Treatment of hot rolling stock made of metal

Abstract

Hot rolling stock (1) made of metal which is rolled in at least one roll stand (2) and then cooled in a cooling section (5) arranged downstream of the at least one roll stand (2). Sound generated by means of a sound generator arrangement (8) is coupled into the rolling stock (1) by a coupling device (1) so that a standing sound wave is formed at least in the region of the rolling stock (1) which is located in the vicinity of the coupling device (10).

Claims

1. A treatment process for hot rolling stock made of metal, the process comprising: rolling the rolling stock in at least one roll stand; cooling the rolling stock in a cooling section arranged downstream in a direction of the rolling of the rolling stock of the at least one roll stand; providing a sound generator arrangement; providing a control device; operating the control device to determine at least one control variable (C) based on actual properties (P) of the rolling stock before cooling in the cooling section and based on set point properties (P*) that the rolling stock is to have after cooling in the cooling section; feeding the sound generator arrangement the at least one control variable (C); generating sound by the sound generator arrangement and coupling the generated sound into the rolling stock upstream of the cooling section for forming a standing sound wave at least in a region of the rolling stock that is located in a vicinity of a coupling device; and operating the sound generator arrangement to set a characteristic quantity of the sound coupled into the rolling stock based on the control variable (C).

2. The treatment process as claimed in claim 1, further comprising: generating the sound at a frequency (f) in the MHz range or above.

3. The treatment process as claimed in claim 1, wherein the characteristic quantity (f, A, φ) is a frequency (f) and/or an amplitude (A) of the sound if the sound generator arrangement comprises a plurality of sound generators and if each sound generator independently couples a sound signal (S) into the rolling stock, for setting a phase position (φ) of the sound signals (S) of the sound generators in relation to one another.

4. The treatment process as claimed in claim 1, further comprising the coupling device comprises a working roller of a last one of the roll stands before the cooling section or comprises a roller that is arranged between the last one of the roll stands and the cooling section, and the process comprising placing the last one of the roll stands against the rolling stock.

5. The treatment process as claimed in claim 1, wherein the rolling stock is a flat rolling stock.

6. The treatment device as claimed in claim 5, wherein the flat rolling stock is a strip.

7. The treatment process as claimed in claim 3, further comprising: if the sound generator arrangement comprises a plurality of sound generators which each independently couples a sound signal (S) into the rolling stock, setting a phase position (φ) of the sound signals (S) of the sound generators in relation to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The properties, features and advantages of this invention described above and also the manner in which they are achieved become clearer and more clearly understandable in connection with the following description of the exemplary embodiments, which are explained more specifically in conjunction with the schematically represented drawings, in which:

(2) FIG. 1 shows a treatment device for a rolling stock,

(3) FIG. 2 shows a design of a second treatment device of FIG. 1,

(4) FIG. 3 shows a third design of the treatment device of FIG. 1,

(5) FIG. 4 shows a portion of a flat rolling stock and

(6) FIG. 5 shows a control device and a sound generator arrangement.

DESCRIPTION OF THE EMBODIMENTS

(7) According to FIG. 1, a hot rolling stock 1 made of metal is rolled in a roll stand 2. The hot rolling stock 1 runs through the rolling stand 2 in a transporting direction x. The hot rolling stock 1 may for example consist of steel. In this case, the temperature T of the hot rolling stock 1 when it leaves the roll stand 2 is usually between 750° C. and 900° C. Alternatively, the hot rolling stock 1 may consist of aluminum. In this case, the temperature T of the hot rolling stock 1 when it leaves the roll stand 2 is generally between 300° C. and 400° C. The hot rolling stock 1 may also consist of some other metal, for example copper. Then the metal in this case is at a material-specific temperature.

(8) Often, before the rolling in the roll stand 2 shown in FIG. 2, the hot rolling stock 1 is rolled in further roll stands arranged upstream of the roll stand 2. The further roll stands are not included in FIG. 1.

(9) The hot rolling stock 1 may in principle have any desired cross section. In many cases, the hot rolling stock 1 is a flat rolling stock, in particular a strip. Accordingly, the roll stand 2 is formed as a roll stand for rolling the flat rolling stock 1. In particular, the roll stand 2 may in this case have back-up rolls 4 in addition to its working rollers 3.

(10) After the rolling in the roll stand 2, the rolling stock 1 continues to be conveyed in the transporting direction x, and therefore runs through a cooling section 5 arranged downstream of the roll stand 2. If the hot rolling stock 1 is a flat rolling stock, the cooling section 5 is formed as a cooling section for cooling the flat rolling stock 1. In the cooling section 5, the rolling stock 1 is cooled by liquid cooling medium 6, usually water, being applied to it. In a way corresponding to the representation in FIG. 1, the cooling medium 6 is generally applied from more than one side, for example, for a flat rolling stock, both from above and from below. In principle, however, cooling from only one side is also possible. For example, for a flat rolling stock, cooling may be exclusively from above or exclusively from below. After the cooling section 5, the hot rolling stock 1 is at a much lower temperature than before it passes the cooling section 5. For example, in the case of steel, the temperature may be lowered to about 300° C.

(11) Further devices may be arranged downstream of the cooling section 5, for example a coiler 7, by which the rolling stock 1 is coiled up, if it is a strip.

(12) A sound generator arrangement 8 generates sound. For this purpose, the sound generator arrangement 8 has a plurality of sound generators 9, for example transducers. The sound is coupled into the hot rolling stock 1 by a coupling device 10. Corresponding to the representation in FIG. 2, the coupling device 10 may, for example, be a roller 11, which is arranged between the roll stand 2 and the cooling section 5 and is placed against the hot rolling stock 1. Alternatively, in a way corresponding to the representation in FIG. 3, the coupling device 10 may be a working roller 3 of the last roll stand 2. It is similarly possible to couple the sound into the hot rolling stock 1 at other points in the transportation of the rolling stock. In particular, coupling in before the roll stand 2, in the cooling section 5, or after the cooling section 5 is also possible.

(13) The coupled-in sound has the effect of forming a standing sound wave, at least in the region of the hot rolling stock 1, that is located in the vicinity of the point at which the sound is coupled into the hot rolling stock 1. FIG. 4 shows this by example for a flat rolling stock. The lines and circles depicted in FIG. 4 indicate those points at which the nodes of the standing sound wave are located, and at which extinction of the sound wave therefore occurs as a result of destructive interference. In between the nodes are the points at which the sound wave is not extinguished, and in particular at some points is at a maximum because of constructive interference.

(14) In many cases, the point at which the sound is coupled into the hot rolling stock 1 is chosen such that a standing sound wave is formed at least between the roll stand 2 and an entry region of the cooling section 5. In some cases, however, other points may also be appropriate.

(15) The sound wave has the effect of influencing the microstructural transformation of the hot rolling stock 1. In particular, the microstructure becomes more fine-grained based on the greater the frequency f of the coupled-in sound, and consequently also of the standing sound wave, is. The frequency f of the coupled-in sound should therefore lie in the MHz range or above, or the sound generator arrangement 8 should be correspondingly formed, to correspond to such a frequency.

(16) The sound generator arrangement 8 is preferably formed as a sound generator arrangement that can be set. In this case, corresponding to the representation in FIG. 5, the sound generator arrangement 8 may be fed at least one control variable C by a control device 12 of the treatment device. In this case, the sound generator arrangement 8 sets a characteristic quantity f, A, φ of the sound coupled into the hot rolling stock 1 in dependence on the control variable C.

(17) For example, corresponding to the representation in FIG. 5, the control device 12 may specify to the sound generator arrangement 8, by means of a control variable C, which frequency f the sound is to have. As an alternative or in addition, the control device 12 may specify to the sound generator arrangement 8 by means of another control variable C which amplitude A the sound is to have. Corresponding to the representation in FIG. 5, if the sound generator arrangement 8 has a plurality of sound generators 9, which each independently couple a sound signal S into the hot rolling stock 1, the amplitude A may possibly be specified individually for the respective sound generator 9 by means of a respective control signal C. For a plurality of sound generators 9, the control device 12 may furthermore also specify to the sound generators 9 of the sound generator arrangement 8, by a respective control variable C, a phase position φ of the sound signals S of the sound generators 9 in relation to one another. This is an alternative or in addition to the influencing of the frequency f and/or the amplitude A. By contrast, the frequency f is generally the same for all sound generators 9.

(18) The at least one control variable C may be determined by the control device 12, according to requirements. For example, actual properties P of the hot rolling stock 1 before the cooling section 5 may be specified to the control device 12. The actual properties P of the hot rolling stock 1 before the cooling section 5 may, for example, be its temperature T and/or at least one geometrical dimension. On a flat rolling stock, the dimension may be its width b or its thickness d (see also FIGS. 1 and 4). As an alternative or in addition, setpoint properties P*, which the hot rolling stock 1 is intended to have after the cooling section 5, may also be specified to the control device 12. The setpoint properties P* may, for example, be desired mechanical properties such as tensile strength, elongation limit, fracture limit, etc. or microcrystalline properties, s for example, fractions of bainite, martensite and the like. The control device 12 in this case determines the control variable C in dependence on the properties P, P* specified to it.

(19) The present invention has many advantages. In particular, it is easily possible when cooling down the hot rolling stock 1 to additionally influence the microstructural transformation independently of the cooling. The microstructural properties of the rolling stock 1 can be improved, set more precisely and especially made more uniform. The construction of the cooling section 5 can be simplified. The distance from the last roll stand 2 can be increased without any problem.

(20) Although the invention has been illustrated more specifically and described in detail by the preferred exemplary embodiment, the invention is not restricted by the examples disclosed and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.

LIST OF DESIGNATIONS

(21) 1 Rolling stock 2 Roll stand 3 Working rollers 4 Back-up rolls 5 Cooling section 6 Cooling medium 7 Coiler 8 Sound generator arrangement 9 Sound generators 10 Coupling device 11 Roller 12 Control device A Amplitudes b Width C Control variable d Thickness f Frequency P Actual properties P* Setpoint properties S Sound signals T Temperature x Transporting direction φ Phase positions