US20070193322A1 - Application of induction heating to control sheet flatness in cold rolling mills - Google Patents

Application of induction heating to control sheet flatness in cold rolling mills Download PDF

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Publication number
US20070193322A1
US20070193322A1 US11/676,908 US67690807A US2007193322A1 US 20070193322 A1 US20070193322 A1 US 20070193322A1 US 67690807 A US67690807 A US 67690807A US 2007193322 A1 US2007193322 A1 US 2007193322A1
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United States
Prior art keywords
flatness
work
rolled product
roller
rollers
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Abandoned
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US11/676,908
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English (en)
Inventor
William Beck
Srinivas Garimella
Michael Globig
Mark Puda
Michael Ringle
Frederic Schultheis
Neal Vernon
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Alcoa Corp
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Individual
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Priority to US11/676,908 priority Critical patent/US20070193322A1/en
Assigned to ALCOA INC. reassignment ALCOA INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: RINGLE, MICHAEL A., GARIMELLA, SRINIVAS S., VERNON, NEIL, BECK, WILLIAM J., SCHULTHEIS, FRED J., PUDA, MARK E., GLOBIG, MICHAEL
Publication of US20070193322A1 publication Critical patent/US20070193322A1/en
Abandoned legal-status Critical Current

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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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • B21B37/30—Control of flatness or profile during rolling of strip, sheets or plates using roll camber control
    • B21B37/32—Control of flatness or profile during rolling of strip, sheets or plates using roll camber control by cooling, heating or lubricating the rolls
    • 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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • 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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • B21B37/44—Control of flatness or profile during rolling of strip, sheets or plates using heating, lubricating or water-spray cooling of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
    • B21B2003/001—Aluminium or its alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/06—Lubricating, cooling or heating rolls
    • B21B27/10—Lubricating, cooling or heating rolls externally
    • B21B2027/103—Lubricating, cooling or heating rolls externally cooling externally
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2263/00—Shape of product
    • B21B2263/04—Flatness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2267/00—Roll parameters
    • B21B2267/18—Roll crown; roll profile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/06—Lubricating, cooling or heating rolls
    • B21B27/10—Lubricating, cooling or heating rolls externally
    • B21B27/106—Heating the rolls
    • 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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • B21B37/42—Control of flatness or profile during rolling of strip, sheets or plates using a combination of roll bending and axial shifting of the rolls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B21B38/02—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring flatness or profile of strips
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B21B38/06—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring tension or compression

Definitions

  • the invention relates to cold rolling, and a method of improving sheet flatness in cold rolled metal sheets utilizing induction heating.
  • Prior methods for forming aluminum strip have been unable to roll the strip uniformly over its entire width, and have not been able to provide rolled products being free of undesirable flatness undulations in the middle area, the edge area or the quarter area of the strip.
  • Unevenly distributed internal stresses resulting from the material being processed with prior methods typically result in edge cracking, wherein edge cracks need to be discarded resulting in sections of the rolled product being cut away and scrapped.
  • Edge cracking in the middle of a coil can require that the entire coil may need to be scrapped.
  • a method of forming metal sheet employs induction heating to thermally expand portions of the diameter of a singular work roll in response to flatness measurements taken from the metal strip downstream from the work roller.
  • the method includes:
  • adjusting the temperature of the singular roller includes selectively heating the edge portions of the work roller to thermally expand the portions of the work roller corresponds to the longitudinal edge of the metal strip to have a greater diameter than the work roller's center portion to provide a work roller having a non-uniform diameter along its width.
  • inductive heating is employed to adjust the temperature, in which inductive heating is provided by induction heating coils that apply heat to the portions of the work rollers that correspond to the portion of the contact surface between the work roller and the longitudinal edge of the metal strip being rolled.
  • the contact surface between the work roller and the metal strip is referred to as the working surface.
  • adjusting the temperature in the singular roller includes two induction heating coils positioned proximate to the singular work roller, wherein the heat applied by each induction heating coil is of a magnitude that adjusts the thermal expansion along a length of one of the work roller's axis such that the effect on the roll gap from the thermal crown on both rollers is fully compensated.
  • tension measurements are provided by a flatness bar positioned downstream from the work rollers that are in contact with at least one surface of the rolled product after being rolled by the working rollers.
  • the flatness bar may include a plurality of probes contacting the upper or lower surface of the metal sheet.
  • the tension measurements may be optically provided by methods including, but not limited to, optical scanning or laser measurements.
  • the tension measurements may be provided acoustically.
  • a method for forming metal sheet includes:
  • a system for rolling metal sheet having a substantially uniform flatness in another aspect of the invention, includes:
  • the induction heating apparatus is configured to eliminate high tension on the strip edges that may be caused by the temperature gradient in the work rolls at the edges of the metal strip.
  • the induction heating apparatus may further include bending jacks, work roll axial sliding mechanisms and a spray cooling system, wherein the bending jacks, axial sliding mechanism and spray cooling system may also be actuated by the mill control interface in response to flatness measurements.
  • FIG. 1 is a schematic view illustrating one embodiment of a system for controlling flatness in rolled sheet in accordance with the invention.
  • FIG. 2 a is a perspective view illustrating one embodiment of a system for controlling flatness in rolled sheet including two induction heaters corresponding to a singular work roller, in accordance with the invention.
  • FIG. 2 b is a perspective view illustrating another embodiment of a system for controlling flatness in rolled sheet including four induction heaters in a stacked arrangement and corresponding to a singular work roller, in accordance with the invention.
  • FIG. 2 c is a perspective view illustrating another embodiment of a system for controlling flatness in rolled sheet including four induction heaters in a side by side arrangement and corresponding to a singular work roller, in accordance with the invention.
  • FIG. 2 d is a perspective view illustrating one embodiment of a cold rolling mill, in accordance with the present invention.
  • FIG. 3 is a plot illustrating one embodiment of a work roller in which the edge portions have been thermally expanded to provide a work roller having a non-uniform diameter along the roller's width.
  • FIG. 4 is a graphical representation of the tension distribution of a rolled product with induction heating to the edge portions of a singular work roller, in accordance with the present invention, in comparison to a rolled product without induction heating to the edge portions of a work roller.
  • FIG. 5 is a graphical representation of the tension distribution of a rolled product with induction heating to the edge portions of a singular work roller, in accordance with the present invention, in comparison to a rolled product without induction heating to the edge portions of a work roller.
  • FIG. 1 is a schematic representation of a cold rolling system 100 , wherein the cold rolling system 100 includes at least two work rolls 5 , an induction coil heating apparatus 10 a, and a flatness measuring device 15 configured to measure the surface flatness of a metal strip 1 being rolled by the work rollers 5 .
  • the work rollers 5 are arranged opposed to one another, in which the gap between the work rollers 5 is referred to as the roll gap 4 .
  • the work rollers 5 may be steel or another rigid metallic material.
  • the sheet to be rolled is inserted between the work rollers 5 and is rolled and drawn in a direction of arrow Z.
  • the metal strip 1 is aluminum or an aluminum alloy.
  • the metal strip 1 has a thickness prior to rolling ranging approximately 0.400′′ to approximately 0.010′′.
  • the metal strip is an aluminum alloy that may be rolled to as thin as approximately 0.008 inch, but it is noted that even lesser thicknesses are possible, wherein the thickness of the rolled product may depend upon the rolled product's intended application.
  • Hot rolling denotes metal sheet processing that have cooled to room temperature, but in the course of numerous cold rolling passes of aluminum sheet the material temperature may rise to approximately 330° F.
  • Hot rolling of aluminum sheet is generally characterized by processing temperatures ranging from approximately 550° F. to approximately 900° F. It is noted that the above temperatures are provided for illustrative purposes only, and are not intended to limit the invention thereto, as the processing temperatures may be modified by various processing conditions, such as rolling speed, number of cold rolling passes, and the degree of cooling between rolling passes.
  • the cross width thickness distribution of the metal strip 1 is defined by the thickness of the metal strip measured from the upper surface of the metal strip to the lower surface of the metal strip across the metal strip's width W 1 .
  • the roll gap profile may be defined as the dimension separating the opposing work surfaces 4 a, 4 b of the work rollers 5 , wherein the dimension separating the opposing work surfaces 4 a, 4 b of the work rollers 5 during rolling may not be uniform along the width of the work rollers 5 .
  • the differences between the geometry of the roll gap 4 and the cross width thickness distribution of the metal strip 1 may result in inconsistencies in the elongation of the metal strip 1 across the metal strip's width W 1 following rolling that may manifest as flatness defects in the rolled product.
  • the mismatch or inconsistencies of the profile of the roll gap 4 and the cross width thickness distribution of the metal strip 1 that typically results in flatness defects may result from a force exerted on the work rollers 5 by the metal strip 1 being rolled, which may be referred to as bending deflections.
  • the mismatch or inconsistencies between the profile of the roll gap 4 , and the cross width thickness distribution of the metal strip 1 that typically results in flatness defects may also result from thermal expansion of the work roller 5 that is at least partially attributed to frictional heat of the rolling process, which creates a thermal camber of the work roller 15 surfaces.
  • the temperature in each of the work rollers 15 typically peaks at the mid point M 1 of the work roller's width W 1 , hence the thermal expansion in each of the work rollers 5 is typically greatest at the work roller's midpoint M 1 and decreases towards the edges of the rolls, which may be referred to as a thermal crown.
  • the rolled product may be pulled under tension, wherein flatness defects may manifest as tight edges, which may have a propensity to crack.
  • the formation of tight edges at the edge portion of the metal strip being at a higher tension than the center portion of the metal strip is typically the limiting factor in the coiling speed of prior methods. It is noted that although bending jacks, coolant sprays, crowns mechanically ground into the work rollers, and work roll side shifting mechanisms may have a positive effect on reducing flatness defects in the center portions of the rolled product, such mechanisms do not provide a substantial reduction in flatness defects formed at the edge portion of the metal strip, such as the formation of tight edges.
  • substantially uniform tension distribution across the width of the rolled product means that when external tension is removed from the rolled product, and the rolled product is placed on a planar surface, there is substantially no lift off of the rolled product from the planar surface on which the rolled product is place. Substantially no lift off means that that lower surface of the rolled product is entirely in contact with the planar surface on which the rolled product is placed. External tension is the tension that is placed upon the sheet during coiling following rolling.
  • the longitudinal fibers across the rolled products width may be of substantially the same length in the absence of external tension.
  • the present invention measures flatness and the existence of flatness defects in the metal strip being rolled, such as tight edges, and in response to the measured flatness defects takes a corrective action that includes at least induction heaters corresponding to the edge portions of a singular work roller.
  • flatness measurements of the metal strip 1 are provided by a flatness measuring device 15 , that is positioned downstream of the work rollers 5 to measure the flatness of the rolled product.
  • the flatness measuring device 15 may be a flatness bar configured to measure a tension distribution of the rolled product from the center portion of the rolled product to the edge portion of the rolled product.
  • measuring a tension distribution from a center portion of the roller product to an edge portion of the roller product means that the tension may be measured in increments from the center of the rolled product across the width of the rolled product to the rolled products edge, wherein each increment may be considered a lane longitudinally extending along the length in the direction in which the rolled product may be rolled.
  • the plurality of rotors measure the cross width tension distribution across the width of the metal strip 1 .
  • the flatness bar may include a plurality of probes contacting the surface of the metal sheet. More particularly, the rolled product is coiled under tension, wherein prior to coiling the rolled product contacts the flatness bar under which a force is induced in the y-direction upon the probes of the flatness bar, as depicted in FIGS. 2 a - 2 c. As discussed above, in some embodiments, the coiling tension provides a sheet that may appear to be visually flat while being coiled, but this application of external tension does not correct to the differences in elongation that manifests as flatness defects when the external tension is removed.
  • the flatness bar may include a plurality of rotors 15 A, preferably having a width of 0.5′′ to 3.0′′, disposed along an arbor, wherein each of the rotors measures force along a lane corresponding to the tension of the metal strip 1 being rolled.
  • the flatness of the metal sheet 1 may be optically measured or may be characterized using lasers.
  • the flatness measuring device may also include a non-contact system that measures the tension distribution of the metal strip using acoustical measurements. The acoustical measurements may be provided by sinusoidally modulating a vacuum under the metal strip 1 . It is noted that the above flatness measuring devices 15 are provided for illustrative purposes and that the present invention is not deemed limited thereto, since any flatness measuring device that is capable of measuring the flatness of the metal strip 1 being rolled, or determine the cross width tension distribution across the width of the metal strip 1 may be utilized and are within the scope of the invention.
  • the induction heating apparatus 10 may be actuated in response to defects in the flatness or tension differentials in the metal strip 1 .
  • Induction heating is a method by which the steel work rollers are heated by a non-contact method of using an alternating magnetic field.
  • the induction heating apparatus is composed of at least a power source which provides a power output at the required power frequency and an induction coil assembly.
  • the power source drives a high frequency alternating electric current through the induction coil assembly.
  • the alternating magnetic field induces a current flow in the singular work roller that may referred to as eddy currents.
  • the current flow through the work roller increases the temperature in the work roller 5 through joule heating.
  • each induction coil 10 may include a ferromagnetic core.
  • the induction coil heating apparatus 10 may further include at least one cooling passage for providing a cooling liquid or may not include cooling passages.
  • the current through the electrically conductive coil may be on the order of about 80 amps to about 200 amps.
  • the power supply to the induction heaters has a fixed operating frequency, wherein the frequency of the electrical current signal sent to the heating coil is about 20 KHz.
  • the current wave to the induction heater is sinusoidal with varying amplitude. Power to the induction heaters is adjusted by changing the amplitude of the sinusoidal current wave over a set number of cycles in a repeating pattern. The duration of the repeating pattern is about 8 cycles of the operating waveform.
  • the current signal is a 20 KHz sinusoidal wave with constant amplitude.
  • adjusting the temperature of the singular work roller includes induction heating coils 10 to induce heating in the portions of the work roller 5 adjacent to the work surface corresponding to the metal strip edges 13 a, 13 b. More specifically, the induction heating coils 10 a, 10 b, 10 c, 10 d are aligned with the portion of the work roller that contacts the longitudinal edge 13 a, 13 b of the metal strip being rolled to provide the rolled product, wherein the longitudinal edge 13 a, 13 b extends along the rolling direction. Referring to FIG.
  • adjusting the heat generated by the induction heating apparatus in the singular work roller includes one induction heating coil 10 a, 10 b positioned at each end of the roller 5 , wherein each induction heating coil 10 a, 10 b corresponds to each edge of the metal strip 1 .
  • adjusting the heat generated by the induction heating apparatus in the singular work roller 5 includes two induction heaters 10 a, 10 b corresponding to each edge 13 a, 13 b of the metal strip 1 , wherein the positioning of the induction coils are in a stacked configuration that may correspond to the circumference of the work roller, as depicted in FIG. 2 b.
  • the induction heating apparatus may include two coils corresponding to each edge 13 a, 13 b of the metal strip 1 , wherein the coils are positioned adjacent to one another, as depicted in FIG. 2 c.
  • each induction coil 10 may correspond to the portion of the work roller 5 adjacent to the work roller's contact surface at which the metal strip 1 is being rolled, which may also be referred to as the working surface.
  • each induction coil 10 may be disposed laterally in a direction parallel to the roller's axis of rotation to reposition the coils to or near the edges of each strip. By providing induction coils 10 that may be laterally disposed the position of the induction coils may be positioned to account for metal strip's having different widths.
  • the induction coils may also include a mechanism to set the gap between the induction coil and the work surface of the work roll.
  • a hydraulic cylinder with a position control moves the induction coil forward until contact with roll is made and then backs off of the roll work approximately 3 mm. It is noted that other dimensions for the gap separating the induction coil from the work roll have also been contemplated and are within the scope of the present invention, so long as the degree of separation allows for effective coupling of the magnetic field from the coil to the roll so eddy currents are induced in the roll.
  • the induction heaters 10 a, 10 b, 10 c, 10 d provide a sufficient heat to thermally expand the diameter of a singular work roller corresponding to the edge of the metal strip to be greater than the diameter of a center portion of the singular roller.
  • singular work roller denotes one work roller of the pair of work rollers 5 , wherein the singular work roller may be either the upper or lower work roller of the pair of work rollers.
  • edge diameter of the singular roller means the diameter of the portion of the singular roller corresponding to the longitudinal edge 13 a, 13 b of the metal sheet.
  • center diameter of the singular work roller denotes the diameter of the portions of the roller between each edge diameter of the singular roller.
  • the energy applied by the induction heating coils to increase surface temperature is of a magnitude that may provide increased thermal expansion at the section of the work roller adjacent to the metal strip's edges 13 a, 13 b relative to the thermal expansion of the central section of the work roller.
  • reference line 50 represents the thermal expansion across the width W 1 of the singular work roller being heated by induction heating, in accordance with the present invention
  • reference line 51 represents the thermal expansion along the width W 1 of the opposing roller that is not being heated by induction heating.
  • the degree of thermal expansion is directly correlated to the temperature of the roller, wherein portions of the roller having higher temperatures have a higher degree of thermal expansion.
  • the degree of thermal expansion in the singular roller 50 is selected to compensate for the thermal expansion 51 in the opposing rolling that does not include induction heaters. More specifically, as depicted by reference line 50 , the increased thermal expansion in the sections of the work roller 5 that are adjacent to the longitudinal edge 13 a, 13 b of metal strip in the work roller having induction heating coils offsets the decrease in thermal expansion in the sections of the work roller adjacent to the metal strip of the opposed work roller that does not induction heating coils, wherein the decrease in thermal expansion may be referred to as a roll off effect.
  • the combination of the increased thermal expansion at the edge of the strip in the singular work roller and the normal roll-off at the edge diameter of the opposing work roller presents the equivalent of a uniform roll gap to the strip being deformed across its width and results in a strip having uniform flatness substantially free of tight edges upon exiting of the rolling mill stand. More specifically, the thermal expansion in the edge diameter of the singular work roller is selected to compensate for the opposing roller that has a greater diameter at the opposing roller's center in comparison to the opposing roller's edge diameter.
  • the change of dimension in the edge diameter of the singular work roller may be on the order of about 0.005 inch, in which greater and lesser degrees of expansion have been contemplated, since the degree of thermal expansion required to correct flatness defects may be effected by process conditions that include, but is not limited to, the rolling speed, rolled product material selection, the degree of heat provided by the induction heating apparatus, as well as the degree of coolant applied to the center portion of the work roller.
  • the rolling mill 100 may also include a cooling spray system 25 in close proximity to the portion of the work rollers 5 that are in contact with the metal strip 1 being rolled.
  • the cooling spray system 25 may spray a cooling liquid 25 A at the portion of the work rollers 5 that contacts the metal strip 1 , wherein the cooling liquid removes a portion of the heat generated by the rolling of the metal strip 1 in the work rollers 5 . Removing the heat generated in the work rollers 5 by the rolling of the metal strip 1 through cooling spay systems cannot by themselves reduce the buildup of a thermal crown that contributes to flatness defects and tight edges.
  • the differential in the sheet flatness of the rolled product may be further reduced by mechanical generation of a force that flexes the work rolls in a direction opposed to the roll flexing caused by the force generated by the metal strip 1 on the work roller 5 during rolling.
  • roll bending jacks 21 and/or side roll shift mechanisms may be utilized to generate an adjustment to the roll gap that compensates for the bending defects of the rolls resulting from the force generated by the metal strip on the work roller during rolling operations.
  • the rolling mill 100 may further include bending jacks 20 corresponding to each work roller 5 , wherein the bending jack 20 may displace a portion of the work rollers 5 along the y-axis to substantially reduce the effect of the thermal crown on the metal strip 1 and along with the roll cooling sprays 25 facilitate the formation of a metal strip 1 having a substantially uniform flatness across the central portion of the strip, but leaving the outer edges of the strip under tension.
  • These bending jacks 20 may be referred to as negative bending jacks, and flex the work roller in a direction opposed to the positive bending jacks 21 .
  • the amount of bending jack force required and its direction is determined by the combination of the amount of flexing of the work roll 5 caused by strip force, the crown ground onto the work roll, and the amount of thermal expansion in the work roll 5 .
  • the work rollers 5 may also include a work roll side shifting mechanism (not shown) being configured to shift each roll 5 along a substantially horizontal axis, such as the x-axis as depicted in FIGS. 2 a - 2 c.
  • the roll diameter of each of the opposing work rollers is ground to vary along its axis, wherein axially shifting the varying rolls to manipulate the roll gap 4 provides a correction factor that may be employed in response to measured flatness defects.
  • the opposing work rollers having varying diameters when axially shifted by work roll side shifting mechanisms provide another means for reducing the effects of thermal crowns buildup and roll bending from the strip force.
  • a pair of backup rollers 6 may be employed in conjunction with the work rollers 5 in a configuration typically referred to as a four high rolling mill stand.
  • the backup rolls 6 are used to support the work rolls and minimize their bending in response to the force of the strip.
  • a pair of intermediate rollers 8 may be disposed between the backup rollers 6 and the work rollers 5 in a configuration typically referred to as a six high rolling mill stand.
  • the intermediate rollers also may include intermediate side shifting mechanisms and intermediate roll bending jacks.
  • the rolling system 100 also includes a rolling mill control interface 30 connected between the flatness measuring device 15 and the rolling mill's actuators.
  • the rolling mill control interface 30 receives a signal from the flatness measuring device 15 representing measurements of differentials in the sheet flatness of the metal strip 1 or the tension distribution across the width of the metal strip 1 .
  • the rolling mill control interface 30 then processes and analyzes the signal in comparison with a predetermined target flatness value or tension distribution.
  • the rolling mill control interface processes the measured signals and formulates control outputs to the mill actuators based on a set of mathematical algorithms.
  • the rolling mill interface 30 includes a computer.
  • the rolling mill control interface 30 then sends actuating signals to at least the cooling spray system 25 , bending jacks 20 or induction heating coils 10 to compensate for differentials measured in the sheet flatness or cross tension distribution of the metal strip resulting in a metal strip 1 having a substantially flat surface that is substantially free of tight edges and thermal crown effects.
  • FIG. 4 graphically depicts a tension distribution across the rolled product that is provided by induction heaters corresponding to the edge diameter of a singular work roller, in comparison to the tension distribution provided by a similiarly prepared rolled product without induction heating.
  • the vertical axis represents the tension (pounds per square inch) that is measured in the rolled product
  • the horizontal axis represents the width of the rolled product, wherein tension measurements were incrementally recorded from a flatness bar in which each zone of the sheet corresponded width of the rolled product.
  • the tension distribution recorded in FIG. 4 is normalized to the nominal coiling tension, which may be on the order of 3000 Psi.
  • the tension distribution of the metal strip processed in accordance with the present invention 61 includes thermal control with induction heaters positioned corresponding to the portions of a singular work roller corresponding to the strip edge of the singular work roller and a roll cooling spray system corresponding to at least a portion of the center portion of the work roller.
  • the tension distribution of the metal strip processed in accordance with the present invention further included bending jacks configured to flex the work rollers in a direction to oppose the normal flexing caused by the force produced on the work roller by the metal strip.
  • the tension distribution of the metal strip processed in accordance with the present invention further included a flatness measuring device and a rolling mill control interface, where tension measurements taken from the flatness measuring device were analyzed by the rolling mill control interface and in response to the tension measurement correction factors were actuated in the bending jacks, roll cooling system, and induction heaters.
  • the comparative example 60 was a metal strip that had been processed with bending jacks and roll cooling to optimize the measured flatness, but did not include induction heaters positioned corresponding to a singular work roller and directed to thermally expand the edge diameter of the work roller to be greater than the work roller's center diameter.
  • an increase in tension in excess of 1000 psi is measured in the edge portions of the rolled product, as indicated by the portions of the flatness measuring device corresponding to zone 1 and zone 20 of FIG. 4 , hence indicating the incidence of tight edges in the rolled product.
  • the center portions of the rolled product of the comparative example 60 as indicated by zone 3 to zone 17 , have a substantially uniform tension distribution indicating substantially no flatness defects in the center portion of the rolled product.
  • Zones 2 and 19 are of low tension, and may be referred to as loose zones, which have a recorded tension being less than the externally applied tension, the externally applied tension including, but not being limited to, the coiling tension.
  • the comparative example 60 indicates that although the bending jacks 20 and cooling spray system 25 reduce the effect of the thermal crown in the center portions of the work rollers 5 , the bending jacks and cooling spray system fail to reduce the incidence of tight edges and adjacent loose zone.
  • FIG. 5 depicts the tension distribution 61 of a rolled product, processed in accordance with the present invention, including thermal control by induction heaters positioned corresponding to the portions of a singular work roller corresponding to the strip edge, and a comparative example 60 not including induction heaters, wherein the coiling speed of approximately 1250 ft/min of the rolled product processed in accordance with the present invention is twice the coiling speed of the comparative example, which is 625 ft/min.
  • Each of the rolled products depicted in FIG. 5 are composed of an Aluminum Association 6061 aluminum alloy and is processed through a two stand cold rolling mill from a thickness of approximately 0.125′′ to approximately 0.0226 ⁇ .
  • the tension distribution of a rolled product processed using induction heating in accordance with the present invention allowed for a coiling speed of 1250 ft/min while having a measured edge tension of approximately 750 psi or less.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Control Of Metal Rolling (AREA)
  • General Induction Heating (AREA)
US11/676,908 2006-02-17 2007-02-20 Application of induction heating to control sheet flatness in cold rolling mills Abandoned US20070193322A1 (en)

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WO2013175158A1 (en) * 2012-05-19 2013-11-28 David Littler Rolling mill temperature control
EP2842646A1 (de) * 2013-08-29 2015-03-04 Siemens Aktiengesellschaft Verfahren und Vorrichtung zum Temperieren von Walzen
US20150233694A1 (en) * 2014-02-17 2015-08-20 Machine Concepts, Inc. Shape sensor devices, shape error detection systems, and related shape sensing methods
US20150258592A1 (en) * 2012-10-09 2015-09-17 Siemens Aktiengesellschaft Width-altering system for strip-shaped rolled material
US20160332203A1 (en) * 2014-01-20 2016-11-17 Jfe Steel Corporation Cold rolling apparatus
US9889480B2 (en) 2013-03-11 2018-02-13 Novelis Inc. Flatness of a rolled strip
US20180085810A1 (en) * 2016-09-27 2018-03-29 Novelis Inc. Rapid heating of sheet metal blanks for stamping
WO2018197579A1 (de) * 2017-04-25 2018-11-01 Muhr Und Bender Kg Verfahren und vorrichtung zum ermitteln der planheit von bandmaterial und bearbeitungsanlage mit einer solchen vorrichtung
CN112974521A (zh) * 2021-02-08 2021-06-18 太原科技大学 一种求解铝合金厚板在同速异径蛇形轧制下曲率的方法
CN114769313A (zh) * 2022-04-24 2022-07-22 中色科技股份有限公司 一种铝板带箔轧机工作辊边部电磁感应加热系统及控制方法
CN115026133A (zh) * 2022-07-26 2022-09-09 一重集团大连工程技术有限公司 一种镁合金轧机工作辊在线加热装置及方法和轧机
US20230107171A1 (en) * 2020-01-29 2023-04-06 Primetals Technologies Japan, Ltd. Rolling mill and rolling method for metal plate
US20230241657A1 (en) * 2020-07-15 2023-08-03 Primetals Technologies Austria GmbH Method and installation for inductively heating flat objects
US11785678B2 (en) 2016-09-27 2023-10-10 Novelis Inc. Rotating magnet heat induction
WO2024041892A1 (de) * 2022-08-24 2024-02-29 Sms Group Gmbh Verfahren, computerprogrammprodukt und kaltwalzgerüst zum kaltwalzen eines metallbandes
CN120079695A (zh) * 2025-04-28 2025-06-03 太原理工大学 一种带材复合装置及带材复合轧制系统

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CN103736742A (zh) * 2013-12-26 2014-04-23 秦皇岛首秦金属材料有限公司 一种中厚板表面纵向边部裂纹控制方法
CN106734241A (zh) * 2016-12-13 2017-05-31 新疆众和股份有限公司 铝箔轧机铝板带afc热喷淋控制系统
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EP4001447B1 (de) * 2019-08-30 2024-05-01 JFE Steel Corporation Stahlblech, element und verfahren zur herstellung davon
CN111266413A (zh) * 2020-02-24 2020-06-12 燕山大学 高硬脆冷轧带材高能电脉冲板形调控方法

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Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013175158A1 (en) * 2012-05-19 2013-11-28 David Littler Rolling mill temperature control
US9764367B2 (en) * 2012-10-09 2017-09-19 Primetals Technologies Germany Gmbh Width-altering system for strip-shaped rolling rock
US20150258592A1 (en) * 2012-10-09 2015-09-17 Siemens Aktiengesellschaft Width-altering system for strip-shaped rolled material
US10130979B2 (en) 2013-03-11 2018-11-20 Novelis Inc. Flatness of a rolled strip
US9889480B2 (en) 2013-03-11 2018-02-13 Novelis Inc. Flatness of a rolled strip
EP2842646A1 (de) * 2013-08-29 2015-03-04 Siemens Aktiengesellschaft Verfahren und Vorrichtung zum Temperieren von Walzen
WO2015028370A1 (de) * 2013-08-29 2015-03-05 Siemens Aktiengesellschaft Verfahren und vorrichtung zum temperieren von walzen
US10207303B2 (en) * 2014-01-20 2019-02-19 Jfe Steel Corporation Cold rolling apparatus
US20160332203A1 (en) * 2014-01-20 2016-11-17 Jfe Steel Corporation Cold rolling apparatus
US9459086B2 (en) * 2014-02-17 2016-10-04 Machine Concepts, Inc. Shape sensor devices, shape error detection systems, and related shape sensing methods
US20150233694A1 (en) * 2014-02-17 2015-08-20 Machine Concepts, Inc. Shape sensor devices, shape error detection systems, and related shape sensing methods
US12376200B2 (en) 2016-09-27 2025-07-29 Novelis Inc. Rotating magnet heat induction
US11242586B2 (en) 2016-09-27 2022-02-08 Novelis Inc. Systems and methods for threading a hot coil on a mill
US10508328B2 (en) * 2016-09-27 2019-12-17 Novelis Inc. Rapid heating of sheet metal blanks for stamping
US10837090B2 (en) 2016-09-27 2020-11-17 Novelis Inc. Magnetic levitation heating of metal with controlled surface quality
US10844467B2 (en) 2016-09-27 2020-11-24 Novelis Inc. Compact continuous annealing solution heat treatment
US20180085810A1 (en) * 2016-09-27 2018-03-29 Novelis Inc. Rapid heating of sheet metal blanks for stamping
US11072843B2 (en) 2016-09-27 2021-07-27 Novelis Inc. Systems and methods for non-contact tensioning of a metal strip
US11785678B2 (en) 2016-09-27 2023-10-10 Novelis Inc. Rotating magnet heat induction
US11377721B2 (en) 2016-09-27 2022-07-05 Novelis Inc. Systems and methods for threading a hot coil on a mill
US12338520B2 (en) 2016-09-27 2025-06-24 Novelis Inc. Pre-ageing systems and methods using magnetic heating
US11821066B2 (en) 2016-09-27 2023-11-21 Novelis Inc. Systems and methods for non-contact tensioning of a metal strip
US11479837B2 (en) 2016-09-27 2022-10-25 Novelis Inc. Pre-ageing systems and methods using magnetic heating
US11499213B2 (en) 2016-09-27 2022-11-15 Novelis Inc. Systems and methods for threading a hot coil on a mill
WO2018197579A1 (de) * 2017-04-25 2018-11-01 Muhr Und Bender Kg Verfahren und vorrichtung zum ermitteln der planheit von bandmaterial und bearbeitungsanlage mit einer solchen vorrichtung
US20230107171A1 (en) * 2020-01-29 2023-04-06 Primetals Technologies Japan, Ltd. Rolling mill and rolling method for metal plate
US12103060B2 (en) * 2020-01-29 2024-10-01 Primetals Technologies Japan, Ltd. Rolling mill and rolling method for metal plate
US20230241657A1 (en) * 2020-07-15 2023-08-03 Primetals Technologies Austria GmbH Method and installation for inductively heating flat objects
US12569896B2 (en) * 2020-07-15 2026-03-10 Primetals Technologies Austria GmbH Method and installation for inductively heating flat objects
CN112974521A (zh) * 2021-02-08 2021-06-18 太原科技大学 一种求解铝合金厚板在同速异径蛇形轧制下曲率的方法
CN114769313A (zh) * 2022-04-24 2022-07-22 中色科技股份有限公司 一种铝板带箔轧机工作辊边部电磁感应加热系统及控制方法
CN115026133A (zh) * 2022-07-26 2022-09-09 一重集团大连工程技术有限公司 一种镁合金轧机工作辊在线加热装置及方法和轧机
WO2024041892A1 (de) * 2022-08-24 2024-02-29 Sms Group Gmbh Verfahren, computerprogrammprodukt und kaltwalzgerüst zum kaltwalzen eines metallbandes
CN120079695A (zh) * 2025-04-28 2025-06-03 太原理工大学 一种带材复合装置及带材复合轧制系统

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AU2007214429A1 (en) 2007-08-23
BRPI0707959A2 (pt) 2011-05-17
CN101384382A (zh) 2009-03-11

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