METHOD AND INSTALLATION FOR COATING A SCALED HOT-ROLLED STRIP

Abstract

The invention relates to a method and an installation for coating a scaled hot-rolled strip (10). The method comprises at least the following steps: (i) providing a hot-rolled strip (10) in the form of a hot-rolled preliminary strip, (ii) preparing the surfaces of the hot-rolled strip (10), and (iii) coating of the hot-rolled strip (10) on at least one prepared surface thereof, wherein the coating is carried out at a temperature of 100 C. and immediately after the descaling of the hot-rolled strip (10).

Claims

1. A method for coating a scaled hot-rolled strip (10), at least comprising the steps of: (i) providing a hot-rolled strip (10) in the form of a hot rolled preliminary strip, (ii) preparing the surfaces of the hot-rolled strip (10), and (iii) coating the hot-rolled strip (10) on at least one prepared surface thereof, wherein the coating is carried out at a temperature of 100 C. and immediately after the descaling of the hot-rolled strip (10), characterized in that, after step (iii), at least one further treatment step (iv) is carried out for the hot-rolled strip (10), in which the hot-rolled strip (10) is provided with an additional coating consisting of a plastic film lamination.

2. The method according to claim 1, characterized in that at step (ii) preparing the hot-rolled strip (10) is carried out by means of a pickling device (14)

3. The method according to claim 1, characterized in that at step (iii) coating of the hot-rolled strip (10) is carried out electrolytically or according to the principle of physical vapor deposition (PVD).

4. The method according to claim 1, characterized in that the hot-rolled strip (10) is trimmed at its side margins before step (ii).

5. The method according to claim 1, characterized in that the hot-rolled strip (10) is lead through a stretch leveler (24) before step (ii).

6. The method according to claim 1, characterized in that, in the further treatment step (iv), which is carried out after step (iii), the hot-rolled strip (10) is provided with an additional coating consisting of a chemical coating and/or of an oiling.

7. An installation (1) for coating a scaled hot-rolled strip (10), comprising a continuous treatment line (2), in which the hot-rolled strip (10) is moved in a direction of movement (T), wherein in the treatment line (2) a pickling device (14) for preparing the surfaces of the hot-rolled strip (10) and at least one first coating device (16) are provided, wherein a coating can be applied to at least one prepared surface of the hot-rolled strip (10) by means of the first coating device (16), wherein the first coating device (16) is configured such that the coating of the hot-rolled strip (10) takes place on at least one side thereof at a temperature of 100 C., characterized in, that a second coating device (20) is provided whichas viewed in the direction of movement (T) of the hot-rolled strip (10)is arranged downstream of the first coating device (16), wherein an additional coating consisting of a plastic film lamination is applied on at least one surface of the hot-rolled strip (10) by means of the second coating device (20).

8. The installation (1) according to claim 7, characterized in thatas viewed in the direction of movement (T) of the hot-rolled strip (10)upstream of the pickling device (14) a first shear (18) is arranged in order to cut off side margins of the hot-rolled strip (10) in a defined manner.

9. The installation (1) according to claim 7, characterized in that a skin pass mill (22) is provided, whichas viewed in the direction of movement (T) of the hot-rolled strip (10)is arranged downstream of the first coating device (16).

10. The installation (1) according to claim 7, characterized in that a stretch leveler (23) is provided, whichas viewed in the direction of movement (T) of the hot-rolled strip (10)is arranged downstream of the first coating device (16).

11. The installation (1) according to claim 7, characterized in that a scale breaker (24) is provided, whichas viewed in the direction of movement (T) of the hot-rolled strip (10)is arranged upstream of the pickling device (14).

12. The installation (1) according to claim 7, characterized in that a connecting device (26) and a first looping pit (28) are provided, each of whichas viewed in the direction of movement (T) of the hot-rolled strip (10)are arranged upstream of the pickling device (14).

13. The installation (1) according to claim 12, characterized in that a second looping pit (30) and a second shear (32) are provided, each of whichas viewed in the direction of movement (T) of the hot-rolled strip (10)are arranged downstream of the first coating device (16).

14. The installation (1) according to claim 9, characterized in that an oiling machine (34) is provided whichas viewed in the direction of movement (T) of the hot-rolled strip (10)is arranged downstream of the second coating device (20).

15. Use of an installation (1) according to claim 7, in which the first coating device (16) remains offline so that the hot-rolled strip (10) is not coated by means of the first coating device (16).

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] Exemplary embodiments of the invention are described in detail with reference to a schematically simplified drawing, where

[0032] FIG. 1 is a schematically simplified flow diagram for carrying out a method according to the present invention,

[0033] FIG. 2 is a schematically simplified side view of an installation according to the invention according to a first embodiment of the invention, and

[0034] FIG. 3-9 are each schematically simplified side views of an installation according to further embodiments of the invention.

[0035] The present invention provides a method and an installation for coating a scaled hot-rolled strip on at least one surface thereof.

[0036] FIG. 1 illustrates a flow chart of essential steps of the method according to the invention:

[0037] First, in a step (i), a hot-rolled strip 10 is provided. Such a hot-rolled strip is a hot rolled preliminary strip which has obtained predetermined material properties during upstream rolling in a hot rolling mill.

[0038] Subsequently, in a step (ii), the surface of the hot-rolled strip 10 is subjected to a pre-treatment to prepare the application of a coating thereon. Such pretreatment may consist of pickling the surface(s) of the hot-rolled strip. Here, the hot-rolled strip is passed through a corresponding pickling device, which is explained elsewhere below.

[0039] In a next step (iii), the hot-rolled strip 10 is then coated on at least one surface thereof. Regarding this process step, it is separately emphasized at this point that the coating of the hot-rolled strip 10 is carried out at moderate temperatures, i.e. at a temperature of 100 C. Due to this relatively low temperature, it is ensured that preset material properties of the hot-rolled strip are preserved.

[0040] Optionally, after step (iii), a further method step (iv) may also be provided, which is illustrated by dashed lines in FIG. 1. In this further method step, an additional coating can be applied to the hot-rolled strip, e.g., in the form of a plastic film lamination and/or in the form of a chemical coating or the like, which is applied by suitable rollers on a surface of the hot-rolled strip. Additionally and/or alternatively, it can also be provided to apply an oiling to at least one surface of the hot-rolled strip in the further process step (iv), e.g., by spraying, rolling or electrostatically.

[0041] FIGS. 2 to 9 show various embodiments of an installation 1 according to the invention, by means of which a treatment of a scaled hot-rolled strip 10 is possible. In the drawing, the same features for the installation 1 are each provided with the same reference numerals.

[0042] FIG. 2 shows the installation 1 according to a first embodiment, in a schematically greatly simplified side view. The installation comprises a treatment line 2, in which a hot-rolled strip 10 is first unwound from a first coiling device 11, wherein the hot-rolled strip 10 at the end of the treatment line 2 is then wound up again by a second coiling device 12. Within the treatment line 2, the hot-rolled strip 10 is moved or transported in a direction of movement T, namely from the first coiling device 11 towards the second coiling device 12.

[0043] In the treatment line 2 are arranged a pickling device 14 anddownstream thereofa first coating device 16. The coating device 16 can be switched on or off as needed, which will be explained separately below.

[0044] By treating the hot-rolled strip 10 in the pickling device 14, its surfaces are suitably prepared to subsequently apply a coating to at least one surface of the hot-rolled strip 10, preferably both surfaces thereof, by means of the first coating device 16. The first coating device 16 may be an electrolytic immersion bath in which the surfaces of the hot-rolled strip 10 are galvanized.

[0045] After the surfaces of the hot-rolled strip 10 in the treatment line 2 have been pickled and then at least one surface of the hot-rolled strip 10 has been provided with a coating, e.g., with a zinc layer, the hot-rolled strip 10 is then wound up again by the second coiling device 12. In this way, a metallic coating of scaled hot-rolled strip 10 is achieved at only low temperatures, without the material properties of the hot-rolled strip 10 being changed or adversely affected.

[0046] FIG. 3 shows an installation 1 according to the invention in accordance with a further embodiment. Here, in comparison with the embodiment of FIG. 2as viewed in the direction of movement T of the hot-rolled strip 10a first shear 18 are arranged upstream of the pickling device 14. This first scissors 18 serves to selectively and definedly trim side margins of the hot-rolled strip 10 so that it is possible to wind up a clean coil with defined side margins on the second coiling device 12. FIG. 4 shows an installation 1 according to the invention according to a further embodiment. Hereas viewed in the direction of movement T of the hot-rolled strip 10a skin pass mill 22 and a second coating device 20 are arranged downstream of the first coating device. Optionally, a stretch leveler 23 may also be arranged between the skin pass mill 22 and the second coating device 20. The second coating device 20 may be a film laminating machine, by means of which the hot-rolled strip 10 is provided with a plastic film lamination. Alternatively, on at least one surface, preferably on both surfaces of the hot-rolled strip 10, i.e., the top and bottom thereof, another coating can be applied by means of the second coating means 20, e.g., a roll coating in the form of a chemical coating or the like, which is applied on the surfaces of the hot-rolled strip 10 by suitable contact rollers.

[0047] The skin pass mill 22 serves to provide the surfaces of the hot-rolled strip 10 with a defined roughness, without causing a reduction in thickness of the hot-rolled strip 10 and losing its preset material properties.

[0048] FIG. 5 shows an installation 1 according to the invention according to a further embodiment. Upstream of the pickling device 14, a first shear 18, and downstream of the first coating device 16, a second coating device 20 and/or a skin pass mill 22 are arranged. To avoid repetition reference is made to the relevant explanation of FIG. 3 and FIG. 4, respectively.

[0049] FIG. 6 shows an installation 1 according to the invention according to a further embodiment, which represents a variation of the embodiment of FIG. 5. In contrastas viewed in the direction of transport T of the hot-rolled strip 10a so-called. scale breaker 24 is arranged upstream of the pickling device 14, namely between the pickling device 14 and the first shear 18. Such a scale breaker 24, may be, according to its function, stretch leveler, which serves in a conventional manner for smoothing the surfaces of the hot-rolled strip 10, but without changing the thickness of the hot-rolled strip 10. Accordingly, when the scale breaker 24 is used, cold rolling of the hot-rolled strip 10 does not occur, and thus does not lead to a significant change in its material properties. This also applies in the same way to the stretch leveler 23 in the embodiment of FIG. 4.

[0050] FIG. 7 shows an installation 1 according to the invention according to a further embodiment, as a variation of the embodiment of FIG. 6, according to whichas viewed in the direction of transport T of the hot-rolled strip 10both a second coating device 20 and a skin pass mill 22 are arranged now downstream of the first coating device 16.

[0051] FIG. 8 shows an installation 1 according to the invention according to a further embodiment, with which a continuous operation of the treatment line 2 through the use of new coils is possible. For this purposeas viewed in the direction of transport T of the hot-rolled strip 10a connecting device 26 and a first looping pit 28 are arranged upstream of the pickling device 14. The connecting device 26 may be a welding device or an affixing device with which the margin regions of two different coils can be welded or affixed. If, when changing a coil whose beginning of the strip is to be connected to the end of the strip of a previous coil, this can be done thanks to the first looping pit 28, in which previously a sufficient amount or length of hot-rolled strip has been buffered or stored. In the same wayas viewed in the direction of transport T of the hot-rolled strip 10a second looping pit 30 and a second shear 32 are arranged downstream of the first coating device. Thanks to these elements, it is possible to wind a batch of a coil of the hot-rolled strip 12 on the second coiling device 12 and to make a corresponding change at the second coiling device 12 for this purpose.

[0052] In the embodiment of FIG. 8, it is further provided to apply an oiling to the hot-rolled strip 10. For this purpose, an oiling machine 34 is arranged downstream of the second shear 32, by means of which can be applied to a top and/or bottom of the hot-rolled strip 10.

[0053] FIG. 9 shows an installation 1 according to the invention according to a further embodiment, which corresponds to a combination of the embodiments according to FIGS. 7 and 8. Thus, in the embodiment of FIG. 9, now a second coating device 20, a skin pass mill 22, a second looping pit 30, a second shear 32, and an oiling machine 34 are arranged downstream of the first coating device 16. To avoid repetition, reference is made to the corresponding explanations for FIGS. 7 and 8.

[0054] In comparison to the embodiment of FIG. 2, in the abovementioned embodiments according to FIGS. 3-9, in addition to the pickling device 14 and the first coating device 16, the following additional installation components are added: [0055] first shear 18, [0056] second coating device 20, [0057] skin pass mill 22, [0058] stretch leveler 24, [0059] connecting device 26, [0060] first looping pit 28, [0061] second looping pit 30, [0062] second shear 32, and/or [0063] oiling machine 34.

[0064] With respect to these additional installation components, it is understood that a combination thereof with the embodiment of FIG. 2 is also possible in other ways than shown and explained by the illustration in FIGS. 3 to 9. Thus, it is possible to use these installation components in other combinations and possibly in a position in the treatment line 2 of installation 1, which are different from the illustrated drawing.

[0065] Finally, it should be noted that in all the above embodiments, the installation 1 can also be operated in such a way that the first coating device 16, by means of which normally, e.g., galvanizing is applied to the hot-rolled strip 10, is turned off. Accordingly, the hot-rolled strip 10 then passes through the treatment line 2, without the surfaces of the hot-rolled strip 10 being galvanized. In this way, when the first coating device 16 is turned off, a pickling of normal steel strips with pickling acid to produce a hot-rolled strip 10 with pickled and oiled surfaces can be realized by installation 1. Here, the oiled surfaces of the hot-rolled strip 10 are produced by means of the oiling machine 34.