EP2366468B1 - Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure - Google Patents

Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure Download PDF

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Publication number
EP2366468B1
EP2366468B1 EP11165552A EP11165552A EP2366468B1 EP 2366468 B1 EP2366468 B1 EP 2366468B1 EP 11165552 A EP11165552 A EP 11165552A EP 11165552 A EP11165552 A EP 11165552A EP 2366468 B1 EP2366468 B1 EP 2366468B1
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EP
European Patent Office
Prior art keywords
rolling
wall thickness
grooved rolls
positions
blank
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Ceased
Application number
EP11165552A
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German (de)
English (en)
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EP2366468A1 (fr
Inventor
Kouji Nakaike
Kenichi Sasaki
Akihito Yamane
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Nippon Steel Corp
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Sumitomo Metal Industries Ltd
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Publication of EP2366468A1 publication Critical patent/EP2366468A1/fr
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B17/00—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling
    • B21B17/02—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling with mandrel, i.e. the mandrel rod contacts the rolled tube over the rod length
    • B21B17/04—Tube-rolling by rollers of which the axes are arranged essentially perpendicular to the axis of the work, e.g. "axial" tube-rolling with mandrel, i.e. the mandrel rod contacts the rolled tube over the rod length in a continuous process
    • 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
    • B21B37/78—Control of tube rolling
    • 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
    • B21B38/04—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring thickness, width, diameter or other transverse dimensions of the product

Definitions

  • This invention relates to a rolling control method, a rolling control apparatus and a control program for a mandrel mill, which make it possible to accurately roll a pierced blank for the entire length or a portion thereof in the lengthwise directions such as a tube end portion to a desired wall thickness when manufacturing a seamless tube or pipe (hereinafter simply referred to as a seamless tube) using a mandrel mill without deteriorating the surface properties of the resulting rolled blank, as well as a seamless tube manufactured by this rolling control method.
  • a rolling control method for a mandrel mill in accordance with the preamble of claim 1 is e.g. known from JP-A 632 38906 .
  • a starting material in the form of a round billet or a rectangular billet is heated to 1200 - 126° C in a rotary hearth heating furnace.
  • the heated round or rectangular billet is then pierced by a piercing mill having a plug and rolls to prepare a hollow pierced blank.
  • the wall thickness of the hollow pierced blank is reduced to a predetermined value by inserting a mandrel bar into the interior of the pierced blank and subjecting the hollow pierced blank to elongation rolling to form a rolled blank using a mandrel mill which usually includes 5 - 8 rolling stands while gripping the outer surface of the pierced blank with grooved rolls in each stand. Then, the mandrel bar is withdrawn from the rolled blank having a decreased wall thickness, and the rolled blank is passed through a reducing mill for sizing into a predetermined outer diameter, thereby producing a desired product in the form of a seamless tube.
  • a pair of opposing grooved rolls has conventionally been installed in each rolling stand of a mandrel mill.
  • a 2-roll type mandrel mill in which grooved rolls are alternatingly disposed such that the roll-reducing directions of the rolls changes by 90° between adjoining stands is particularly common.
  • a 4-roll type mandrel mill in which four grooved rolls are provided in each stand with the roll-reducing directions forming angles of 90° is also sometimes used.
  • a 3-roll type mandrel mill in which three grooved rolls are provided in each stand such that the roll-reducing directions of the rolls form angles of 120° and such that the roll-reducing directions varies by 60° between adjoining stands has also been proposed.
  • Patent Document 1 discloses a rolling control method in which an elongation rolling step using a mandrel mill, which is a step prior to a sizing step, is controlled so that the wall thickness of the end portions of the resulting rolled blank is increased, specifically by setting the gap between the grooved rolls installed in the finishing stand or stands of the mandrel mill such that the wall thickness of the end portions of the rolled blank after passing through the finishing stand or stands of the mandrel mill cancels out the decrease in the wall thickness of the end portions in the axial directions of the rolled blank which takes place in the sizing step.
  • Patent Document 2 describes a method of manufacturing a seamless tube which is accurately rolled to a desired wall thickness by controlling the opening size of the gap between grooved rolls installed in the finishing stand or stands of a mandrel mill in accordance with the actual wall thickness of a rolled blank measured on the exit side of the mandrel mill.
  • the wall thickness of a rolled blank on the exit side of a mandrel mill is measured using a thickness gauge installed on the exit side of the mandrel mill, and when the measured value of the wall thickness of the rolled blank on the exit side of the mandrel mill is smaller than a desired wall thickness, the opening size of the gap between the grooved rolls is adjusted so as to increase in accordance with the difference from the desired wall thickness, i.e., the rolling positions (rolling force-acting positions) of grooved rolls are moved outwards with respect to their initial rolling positions, whereby the accuracy of the wall thickness of a seamless tube can be increased.
  • the present invention was made in order to solve the above-described problems of the prior art, and its object is to provide a rolling control method, a rolling control apparatus and control program which make it possible to accurately perform rolling a pierced blank to a desired wall thickness for the entire length or a portion thereof, such as the end portions, when manufacturing a seamless tube using a mandrel mill, and a seamless tube manufactured by the rolling control method.
  • the present inventors performed diligent research concerning why a pierced blank could not be accurately rolled to a desired wall thickness and concerning the cause of a deterioration in the surface properties of a rolled blank by the method described in Patent Document 1. As a result, they discovered the following phenomenon. Normally, in a finishing stand of a mandrel mill (a stand in which grooved rolls which lastly contact a plurality of portions which have the same circumferential position of a pierced blank are installed), the reduction achieved by the grooved rolls in this stand is set to a small value in order to obtain good surface properties of the resulting rolled blank formed by finish rolling.
  • the idle rolling phenomenon which may occur in the bottom portions of the grooves in grooved rolls is a situation in which the wall thickness of a pierced blank in the position opposing the bottom portions of the grooves of grooved rolls on the entrance side of the finishing stand of a mandrel mill (the wall thickness of a pierced blank in the position opposing the bottom portions of the grooves of grooved rolls on the entrance side of a finishing stand means the wall thickness of the pierced blank in the position opposing the flange portions of grooved rolls in the rolling stand one stand upstream of the finishing stand, where the flange portions mean the portions positioned at 90° with respect to the bottom portions of the grooves of grooved rolls in the case of a 2-roll mandrel mill or the portions midway between the bottom portions of the grooves of adjoining grooved rolls in the case of a 3- or higher mandrel mill) becomes smaller than the gap between the mandrel bar and the grooved rolls in the finishing stand so that rolling does not take place in the finishing stand of the mand
  • the roll-reducing directions are limited to the directions perpendicular to the plate-shaped material, and if the gap between the rolls installed in an upstream stand is set so as to be at least as large as the gap between the rolls installed in a downstream stand, idle rolling does not occur at the time of reduction using the rolls installed in the downstream stand.
  • the positions at which rolling force is applied to the tube i.e., the positions of the bottom portions of the grooves of grooved rolls, differs between adjoining stands in the circumferential directions of a pierced blank to be rolled, and not only the wall thickness of the portions of the pierced blank opposing the bottom portions of the grooves of the grooved rolls but also the wall thickness of the portions of the pierced blank, which oppose the flange portions of the grooved rolls and to which a rolling force is not directly applied, reduces to a certain extent.
  • the reduction in wall thickness of the portions of a pierced blank opposing the flange portions of grooved rolls becomes larger than estimated, even if the gap between the grooved rolls installed in the upstream stand is set to be at least the gap between the grooved rolls installed in the downstream finishing stand, when the portions of a pierced blank which underwent a large reduction in wall thickness which opposed the flange portions of the grooved rolls in the upstream stand are rolled in the bottom portions of the grooves of the grooved rolls of the finishing stand, the wall thickness in these portions of the pierced blank sometimes becomes smaller than the gap between the mandrel bar and the grooved rolls in the finishing stand. As a result, the idle rolling phenomenon occurs in the bottom portions of the grooves of the grooved rolls.
  • the pierced blank can no longer be accurately rolled to a desired wall thickness in the finishing stand.
  • the wall thicknesses of the portions of the pierced blank opposing the flange portions of the grooved rolls installed in the upstream stand excessively decreases to such an extent that idle rolling occurs in the finishing stand, the wall thickness of the resulting rolled blank on the exit side of the finishing stand ends up becoming smaller than a desired wall thickness.
  • the primary purpose of rolling in the finishing stand of a mandrel mill is to make the inner and outer surfaces of a rolled blank smooth and regular by applying a light rolling force with a small amount of rolling reduction.
  • the idle rolling phenomenon manifests in the bottom portions of the grooves in the finishing stand, there end up being portions which do not undergo rolling force at all in that stand, and as a result, the surface properties of the resulting seamless tube worsen.
  • the present inventors discovered that the reason why a pierced blank cannot be accurately rolled to a desired wall thickness by elongation rolling and why the surface properties of the resulting rolled blank worsens resides in the idle rolling phenomenon occurring in the bottom portions of the grooves of the grooved rolls in a finishing stand of a mandrel mill. They performed further diligent investigations concerning a method capable of elongation rolling which does not produce the idle rolling phenomenon in the bottom portions of the grooves of grooved rolls.
  • a rolling control method for a mandrel mill having a plurality of rolling stands including a finishing stand by moving outwards the rolling positions of first grooved rolls installed in the finishing stand when a pierced blank is rolled in the finishing stand, characterized in that a thickness gauge which measures the wall thickness of the resulting rolled blank in the roll-reducing directions at each stand is installed on the exit side of the finishing stand, a previously set target wall thickness of a rolled blank is compared with the actual wall thickness of the rolled blank measured by the thickness gauge at the finishing stand, and if the actual wall thickness is smaller than the target wall thickness, movement of the rolling positions of the first grooved rolls is terminated for the next pierced blank to be rolled.
  • a thickness gauge is installed at the exit of a finishing stand, and in the finishing stand a previously set target wall thickness for a rolled blank is compared with the actual wall thickness of the rolled blank measured by the thickness gauge.
  • the actual wall thickness is smaller than the target wall thickness, there is the possibility that the idle rolling phenomenon is occurring in the bottom portions of the grooves of first grooved rolls installed in this stand. Accordingly, in this case, it is determined that the idle rolling phenomenon is occurring in the bottom portions of the grooves, and movement of the rolling positions of the first grooved rolls is terminated for the next pierced blank to be rolled.
  • the above method determines whether or not the idle rolling phenomenon is occurring in the bottom portions of the grooves by comparing the actual wall thickness with a target wall thickness. Instead, it is also possible to compare the amount of movement of the rolling positions of the first grooved rolls with the amount of change of the actual wall thickness of the rolled blank measured by the thickness gauge in the directions of movement of the first grooved rolls and to determine that the idle rolling phenomenon is occurring in the bottom portions of the grooves when the amount of change of the actual wall thickness is smaller than the amount of movement of the rolling positions of the first grooved rolls.
  • the bottom portions of the grooves of the first grooved rolls after movement of the rolling positions do not contact the outer peripheral surface of the pierced blank, and there is the possibility that the idle rolling phenomenon is occurring in the bottom portions of the grooves, so it can be determined that the idle rolling phenomenon is occurring in the bottom portions of the grooves.
  • the present invention provides a rolling control method for a mandrel mill having a plurality of rolling stands including a finishing stand by moving the rolling positions of first grooved rolls installed in the finishing stand outwards, characterized by installing a thickness gauge which measures the wall thickness of a rolled blank on the exit side of the finishing stand, comparing the amount of movement of the rolling positions of the first grooved rolls with the amount of change of the actual wall thickness of the rolled blank measured by the thickness gauge in the directions of movement of the first grooved rolls, and terminating movement of the rolling positions of the first grooved rolls for the next pierced blank to be rolled if the amount of change in the actual wall thickness is smaller than the amount of movement of the rolling positions.
  • the present invention is a rolling control apparatus for a mandrel mill having a plurality of rolling stands including a finishing stand and comprising a rolling position adjusting unit for adjusting the rolling positions of grooved rolls installed in the finishing stand and an arithmetic and control unit which instructs the rolling position adjusting unit as to an amount of adjustment of rolling positions for the grooved rolls, characterized in that the arithmetic and control unit is connected to a thickness gauge which is installed on the exit side of the finishing stand and which measures the wall thickness of the resulting rolled blank in the roll-reducing directions at each stand, and in that it carries out a rolling control method as set forth in claim 1 by instructing the rolling position adjusting unit to terminate adjustment of rolling position depending on the output of the thickness gauge.
  • the present invention is a rolling control program for operating an arithmetic and control unit which is connected to a rolling position adjusting unit for adjusting the rolling positions of grooved rolls installed in a finishing stand among a plurality of rolling stands constituting a mandrel mill and to a thickness gauge installed on the exit side of the finishing stand for measuring the wall thickness of a rolled blank in the roll reducing directions at each stand and which instructs the rolling position adjusting unit as to an amount of adjustment of rolling positions for the grooved rolls, characterized in that the arithmetic and control unit is operated so as to carry out a rolling control method as set forth in claim 1 by instructing the rolling position adjusting unit to terminate adjustment of rolling position depending on the output of the thickness gauge.
  • the present invention when manufacturing a seamless tube using a mandrel mill, it is possible to accurately roll a pierced blank for the eitire length of a portion in the lengthwise directions such as an end portion to a desired wall thickness without worsening the surface conditions or properties of the resulting rolled blank.
  • Figure 1 is block diagram schematically showing the structure of a rolling control apparatus for carrying out a rolling control method for a mandrel mill.
  • a rolling control apparatus 1 has a first rolling position adjusting unit 11, a second rolling position adjusting unit 12, and an arithmetic and control unit 13.
  • the first rolling position adjusting unit 11 is constituted by a cylinder or similar device for adjusting the rolling positions of grooved rolls installed in a finishing stand #i among a plurality of stands constituting a mandrel mill M.
  • the second rolling position adjusting unit 12 is constituted by a cylinder or similar device for adjusting the rolling positions of grooved rolls installed in the closest upstream stand to the finishing stand #i in the mill having the same roll-reducing directions (as the finishing stand), i.e., in stand #(i-2) positioned just two stands upstream of the finishing stand #i.
  • the arithmetic and control unit 13 is connected to the first rolling position adjusting unit 11 and the second rolling position adjusting unit 12 and is constructed so as to instruct the first rolling position adjusting unit 11 and the second rolling position adjusting unit 12 as to an appropriate amount of adjustment of rolling positions based on the current location of the end portions of a pierced blank S being rolled.
  • Each of the first rolling position adjusting unit 11 and the second rolling position adjusting unit 12 have a mechanism which can move the rolling positions of the grooved rolls installed in the stand during rolling in accordance with the portion (the leading end portion, the central portion, or the trailing end portion) of a single pierced blank S which is being rolled in that stand.
  • the arithmetic and control unit 13 is constituted by a computer equipped with hardware such as a CPU, a memory, an external storage device, and an external input/output interface. By suitably operating this hardware in accordance with a control program stored therein, it functions as a first rolling position setting part 131 and a second rolling position setting part 132.
  • An end portion sensing signal which indicates that an end portion of the pierced blank S was detected, for example, by a sensor (not shown) installed on the entrance side of the mandrel mill M is input to the first rolling position setting part 131.
  • the distance between the sensor and stand #i, the traveling speed of the pierced blank S, the elongation percentage of the pierced blank S in the mandrel mill M and similar parameters are input to this part from an upper level process computer (not shown), for example.
  • the first rolling position setting part 131 calculates the current position of the end portions of the pierced blank S. Specifically, it calculates the timing with which the end portions (leading end portion and trailing end portion) of the pierced blank S reach and leave the finishing stand #i.
  • the first rolling position setting part 131 determines an amount of adjustment of rolling positions for the first grooved rolls installed in the finishing stand #i, and it transmits the amount of adjustment of rolling positions which was determined to the first rolling position adjusting unit 11. Specifically, the rolling positions A of the first grooved rolls at the time of rolling of the end portions of the pierced blank S in the finishing stand #i and the rolling positions B of the first grooved rolls at the time of rolling the central portion of the pierced blank S are stored in the first rolling position setting part 131.
  • the first rolling position setting part 131 sets the difference (A - B) as the amount of adjustment of rolling positions so that the first grooved rolls will move from rolling positions B to rolling positions A by the time that the leading end portion of the pierced blank S reaches the finishing stand #i, and it transmits this value to the first rolling position adjusting unit 11.
  • the first rolling position setting part 131 sets the difference (B - A) as the amount of adjustment of rolling positions so that the first grooved rolls will move from rolling positions A to rolling positions B as soon as the leading end portion of the pierced blank S leaves the finishing stand #i, and it transmits this value to the first rolling position adjusting unit 11. Thereafter, it again sets the difference (A - B) as the amount of adjustment of rolling positions when the trailing end portion of the pierced blank S reaches the finishing stand #1 and it transmits this value to the first rolling position adjusting unit 11.
  • the difference (B - A) as the amount of adjustment of rolling positions so that the first grooved rolls will move from rolling positions A to rolling positions B in the period from when the trailing end portion of the pierced blank S leaves the finishing stand #1 until the leading end portion of the next pierced blank S to be rolled reaches the finishing stand #1, and it transmits this value to the first rolling position adjusting unit 11.
  • the rolling positions of the first grooved rolls installed in the finishing stand #i can be moved outwards, i.e., to rolling positions A, when the end portions of a pierced blank S are rolled in the finishing stand #i.
  • Rolling positions A and B vary depending on the dimensions, the wall thickness., the material, and the like of the pierced blank S being rolled, so a plurality of combinations of rolling positions A and B corresponding to various dimensions, wall thickness, material, and the like are stored in the first rolling position adjusting unit 11, and appropriate rolling positions A and B are selected in accordance with the dimensions, wall thickness, material, and the like of the pierced blank S which are input from the upper level process computer, for example.
  • end portion sensing signals and the like are input from the outside to the second rolling position setting part 132, and the timing with which the end portions (leading end portion and trailing end portion) of the pierced blank S reach and leave the upstream stand #(i-2) is calculated.
  • the second rolling position setting part 132 sets the amount of adjustment of rolling positions for the second grooved rolls installed in the upstream stand #(i-2) based on the calculated timing in the same manner as for the first rolling position setting part 131 and transmits the amount of adjustment of rolling positions which was set to the second rolling position adjusting unit 12.
  • the amount of adjustment of rolling positions which is transmitted to the second rolling position adjusting unit 12, i.e., an amount corresponding to the amount of movement when moving the rolling positions of the second grooved rolls installed in the upstream stand #(i-2) outwards when rolling the end portions of the pierced blank S in the upstream stand #(i-2) need not be set to the same value as the amount of adjustment of rolling positions transmitted to the first rolling position adjusting unit 11. For example, it can be set to a value resulting from multiplying by a predetermined coefficient greater than 0 and smaller than 1 (such as 0.8).
  • a rolling control apparatus 1 when rolling the end portions of a pierced blank S not only in the finishing stand #i but also in the upstream stand #(i-2), the rolling positions of the second grooved rolls installed in the upstream stand #(i-2) are moved outwards. Therefore, the rolling reduction in the bottom portions of the grooves when rolling the pierced blank S in the second grooved rolls is decreased, and an excessive decrease in the wall thickness of the portions opposing the flange portions of the grooved rolls installed in the next stand #(i-1) is eliminated. Therefore, the occurrence of the idle rolling phenomenon in the bottom portions of the grooves at the time of rolling with the first grooved rolls installed in the finishing stand #i is prevented. Accordingly, the end portions of a pierced blank S can be accurately rolled to a desired wall thickness, and a deterioration in the surface properties of the resulting rolled blank S can be prevented.
  • the second rolling position setting part 132 sets the amount of adjustment of rolling positions, namely, the amount of adjustment necessary to modify the rolling positions to the previously stored outwards positions when the signal indicating that the leading end portion of the pierced blank S has been sensed is input from the exterior, and it transmits the set amount of adjustment of rolling positions to the second rolling position adjusting unit 12.
  • the second rolling position adjusting unit 12 acts to move the rolling positions of the second grooved rolls outwards based on the transmitted amount of adjustment of rolling positions.
  • the modified rolling positions are maintained at the same value throughout rolling of the pierced blank S.
  • Figure 2 is a block diagram schematically showing the structure of a rolling control apparatus for carrying out a rolling control method for a mandrel mill.
  • a rolling control apparatus 2 has a rolling position adjusting unit 21 and an arithmetic and control unit 22.
  • the rolling position adjusting unit 21 has a mechanism which is constituted by a cylinder or similar device for adjusting the rolling positions of grooved rolls installed in the finishing stand #i among a plurality of rolling stands constituting a mandrel mill M and which can move the rolling positions of the grooved rolls in accordance with the portion being rolled (leading end portion, central portion, or trailing end portion) of a single pierced blank S during rolling.
  • the arithmetic and control unit 22 is constituted by a computer having hardware such as a CPU in the same manner as in the first embodiment, but it differs from the example of Figure 1 in that it is connected to a thickness gauge I which measures the wall thickness of the resulting rolled blank S in the roll-reducing directions at each stand (for example, the wall thickness in 4 directions when the mandrel mill M is a 2-roll type) and which is installed on the exit side of the finishing stand #i (in this embodiment, on the exit side of the mandrel mill M).
  • a thickness gauge I which measures the wall thickness of the resulting rolled blank S in the roll-reducing directions at each stand (for example, the wall thickness in 4 directions when the mandrel mill M is a 2-roll type) and which is installed on the exit side of the finishing stand #i (in this embodiment, on the exit side of the mandrel mill M).
  • the arithmetic and control unit 22 suitably drives hardware in accordance with a control program stored therein, whereby it functions as a rolling position setting part 221 and an idle rolling determining part 222. Depending on the output of the thickness gauge I, it instructs the rolling position adjusting unit 21 to stop adjustment of the rolling positions. In the following paragraph, it will be explained more concretely.
  • an end portion sensing signal for the pierced blank S and the like are input to the rolling position setting part 221, and it calculates the timing when the end portions (the leading end portion and the trailing end portion) of the pierced blank S reach and leave the finishing stand #i.
  • the rolling position setting part 221 stores the rolling positions of the grooved rolls when rolling the end portions and the central portion of the pierced blank S in the finishing stand #i.
  • the rolling position setting part 221 sets an amount of adjustment of rolling positions for the grooved rolls installed in the finishing stand #i based on the calculated timing and the stored rolling positions of the grooved rolls, and it transmits the set amount of adjustment of rolling positions to the rolling position adjusting unit 21. As a result, when the end portions of the pierced blank S are rolled in the finishing stand #i, the rolling positions of the grooved rolls installed in the finishing stand #i can be moved outwards by an amount corresponding to the amount of adjustment of rolling positions.
  • the output of the thickness gauge I (the actual wall thickness of the end portions of the rolled blank S) is input to the idle rolling determining part 222.
  • the target wall thickness of the end portions of the rolled blank S is previously stored in the idle rolling determining part 222.
  • the idle rolling determining part 222 compares the target wall thickness and the actual wall thickness of the rolled blank S, and when the actual wall thickness is smaller than the target wall thickness, namely, when at least one values of the actual wall thickness measured in the roll-reducing directions for the finishing stand #i is smaller than the target wall thickness, it is determined that the idle rolling phenomenon is occurring in the bottom portions of the grooves, and in other cases, it is determined that the phenomenon is not occurring.
  • the target wall thickness of the end portions of the rolled blank S is a value which varies in accordance with the dimensions of the pierced blank S being rolled, the target wall thickness of the central portion, the material of the pierced blank, and the like, so a plurality of target wall thicknesses corresponding to the dimensions, the wall thickness of the central portion, the material, and the like are stored in the first rolling position adjusting unit 11.
  • the target wall thickness is suitably selected in accordance with the dimensions of the pierced blank S, the wall thickness of the central portion, the material, and the like input from an upper level process computer.
  • the rolling position setting part 221 issues an instruction to terminate outwards movement of the rolling positions of the grooved rolls for the next pierced blank S to be rolled. Namely, when the end portions of the pierced blank S are rolled, it transmits an instruction to the rolling position adjusting unit 21 to maintain the rolling positions the same as when rolling the central portion of the pierced blank S. Specifically, it sets the amount of adjustment of rolling positions when rolling the end portions of the pierced blank S to zero, and it transmits this value to the rolling position adjusting unit 21.
  • the idle rolling determining part 222 determines that the idle rolling phenomenon is not occurring in the bottom portions of the grooves, for the next pierced blank S to be rolled as well, amounts of adjustment of rolling positions are set in accordance with the previously stored rolling positions of the grooved rolls when rolling the end portions and the central portion of the pierced blank S, and these values are transmitted to the rolling position adjusting unit 21.
  • a rolling control apparatus 2 movement of the grooved rolls outwards can be terminated for the next pierced blank S to be rolled so that the rolling reduction by the grooved rolls is not decreased, and the occurrence of the idle rolling phenomenon in the bottom portions of the grooves in the finishing stand #i can be prevented.
  • the end portions of the pierces blank S can be accurately rolled to a desired wall thickness, and worsening of the surface properties of the rolled blank S can be prevented.
  • the present invention is different to this mode as now described.
  • the rolling positions of the grooved rolls when rolling the end potions of the pierced blank S can be updated to a new position which is inward by the amount of the difference between the two wall thicknesses, and the new position is stored.
  • the amount of adjustment of rolling positions can be set in accordance with the previously stored rolling positions when rolling the central portion of the pierced blank S and the updated and stored new rolling positions when rolling the end portions of the pierced blank S, and these values can be transmitted to the rolling position adjusting unit 21.
  • modification of the set value in accordance with the actual wall thickness measured by the thickness gauge I can be terminated, and the set value for the pierced blank which was rolled this time can also be used for the next pierced blank S to be rolled.
  • the grooved rolls can be prevented from endlessly moving outwards.
  • the idle rolling determining part 222 compares the target wall thickness and the actual wall thickness of the rolled blank S and determines whether or not the idle rolling phenomenon is occurring in the bottom portions of the grooves based on the magnitude of the difference.
  • the method used by the idle rolling determining part 222 to determine whether the idle rolling phenomenon is occurring in the bottom portions of the grooves is not limited to this method.
  • the amount of movement of the rolling positions of the grooved rolls and the amount of change in the actual wall thickness of the rolled blank S measured by the thickness gauge I in the directions of movement of the grooved rolls can be compared, and if the amount of change of the actual wall thickness is smaller than the amount of movement of the rolling positions of the grooved rolls, it can be determined that the idle rolling phenomenon is occurring in the bottom portions of the grooves.
  • the idle rolling determining part 222 first refers to the amount of adjustment of rolling positions set by the rolling position setting part 221, i.e., an amount corresponding to the amount of outward movement of the rolling positions of the grooved rolls when rolling the end portions of the pierced blank S. Then it compares the amount of adjustment of rolling positions which was referred to and the amount of change of the actual wall thickness calculated from the actual wall thickness (the actual wall thickness in the directions of movement of the grooved rolls) at the end portions and the central portion of the rolled blank S (i.e., the difference between the actual wall thickness of the end portions and the actual wall thickness of the central portion) input from the thickness gauge I. If the amount of change in the actual wall thickness is smaller than the amount of adjustment of rolling positions which was referred to, it is determined that the idle rolling phenomenon is occurring in the bottom portions of the grooves.
  • a rolling control method was applied to as 2-roll type mandrel mill having 6 stands (in which the finishing stands were the #5 and #6 stands), and a rolling test was carried out under the following conditions.
  • the rate of wall thickness defects in the resulting rolled blank was evaluated for Reference Examples 1-1 through 1-3 and Comparative Example 1.
  • the difference between the measured wall thickness and the target value of the wall thickness (for example, in the case of Example 1, the target value of the wall thickness of the end portions is 5.5 mm) exceeds ⁇ 2% of the target value of the wall thickness, it is determined that there is a wall thickness defect.
  • the pattern shown in Figure 3 was modified based on the actual wall thickness of the rolled blank which was rolled lastly measured by the thickness gauge, and the rolling positions of the grooved rolls were moved outwards based on the modified pattern. Namely, in order to make the actual wall thickness approach the target wall thickness, the set value (amount of outwards movement of rolling positions) was modified by an amount corresponding to the difference between the measured wall thickness and the target wall thickness.
  • #5 and #6 rolling was carried out in the same manner as in Reference Example 2-3.
  • the finishing stands (#5 and #6 stands) having roll-reducing directions which are the same as the directions of wall thickness measurement for which the actual wall thickness was smaller than the target wall thickness (at least one of the #3 and #4 stands)
  • rolling was carried out with the rolling positions of the grooved rolls moved outwards according to the same pattern as for the #5 and #6 stands.
  • Example 2-1 and 2-3 through 2-7 and Example 2-2 and Comparative Example 2 the rate of wall thickness defects in the resulting rolled blanks after: rolling was evaluated.
  • the rate of wall thickness defects was calculated using the above-described equation.
  • the frequency with which the rolling positions of the grooved rolls installed in the #5 and #6 stands which are finishing stands were moved outwards by at least 1 mm from the initially set values was also evaluated. This frequency is an evaluation index corresponding to the frequency with which the grooved rolls in the finishing stands move endlessly outwards when the idle rolling phenomenon is occurring in the bottom portions of the grooves and the actual wall thickness has become smaller than the target wall thickness.
  • a pierced blank When manufacturing a seamless tube using a mandrel mill, a pierced blank can be accurately rolled to a desired wall thickness for the entire length or a portion thereof such as the end portions.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Claims (4)

  1. Procédé de contrôle de laminage pour un laminoir continu (M) ayant une pluralité de cages de laminage comprenant une cage de finition (#i) en déplaçant les positions de laminage des premiers cylindres rainurés installés dans la cage de finition (#i) vers l'extérieur, caractérisé par les étapes consistant à installer une jauge d'épaisseur (I) qui mesure l'épaisseur de paroi d'une ébauche laminée sur le côté de la sortie de la cage de finition, comparer la quantité de mouvement des positions de laminage des premiers cylindres rainurés avec la quantité de changement de la véritable épaisseur de paroi de l'ébauche laminée mesurée par la jauge d'épaisseur (I) dans les directions de déplacement des premiers cylindres rainurés, et terminer le déplacement des positions de laminage du premier cylindre rainuré pour l'ébauche percée suivante à laminer si la quantité de changement de la véritable épaisseur de paroi est inférieure à la quantité de déplacement des positions de laminage.
  2. Appareil de contrôle de laminage (1) pour un laminoir continu (M) ayant une pluralité de cages de laminage comprenant une cage de finition (#i) et comprenant une unité d'ajustement de position de laminage (21) pour ajuster les positions de laminage des cylindres rainurés installés dans la cage de finition (#i) et une unité arithmétique et de contrôle (22) qui donne l'instruction à l'unité d'ajustement de position de laminage (21) concernant une quantité d'ajustement des positions de laminage pour les cylindres rainurés, caractérisé en ce que l'unité arithmétique et de contrôle (22) est raccordée à une jauge d'épaisseur (I) qui est installée du côté de la sortie de la cage de finition (#i) et qui mesure l'épaisseur de paroi de l'ébauche laminée résultante dans les directions de réduction de laminage à chaque cage, et en ce qu'il réalise un procédé de contrôle de laminage selon la revendication 1, en donnant l'instruction à l'unité d'ajustement de position de laminage (21) de terminer l'ajustement de la position de laminage en fonction du résultat de la jauge d'épaisseur (I).
  3. Programme de contrôle de laminage pour actionner une unité arithmétique et de contrôle (22) qui est raccordée à une unité d'ajustement de position de laminage (21) pour ajuster les positions de laminage des cylindres rainurés installés dans une cage de finition (#i) parmi une pluralité de cages de laminage constituant un laminoir continu (M) et à une jauge d'épaisseur (I) installée du côté de la sortie de la cage de finition (#i) pour mesurer l'épaisseur de paroi d'une ébauche laminée dans les directions de réduction de laminage à chaque cage et qui donne l'instruction à l'unité d'ajustement de position de laminage (21) concernant une quantité d'ajustement des positions de laminage pour les cylindres rainurés, caractérisé en ce que l'unité arithmétique et de contrôle (22) est actionnée afin de réaliser un procédé de contrôle de laminage selon la revendication 1, en donnant l'instruction à l'unité d'ajustement de position de laminage (21) de terminer l'ajustement de la position de laminage en fonction du résultat de la jauge d'épaisseur (I).
  4. Procédé pour fabriquer un tube sans soudure utilisant un laminoir continu (M) qui réalise le procédé de contrôle de laminage selon la revendication 1.
EP11165552A 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure Ceased EP2366468B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004192912A JP4370572B2 (ja) 2004-06-30 2004-06-30 マンドレルミルの圧延制御方法、圧延制御装置、制御プログラム及び継目無管
EP05765198A EP1779939B1 (fr) 2004-06-30 2005-06-30 Méthode de commande de laminage pour laminoir continu, dispositif de commande de laminage et programme de commande

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
EP05765198A Division EP1779939B1 (fr) 2004-06-30 2005-06-30 Méthode de commande de laminage pour laminoir continu, dispositif de commande de laminage et programme de commande
EP05765198.6 Division 2005-06-30

Publications (2)

Publication Number Publication Date
EP2366468A1 EP2366468A1 (fr) 2011-09-21
EP2366468B1 true EP2366468B1 (fr) 2012-09-12

Family

ID=35782782

Family Applications (5)

Application Number Title Priority Date Filing Date
EP05765198A Ceased EP1779939B1 (fr) 2004-06-30 2005-06-30 Méthode de commande de laminage pour laminoir continu, dispositif de commande de laminage et programme de commande
EP11165550A Ceased EP2366467B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure
EP10002571A Ceased EP2193855B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et tube ou conduit sans soudure
EP11165541A Ceased EP2366466B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure
EP11165552A Ceased EP2366468B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure

Family Applications Before (4)

Application Number Title Priority Date Filing Date
EP05765198A Ceased EP1779939B1 (fr) 2004-06-30 2005-06-30 Méthode de commande de laminage pour laminoir continu, dispositif de commande de laminage et programme de commande
EP11165550A Ceased EP2366467B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure
EP10002571A Ceased EP2193855B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et tube ou conduit sans soudure
EP11165541A Ceased EP2366466B1 (fr) 2004-06-30 2005-06-30 Procédé de contrôle de roulement, appareil de contrôle de roulement et programme pour laminoir continu et procédé de fabrication de tube ou de conduit sans soudure

Country Status (5)

Country Link
EP (5) EP1779939B1 (fr)
JP (1) JP4370572B2 (fr)
CN (2) CN101264483B (fr)
MX (1) MXPA06014866A (fr)
WO (1) WO2006003975A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4863131B2 (ja) * 2009-06-08 2012-01-25 住友金属工業株式会社 マンドレルミルの圧延制御方法、圧延制御装置、制御プログラム及び継目無管
WO2011018956A1 (fr) * 2009-08-11 2011-02-17 住友金属工業株式会社 Dispositif pour régler la position d’une vis de serrage d’un cylindre de laminoir faisant partie d’un laminoir continu à trois cylindres, et procédé de fabrication d’un tuyau sans soudure
ITMI20121559A1 (it) * 2012-09-19 2014-03-20 Sms Innse Spa Miglioramento in un impianto di laminazione
DE102014110980B4 (de) 2014-08-01 2017-10-26 Vallourec Deutschland Gmbh Verfahren zur Herstellung von warmgewalzten nahtlosen Rohren mit verdickten Enden

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60154810A (ja) * 1984-01-25 1985-08-14 Sumitomo Metal Ind Ltd 管圧延制御方法
JPS63230214A (ja) * 1987-03-17 1988-09-26 Sumitomo Metal Ind Ltd 管圧延制御方法
JPS63238906A (ja) 1987-03-27 1988-10-05 Sumitomo Metal Ind Ltd マンドレルミルの圧延制御方法
JPH06190406A (ja) * 1992-12-24 1994-07-12 Sumitomo Metal Ind Ltd 管の延伸圧延機の圧延制御方法
JPH0871616A (ja) 1994-09-01 1996-03-19 Sumitomo Metal Ind Ltd 継目無管の圧延装置および圧延制御方法
JP2001293511A (ja) * 2000-04-11 2001-10-23 Sumitomo Metal Ind Ltd 金属管の延伸圧延法および延伸圧延機
JP3569502B2 (ja) * 2001-06-14 2004-09-22 東芝三菱電機産業システム株式会社 連続圧延機の板厚制御装置
DE10201717C1 (de) * 2002-01-18 2003-04-10 Sms Meer Gmbh Verfahren und Vorrichtung zum Walzen eines Rohres

Also Published As

Publication number Publication date
CN101264483B (zh) 2011-03-23
EP1779939A4 (fr) 2008-08-06
EP2193855A1 (fr) 2010-06-09
EP2366468A1 (fr) 2011-09-21
JP2006015353A (ja) 2006-01-19
CN1980751A (zh) 2007-06-13
CN101264483A (zh) 2008-09-17
EP2366466B1 (fr) 2012-09-12
CN1980751B (zh) 2011-01-12
JP4370572B2 (ja) 2009-11-25
EP1779939A1 (fr) 2007-05-02
EP2193855B1 (fr) 2012-05-09
EP2366466A1 (fr) 2011-09-21
EP1779939B1 (fr) 2012-06-13
MXPA06014866A (es) 2007-11-22
WO2006003975A1 (fr) 2006-01-12
EP2366467B1 (fr) 2012-09-19
EP2366467A1 (fr) 2011-09-21

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