Method for preventing shape changes in metal coils, in particualr for preventing a collapsing of newly wound hot coils

Abstract

The invention relates to a method for preventing shape changes in metal coils, in particular for preventing a collapsing of newly wound hot coils. In the method, a metal coil, in particular a newly wound hot coil, is rotated about its longitudinal axis intermittently in a first rotational direction and then rotated back in a second opposing rotational direction, or further rotated in the first rotational direction.

Claims

1. A method for preventing shape changes in metal coils, comprising: intermittently first and second rotating a metal coil about a longitudinal axis of the metal coil, wherein the first rotating is forward in a first direction of rotation around a first angle of rotation; and wherein the second rotating is subsequent to the first rotating, in a second direction one of opposite the first direction around a second angle of rotation, and further in the first direction around a third angle of rotation; wherein the first direction is counter to a coiling direction of the metal coil; wherein the first rotating and the second rotating are performed so that the metal coil is not rotated beyond a coil start on an outer circumference of the metal coil; wherein the first angle of rotation is between 22.5 and 135; and wherein there is a rest interval between the first rotating and the second rotating.

2. The method as claimed in claim 1, wherein the metal coil is a newly wound hot coil.

3. The method as claimed in claim 1, wherein the metal coil is rotated in a cycle several times, the cycle comprising the first rotating and the second rotating.

4. The method as claimed in claim 1, wherein at least one of the following is set according to a material of the metal coil: the first angle of rotation of the first rotating; the second angle of rotation of the second rotating in the second direction, when the second rotating is in the second direction; and the third angle of rotation of the second rotating further in the first direction, when the second rotating is further in the first direction.

5. The method as claimed in claim 1, wherein the rest interval between the first rotating and the second rotating is set according to a material of the metal coil.

6. The method as claimed in claim 1, further comprising: removing the coil from a coiler before the first rotating; wherein a start of the first rotating of the metal coil after removal from the coiler is set according to a material of the metal coil.

7. The method as claimed in claim 1, wherein at least one of: the first angle of rotation of the first rotating; the second angle of rotation of the second rotating in the second direction, when the second rotating is in the second direction; and the third angle of rotation of the second rotating further in the first direction, when the second rotating is further in the first direction, is from a range of about 45 to 135.

8. The method as claimed in claim 1, wherein the first angle of rotation is the same as at least one of: the second angle of rotation of the second rotating in the second direction, when the second rotating is in the second direction; and the third angle of rotation of the second rotating further in the first direction, when the second rotating is further in the first direction.

9. The method as claimed in claim 1, wherein the rest interval between the first rotating and one of: the second rotating in the second direction, when the second rotating is in the second direction; and the second rotating further in the first direction, when the second rotating is further in the first direction, is in a range of about 100 seconds to 300 seconds.

10. The method as claimed in claim 1, further comprising: removing the coil from a coiler before the first rotating; wherein the initial forward rotating of the metal coil is performed for about 100 s to 300 s after removal from a coiler.

11. The method as claimed in claim 1, wherein the metal coil consists of one of a high-carbon steel, a press-hardening steel, a multi-phase steel, and an advanced high-strength steel grade (AHSS) steel.

12. The method as claimed in claim 1, further comprising at least one of: before the first rotating: removing the metal coil from a coiler, binding the metal coil and weighing the metal coil; and after the second rotating, depositing the metal coil in a coil store.

13. The method as claimed in claim 1, further comprising at least one of: sampling the metal coil; strapping the metal coil; weighing the metal coil, and measuring the metal coil.

14. The method as claimed in claim 1, wherein the method is carried out during a phase transformation of the metal coil from austenite to ferrite.

15. The method as claimed in claim 1, wherein the first angle of rotation is between 45 and 135.

16. The method as claimed in claim 15, wherein the first angle of rotation is between 75 and 105.

17. The method as claimed in claim 1, wherein the second rotating in the second direction is opposite the first direction around the second angle of rotation.

18. A transport system for preventing shape changes in metal coils, comprising: a transport device with a coil support having at least a first rotatable and a second rotatable transport roller; and at least one external drive unit, configured to be coupled mechanically to one of the rotatable transport rollers in order to drive said transport roller; wherein the system is configured to intermittently first and second rotate a metal coil in a first rotation and in a second rotation about a longitudinal axis of the metal coil, wherein the first rotation is forward in a first direction of rotation around a first angle of rotation; and wherein the second rotation is subsequent to the first rotation, in a second direction one of opposite the first direction around a second angle of rotation, and further in the first direction around a third angle of rotation; wherein the first direction is counter to a coiling direction of the metal coil; wherein the first rotation and the second rotation are performed so that the metal coil is not rotated beyond a coil start on an outer circumference of the metal coil; and wherein there is a rest interval between the first rotation and the second rotation.

19. The transport system as claimed in claim 18, further comprising a controller coupled to the transport device and the at least one external drive unit, the controller configured to perform the first rotation and the second rotation.

20. A transport system for preventing shape changes in metal coils, comprising: a transport device with a coil support having at least a first rotatable and a second rotatable transport roller; at least one drive unit configured to drive said transport roller; and a controller coupled to the transport device and the at least one drive unit, the controller configured to intermittently first and second rotate a metal coil in a first rotation and in a second rotation about a longitudinal axis of the metal coil, the first rotation being forward in a first direction of rotation around a first angle of rotation, the second rotation being subsequent to the first rotation and in a second direction one of: opposite the first direction around a second angle of rotation, and further in the first direction around a third angle of rotation; wherein the first direction is counter to a coiling direction of the metal coil; wherein the first rotation and the second rotation are performed so that the metal coil is not rotated beyond a coil start on an outer circumference of the metal coil; and wherein there is a rest interval between the first rotation and the second rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above-described properties, features and advantages of this invention and the manner in which In the drawings:

(2) FIG. 1 shows a pallet system for carrying out a coil rotation according to a first embodiment;

(3) FIG. 2 shows an MCS system for carrying out a coil rotation according to a second embodiment; and

(4) FIG. 3 shows a discharge station with a floor rolling station for carrying out a coil rotation according to a third embodiment.

DETAILED DESCRIPTION

(5) Intermittent coil rotation, continuous forward and (reverse) backward coil rotation without a pause and continuous coil rotation in one and the same direction during the transport processto prevent collapse/ovalization of a coil (FIGS. 1 to 3) is described in the following.

(6) The embodiments described below in accordance with FIGS. 1 to 3 show possibilities or implementations of how collapse or ovalization of a newly formed hot coil 1 (abbreviated to coil 1) can be prevented.

(7) Here, the embodiments relate in each case to a segment of the processing sequence in the production of a metal strip in a hot rolling mill.

(8) The metal strips to be produced arethere is a trend toward thissteels of new high-, higher- or very high-strength steel grades, such as high-carbon steels, press-hardening steels, multi-phase steels or advanced high-strength steel grade (AHSS) steels.

(9) During the processing sequence in the production of the metal strip, it is necessary that the metal strip which has been wound on a coiler 10 to form the coil 1 after a hot rolling process, i.e. the newly wound hot coil 1 or coil 1 (which usually has a temperature of up to 850 C. and a weight of up to 50 t) should be transported away from the coiling station or coiler 10 and toward various processing stations (14, 15).

(10) In the individual processing stations (14, 15), the coils 1 are post-processed, for example bound 15, marked, weighed 14, measured and/or inspected, before they are deposited in a coil store 16.

(11) For the transport process required in this case for the coil 1away from the coiler 10 and toward the coil store 16a transport device 20 or transport system 50 is required, which will be described belowin various embodiments.

(12) Owing to the increasingly strong steel grades in the production of metal strips, phase transformation in the metal strip thus also takes place during this transport process, which phase transformation in turn leads to unwanted volume changes and shape changes/deviations (collapse/ovalization) in the coil 1.

(13) Intermittent coil rotation to prevent collapse/ovalization of a coil is described in the following.

(14) In order to prevent this ovalization of the coil 1, it is provided that the coil 1 to be transported is rotated intermittently (about its longitudinal axis 2) forward 3 away from the coiler 10 and toward the coil store 16 and backward (in reverse) 4 (or alternatively rotated further 17)if appropriate repeatedlyduring the transport process.

(15) Transport devices/systems described below are set up for such coil treatment/rotation 3, 4 (, 17) and can thus contribute to preventing the collapse or ovalization of the coil 1.

(16) Pallet (Circulation) System 30 (FIG. 1)

(17) FIG. 1 shows a pallet 20 of a pallet circulation system 30, which pallet circulation system 30 transports coils 1 away from the coiler 10 toward the coil store 16by means of pallets 20 moved on a conveying section 31 by pallet circulation carriages.

(18) In this case, the coils to be transported are loaded along their longitudinal axis onto the respective pallet circulation carriage.

(19) For this purpose, a newly wound hot coil 1 or coil 1 is removed 11 from the coiler 10 and deposited on the pallet 20, as FIG. 1 illustrates. The pallet 20 is moved via the conveying section 31 (if appropriate via the processing stations 14, 15) to the coil store 16, in which the coil 1 is then deposited, whereby the coil 1 is then or has been transported in this way from the coiler 10 to the coil store 16.

(20) As FIG. 1 shows, the pallet 20 provides a coil support 21 in the form of a support saddle 24, on which the coil 1 to be transported is deposited or, as FIG. 1 shows, has been deposited.

(21) For this purpose, as FIG. 1 also shows, this support saddle 24 has two saddle supports 25, 26, which are arranged at a distance from one another and which preferably each have a roller 22, 23 drivable by means of an integrated drive 27 (not visible).

(22) By means of corresponding adjustment systems 32 on the pallet 20 or on the saddle supports 25, 26 (not visible), the two rollers 22, 23 forming the coil support 21/coil saddle 24 can be moved horizontally and vertically, thereby making it possible to adjust the height and/or spacing of the rollers 22, 23and thus to adapt the coil support 21 to the coils 1 to be transported.

(23) The integrated drives 27 of the rollers 22, 23 carrying the coil 1 are controlled by means of a controller 29, enabling the coil 1 deposited on them to be rotatedin a controlled mannerabout its longitudinal axis 2.

(24) The coil rotation 3, 4 (, 17) takes place according to a predeterminable cycle regime, whichif appropriate several timesprovides an intermittent forward 3 and (reverse) backward rotation 4 (or alternatively further rotation 17) (cycle).

(25) For this purpose, the controller 29 determines the corresponding rotation parameters, such as the start of the rotation, direction of rotation 5, 6, duration of a rotation, pause duration between two rotations, rotational speed, angle of rotation 8, 9, number of rotations/cycles, start/end of the overall cycle and many other factorsaccording to the material, the size, the circumference, the diameter, the weight and the temperature as well as the metal strip thickness of the coil 1and controls the integrated drives 27 of the rollers 22, 23 in accordance therewith.

(26) Possible cycle or rotation regimes can be carried out as follows: 1. Steel grade: high-/higher-/very high-strength steel, e.g. AHSS steel Coil weight: 20 t-30 t Start of the rotation regime: 1 min after removal from coiler 10 (11) Number of cycles: 10 Cycle pause/intra-cyclical pause between the forward 3 and the (reverse) backward rotation 4 (or the further rotation 17): 1 min Pause between two cycles/inter-cycle pause or pause between cycles: 1 min Angle of rotation 8 of the forward rotation 3: 90 Angle of rotation 9, 18 of the (reverse) backward rotation 4 or the further rotation 17: 90 First/initial direction of rotation 5: preferably counter to coiling direction 7

(27) Note: Preferably no rotation 3, 4, 17 beyond the coil/strip start 12 at the outer circumference 13. Post- and intermediate processing operations 14, 15 are carried out after completion of the cycle or rotation regime. 2. Steel grade: high-/higher-/very high-strength steel, e.g. high-carbon steel Coil weight: 30 t-45 t Start of the rotation regime: 200 s after removal from the coiler 10 (11) Number of cycles: 15 Cycle pause/intra-cyclical pause between the forward 3 and the (reverse) backward rotation 4 (or the further rotation 17): 1.5 min Pause between two cycles/cycles pause or inter-cycle pause: 1.5 min Angle of rotation 8 of the forward rotation 3: 75 Angle of rotation 9, 18 of the (reverse) backward rotation 4 or the further rotation 17: 75 First/initial direction of rotation 5: preferably counter to coiling direction 7

(28) Note: Preferably no rotation 3, 4, 17 beyond the coil/strip start 12 on the outer circumference 13. Post- and intermediate processing operations 14, 15 are carried out after completion of the cycle or rotation regime. 3. Steel grade: high-/higher-/very high-strength steel, e.g. multi-phase steel Coil weight: 25 t-40 t Start of the rotation regime: 10 s after withdrawal from the coiler 10 (11) Number of cycles: 8 or until completion of the phase transformation Cycle pause/intra-cyclical pause between the forward 3 and the (reverse) backward rotation 4 (or the further rotation 17): 2 min Pause between two cycles/cycles pause or inter-cycle pause: 2 min Angle of rotation 8 of the forward rotation 3: 90 Angle of rotation 9, 18 of the (reverse) backward rotation 4 or the further rotation 17: 90 First/initial direction of rotation: preferably counter to coiling direction 7

(29) Note: Preferably no rotation 3, 4, 17 beyond the coil/strip start 12 at the outer circumference 13. Post- and intermediate processing operations 14, 15 are carried out after completion of the cycle or rotation regime.

(30) MCS System 33 (FIG. 2)

(31) FIG. 2 shows a transport carriage 20, a modular coil shuttle (MCS) car (MSC for short) 20, by means of which coils 1 can be transported via the conveying section 31 away from the coiler 10 toward the coil store 16 (and also rotated 3, 4, 17).

(32) For this purpose, a newly wound hot coil 1 or the coil 1 is removed 11 from the coiler 10 and deposited on the MCS 20in accordance with the pallet circulation system 30 (FIG. 1)as FIG. 2 illustrates. The MCS 20 is moved (if appropriate via the processing stations 14, 15) to the coil store 16, in which the coil 1 is then deposited, whereby the coil 1 is then or has been transported in this way from the coiler 10 to the coil store 16.

(33) As FIG. 2 shows, the MCS 20in a manner corresponding to the pallet 20 (FIG. 1)provides a support saddle 24 (as a coil support 21), on which the coil 1 to be transported is deposited or, as FIG. 2 shows, has been deposited.

(34) For this purpose, as FIG. 2 also shows, this support saddle 24 has two saddle supports 25, 26, which are arranged at a distance from one another and which each have a roller 22, 23 drivable by means of an integrated drive 27 (not visible).

(35) By means of corresponding adjustment systems 32 on the MCS 20 or on the saddle supports 25, 26 (indicated, in FIG. 2), the two rollers 22, 23 forming the coil support 21/coil saddle 24 can be moved horizontally and vertically, thereby making it possible to adjust the height and/or spacing of the rollers 22, 23and thus to adapt the coil support 21 to the coils 1 to be transported.

(36) The integrated drives 27 of the rollers 22, 23 carrying the coil 1 are controlled by means of a controller 29, enabling the coil 1 deposited on them to be rotated 3, 4, 17in a controlled mannerabout its longitudinal axis 2.

(37) The coil rotation 3, 4, 17 takes place according to a predeterminable cycle regime (cf. this in the pallet circulation system 30), whichif appropriate several timesprovides an intermittent forward 3 and (reverse) backward rotation 4 or further rotation 17 (cycle).

(38) For this purpose, the controller 29 determines the corresponding rotation parameters (see above in the pallet circulation system 30), such as the start of the rotation 3, 4, 17, the angle of rotation 8, 9, 18, the direction of rotation 5, 6, the duration of a rotation 3, 4, 17, the pause duration between two rotations, the rotational speed, the number of rotations/cycles, the start/end of the overall cycle and many other factorsaccording to the material, the size, the circumference, the diameter, the weight and the temperature as well as the metal strip thickness of the coiland controls the integrated drives 27 of the rollers 22, 23 in accordance therewith.

(39) Possible cycle or rotation regimes are as described above.

(40) As an alternative (not shown) in the pallet circulation system 30 and the MCS system 33with rollers 22, 23 driven in an integrated manner thereit is also possible to provide rollers 22, 23 on the pallet 20 or on the MCS 20, which rollers are driven by externally couplable drives 28.

(41) For this purpose, one or more stations can be provided along the transport section 31 or in connection with the transport section 31, which stations establish a mechanical connection with the rollers 22, 23 and produce a rotation 3, 4, 17 of the rollers 22, 23 and thus of the coil 1.

(42) Discharge Station 52 with Floor Rolling Station 51 (FIG. 3)

(43) FIG. 3 shows a segment of a conveying section 31 in a hot rolling mill for producing a metal strip.

(44) Here, as shown in FIG. 3, coils 1 are removed from two coilers 10 onto a transport carriage 20 and are transported via a circuit 34 to finishing or intermediate processing stations 14, 15 (here weighing station 14 and strapping station 15) (before they are then transported to a coil store 16 and deposited there (not shown or only indicated)).

(45) In this case, as FIG. 3 illustrates, two floor rolling stations 51 are arranged along the circuit 34 (indicated).

(46) In a manner corresponding to the pallet 20 (FIG. 1) and the MCS 20 (FIG. 2), these floor rolling stations 51 are equipped with driven rollers 22, 23 (with integrated drives 27), thereby enabling coils 1 laid there to be rotated 3, 4, 17 in accordance with a specific rotation regime (see above).

(47) Coils 1 moved toward the floor rolling stations 51 are temporarily removed there from the transport carriage 20 and transferred to the respective floor rolling station 51, where they are rotated in accordance with a specific rotation regime (see above). After completion of the rotation regime, the coils 1 are transferred back to the transport carriage 20 and transported onward.

(48) Continuous forward and (reverse) backward coil rotation to prevent collapse/ovalization of a coil is described in the following.

(49) To prevent the above-described disadvantageous ovalization of a coil 1, the above-described MCS 20 can also be used as follows after a rotation regime (cf. FIGS. 1 to 3).

(50) Here, the coil is rotated forward 3 about its longitudinal axis 2 in the first direction of rotation 5 and is rotated back 4 without a pause, i.e. without the cycle pause/intra-cyclical pause, in the second, opposite direction of rotation 6, wherein the forward 3 and the reverse rotation 4 take place several times one after the other without a pause, i.e. without the inter-cycle pause/pause between cycles.

(51) Relevant regime parameters can be set in this case: Steel grade: high-/higher-/very high-strength steel, e.g. AHSS steel Coil weight: 20 t-30 t Start of the rotation regime: with the start of the transport process, 1 min after removal from the coiler 10 (11) End of the rotation regime: on completion of the transport process at the coil store 16 Number of cycles: Multiple Cycle pause/intra-cyclical pause between the forward 3 and the (reverse) backward rotation 4: none Pause between two cycles/inter-cycle pause or pause between cycles: none Angle of rotation 8 of the forward rotation 3: 90 Angle of rotation 9 of the (reverse) backward rotation 4: 90 First/initial direction of rotation 5: preferably counter to coiling direction 7

(52) Note: Preferably no rotation 3, 4 beyond the coil/strip start 12 at the outer circumference 13. Post- and intermediate processing operations 14, 15 are carried out after completion of the rotation regime.

(53) Continuous, slow coil rotation in one and the same direction of rotation during the entire coil transport to prevent collapse/ovalization of a coil is described in the following.

(54) To prevent the above-described disadvantageous ovalization of a coil 1, the above-described MCS 20 can also be used as follows after a rotation regime (cf. FIGS. 1 to 3).

(55) Here, the coil is rotated 19 without interruption about its longitudinal axis 2 in one and the same direction of rotation 35 in the coiling direction 7 of the coil 1 during the entire transport process between removal 11 from the coiler 10 and deposition in the coil store 16.

(56) Relevant regime parameters can be set in this case: Steel grade: high-/higher-/very high-strength steel, e.g. AHSS steel Coil weight: 20 t-30 t Start of the rotation regime: with the start of the transport process, 1 min after removal from the coiler 10 (11) End of the rotation regime: on completion of the transport process at the coil storage 16 Number of cycles: none, rotation only in the coiling direction Rotational speed: slow (for example at 10 min per revolution).

LIST OF REFERENCE SIGNS

(57) 1 metal coil, hot coil, coil 2 longitudinal axis 3 forward rotation 4 (reverse) backward rotation 5 first direction of rotation of the forward rotation or further rotation 6 second, opposite direction of rotation of the (reverse) backward rotation 7 coiling direction 8 angle of rotation of the forward rotation 9 angle of rotation of the (reverse) backward rotation 10 coiler 11 removal from a coiler 12 coil start 13 outer circumference 14 weighing (weighing station) 15 binding, strapping (binding station) 16 coil store 17 further rotation 18 angle of rotation of the further rotation 19 (continuous, uninterrupted) rotation 20 transport device, transport carriage, pallet, MCS car 21 coil support 22 first (driven/drivable) (transport) roller 23 second (driven/drivable) (transport) roller 24 coil/support saddle 25 first saddle support 26 second saddle support 27 integrated drive 28 external (couplable) drive unit 29 controller 30 pallet circulation system 31 conveying/transport section 32 adjustment system 33 MCS system 34 circuit 35 one and the same direction of rotation 50 transport system 51 transport station, floor rolling/floor rotating station 52 discharge station