Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
  • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
  • B21B1/463—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
  • B21B13/22—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories for rolling metal immediately subsequent to continuous casting, i.e. in-line rolling of steel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/46—Roll speed or drive motor control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
  • B21B45/0203—Cooling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/12—Accessories for subsequent treating or working cast stock in situ
  • B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B15/00—Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B2015/0057—Coiling the rolled product
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
  • B21B45/0203—Cooling
  • B21B45/0209—Cooling devices, e.g. using gaseous coolants
  • B21B45/0215—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes
  • B21B45/0218—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes for strips, sheets, or plates

Definitions

• the application belongs to metallurgical metal processing field, more specifically relates to a continuous casting and rolling process for medium plate.
• the traditional process comprise continuous casting thick billet with thickness of 200mm ⁇ 250mm, flame cutting, heating by walking-beam furnace, descaling, rolling by rough rolling group, shearing, descaling, rolling by finishing rolling train, stream cooling, coiling.
• the CSP process comprises continuous casting thin billet with thickness of 50mm ⁇ 70mm, flame cutting, heating by tunnel furnace, descaling, rolling by finishing rolling train, stream cooling, coiling.
• the ASP process has advantages of low cost, low investment, flexible production organization, simple maintaining, and low accident rate. But it still has disadvantages, for example, it uses too many old devices, the power of the motor of finishing rolling train is low, the speed of the roller table is low, the capacity of water supply is not enough, the strength of rolling mills' transmission system is not enough, the configuration of the power supply system is aging and so on. Therefore, the development of the technology is more or less limited, resulting that output can't reach requirement and the production development also be limited, and further the width precision, surface quality and shape control have certain limitation.
• the invention is aimed at eliminating the disadvantages of the above plate production process.
• the objects of the invention is to enhancing some crucial technique so as to save energy, not only improving the heating quality of billet but also improving the uniformity of plate thickness and quality of plate shape.
• the invention has advantage of high width precision, improves the work rate and output of the rolling mill, and makes the continuous casting and rolling process for medium plate meet the requirement of modem manufacturing.
• the production process of the invention substantially employs that of 02132970.2, and also makes some improvements basing on the former process, so as to improve the production capacity of the invention, broaden the range of the production categories, and meanwhile gain new revolution in the fields of shape control, width precision control and surface quality control.
• the invention also can realize direct rolling of some steel grades.
• the solution of the invention is a continuous casting and rolling process for medium plate comprising the following steps:
• the exiting roller tables are covered by insulating covers, such that the temperature drop of the casting billet and the temperature difference between the intermediate billet's head and tail are reduced and the temperature of the billet when entering the finishing rolling mill can be increased by 30 °C ⁇ 50 °C and the temperature difference between the billet's head and tail can be decreased by 30°C ⁇ 50°C..
• the vertical roller of the front and back vertical rollers provided in the rough rolling mill is top-attaching driven type, the size of rollers is ⁇ 1200mm/ ⁇ 1100mm ⁇ 430mm, and the power of main motor is AC1200kW X 2X 200/400r/min.
• the vertical roller of the vertical rollers provided before F1 is top-driven attached type, the size of rollers is ⁇ 750mm/ ⁇ 600mm ⁇ 350mm, and the main drive motor is 2-AC 370kW X 550r/min.
• hydraulic low-inertia kinks are provided between the finishing rolling stands in order to control tension between finishing rolling train and improve plate quality.
• the cooling device is provided with 12 sets of online high-level water tank with a water amount of 1700m 3 /h and a water pressure of 0.05Mpa ⁇ 0.08Mpa.
• Said mold is a mold for billet continuous casting which has a cavity whose four corners are in form of right angle or round angle or straight bevel angle
• the right angle mold is traditional billet mold which is composed by two wide sidewalls and two narrow sidewalls with a right angle being formed between respective wide sidewall and narrow sidewall
• the round angle or straight bevel angle mold for billet continuous casting is composed by two wide sidewalls and two narrow sidewalls, at both sides of each narrow sidewall, namely the inner sides connected with the wide sidewalls, respectively have a row of right-triangle shaped flange, the bevel of which directs to inside, one right-angle surface joins to the inner surface of the narrow sidewalls, and another right-angle surface is in the same plane with the side face of the narrow sidewalls, namely the another right-angle surface is an extension of the side face of the narrow sidewalls.
• said four-streams-merging-one technique optimizes logistics in three walking-beam furnaces with cushioning zone into which the medium plate in single roller table of two casters with four streams is directly fed, so as to exert the producing capacity of caster, furnace and rolling line and realize half-rigid connection of rolling line, furnace and caster.
• Said three kinds of timing control are:
• the invention has the following advantages:
• the invention improves the continuous casting and rolling process for medium/thin plate in terms of layout, devices and production process, so that the production ability, development of new grades, production quality are improved with the present invention, production capacity reaches 5000,000t per year, width precision within 0 ⁇ 10mm reaches 98.5%, the adjustment ability for shape control and crown control reaches advanced world standard, control ability of surface quality fully reaches the quality standard requirements of automobile's high grade panel (05), and the proportion of thin plate reaches advanced world standard.
• the invention applies to a continuous casting and rolling process for 2150 medium plate.
• Molten steel passes through three 250t top-bottom blowing converter, two molten iron desulphurizing and slag skimming station, two LF ladle furnace and one RH-TB vacuum processing device, and before being cast, it may be refined by LF ladle furnace or RH-TB vacuum processing device.
• Continuous casting molten steel passes through mold, to form continuous casting billet having section thickness of 100mm-170mm, width of 900-2000mm and length of 11m ⁇ 18m by hydraulic oscillating, continuously bending and continuously straightening, and then the billet is subjected to flame cutting.
• the billet has a maximum single weight of 38t, the average number of continuously casting furnaces is 30, and the average casting time is 37.3 minute per one furnace. Because of employing the technique of mold hydraulic oscillating, the quality of casting billet can be improved and also the billet surface defect can be eliminated.
• Direct rolling, hot feeding and hot charging by two casters with four streams and four-streams-merging-one technique in which each of the two continuous casters' knockout roller tables respectively connects with entering roller table and exiting roller table of heating furnace, achieving rapid hot feeding and hot charging or direct rolling for continuous casting billet; continuous casting billet is fed to entering roller table of heating furnace through convey roller table, then fed into walking-beam furnace by long-course steel loader of the heating furnace in order to be heated.
• the invention uses direct rolling technique for some kinds of carbon steel and certain kinds of lower alloy steel.
• the exiting roller table of the continuous caster connects with the entering roller table of the heating furnace so that the continuous casting billet is directly fed into the heating furnace by the roller table for hot charging.
• the hot charging temperature averagely is no less than 700°C.
• One exiting roller table of the continuous caster connects with the exiting roller table of the heating furnace.
• its length is automatically measured and also its temperature is measured by pyrometer, in order that the billet can be centered according the layout and then be heated.
• a computer is used to optimize the heating control based on the temperature of the billet entering the furnace.
• the billets are heated to 1150°C ⁇ 21250°C in the furnace, carried out of the furnace by the extractor of the furnace, and placed on the exiting roller table. This can not only save energy, but also shorten heating time and improve heating quality of the billet.
• Some kinds of carbon steel and certain kinds of lower alloy steel, for example silicon steel may apply "lower temperature exiting" rolling technique, realizing rolling of different steel grades.
• the long-course steel loader used in the present invention not only makes the furnace having the ability of heating billet but also has the cushion ability for matching continuous casting and rolling pace. If the rolling mill temporarily halts for a short while, it at most can store nine cushioning billets, therefore the casting production is not affected.
• the four-streams-merging-one technique optimizes logistics in three walking-beam furnaces with cushioning zone into which the medium plate in single roller table of two casters with four streams is directly fed, so as to exert the producing capacity of caster, furnace and rolling line and realize half-rigid connection of rolling line, furnace and caster.
• Said three kinds of timing control are:
• Rough rolling the heated or direct rolled billet is conveyed by roller tables and passes through high-pressure water descaling box after the furnace so as to remove scale, and then enters into four-roller reversible rough rolling mill so as to be rolled.
• the four-roller reversible rough rolling mill has attached front and back vertical rollers with a type of top-attaching driven.
• the size of rollers is ⁇ 1200/ ⁇ 1100mm X 430mm, the maximum single-pass side-pressing amount is 50mm, the maximum rolling pressure is 3800kN, the rolling speed is 0 ⁇ 5.89m/s, and the power of main motor is AC1200kW X 2 X 200/400r/min.
• the front and back vertical rollers of the four-roller reversible rough rolling mill are provided with automatic width control system (AWC), its main purpose being to correct error of billet width caused by rolling pressure change and correct the width difference between the billet's head and tail.
• Width gage and pyrometer are provided after the four-roller reversible rough rolling mill, so as to monitor width and temperature of billet and provide correction data for setting of finishing rolling mill.
• the four-roller reversible rough rolling mill is also provided with dust removal device.
• Insulating cover is provided at the exiting roller table in order to reduce temperature drop of intermediate billet and temperature difference between the billet's head and tail.
• Intermediate billet is conveyed to truncate scissor via insulating cover so as to truncate its head and tail.
• Detector is provided in front of the truncate scissor in order to detect the shape of the billet's head, so as to reduce temperature drop of intermediate billet and temperature difference between the billet's head and tail, and also the temperature at the time of entering finishing rolling mill can be improved by 30°C ⁇ 50°C and the temperature difference between the billet's head and tail can be shorten by 30°C ⁇ 50°C. Therefore, it can realize the optimal truncation of the scissor, in order to reduce truncation loss and increase yield.
• Edge heater is provided in front of the scissor.
• the heater's parameters are as follows: the power of the main motor is 2 X 3000kW, the heating depth is 40mm ⁇ 60mm, the heating width is 100mm ⁇ 150mm, and the temperature rise is 60 °C ⁇ 100°C. This helps to improve temperature uniformity of the billet, reduce edge crack, and improve mischcrystal of edge microstucture. Also this helps to stabilize operation of the finishing rolling mill, and simultaneously this can satisfy the requirement of dual phase steel development.
• the billet After being truncated head and tail, the billet enters into the high-pressure water descaling box before finishing rolling mill in order to remove regeneration scale.
• billet passes through the small vertical roller device F 1 E before finishing rolling mill F 1 so as to be rolled.
• the maximum pressing amount is 10mm
• the maximum rolling pressure is 1000kN
• the main driving motor is 2-AC 370kW X 550r/min.
• the billet is rolled into 1.8mm ⁇ 25.4mm final plate.
• F1 ⁇ F7 finishing rolling train all employ a device for axial shifting and bending working roller, the maximum shifting course is ⁇ 200mm, and the bending force is 1500kN.
• F3 ⁇ F6 in ASP have the device for axial shifting and bending working roller, and bending force only has positive value, no negative value.
• This not only can control thickness difference of plate section (crown and wedge) and plate flatness, but also can realize free rolling and increase rolling yield.
• the production line uses hydraulic low-inertia kink in order to control tension between finishing rolling train and improve plate quality.
• Stream cooling it uses three-stage stream cooling technique, in which roughly adjusting valve set and precisely adjusting valve set as well as 12 sets of online high-level water tank are provided, so as to stabilize water amount and water pressure of each cooling stage.
• the water amount is 1700m 3 /h
• the water pressure is 0.05Mpa ⁇ 0.08Mpa
• the side water-jet pressure is 1Mpa ⁇ 1.2Mpa, so as to assure the plate's lengthwise temperature uniformity.
• Coiling it uses stepping-controlled full hydraulic coiler to coil plate, in which automatic stepping control is performed by hydraulic-controlled side guide, pinch roller, wrapper roller's collapsible reels and high-responsivity wrapper roller to realize precise centering and micro-tension coiling of plate, reduce towered-shape, avoid the impaction of plate's head on wrapper roller and eliminate impression of plate's head and wrapper roller on plate
• the automatic system of the production line is three-grade computer control system, the first grade being basic automatic system, the second grade being procedure control computer system and the third grade being production control computer system.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Metal Rolling (AREA)

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ID=37029543

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Cited By (7)

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• 2005
  • 2005-03-28 CN CNA2005100461333A patent/CN1840252A/zh active Pending
• 2006
  • 2006-03-27 AT AT06722170T patent/ATE515334T1/de active
  • 2006-03-27 EP EP06722170A patent/EP1870172B1/de not_active Expired - Fee Related
  • 2006-03-27 WO PCT/CN2006/000518 patent/WO2006102835A1/zh not_active Application Discontinuation
  • 2006-03-27 KR KR1020077024084A patent/KR100960096B1/ko not_active IP Right Cessation
  • 2006-03-27 AU AU2006228889A patent/AU2006228889B2/en not_active Ceased

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