US3802235A - Rolling mill gauge control method and apparatus including x-ray correction - Google Patents

Rolling mill gauge control method and apparatus including x-ray correction Download PDF

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Publication number
US3802235A
US3802235A US00303724A US30372472A US3802235A US 3802235 A US3802235 A US 3802235A US 00303724 A US00303724 A US 00303724A US 30372472 A US30372472 A US 30372472A US 3802235 A US3802235 A US 3802235A
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gauge
roll stand
workpiece
roll
stand
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R Fox
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AEG Westinghouse Industrial Automation Corp
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Westinghouse Electric Corp
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Priority to BE793761D priority Critical patent/BE793761A/xx
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Priority to US00303724A priority patent/US3802235A/en
Priority to AU50356/72A priority patent/AU458930B2/en
Priority to FR7300337A priority patent/FR2205375B1/fr
Priority to JP12408873A priority patent/JPS5340939B2/ja
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Assigned to AEG WESTINGHOUSE INDUSTRIAL AUTOMATION CORPORATION reassignment AEG WESTINGHOUSE INDUSTRIAL AUTOMATION CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION
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    • 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
    • B21B37/16—Control of thickness, width, diameter or other transverse dimensions

Definitions

  • An automatic gauge control is disclosed to provide on line control of the delivery gauge or thickness from at least one roll stand of a rolling mill.
  • the gauge error (gl. of the workpiece Strip leaving that one to stand is E 58] d 72/6 9 16 termined to include an X-ray gauge error portion and o earc I is corrected by predetermined adjustment of that one roll stand to provide a desired gauge correction in re- [56] SSE T lation to that one roll stand.
  • CONTROL i CONTROL INFORMATION II were J I DEV CES- CONTROL L' SYSTEM 5
  • the present invention relates to workpiece strip metal tandem rolling mills and more particularly to roll force gauge control systems and methods used in operating such rolling mills.
  • the unloaded roll opening and the speed at each tandem mill stand for each reversing mill pass are set up to produce successive workpiece strip or plate reduction resulting in work product at the desired gauge.
  • the loaded roll opening at a stand equals the stand delivery gauge or thickness on the basis of theusual assumption that there is little or no elastic workpiece recovery.
  • a stand automatic gauge control system is employed if it is necessary that the stand delivery gauge be closely controlled.
  • a stand gauge control system is normally used for a reversing mill stand and for predetermined stands in tandem rolling mills.
  • the roll force gauge control system uses Hookes law in controlling the screwdown position at a rolling stand, i.e., the loaded roll opening underworkpiece rolling conditions equals the unloaded roll opening or screwdown position plus the mill stand spring stretch caused by the separating force applied to the rolls by the workpiece.
  • a load cell or other force detector measures the roll separating force at each controlled roll stand and the screwdown position is controlled to balance roll force changes from a reference value and thereby hold the loaded roll opening at a substantially constant value.
  • I-lot strip mill automatic gauge control including evaluation of roll force feedback infonnation involves the combination of a number of process variables, such as roll force, screw position, and mill spring which are all used to evaluate the gauge of the strip as it is worked in each stand.
  • process variables such as roll force, screw position, and mill spring which are all used to evaluate the gauge of the strip as it is worked in each stand.
  • an X-ray gauge is used on the strip as it passes out of .the last stand to evaluate the absolute strip gauge produced.
  • the two gauge error detection system that are commonly used are the X-ray and roll force.
  • X-ray gauges can be placed between each stand, but they are expensive, difficult to maintain, and can detect errors only as the strip passes between stands.
  • the roll force error detection system is much less expensive, and can be more easily implemented in relation to the operation of all stands, to detect errors in gauge as the strip passes between the rolls of a particular roll stand, providing immediate evaluation of desired corrections to the roll openings.
  • the roll force system provides only a relative evaluation of the gauge, since it measures the amount of gauge deviation from a reference gauge, such as the gauge at the head end of the strip
  • a reference gauge such as the gauge at the head end of the strip
  • a practical combination of the two systems uses rollforce feedback to calculate fast corrections to fluctuations on gauge, and an X-ray to evaluate the absolute gauge of the strip coming out of the last stand.
  • the fast corrections are calculated from the roll force feedback, the stand screwdown position, and the modulus of elasticity of the rolling stand.
  • the slower X-ray gauge evaluation calculates simultaneous corrections to several stands, so that the absolute balue of the gauge may be brought to the desired value.
  • the roll force gauge control system is an analog arrangement including analog comparison and amplification circuitry which responds to roll force and screwdown position signals to control the screwdown position and hold the following equality:
  • a F measured change in roll force from an initial force
  • a SD controlled change in screwdown position from an initial screwdown position.
  • the lock-on screwdown position LOSD and the lock-on roll separating force LOF are measured to establish what strip delivery gauge G rolling operation proceeds, the roll stand separating force F and the roll stand screwdown position value SD are monitored periodically and any undesired change in roll separating force is detected and compensated for by a corresponding correction change in screwdown position.
  • the lock-on gauge LOG is equal to the lockon'screwdown LOSD plus the lock-on force LOF multiplied by the mill stand spring modulus K.
  • the workpiece strip delivery gauge G leaving the roll stand at any time during the rolling operation is in accordance with above Equation (1) and is equal to the unloaded screwdown position SD plus the roll separating force F multiplied by the mill spring modulus K.
  • the roll force determined gauge error GE in relation to a particular roll stand is derived by subtracting the lock-on gauge LOG from the delivery gauge G.
  • Equations 3, 4 and 5 set forth these relationships.
  • X-ray monitor gauge control system is usually employed to produce screwdown offset for the roll force control.
  • an X-ray or other radiation gauge sensing device is placed at one or more predetermined process points and usually at least at a process point following the delivery end after the last roll stand of the mill in order to sense actual delivery gauge after a workpiece transport delay from the point in time at which the actual delivery gauge is produced at the preceding stand or stands.
  • the monitor system compares the actual delivery gauge with the desired delivery gauge and develops an X-ray gauge error as an analog feedback control signal to adjust the operation of the reversing mill roll force gauge control system or one or more predetermined tandem mill stand roll force gauge control systems to supply desired steady state mill delivery gauge. in this manner, the conventional monitor system provides for transport delayed correction of steady state gauge errors which are caused or which are tending to be caused by a single mill variable or by a combination of mill variables.
  • G is the delivery gauge or thickness of the material leaving a given roll stand.
  • I S is the workpiece speed leaving that same roll stand.
  • W is the width of the workpiece leaving that same roll stand. Since the workpiece width remains substantially constant during the passage through the rolling mill, this mass flow relationship becomes:
  • XG(N) is the calculated mass flow delivery X-ray gauge leaving stand N.
  • XG(LS) is the X-ray measured delivery gauge leaving the last stand.
  • S(N) is the measured speed of the workpiece leaving stand N.
  • S(LS) is the measured speed of the workpiece leaving the last stand.
  • A'programmed digital computer system can be employed to make the gauge error ccgregtiorrscrewdown SUMMARY OF THE INVENTION
  • FIG. 1 shows a schematic diagram of a tandem hot steel strip rolling mill and an automatic gauge control system arranged foroperation in accordance with the present invention
  • FIG. 2 illustrates the typical mill spring curve and workpiece reduction curve for a given rolling mill stand and the operation of that roll stand for reducing the gauge of a workpiece passed through the roll stand;
  • FIG. 3 illustrates, in relation to the mill spring curve and the workpiece reduction curve, the effect of a correction made to the screwdown position setting for changing the unloaded roll opening of a roll stand to provide a desired change in the workpiece gauge delivered from that roll stand;
  • FIG. 4 shows an illustrative gauge error detection operation in relation to the initial lock on conditions at the head end of the workpiece
  • FIG. 5 shows a schematic illustration of the gauge error correction operation in accordance with the present invention.
  • FIG. 6 shows an illustrative logic flow chart of a suitable gauge error correction control program operative in accordance with the present invention.
  • FIG. 1 a tandem hot strip steel finishing mill 11 operated with improved gauge control performance by a process control system 13 in accordance with the principles of the invention.
  • a process control system 13 in accordance with the principles of the invention.
  • the invention is applicable to various types of mills in which roll force gauge control is employed.
  • the tandem mill 11 includes a series of reduction rolling stands with only two of the stands S1 and S6 shown.
  • a workpiece l5 enters the mill 11 at the entry end in the form of a bar and it is elongated as it is transported through the successive stands to the delivery end of the mill where it is coiled as a strip on a downcoiler 17.
  • the entry bar would be of known steel grade class and it typically would have a known input gauge or thickness of about 1 inch and a width within some limited range such as 20 inches to inches.
  • the delivered strip would usually have approximately the same width and a thickness based upon the production order for which it is intended.
  • the successive stands operate at successively higher speeds to maintain proper workpiece mass flow.
  • Each stand produces a predetermined reduction or draft such that the total mill draft reduces the entry bar to strip with the desired gauge or thickness.
  • Each stand is conventionally provided with a pair of backup rolls l9 and 21 and a pair of work rolls 23 and 25 between which the workpiece 15 is passed.
  • a large DC drive motor 27 is controllably energized at each stand to drive the corresponding work rolls at a controlled speed.
  • the sum of the unloaded work roll opening and the mill stretch substantially defines the workpiece gauge delivered from any particular stand in accordance with Hookes law.
  • a pair of screwdown motors 29 (only one shown at each stand) position respective screwdowns 31 (only one shown at each stand) which clamp against opposite ends of the backup rolls and thereby apply pressure to the work rolls.
  • the two screwdowns 31 at a particular stand would be in identical positions, but they can be located in different positions for strip guidance during threading, for flatness or other strip shape control purposes or possibly for another purposes.
  • a conventional screwdown position detector or encoder 33 provides an electrical signal representation of screwdown position at each stand.
  • a screwdown position detection system which includes the screwdown position detectors 33 can be provided and calibrated from time to time.
  • Roll force detection is provided at each of predetermined stands by a conventional load cell 35 which generates an electrical analog signal in accordance with the stand roll force.
  • each roll force controlled stand is provided with a load cell 35 and in many cases stands without roll force gauge control would also be equipped with load cells.
  • Th number of stands to which roll force gauge control is applied is predetermined during the mill design in accordance with cost-performance standards, and increasingly there is a tendency to apply roll force gauge control to all of the stands in a tandem hot strip steel mill. In the present case, a roll force gauge control system is assumed to be employed at each of the stands.
  • Conventional motorized sideguards 37 are located at predetermined points along the mill length. The sideguards are operated during mill setup on the basis of the widths of the upcoming workpiece thereby defining the sides of the workpiece travel path for guidance purposes.
  • the process control system 13 provides automatic control for the operation of the tandem mill 11 as well as desired control for associated production processes (not indicated) such as the operation of a roughing mill.
  • the process control system 13 can include a programmed process control digital computer system which is interfaced with the various mill sensors and the various mill control devices to provide control over many of the various functions involved in operating the tandem mill 1].
  • the control system 13 can also include conventional manual and/or automatic analog controls for selected process control functions.
  • automatic gauge control system 39 can include a digital computer systern operative to provide the finishing mill on-line roll force gauge control function, such as a Prodac 2000 (P2000) sold by Westinghouse Electric Corporation.
  • P2000 Prodac 2000
  • a descriptive book entitled Prodac 2000 Computer Systems Reference Manual has been published in 1970 by Westinghouse Electric Corporation and made available for the purpose of describing in greater detail this computer system and its operation.
  • the digital computer processor can be associated with well known predetermined input systems typically including a conventional contact closure input system which scans contact or other signals representing the status of various process conditions, a conventional analog input system which scans and converts process analog signals, and operator controlled and other information input devices and systems 31 such as paper tape teletypewriter and dial input systems.
  • information input devices 41 are generally indicated by a single block in FIG. 1 although different input devices can and typically would be associated with the control system.
  • Various kinds of information are entered into control system through the input devices 41 including, for example, desired strip delivery gauge and temperature, strip entry gauge and width and temperature (by entry detectors if desired), grade of steel being rolled, plasticity tables, hardward oriented programs and control programs for the programming system, and so forth.
  • the principal control action outputs from the automatic gauge control or AGC system include screwdown positioning reference commands which are applied to respective screwdown positioning controls 55.for operating the screwdown motors 29 for screw movement, and speed control signals which are applied to the respective speed and tension control system 53 to cause a change indrive speed to compensate for a change in thickness being made by a screwdown movement.
  • Display and printout devices 51 such as numeral display, tape punch, and teletypewriter systems can also be provided to keep the mill operator generally informed about the mill operation and in order to signal the operator regarding an event or alarm condition which may require some action on his part.
  • the printout devices are also used to log mill data according to computer log program direction.
  • the AGC system uses Hookes law to determine the total amount of screwdown movement required at each roll force controlled stand at the calculating point in time for roll force and gauge error correction, i.e., for loaded roll opening and stand delivery gauge correction to the desired value.
  • the calculation defines the total change in the unloaded roll opening required to offset the gauge error causing condition.
  • the on line gauge control system operates the stands to produce strip product having desired gauge and proper shape,.i.e., flat with slight crown.
  • On linegauge control is produced by the roll force gauge control loops at the stands and the previously noted X-ray monitor gauge control system.
  • the X-ray gauge 47 produces the X-ray gauge error or deviation signal which indicates the difference between actual strip delivery thickness and desired or target strip delivery thickness.
  • the AGC system operates at predetermined time periods such as every 2/10 second with the screwdown position detector and load cell provided signals from each stand as well as the X-ray gauge error signal to determine the respective stand screwdown adjustment control actions required for producing desired strip delivery gauge.
  • a mill modulus characteristic or mill spring curve 100 defines the separation between a pair of workpiece reducing mill stand work rolls as a function of separating force and as a function of screwdown position.
  • the slope of the mill spring curve 100 is the well known mill spring modulus or constant K which is subject to variation as well known to persons skilled in the art.
  • the entry gauge H of the workpiece passed through the roll stand is reduced to the indicated delivery gauge H, as defined by the intersection of the mill spring curve 100 and the product reduction curve 102 to establish the stand roll force required for the indicated operation.
  • the unloaded roll opening sometimes called the screwdown because of the screw and nut system used for adjusting the roll opening, is the gauge that would be delivered if-there were no roll separating force.
  • the delivery gauge increases, since the mill deflects as shown by the mill spring curve 100. If no force was exerted on the product being rolled, the gauge would not be reduced and the delivery gauge would be equal to the entry gauge.
  • the roll force increases, the product is plastically deformed and the delivery gauge decreases.
  • the slope of the mill spring characteristic line is called the mill modulus (K) and the slope of the product reduction characteristic is called the product plasticity (P).
  • the delivery gauge is determined by the equilibrium point at which the force exerted by the mill is equal to the force required to deform the product. Changes in entry gauge and product hardness result in a change in roll force and delivery gauge. The automatic gauge control moves the screwdown to correct for these gauge changes.
  • the main advantage of the roll force gauge control system is its ability to detect changes in gauge the instant they take place, as the product is being rolled in the stand. A shift in delivery thickness can be caused by a change in entry thickness or a change in hardness (usually caused by a change in temperature). This change in delivery gauge is immediately detected by monitoring the roll separating force of the roll stand.
  • the stand workpiece delivery gauge I-I equals the unloaded roll opening as defined by the screwdown position SDREF plus the mill stretch (F*K) caused by the workpiece. If the screwdown calibration is incorrect, i.e., if the number assigned to the theoretical roll facing screwdown position is something other than zero because of roll crown wear or other causes, the stand workpiece delivery gauge H then equals the unloaded roll opening plus the mill stretch, plus or minus the calibration drift.
  • the amount of mill stretch depends on the product deformation characteristic or reduction curve 102 for the workpiece.
  • the reduction curve 102 for a strip of predetermined width represents the amount of force F required to reduce the workpiece from the stand entry gauge (height) H
  • the workpiece plasticity P is the slope of the curve 10 2,and the curve 102 is shown as being linear although a small amount of nonlinearity would normally exist.
  • Desired workpiece delivery gauge H D is produced since the amount of force F required to reduce the workpiece from H to H is equal to the amount of roll separating force required to stretch the rolls to a loaded roll opening H i.e., the intersection of the mill spring curve 100 at an initial screwdown opening SDREF indicated by mill spring curve 100 and the workpiece reduction curve 102 lies at the desired gauge value H
  • the actual stand present gauge Hx is not the same'as the desired gauge H there is a gauge error GE to be corrected. This condition can be corrected by changing th provided screwdown position reference SDREF to the stand, such that a new mill spring curve 104 becomes operative to result in the desired gauge H being delivered from the roll stand and the gauge error GE is now removed.
  • ASD(N) exit GE(N) [(P(N)/K(N)) 1 ferred in terms of inches of screwdown position change per millions of pounds of roll force.
  • Th exit gauge error leaving stand (N) equals the sum of a first quantity, which is the difference between the presently measured screwdown position LOSD(N), and a seocnd quantity, which is the determined mill spring modulus K(N) times the difference between the presently measured roll separation force P(N) and the initial lock on roll force LOF(N).
  • the roll force gauge control system maintains substantially constant delivery gauge out of reach roll stand in relation to the initially setup lock on gauge at the head-end of each workpiece strip.
  • the X-ray gauge sensing device located after the last roll stand is used to determine the X-ray delivery gauge deviation leaving the rolling mill, in relation to the measured actual gauge and the desired reference gauge.
  • the particular roll stands selected by the operator for X-ray monitor correction are adjusted in operation to bring the final delivery gauge or thickness leaving the rolling mill into agreement with the desired refernce gauge, if the X-ray gauge deviation is not too large.
  • the measured output X-ray gauge deviation from the X-ray device is processed by the following Equation relationship:
  • the X-ray gauge error XGE(N) at stand (N) is utilized in combination with the roll force determined exit gauge error GE(N) to establish the desired screwdown position adjustment ASD(N) in accordance with the relationship of above Equation (1 l) modified as fo llowsi
  • the exit gauge error leaving last stand (LS) in relation to the operational variables sensed at the last stand (LS), and this utilizes above Equation (5) for this purpose.
  • FIG. 6 a flow chart to illustrate the operation of this program.
  • a check is made to see that the operator has selected the X-ray monitor operation to be operative.
  • a check is made to see that a particular X-ray device is selected for operation in the event that two X-ray devices are provided after the last stand.
  • a determination is made that the selected X-ray device is measuring strip gauge. If any one of the determinations at steps 600, 602 and 604 is negative then the program ends.
  • the operator desired target or nominal workpiece strip gauge leaving the rolling mill is read from storage.
  • gauge is herein used to mean the same as workpiece strip thickness, and it is commonly also spelled gage by persons skilled in this art.
  • the percent deviation between the desired nominal or reference gauge and the X-ray device measured actual gauge is now determined.
  • a limit check is-made, and if it is too large a flag is set and an alarm message printed at step 6l2 and the rogram ends. If the percent deviation is not too large, at step 614 a check is made to see if the head-end time delay has expired; and if it has not the program ends.
  • a determination is made to see if this is the first check on this strip.
  • step 620 a check is made to see if monitor hold is selected by the operator and if so at step 622 the present gauge is held. lf the check at step 618 was negative, the program goes to step 624 to set the drive number equal to last stand. If the check at step 620 was negative, the program goes to step 626 to determine if the gauge deviation gauge error is the maximum allowable. At step 628 a selection is made of the closest alternate gauge from the stored gauge table provided by the operator. From step 622 the program goes to step 630 to calculate a new percent deviation. At step 632 the monitor hold light is turned on. The comparison made at step 626 is provided to determine if the percent deviation is greater than some operator predetermined limit value, such as 10 percent. At step 628 a look-up table operation is provided in relation to operator provided values to reapply the desired or nominal strip gauge. At step 630 a new percent deviation is determined in relation to this new desired strip gauge.
  • the drive number is set equal to the last stand in preparation of determining the last stand speed and a mass flow relationship including proportional integration of the established gauge error to be performed on a selected stand by stand basis, generally three such stands are selected by the operator.
  • the last stand is addressed, and now the correction of the selected stand occurs.
  • a check is made to see if the selected stand has calibrated screws, and at step 628 a check is made to see if the X-ray monitor operation has been selected by the operator for this stand.
  • the X-ray correction is determined for the selected stands in accordance with above Equation (13), including the proportional integration function. This operation is continued for all selected stands.
  • step 634 the stand drive number is decremented at step 632 and a check is made at step 634 to see if this stand is number zero.
  • steps 636 and 638 the correction is limited.
  • step 640 if the stand roll force gauge control system is turned off, at step 642 the present screw position is read and an X-ray correction is output for this stand at step 644; this permits providing only the X-ray correction with the roll force system turned off for a given stand when desired by the operator.
  • step 646 a check is made to see if enough stands have been corrected.
  • step 634 a check is made to see if this stand under consideration is the first stand and at step 634 the stand number is decremented to continue the operation for all selected stands.
  • the typical AGC control program is written as a loop operation such that one set of coding processes all of the roll stands, and every time the program operates thrugh the loop a calculation is made when appropriate for each of the roll stands in relation to the gauge error and the X-ray gauge error correction.
  • the following table shows illustrative values of the first adjustment factor .Il/J2 as utilized in relation to above Equation (13) as well as the second adjustment factor 13/14 when plotted in relation to the respective stand numbers of a typical tandem rolling mill.
  • Jl/JZ J3IJ4 1 0.40 1.00 2 0.50 1.00 3 0.60 1.00 4 0.70 1.00 5 0.80 1.00 6 0.90 1.00 7- 1.00 1.00
  • Equation (13) operates on the X-ray gauge deviation as a proportional integrator, such that the first term of the Equation provides a substantially instantaneous response to changes in the X-ray gauge deviation measured by the X-ray device, while the second term of the Equation provides an integral response to the long term trends of the X-ray gauge deviation measured by the X-ray device.
  • Previous gauge control systems used the X-ray device to measure the deviation in gauge from the nominal selected value of desired delivery gauge by a comparison of the actual delivery gauge with the desired target delivery gauge to give this gauge deviation. This gauge deviation was applied as an offset recalibration to the screw position reading.
  • the present control arrangement takes a different approach, by determining the X-ray correction and applying the correction to the roll force gauge control Equation as an additional term in relation to the gauge error.
  • the previous offset was not GENERAL DESCRIPTION OF INSTRUCTION PROGRAM LISTING
  • Appendix there is included an instruction program listing that has been prepared to control the roll force automatic gauge control operation of a tandem rolling mill in accordance with the here disclosed control system and method.
  • the instruction program listing is written in the machine language of the PRODAC P2000 digital computer system, which is sold by Westinghouse Electric Corporation for real time process control computer applications. Many of these digital computer systems have already been supplied to customers, including customer instruction books and descriptive documentation to explainto persons skilled in this art the operation of the hardware logic and the executive software of this digital computer system. This instruction program listing is included to provide an illustration of one suitable embodiment of the present control system and method that has actually been prepared.
  • Step One Study the workpiece rolling mill and its operation to be controlled, and then stablish the e q n wlsy sm and. sthsqwn spt Step Two Develop an understanding of the control system logic analysis, regarding both hardware and software.
  • Step Three Prepare the system flowcharts and/or the more detailed programmer's tlowcharts.
  • Step Four Prepare the actual computer instruction P o ra t rom, it? tier shar a What we claim is: t
  • a gauge control system for a rolling mill having at least one roll stand (N) operative to reduce the gauge of a workpiece passed through said roll stand and including a device for measuring the gauge deviation of the workpiece leaving said rolling mill, said system comprising:
  • means for determining a gauge error of said workpiece leaving said one roll stand in relation to said measured gauge deviation means operative in relation to said gauge error for determining the required adjustment of said one roll stand in accordance with a predetermined relationship including the mill spring modulus of said one roll stand and the workpiece plasticity in relation to said one roll stand, and means for controlling the operation of said one roll stand in accordance with said required adjustment.
  • K is the mill spring modulus of said one roll stand
  • the gauge control system of claim 1 including means for determining a second gauge error of said workpiece leaving said one roll stand in relation to the roll force, and screwdown position of said one roll stand,
  • K(N) is the mill spring modulus of said one roll stand (N)
  • a gauge control system for a rolling mill having at least a first roll stand and a last roll stand operative with respective initial roll opening settings to reduce the gauge of a workpiece passed through said rolling mill and including a device positioned after said last roll stand for measuring the gauge deviation of said workpiece leaving said rolling mill, said system comprising:
  • XGE(N) Gauge Deviation (S(LS)/S(N)) RF(1) OLDXGE(N) RF(2)
  • XGE(N) is a gauge error at said first roll stand (N) in relation to said gauge deviation
  • a gauge control system for a rolling mill having a plurality of roll stands operative to reduce the gauge of 'a workpiece passed through each of said roll stands and including a device for measuring the gauge deviation of the workpiece leaving said rolling mill, said system comprising:
  • ASD(N) is the required adjustment of each said roll stand (N)
  • K(N) is the mill spring modulus in relation to each roll stand (N)
  • XGE(N) X-ray Deviation (S(LS)/S(N)) RF(1) OLDXGE(N) RF(2)
  • OLDXGE(N) is the integral of the gauge error in relation to said one roll stand (N)
  • RF(2) is a second predetermined response factor

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US00303724A 1972-11-06 1972-11-06 Rolling mill gauge control method and apparatus including x-ray correction Expired - Lifetime US3802235A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE793761D BE793761A (fr) 1972-11-06 Procede et appareil de commande de calibre de laminoir comprenant la correction aux rayons x
US00303724A US3802235A (en) 1972-11-06 1972-11-06 Rolling mill gauge control method and apparatus including x-ray correction
AU50356/72A AU458930B2 (en) 1972-11-06 1972-12-21 Improvements in or relating to rolling mill control method andi apparatus including xray correction
FR7300337A FR2205375B1 (ja) 1972-11-06 1973-01-05
JP12408873A JPS5340939B2 (ja) 1972-11-06 1973-11-06

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US4558576A (en) * 1983-11-14 1985-12-17 Morgan Construction Company Automatic gauge control system for multi-stand tied block rod rolling mill
US7104943B2 (en) * 2003-10-08 2006-09-12 G.D Societa' Per Azionivia Method and unit for flexing a flat blank for producing a rigid package

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US3561237A (en) * 1967-11-29 1971-02-09 Westinghouse Electric Corp Predictive gauge control method and apparatus for metal rolling mills
US3625037A (en) * 1969-02-25 1971-12-07 Hunter Eng Co Automatic gauge control system for a rolling mill

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Publication number Priority date Publication date Assignee Title
US3328987A (en) * 1964-05-14 1967-07-04 Crucible Steel Co America Gage-control apparatus
US3561237A (en) * 1967-11-29 1971-02-09 Westinghouse Electric Corp Predictive gauge control method and apparatus for metal rolling mills
US3625037A (en) * 1969-02-25 1971-12-07 Hunter Eng Co Automatic gauge control system for a rolling mill

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4558576A (en) * 1983-11-14 1985-12-17 Morgan Construction Company Automatic gauge control system for multi-stand tied block rod rolling mill
US7104943B2 (en) * 2003-10-08 2006-09-12 G.D Societa' Per Azionivia Method and unit for flexing a flat blank for producing a rigid package

Also Published As

Publication number Publication date
FR2205375A1 (ja) 1974-05-31
JPS5340939B2 (ja) 1978-10-30
JPS4978659A (ja) 1974-07-29
AU458930B2 (en) 1975-02-20
AU5035672A (en) 1974-06-27
BE793761A (fr) 1973-07-09
FR2205375B1 (ja) 1977-12-30

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