EP0387236B1 - Method of and installation for rolling wire and bars - Google Patents

Abstract

The invention relates to a method of and an installation for rolling wire or bars (6). In order to roll rolling stock with little capacity for deformation and/or a high resistance to deformation at room temperature, provision is made according to the invention to heat up a start-up length of the rolling stock at the beginning of rolling, to guide the insufficiently heated rolling stock in front of this start-up length (in the delivery direction) past the entry to the rolling apparatus (2) until attainment of the deformation temperature is detected, whereupon the lengths of the rolling stock which have a temperature less than that of the desired deformation temperature are cut off and only the rolling stock at the deformation temperature is fed in for deformation by rolling. <IMAGE>

Description

The invention relates to a method according to the preamble of patent claim 1 and an arrangement according to the preamble of patent claim 14 for rolling difficult-to-deform wire or rod material, in which the rolling stock is heated before the deformation and is subjected to a reduction in cross section with at least two successive rolling steps in a rolling device.

In the case of processes and arrangements such as those described in LEITHER-PLÖCKINGER: "Die Edelstahlfertigung", pages 817 - 826, 1965 Springer Verlag or E. HOUDREMONT: "Handbuch der Sonderstahlkunde", 1956, pages 1028-1030, Springer Verlag Difficulties arise when rolling material to be rolled, which has little deformation capacity or high deformation resistance at room temperature. If such rolling stock is fed to the rolling device, there is such a consolidation in the first rolling stand that the rolling stock tends to break or break open or assumes such strength that the rolls of subsequent rolling stands are damaged or further deformation is not possible. Broken areas of the rolling stock are responsible for this, which include can adhere to the surface of the rolling stock and thus adversely change the thickness of the rolling stock fed to the subsequent rolling stands.

To avoid these disadvantages, a method of the type mentioned at the outset is characterized in that, at the start of rolling, a start-up section of the rolling stock is heated, so that the start-up section is guided past the inlet of the rolling devices until a temperature measurement carried out on the moving rolling stock in front of the rolling devices reaches reaching Determines the deformation temperature of the rolling stock heated in the heating section, preferably by inductive or resistance heating, whereupon the sections of the rolling stock which have not been heated sufficiently or to a lower than the desired deformation temperature, in particular the sections of the rolling stock which are in front of the sufficiently heated area at the time of measurement in the withdrawal direction, are separated, and only the rolling stock which has the deformation temperature is fed to the rolling deformation. This procedure ensures that areas of the rolling stock which have a temperature which is below a desired deformation temperature and are therefore not sufficiently capable of being rolled are not fed to the rolling devices. By appropriately measuring the temperature of the rolling stock and separating the rolling stock that is too low (both at the inlet and at the outlet) as precisely as possible at the point at which the rolling stock reaches the desired deformation temperature, only rolling stock with the desired deformation temperature is fed to the rolling device.

Depending on the desired procedure, provision can be made for the beginning of the withdrawal or the movement of the rolling stock to wait until the starting section has reached the desired deformation or rolling temperature. In this way it is achieved that only small sections of the rolling stock have to be separated, since the front end of the rolling stock can be brought almost completely to the desired deformation temperature in a heating section.

It is advantageous if after the insufficiently heated rolling stock or the starting section has been cut off, the separated part is drawn off at a higher speed than the current movement of the rolling stock through the heating section. This increased speed is advantageous in order to gain time for the deflection maneuver. The time available for this is given by the time span that the sufficiently heated rolling stock needs to cover the distance between the separation and the articulation.

In a preferred embodiment of the invention it is provided that when a drop in the temperature of the rolling stock below the deformation temperature, in particular in the end region of the drawn rolling stock, is detected, the lower end section of the rolling stock is separated before it enters the rolling device. This procedure is particularly important for the end region of the rolling stock, which e.g. can not be heated sufficiently in a resistance heating section due to the lack of a corresponding contact and is thus separated so as not to damage the rolling devices.

It is advantageously provided that when steels are used as the temperature at which separation takes place, a temperature of below 400 ° C. and a deformation temperature of at most 1100 ° C., preferably 950 ° C., possibly at most AC1 temperature or transition temperature into the gamma structure of the alloy is selected or that in the case of copper-phosphorus alloys, in particular with 5 to 15%, preferably about 10%, phosphorus, rolling stock is separated off at a temperature below 200 ° C., in particular below 150 ° C., and a deformation temperature of 250 ° C, preferably 220 ° C, is not exceeded.

An arrangement for rolling wire or rod material, consisting essentially of a heating device, a separating and guiding device and a deformation device, in which a reduction in cross-section can be given to the rolling stock in at least two successive rolling steps, in particular for carrying out the method according to one of claims 1 to 13 is characterized in accordance with the invention in that for rolling of small deformation capacity or brittleness and / or high deformation resistance at room temperature, for example hardenable steels, high-speed steel, copper-phosphorus alloys or the like, the at least two-stage rolling device, in particular with successive ones Roll stands a heating device, in particular an electrical rapid heating device with an energy input into the rolling stock by induction or direct current passage is arranged, between the heating device and the rolling device a known separation device is provided with a steering device for the rolling stock for optional adjustment of a passing of the rolling stock to the rolling device or a supply of the rolling stock to the rolling device and that the heating device at least one temperature measuring device for the rolling stock is subordinated, by which the activity of the known separating device and the rolling stock guide or steering device is controlled. With this simply constructed arrangement it is achieved that areas of the rolling stock that are not heated to the deformation temperature, ie the beginning and end areas, can be separated in an exact manner, so that no damage to the rolling stands occurs. Such a switching and control mechanism for cutting ends of rod-like products is known per se, for example from DE-OS 24 30 790.

An advantageous construction of this arrangement results when the steering device has guides, preferably tubular, that can be adjusted by an adjusting device, with inlet openings for the rolling stock, one of which can be aligned with the roller inlet of the roller device and the other into a position that leads past the roller device. This allows the rolling stock to be rapidly steered in the direction of the rolling device or past it.

To control the arrangement, it is expedient if a control device is provided, with which the steering device, the separating device and, if appropriate, the temperature in the heating section can be controlled or regulated depending on the temperature measured on the rolling stock with the temperature measurement. It can also be provided that the heating device is followed by at least one temperature measuring device for the rolling stock, from which the activity of the separating device may be controlled. In the same way, it can also be provided that the adjusting device is controlled by the temperature measuring device. Depending on the temperature of the rolling stock, the individual devices become automatic or manual controlled. At the same time, appropriate regulation of the temperature in the heating section can ensure appropriate heating of the rolling stock.

Further preferred embodiments of the invention result from the following description, the patent claims and the drawing.

The invention is explained in more detail below, for example, with reference to the drawing. 1, 1a and 1b show a first embodiment of an arrangement according to the invention in different operating stages and FIGS. 2, 2a and 2b show a second embodiment of an arrangement according to the invention, likewise in different operating stages.

Fig. 1 shows a first embodiment of an arrangement according to the invention. The rolling stock 6 to be rolled, in the present case wire material, is drawn off from a drum 7. The rolling stock 6 is heated in a heating section 1 with contact rollers 8 and 9, which are connected via the lines 10 die to a power source, by resistance heating. The contact roller 8, as shown in dashed lines, is variable in terms of its distance from the contact roller 9 in order to enable different heating speeds or the adaptation to different wire materials. The front end of the rolling stock 6 is located in the area of a first temperature measuring device 5, for example a thermocouple, which continuously measures the temperature of the rolling stock 6. With 11 a compensation guide is designated, in which a temperature compensation of the rolling stock 6 or subsequent heating can optionally take place. The rolling stock 6 (FIG. 1a) is then passed through a separating device 4, which in the present case is formed by guillotine shears. The separating device 4 can be displaced in the direction of arrow 41 in the pull-off direction, in particular at the same speed as the feed movement of the rolling stock, so that the rolling stock 6 does not stop in its movement when the rolling stock 6 is separated. Another temperature measuring device 5 ' is provided in order to measure the rolling stock 6 before it enters a steering device 3 with a guide unit 21, which is pivotably mounted on its bearing end on a bearing 25. The outlet of the guide unit 21 can be aligned with one of two guides 15, 16, for example pipes. The two guides 15, 16 are pivotally mounted on a pivot lever 17, which causes the outlet-side end of the guide unit 21 to be aligned with one of the two inlet openings of the guides 15, 16; For this purpose, the lever 17 is adjusted by means of a hydraulic or pneumatic adjusting device 18, for example, which in the present case is mounted below the lever 17 and engages in the end region of the lever. The outlet-side end of the one guide tube 16 leading to the rolling device is pivotally mounted on a bearing unit 23. The guide tubes 15, 16 are also connected in their inlet-side and outlet-side areas so that they execute their movements together. The guide tube 15 is curved away from the rolling device 2 and directed towards a pair of rollers 19 for the removal of the rolling stock 6. The rolling device 2 is formed by a plurality, ie at least two, roll stands 12 which are arranged directly one behind the other in order to apply the corresponding cross-sectional change to the rolling stock 6. A drum 13 serves to roll up the cross-section-reduced rolling stock 6.

In Fig. 1, the arrangement of the guide unit 21 and the guides 15, 16 is such that the initially insufficiently heated rolling stock 6 entering the guide unit 21 is guided through the guide 15 to the draw-off roller pair 19. This position is also shown in FIG. 1 a, the rolling stock 6 to be separated having already been introduced into the rolls 19.

When the rolling stock 6 moves from the position shown in FIG. 1, the rolling stock 6 is heated in the heating section and its temperature is measured by means of the temperature measuring device 5 and / or 5 '. The temperature measurement values can either be read off and the separating device 4 operated manually, or a control device 20̸ is expediently provided for controlling the individual devices. If the temperature measuring devices 5, 5 'determine on exit from the heating section 1 and / or before entering the guide unit 21 that the rolling stock 6 has reached sufficient deformation temperature, the starting section of the rolling stock 6 which is not sufficiently heated is separated by the separating device 4 The position, ie the point in time of the cut, is determined by the control device 20̸ and is preferably applied as immediately as possible at the beginning of the area in which it is determined that the rolling stock has reached the desired temperature in order to keep waste of the rolling stock as low as possible. The new front end of the rolling stock 6 formed by the separation and having the deformation temperature is then fed directly to the rolling device 2.

At the moment the cut is completed, the take-off rollers 19 are brought to a higher speed in order to allow sufficient time for the guide unit 21 and the guides 15 and 16 to be moved into a position, as shown in FIG. 1 b, according to which the guide unit 21 is aligned with the guide 16 facing the rolling device 2. In the embodiment shown, the guide unit 21 and the guides 15, 16 are adjusted or aligned simultaneously.

A similar process also takes place for the end area of the rolling stock 6. At the moment when the end of the rolling stock 6 comes out of contact with the first contact roller 8 of the heating section 1, this rolling stock area is no longer heated and its temperature drops below a certain range the desired deformation temperature. With the temperature measuring device 5 this area is localized and with the separating device 4 in front of this area the end section of the rolling stock 6 is separated. A conversion of the guide unit 21 and the tubes 15, 16 formed steering device is not absolutely necessary in this case, since the end portion of the rolling stock, if it is no longer driven, remains, while the sufficiently heated rolling stock 6 is pulled by the rolling device 2 and wound on the drum 13. If the non-heated end section of the rolling stock 6 is sufficiently long, it can be steered and pulled off with a drive roller unit 27 (FIG. 1b) while simultaneously adjusting the steering device into the take-off rolls 19.

Fig. 2 shows another embodiment of an arrangement according to the invention, which essentially differs in the design of the steering device 3. The separating device 4 is followed by a stationary, immovable guide unit 21, against which the inlet openings 26 of the guides (tubes) 15, 16 can be aligned by means of the adjusting device 18. The tube 15 is curved away from the roller device 2 and directed onto the take-off rollers 19, while the tube 16 is guided into the roller device 2. Controlled by the control device 20̸, the adjusting device 18 adjusts one of the inlet openings 26 of the pipes 15, 16 in front of the guide unit 21, depending on whether the incoming rolling stock 6 is to be discharged or is to be fed to the rolling device 2. The rolling device 2 is further followed by a guide 22 which leads to the drum 13. One guide 16 is mounted on the bearing 23 as a gift and is firmly connected to the other guide.

2 shows the approach position, FIG. 2a shows the position in which the approach section of the rolling stock 6 is guided past the rolling device 2, and FIG. 2b shows the arrangement according to the invention in rolling operation, the rolling stock 6 being guided through the rolling device 2 at the desired deformation temperature .

2, 2a and 2b is a rotating separator 4 Scissors are provided, which in the present case are not designed to be movable with the rolling stock 6. Furthermore, only one temperature measuring device 5 is provided, or the temperature measuring device 5 ', which has only a control function, is omitted.

It is also possible to provide a separate adjustment device for each of the guides 15, 16, the movements of the guides being coordinated accordingly; in this case the guides are adjustable independently of each other.

It is noted that the heating section can be of any type known to those skilled in the art. The rolling devices are also of a known type.

Claims (25)

1. A process for rolling wire material or bar material, in which the rolling stock - which exhibits low deformability or high brittleness and/or high deformation resistance at room temperature, e.g. hardenable steels, high-speed steels, copper-phosphorus alloys or the like - is heated before shaping and is subjected to a reduction of cross-section in rolling devices in at least two consecutive rolling steps, characterised in that an initial portion of the rolling stock is heated at the start of rolling, in that the initial portion is guided past the inlet of the rolling devices until it is established by measuring the temperature of the moved rolling stock in front of the rolling devices that the rolling stock, which has been heated in the heating section, preferably by inductive or resistance heating, has reached the shaping temperature, whereupon the portions of the rolling stock which have not been heated sufficiently or have been heated to a temperature lower than the desired shaping temperature, in particular those portions located in front of the sufficiently heated region in the draw-off direction at the time of measurement, are severed, and only the rolling stock which has reached the shaping temperature is supplied to rolling shaping.
2. A process according to Claim 1, characterised in that the initial portion is heated when the rolling stock is still at rest.
3. A process according to Claim 1 or 2, characterised in that the draw-off or movement of the rolling stock is not started until the initial portion has reached the desired shaping or rolling temperature.
4. A process according to any one of Claims 1 to 3, characterised in that the temperature of the rolling stock is measured continuously at at least one point between the heating section and the entrance into the rolling devices and, once it has been established that the shaping temperature has been reached, the rolling stock is severed at the point at which the shaping temperature was first measured, or at a point located upstream in the direction of movement.
5. A process according to any one of Claims 1 to 4, characterised in that, once the insufficiently heated rolling stock or initial portion has been severed, the severed part is drawn off at a higher speed than the instantaneous movement of the rolling stock through the heating section.
6. A process according to any one of Claims 1 to 5, characterised in that, once the initial portion has been severed, the end of the rolling stock heated to the shaping temperature is directed or guided into the rolling devices.
7. A process according to any one of Claims 1 to 6, characterised in that, when a drop in the temperature of the rolling stock below the shaping temperature is established, in particular in the end region of the drawn-off rolling stock, the (end) portion of the rolling stock having the lower temperature is severed before it enters into the rolling device.
8. A process according to Claim 7, characterised in that the severing takes place at the point or downstream of the point where the rolling stock falls below a permissible minimum shaping temperature.
9. A process according to Claim 7 or 8, characterised in that the severed (end) portion is guided past the rolling device, or is stopped in front of the latter.
10. A process according to any one of Claims 1 to 9, characterised in that, in the case of steels, a temperature of below 400°C is selected as the temperature at which severing takes place, and a shaping temperature is selected which is at most 1100°C, preferably 950°C, and, where appropriate, at most the AC1 temperature or the temperature at which the alloy is transformed into the gamma structure.
11. A process according to any one of Claims 1 to 9, characterised in that, in the case of copper-phosphorus alloys, in particular with 5 to 15 %, preferably approximately 10 %, phosphorus, rolling stock is severed at a temperature below 200°C, preferably below 180°C, in particular below 150°C, and a shaping temperature of 250°C, preferably 220°C, is not exceeded.
12. A process according to any one of Claims 1 to 11, characterised in that the cross-section is reduced by a total of at least 40 %, preferably 60 %, in at least two rolling steps.
13. A process according to any one of Claims 1 to 12, characterised in that the rolling takes place in the first pass at an intake speed of at least 0.2 m/s, preferably at at least 0.5 m/s.
14. An arrangement for rolling wire material or bar material, consisting of a heating device, a separating and guiding device and a shaping device, in which the rolling stock can be given a reduction of its cross-section in at least two consecutive rolling steps, in particular in order to carry out the process according to any one of Claims 1 to 13, characterised in that, in order to roll rolling stock which exhibits low deformability or high brittleness and/or high deformation resistance at room temperature, e.g. hardenable steels, high-speed steel, copper-phosphorus alloys or the like, the rolling device (2), which comprises at least two stages and in particular comprises roll stands (12) arranged in direct succession, is preceded by a heating device (1), in particular an electrical high-speed heating device (8,9,10) where energy is transferred to the rolling stock (6) by induction or direct current passage, a known separating device (4) being provided between the heating device (1) and the rolling device (2), with a directing device (3, 15, 15, 21) for the rolling stock (6) for adjusting whether the rolling stock (6) is guided past the rolling device (2) or alternatively supplied to the rolling device (2), and in that the heating device (1) is followed by at least one temperature measuring device (5, 5') for the rolling stock (6), which where appropriate controls the activity of the known separating device (4) and the rolling-stock guiding and directing device (3).
15. An arrangement according to Claim 14, characterised in that the separating device (4) is displaceable in the draw-off direction of the rolling stock (6), in particular at the draw-off speed of the rolling stock (6).
16. An arrangement according to any one of Claims 14 or 15, characterised in that the separating device (4) is formed by hammer shears, rotating shears or the like.
17. An arrangement according to any one of Claims 14 to 16, characterised in that the directing device (3) comprises guides (15, 16) with inlet openings (26) for the rolling stock (6), which guides (15, 16) are preferably tubular and adjustable by an adjusting device (18), one of which can be aligned with the rolling entrance of the rolling device (2) and one of which can be aligned into a position leading past the rolling device (2).
18. An arrangement according to any one of Claims 14 to 17, characterised in that a controlling device (20) is provided, with which the directing device (3), the separating device (4) and where appropriate the temperature in the heating section (1) can be controlled and regulated in dependence on the temperature of the rolling stock (6) measured by the temperature measuring device (5, 5').
19. An arrangement according to Claim 17 or 18, characterised in that the guide (15) leading past the rolling device (2) is followed by a draw-off device (19), with which the rolling stock (6) can be drawn off at a higher speed than its speed in the heating section (1).
20. An arrangement according to any one of Claims 17 to 19, characterised in that the adjusting device (18) is driven hydraulically (e.g. a hydraulic cylinder), electrically, electromagnetically or mechanically.
21. An arrangement according to any one of Claims 17 to 20, characterised in that the guide (15) leading past the rolling device (2) is bent away from the rolling entrance.
22. An arrangement according to any one of Claims 17 to 21, characterised in that the adjusting device (18) is controlled by the temperature measuring device (5, 5').
23. An arrangement according to any one of Claims 17 to 22, characterised in that the inlet openings (26) of the two guides (15, 16) are arranged directly adjacent one another.
24. An arrangement according to any one of Claims 17 to 23, characterised in that the inlet openings (26) are preceded by a guide unit (21) for the rolling stock (6), which is adjustable by the adjusting device (18) where appropriate and with which one of the guides (15, 16) can be brought into alignment.
25. An arrangement according to any one of Claims 17 to 24, characterised in that the adjusting device (18) acts upon the guides (15, 16) in the region of the inlet openings (26), these guides (15, 16) being fastened or connected to one another where appropriate and one of them being mounted pivotably at its end opposite the inlet openings (26) where appropriate.

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