Process for operating a thermal treatment line for the flexible thermal treatment of metal pre-products

Abstract

A process for operating a thermal treatment line for the flexible thermal treatment of metal pre-products, a thermal treatment line configured and suitable for carrying out the process, and a casting-rolling mill and a process for operating a casting-rolling mill having a thermal treatment line are disclosed. In comparison with previous thermal treatment lines and processes for operating said thermal treatment lines, the disclosed thermal treatment line allows flexible operation. Emissions and production costs in the process are thereby reduced.

Claims

1.-16. (canceled)

17. A process for operating a thermal treatment line for a flexible thermal treatment of a metal pre-product, the thermal treatment line comprising a loading bed (3) for introducing the metal pre-product into the thermal treatment line; an unloading bed (12) for discharging the metal pre-product from the thermal treatment line; at least one first heating device (7) for thermally treating the metal pre-product; at least one second heating device (9) for thermally treating the metal pre-product, in particular for heating to a forming temperature of the metal pre-product; and at least three transport devices (6, 8, 10) for transporting and/or temporarily storing the metal pre-product and at least two transfer points (18, 19) for transferring the metal pre-product between the at least three transport devices (6, 8, 10), wherein a first transport device (6) of the at least three transport devices (6, 8, 10) connects the loading bed (3) at least to the first heating device (7) and a first transfer point (18) of the at least two transfer points (18, 19), wherein a second transport device (8) of the at least three transport devices (6, 8, 10) connects the first heating device (7) and the first transfer point (18) to the second heating device (9) and a second transfer point (19) of the at least two transfer points (18, 19), and wherein a third transport device (10) of the at least three transport devices (6, 8, 10) connects the second heating device (9) and the second transfer point (19) to the unloading bed (12), the process comprising: introducing the metal pre-product into the thermal treatment line; temporarily storing and/or transporting the metal pre-product by the first transport device (6) from the loading bed (3) to the first transfer point (18) or the first heating device (7); thermally treating the metal pre-product in the first heating device (7) and thereafter transferring the metal pre-product to the second transport device (8) or transferring the metal pre-product from the first transport device (6) to the second transport device (8); temporarily storing and/or transporting the metal pre-product by the second transport device (8) to the second transfer point (19) or the second heating device (9); thermally treating the metal pre-product in the second heating device (9) and thereafter transferring the metal pre-product to the third transport device (10) or transferring the metal pre-product from the second transport device (8) to the third transport device (10); temporarily storing and/or transporting the metal pre-product by the third transport device (10) to the unloading bed (12); and discharging the metal pre-products from the thermal treatment line; wherein, in a first operating mode, the metal pre-product is transported without thermal treatment from the loading bed (3) to the unloading bed (12) by the at least three transport devices (6, 8, 10); or in a second operating mode, the metal pre-product is transported to the second heating device by the first transport device (6) and the second transport device (8), the metal pre-product undergoes thermal treatment in the second heating device, and the metal pre-product is transported from the second heating device to the unloading bed by the third transport device; or in a third operating mode, the metal pre-product is transported to the first heating device (7) by the first transport device (6), the metal pre-product undergoes thermal treatment in the first heating device (7); the metal pre-product is transported to the second heating device (9) by the second transport device (8), the metal pre-product undergoes further thermal treatment in the second heating device (9), and the metal pre-product is transported from the second heating device (9) to the unloading bed (12) by the third transport device (10); or in a fourth operating mode, the metal pre-product is transported to the first heating device (7) by the first transport device (6), the metal pre-product undergoes thermal treatment in the first heating device (7), and the metal pre-product is transported from the first heating device (7) to the unloading bed (12) by the second transport device (8) and the third transport devices (10); and wherein a control system selects the first operating mode, the second operating mode, the third operating mode, or the fourth operating mode as a function of process parameters selected from the group consisting of a material, a material flow, a temperature of the metal pre-product on the loading bed (3), a target temperature of the metal pre-product on the unloading bed (12), an energy availability, and an energy costs; and wherein the control system optimizes at least a total energy consumption of the process by selecting the first operating mode, the second operating mode, the third operating mode, or the fourth operating mode.

18. The process according to claim 17, wherein at least one of the at least three transport devices (6, 8, 10) is at least partially formed as a cooling line (11) and/or cooling bed; and wherein the metal pre-product is cooled in a targeted manner upon transport by the at least one of the at least three transport devices (6, 8, 10).

19. The process according to claim 17, wherein the second heating device (9) is an induction furnace; and wherein the metal pre-product is heated inductively.

20. The process according to claim 17, wherein the first heating device (7) is a gas-fired furnace; and wherein the metal pre-product is heated by exothermic gas conversion.

21. The process according to claim 17, wherein a heating device (6, 7) uses a combination of induction heating and combustion of gas for heating the metal pre-product.

22. The process according to claim 17, wherein a separating device (5) is present in the thermal treatment line; and wherein the metal pre-product is divided into smaller units by the separating device.

23. The process according to claim 17, wherein a connecting device (6) is present in the thermal treatment line; and wherein the metal pre-product is connected to a further metal pre-product by the connecting device to form a larger unit.

24. A thermal treatment line for flexible thermal treatment of a metal pre-product, comprising: a loading bed (3) for introducing the metal pre-product into the thermal treatment line; an unloading bed (12) for discharging the metal pre-product from the thermal treatment line; at least one first heating device (7) for thermally treating the metal pre-product; at least one second heating device (9) for thermally treating the metal pre-product, in particular for heating to a forming temperature of the metal pre-product; and at least three transport devices (6, 8, 10) for transporting and/or temporarily storing the metal pre-product and at least two transfer points (18, 19) for transferring the metal pre-product between the at least three transport devices (6, 8, 10), wherein a first transport device (6) of the at least three transport devices (6, 8, 10) connects the loading bed (3) at least to the first heating device (7) and a first transfer point (18) of the at least two transfer points (18, 19), wherein a second transport device (8) of the at least three transport devices (6, 8, 10) connects the first heating device (7) and the first transfer point (18) to the second heating device (9) and a second transfer point (19) of the at least two transfer points (18, 19), and wherein a third transport device (10) of the at least three transport devices (6, 8, 10) connects the second heating device (9) and the second transfer point (19) to the unloading bed (12), wherein the thermal treatment line is configured for introducing the metal pre-product into the thermal treatment line; temporarily storing and/or transporting the metal pre-product by the first transport device (6) from the loading bed (3) to the first transfer point (18) or the first heating device (7); thermally treating the metal pre-product in the first heating device (7) and thereafter transferring the metal pre-product to the second transport device (8) or transferring the metal pre-product from the first transport device (6) to the second transport device (8); temporarily storing and/or transporting the metal pre-product by the second transport device (8) to the second transfer point (19) or the second heating device (9); thermally treating the metal pre-product in the second heating device (9) and thereafter transferring the metal pre-product to the third transport device (10) or transferring the metal pre-product from the second transport device (8) to the third transport device (10); temporarily storing and/or transporting the metal pre-product by the third transport device (10) to the unloading bed (12); and discharging the metal pre-products from the thermal treatment line; wherein, in a first operating mode, the metal pre-product is transported without thermal treatment from the loading bed (3) to the unloading bed (12) by the at least three transport devices (6, 8, 10); or in a second operating mode, the metal pre-product is transported to the second heating device by the first transport device (6) and the second transport device (8), the metal pre-product undergoes thermal treatment in the second heating device, and the metal pre-product is transported from the second heating device to the unloading bed by the third transport device; or in a third operating mode, the metal pre-product is transported to the first heating device (7) by the first transport device (6), the metal pre-product undergoes thermal treatment in the first heating device (7); the metal pre-product is transported to the second heating device (9) by the second transport device (8), the metal pre-product undergoes further thermal treatment in the second heating device (9), and the metal pre-product is transported from the second heating device (9) to the unloading bed (12) by the third transport device (10); or in a fourth operating mode, the metal pre-product is transported to the first heating device (7) by the first transport device (6), the metal pre-product undergoes thermal treatment in the first heating device (7), and the metal pre-product is transported from the first heating device (7) to the unloading bed (12) by the second transport device (8) and the third transport devices (10); and wherein a control system selects the first operating mode, the second operating mode, the third operating mode, or the fourth operating mode as a function of process parameters selected from the group consisting of a material, a material flow, a temperature of the metal pre-product on the loading bed (3), a target temperature of the metal pre-product on the unloading bed (12), an energy availability, and an energy costs; and wherein the control system optimizes at least a total energy consumption by selecting the first operating mode, the second operating mode, the third operating mode, or the fourth operating mode.

25. The thermal treatment line according to claim 24, wherein at least one of the at least three transport devices (6, 8, 10) includes driven rollers, conveyor chains and/or pushers, for moving the metal pre-product longitudinally and transversely to a main conveyor line (15).

26. The thermal treatment line according to claim 24, further comprising a driven roller track arranged in the thermal treatment line for connecting two or of more of the loading bed (3), the unloading bed (12), the at least one first heating device (7), the at least one second heating device (9), and the at least three transport devices (6, 8, 10).

27. The thermal treatment line according to claim 26, wherein the driven roller track is at least partially insulated.

28. The thermal treatment line according to claim 26, wherein at least one transport device (6, 8, 10) of the at least three transport devices (6, 8, 10) is at least partially insulated.

29. The thermal treatment line according to claim 26, wherein the thermal treatment line includes a cooling line (11) and/or a cooling bed for targeted cooling of the metal pre-product; and wherein the cooling line (11) and/or the cooling bed is connected to at least one of the at least three transport devices (6, 8, 10), the at least one first heating device (7), the at least one second heating device (9), the a loading bed (3), and/or the unloading bed (12).

30. The thermal treatment line according to claim 26 wherein at least one of the at least three transport devices (6, 8, 10) has a loading and/or unloading device.

31. A casting-rolling mill, comprising: the thermal treatment line according to claim 26; and a series of units for casting and rolling the metal pre-product into a semi-finished or finished product, wherein the thermal treatment line is arranged between a casting mill (2) and a first rolling mill stand (14); and wherein the thermal treatment line includes a higher-level control system for controlling production process steps of the thermal treatment line.

32. A process, comprising: providing the casting-rolling mill according to claim 31, wherein the higher-level control system of the casting-rolling mill (2) monitors the material flow through the casting-rolling mill; and wherein, in an event of a planned or unplanned deviation from a mass flow through the casting mill (2) to a mass flow through the rolling mill, the higher-level control system uses the thermal treatment line as a temporary storage for metal pre-products or introduces or discharges metal pre-products, wherein the higher-level control system optimizes the material flow through the casting-rolling mill with regard to an availability of cold pre-products, emissions of furnaces, costs, a material yield and/or a quality; and wherein the higher-level control system optimizes at least a casting speed, an amount of cooling water and a process parameters of the thermal treatment line in relation to total emissions of the casting-rolling mill and total production costs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 shows possible process routes for the operating modes of a thermal treatment line.

[0045] FIG. 2 shows a material flow through the thermal treatment line.

DETAILED DESCRIPTION

[0046] The invention is described in detail below with reference to the specified figures in the form of exemplary embodiments. In all figures, the same technical elements are designated with the same reference signs.

[0047] FIG. 1 shows the possible process routes within the thermal treatment line as a flow chart. A cold or hot pre-product can be fed into the thermal treatment line as input. In the case shown here, a hot pre-product comes from a continuous casting mill 2. Alternatively, pre-products from, for example, an insulation hood or other devices for controlled cooling can also be fed hot from the casting process.

[0048] The feed of the pre-products to the thermal treatment line is carried out by means of the loading bed 3. The loading bed 3 can be connected to the continuous casting 2 via roller tracks, for example. For the cold charging from a cold store 1, the loading bed 3 is loaded with a crane, for example. The loading bed 3 can also have devices that make it possible to separate or combine pre-products.

[0049] The loading bed 3 is connected to a first transport bed 6, such that the pre-product can be transported from the loading bed 3 to a first transfer point 18 or the first gas furnace 7. The first gas furnace 7 can thermally treat the pre-product in a targeted manner, for example by heating and holding it at a temperature at which the pre-product has a substantially austenitic microstructure.

[0050] The first transfer point 18 connects the first transport bed 6 with the second transport bed 8. As a result, the pre-product can reach the second conveyor bed 8 without passing through the first gas furnace 7. The second conveyor bed 8 can likewise receive the pre-product from the first gas furnace 7. The second transport bed 8 is suitable for transporting the pre-product to a second transfer point 19 or transferring it to a second furnace 9, for example an induction furnace. In the second furnace 9, the surface of the pre-product can be heated to the target temperature in a short time.

[0051] Both the second transfer point 19 and the second furnace 9 can transfer the pre-product to a third conveyor bed 10. The third transport bed 10 has an integrated cooling line 11. The pre-product can be cooled in a targeted manner by means of the cooling line 11. The cooling line 11 is not necessarily in operation upon every transport process through the third transport bed 10.

[0052] The third transport bed 10 transfers the pre-product to an unloading bed 12. The unloading bed 12 can also be formed here as a direct feed to a first rolling mill stand 14 or a scale washer 13. Furthermore, a pre-product can also be discharged by means of the unloading bed 12. The unloading bed 12 can also contain means that make it possible for the pre-products to be separated or combined.

[0053] FIG. 2 shows the schematic structure of an apparatus for carrying out the process. A main conveying direction 15 allows the pre-products to take the shortest route from the continuous casting 2 to a scale washer 13 and the first rolling mill stand 14, thereby undergoing thermal treatment only in the second furnace 9. This makes possible a continuous casting-rolling process with minimal use of additional energy from a furnace.

[0054] A connecting device 4 is arranged between the loading bed 3 and the first transport bed 6. This connecting device 4 can, for example, be formed as an insulated roller track. As a result, the distance between the continuous casting 2 and the separating device 5 can be bridged without major temperature loss. The separating device 5 can separate the previously continuous strand from the continuous casting 2 into individual portions.

[0055] A further conveying direction 16 is arranged parallel to this main conveying direction 15. This connects the cold store I with the scale washer 13 and the first rolling mill stand 14 by the shortest route. On this route, the first furnace 7 is passed through and, if necessary, an integrated cooling line 11 arranged in the third transport bed 10 is used. In addition to the transport function, the transport beds 6, 8, 10 can in each case undertake a parallel displacement between these two conveying directions 15, 16 or discharge the pre-product (17).

TABLE-US-00001 REFERENCE NUMERALS Number Description 1 Cold store 2 Continuous casting 3 Loading bed 4 Connecting device 5 Separating device 6 First transport bed 7 First heating device/first furnace 8 Second transport bed 9 Second heating device/second furnace 10 Third transport bed 11 Cooling line 12 Unloading bed 13 Scale washer 14 First rolling mill stand 15 Main conveying direction 16 Parallel conveying direction 17 Discharge to cold store 18 First transfer point 19 Second transfer point 20 Rolling mill