever rolling mill, the top cross the 90 176。 arrangement, the oil film bearings [13].The mill two groups of collective drive, so called “minino twist advantage is tungsten carbide roll rings installed to extend the pass life, the main motor and gear reduction from four sets of two sets, 22% less cost than conventional independent prefinishing mill, and rolling section, rolling force, cantilever shorting mill stiffness without 39。s Anshan Iron and Steel wire rod plant in each line of the prefinishing area using two Φ230mm micro no twist mill Hangzhou Iron and Steel, Baotou Steel, silver water new highspeed wire rod factory prefinishing mill uses a micro no twist mill ”approach, achieved good of the heavy and super heavyduty Vshaped structure The rolling speed increases and the size range increases, highspeed twisting mill group last one finished size is sometimes great, its upper limit has been increased to Φ26mm, when the size of the line corresponding increase, coupled with low temperature rolling and also applies to the rolled alloy steel products and other factors, a sharp increase in the rolling this end, the improvement of the oil film bearing, have developed a Vshaped structure of the heavyduty and heavy load notwist finishing mill, Vis the roll box embedded in a Vshaped base, the more simple to install, better force of