Method for setting a conicity of a die of a strand casting installation, and device for a strand casting installation

Abstract

A strand casting installation in which a conicity of a die is set during a casting procedure by measuring temperature values along a centric measuring path running in a casting direction along an adjustably disposed die wall; measuring temperature values along a peripheral measuring path running in a casting direction along the adjustably disposed die wall, wherein the peripheral measuring path runs between the centric measuring path and a lateral periphery of the die wall, and a spacing of the peripheral measuring path from the lateral periphery of the die wall is smaller than a spacing of the centric measuring path from the other lateral periphery of the die wall; determining a centric temperature distribution curve along the centric measuring path from the temperature values measured along the centric measuring path; determining a peripheral temperature distribution curve along the peripheral measuring path from the temperature values measured along the peripheral measuring path; determining a first area under the centric temperature distribution curve, and a second area under the peripheral temperature distribution curve; determining a difference between the second area and the first area; and setting the conicity of the die taking into account the difference.

Claims

1. A device for a strand casting installation, comprising: at least one die having mutually opposite, adjustably disposed die walls; at least one adjustment mechanism for adjusting the die walls; at least one actuation electronics system for actuating the adjustment mechanism; at least one centric sensor installation, connected to the at least one actuation electronics system, for measuring temperature values along at least one centric measuring path running in a casting direction along one of the adjustably disposed die walls; at least one peripheral sensor installation, connected to the at least one actuation electronics system, for measuring temperature values along at least one peripheral measuring path running in the casting direction along the adjustably disposed die walls, wherein the at least one peripheral measuring path runs between the at least one centric measuring path, and a lateral periphery of the die wall, and a spacing of the at least one peripheral measuring path from said lateral periphery of the die wall is smaller than a spacing of the at least one centric measuring path from an other lateral periphery of the die wall; wherein the at least one actuation electronics system is configured to determine a centric temperature distribution curve along the at least one centric measuring path from the temperature values provided by the at least one centric sensor installation and measured along the at least one centric measuring path, determine a peripheral temperature distribution curve along the at least one peripheral path from the temperature values provided by the at least one peripheral sensor installation and measured along the at least one peripheral measuring path, determine a first area under the centric temperature distribution curve and a second area under the peripheral temperature distribution curve, determine a difference between the second area and the first area; and set a conicity of the die taking into account the difference by actuating the at least one adjustment mechanism.

2. The device according to claim 1, wherein the at least one actuation electronics system is operative to: increase the conicity of the die by actuating the at least one actuation electronics system when the difference is a negative value which is smaller than a pre-defined negative minimum value; reduce the conicity of the die by actuating the at least one adjustment mechanism when the difference is a positive value which is larger than a pre-defined positive minimum value; and maintain the conicity of the die without actuating the at least one adjustment mechanism when the difference is in an open interval having an upper limit that is the positive minimum value, and a lower limit that is the negative minimum value.

3. The device according to claim 2, wherein the at least one actuation electronics system is operative to vary the conicity of the die by actuating the at least one adjustment mechanism more intensely the more the difference differs from zero.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) FIG. 1A shows a schematic sectional illustration of a portion of a die with an optimal conicity;

(3) FIG. 1B shows a schematic sectional illustration of a portion of a die with an inadequate conicity;

(4) FIG. 1C shows a schematic sectional illustration of a portion of a die with an excessive conicity;

(5) FIG. 1D shows a schematic sectional illustration of a portion of a die with an overly excessive conicity;

(6) FIG. 2 shows a diagram which shows a narrow side shape of a cast strand within a die with an excessive conicity, and a narrow side shape of the strand outside the die;

(7) FIG. 3 shows a diagram which shows a centric temperature distribution curve and a peripheral temperature distribution curve; and

(8) FIG. 4 shows a schematic illustration of an exemplary embodiment for a device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(9) The same components, or functionally equivalent components, respectively, are provided with the same reference signs in the figures. A repeat of the description of said components may be omitted.

(10) FIGS. 1A to 1D show in each case a device 32 for a strand casting installation (not shown), in particular a slab strand casting installation.

(11) The device 32 comprises a die 1 with mutually opposite, adjustably disposed die walls 3, disposed on narrow sides of the die 1, only one of said die walls 3 being shown in FIGS. 1A to 1D, and die walls 2 disposed on the broad sides of the die 1, the die walls 3 during a casting procedure being clamped between the die walls 2.

(12) The device 32 furthermore comprises an adjustment mechanism (not shown) for adjusting the die walls 3, and an actuation electronics system (not shown) for actuating the adjustment mechanism.

(13) Moreover, the device 32 comprises a first centric sensor installation 24, connected to the actuation electronics system, for measuring temperature values along a first centric measuring path running in a casting direction that runs transversely to the drawing plane along the adjustably disposed die wall 3, and a second centric sensor installation (not shown), connected to the actuation electronics systems, for measuring temperature values along a second centric measuring path running in the casting direction along the further adjustably disposed die wall (not shown).

(14) The device 32 moreover comprises two peripheral sensor installations 27 and 28, connected to the actuation electronics system, for measuring temperature values along in each case one peripheral measuring path running in the casting direction along the adjustably disposed die wall 3, wherein each peripheral measuring path runs between the centric measuring path and a lateral periphery of the die wall 3, and a spacing of the respective peripheral measuring path from said lateral periphery of the die wall 3 is smaller than a spacing of the centric measuring path from the other lateral periphery of the die wall 3. The device 32 furthermore comprises two peripheral sensor installations (not shown), connected to the actuation electronics system, for measuring temperature values along in each case one peripheral measuring path running in the casting direction along the further adjustably disposed die wall (not shown), wherein each peripheral measuring path runs between the centric measuring path and a lateral periphery of the die wall, and a spacing of the respective peripheral measuring path from said lateral periphery of the die wall is smaller than a spacing of the centric measuring path from the other lateral periphery of the die wall.

(15) The actuation electronics system is specified for determining a centric temperature distribution curve along the respective centric measuring path from the temperature values measured along the respective centric measuring path. The actuation electronics system is furthermore specified for determining a peripheral temperature distribution curve along the respective peripheral measuring path from the temperature values measured along the respective peripheral measuring path. The actuation electronics system is moreover specified for determining a first area under the respective centric temperature distribution curve and a second area under the respective peripheral temperature distribution curve. The actuation electronics system is furthermore specified for determining for each die wall 3 a difference between the second area and the respective first area. The actuation electronics system is furthermore specified for setting the conicity of the die 1 while taking into account the difference.

(16) The actuation electronics system is specified for increasing the conicity of the die 1 when the respective difference is a negative value which is smaller than a pre-defined negative minimum value, for reducing the conicity of the die 1 when the respective difference is a positive value which is larger than a pre-defined positive minimum value, and for maintaining the conicity of the die 1 when the respective difference is in an open interval of which the upper limit is the positive minimum value, and of which the lower limit is the negative minimum value. In particular, the actuation electronics system is specified for varying the conicity of the die 1 more intensely the more the respective difference differs from zero.

(17) FIG. 2 shows a diagram which shows a narrow side shape 8 of a cast strand within a die with an excessive conicity, and a narrow side shape 9 of the strand outside the die. The spacing along the narrow side from one broad side of the strand is plotted on the ordinate. The deviation from an ideal narrow side shape is plotted on the abscissa. The narrow side shape 8 is configured as a concavity which is generated by an excessive conicity of the die. Therefore, there is no contact with a die wall on a narrow side in a central region of the narrow side shape 8, on account of which the strand on the narrow side has a strand shell of which the thickness decreases in the direction of the center of the narrow side. When this strand exits the die, on account of the creep of the metal melt contained therein, and on account of the thinner configuration of the strand shell in the central region of the narrow side of the strand, a bulge 10 arises on the strand. This bulging of the narrow sides can be prevented by the method according to the invention, or the device according to the invention, respectively, in that it is detected whether there is a respective concavity on a narrow side of the strand within the die, the conicity of the die then being reduced if said concavity is present.

(18) FIG. 3 shows a diagram which shows a centric temperature distribution curve 11 and a peripheral temperature distribution curve 12. The spacing along the narrow side from a broad side of the strand is plotted on the ordinate. The temperature is plotted on the abscissa. The areas 13, 14, and 15 which represent the respective difference between the second temperature distribution curve 12 and the first temperature distribution curve 11 are present between the temperature distribution curves 11 and 12. The areas 13 and 15 herein are assigned to a negative difference, while the area 14 is assigned to a positive difference. This shows that even in the case of an optimal conicity of the die an inadequate conicity is usually provided in the entry region of the die (cf. area 13), while an excessive conicity can be provided in an adjoining region of the die (cf. area 14). This can be detected by the method according to the invention, or by the device according to the invention, respectively.

(19) FIG. 4 shows a schematic illustration of an exemplary embodiment for a device 17 according to the invention for a strand casting installation (not shown), in particular a slab strand casting installation.

(20) The device 17 comprises a die with mutually opposite, adjustably disposed die walls 19 and 20 which are disposed on narrow sides of the die 18. The die walls on the broad sides of the die 18 that are connected to said die walls 19 and 20 are not shown.

(21) The device 18 moreover comprises an adjustment mechanism 21 for adjusting the die walls 19 and 20. The adjustment mechanism 21 for each adjustably disposed die wall 19 and 20, respectively, comprises two actuator drives 22, the inclination angle of the respective die wall 19 or 20, respectively, being variable by actuating said actuator drives 22.

(22) The device 18 furthermore comprises an actuation electronics system 23 for actuating the adjustment mechanism 21. To this end, the actuation electronics system 23 is connected to the actuator drives 22 in a signal-technical manner.

(23) The device 17 furthermore comprises a first centric sensor installation 24, connected to the actuation electronics system 23, for measuring temperature values along a first centric measuring path running in a casting direction (indicated by the arrow 25) along the adjustably disposed die wall 19, and a second centric sensor installation 26, connected to the actuation electronics system 23, for measuring temperature values along a second centric measuring path running in a casting direction (indicated by the arrow 25) along the adjustably disposed die wall 20.

(24) The device 17 moreover comprises two peripheral sensor installations 27 and 28, connected to the actuation electronics system 23, for measuring temperature values along in each case one peripheral measuring path running in the casting direction along the adjustably disposed die wall 19, wherein each peripheral measuring path runs between the centric measuring path and a lateral periphery of the die wall 19, and a spacing of the respective peripheral measuring path from said lateral periphery of the die wall 19 is smaller than a spacing of the centric measuring path from the other lateral periphery of the die wall 19. The device 17 furthermore comprises two peripheral sensor installations 29 and 30, connected to the actuation electronics system 23, for measuring temperature values along in each case one peripheral measuring path running in the casting direction along the adjustably disposed die wall 20, wherein each peripheral measuring path runs between the centric measuring path and a lateral periphery of the die wall 20, and a spacing of the respective peripheral measuring path from said lateral periphery of the die wall 20 is smaller than a spacing of the centric measuring path from the other lateral periphery of the die wall 20. This is shown in the right-hand part of FIG. 4 which shows a view of the die 18 from above. Moreover, the die walls 31 on the broad sides of the die 18 are shown in the right-hand part of FIG. 4.

(25) The actuation electronics system 23 is specified for determining a centric temperature distribution curve along the respective centric measuring path from the temperature values measured along the respective centric measuring path. The actuation electronics system 23 is furthermore specified for determining a peripheral temperature distribution curve along the respective peripheral measuring path from the temperature values measured along the respective peripheral measuring path. The actuation electronics system is moreover specified for determining a first area under the respective centric temperature distribution curve and a second area under the respective peripheral temperature distribution curve. The actuation electronics system 23 is furthermore specified for determining for each die wall 19 or 20, respectively, a difference between the second area and the respective first area. The actuation electronics system 23 is furthermore specified for setting the conicity of the die 18 while taking into account the differences.

(26) The actuation electronics system 23 is specified for increasing the conicity of the die 18 by actuating the adjustment mechanism 21 when the respective difference is a negative value which is smaller than a pre-defined negative minimum value, for reducing the conicity of the die 18 by actuating the adjustment mechanism 21 when the respective difference is a positive value which is larger than a pre-defined positive minimum value, and for maintaining the conicity of the die 18 without actuating the adjustment mechanism 21 when the respective difference is in an open interval, the upper limit thereof being the positive minimum value and the lower limit thereof being the negative minimum value. In particular, the actuation electronics system 23 is specified for varying the conicity of the die 8 by actuating the adjustment mechanism 21 more intensely the more the respective difference differs from zero.

(27) The entire disclosure of DE 10 2014 227 013 A1 is hereby incorporated by reference.

(28) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.