EP1812609B1 - Method and device for shaping wire-shaped and rod-shaped starting materials close to finishing wire gauge - Google Patents

Description

The present invention relates to a method for near net deformation of wire and rod-shaped starting material according to the preamble of claim 1, a device suitable for carrying out the method according to claim 26.

The production of relatively narrow and flat bands of steel materials, hereinafter referred to as flat profiles, can be done in various ways, depending on the required material properties, the dimensions of the flat profiles to be produced and the intended use of the flat profiles. Under flat profiles are usually understood profile shapes in which the width of the cross section is not greater than 10-20 times the thickness. Such flat profiles are used for functional components and often wear parts in technical equipment, e.g. used for springs or the like. Components in the automotive, aircraft and space industry, in equipment construction and agricultural machinery. Also, such flat profiles are used as starting material e.g. used for the production of saws, saw blades, bushing chains for motorcycles and bicycles, rollers, rolling bearings, ski edges or also for piston rings. Frequently, these flat profiles are mechanically highly stressed components whose strength properties, in addition to compliance with required cross-sectional shapes and dimensions, are of central importance.

In commonly required properties of such flat profiles are often cut out of wider steel strips by longitudinal division, which commercially available steel strips can be used as starting material, which can be brought by known hot and / or cold rolling operations to the appropriate dimensions. The setting of the material properties is usually unproblematic in such steel bands, but changes in the longitudinal division of the material of the flat profiles no longer compared to that of the steel strips. However, flat profiles produced in this manner have the disadvantage of not having certain or advantageous configurations of the edges of the flat profiles required or required due to the later uses of the flat profiles, which have quite important advantages for the serviceability or service life of components produced therefrom. Thus, after the longitudinal division of steel strips made of wide steel strips, edge forming must be worked on by additional machining processes after longitudinal slitting, resulting in additional costs.

Another way to produce such flat profiles is to pull the materials as a wire by appropriately shaped drawing dies that automatically produce the required profile cross-sections and their fine geometry as well as the edge design. The problem with the drawing of corresponding flat profiles, which are otherwise widespread for wire production, is, on the one hand, the relatively low pull rates that can be achieved due to the otherwise excessively high wear on the drawing molds, and, on the other hand, the strain hardening of the materials due to the forming which occurs when drawing appropriate materials, which can only be achieved by expensive intermediate heat treatments the drawn wires can be reversed. As a result, such a production of flat profiles consuming and technically not without problems.

It is also known to produce corresponding flat profiles by cold rolling by a relatively small cross-sectional decreases, for example, as a round wire running starting material gradually and depending on the deformation by cold rolling is formed into a flat profile. It is also possible to ensure the dimensions and the required edge shapes by appropriate technology management. The disadvantage here, however, as in all cold rolling, that the cold-rolled materials similar to pulling a corresponding strain hardening subject and therefore must be treated in the same way analogous to the necessary heat treatment during drawing. Especially with strong cross-sectional changes but this is a frequent intermediate annealing of the materials in the course of cold rolling required.

It is therefore an approach to further develop the rolling of flat profiles of wire-like starting material has become known in which after EP 0 314 667 B2 hot rolling is carried out instead of cold rolling in order to carry out the substantial change in cross section during the forming of the wire-like starting material in the much easier deformable warm state of the material. For this purpose, the wire-like starting material is heated by conductive heating to a temperature of at most A ₁ or the transition temperature in the γ-region of the alloy and then rolled in a multiple stand. Subsequently, the rolled flat profile can then be cooled. A disadvantage of this approach is that although the deformation is relatively final dimensional feasible, the control of the material properties of the material in such a process control but anything but easy. Also, the processing of steel materials is limited only to certain classes of materials.

In the EP 0 560 115 A1 For example, a method is described for near net rolling of fine steel or wire. There is only a passive temperature compensation in the form of temperature compensation section after a rolling process and described without direct heating before rolling, which is traversed after a conventional cooling in a water tank. Therefore, the passive temperature compensation in the form of a temperature compensation line is necessary to set before a further rolling stage a reasonably defined state of the rolling stock. The object of the present invention is therefore to provide a method for near net deformation of wire and rod-shaped starting material, which combines the advantages of thermoforming of wire and rod-shaped starting material with compliance with the process parameters relevant to the material characteristics process, thereby producing a variety of different, but nevertheless allows very consistent adjustable material and workpiece properties.

The solution of the object according to the invention results with regard to the method for continuous running of strip steel from the characterizing features of claim 1, with respect to the device suitable for carrying out the method of the characterizing features of claim 26th

Further advantageous embodiments of the invention will become apparent from the dependent claims.

The invention according to claim 1 is based on a method for rolling technical deformation of wire and rod-shaped starting material, in particular for rolling flat profiles of wire rod, in which the heating of the starting material takes place in a heating station to a desired temperature, the starting material deformed in at least one rolling operation and then cooled. Such a generic method is further developed in that after the heating of the undeformed starting material in the Aufheizstation the starting material then cooled in a cooling station having a tempered metal bath for setting a rolling temperature to a predetermined temperature for setting a predetermined structure over a contact time, at this temperature In terms of rolling technique, it is shaped into a flat profile and subsequently cooled and / or after-treated in accordance with structural properties to be set. Due to the targeted cooling of the material to the desired rolling temperature before performing the rolling process can be achieved in spite of the previous heating of the material to a required to trigger the desired microstructural transformations, usually higher temperature that exactly the starting structure are set before rolling the Vormaterials can, which ensures the desired structural properties of the flat profile together with the change in the material due to the rolling and the rolling optionally downstream aftertreatment of the flat profile. In this case, by heating the starting material to eg a temperature that ensures safe Austenitiserung above the A ₃ temperature ensures a corresponding microstructure transformation, which then sets by the targeted cooling of the starting material to the temperature required for rolling a microstructure state in the essentially the starting point for changing the microstructure of the flat profile to the finished, near-end cross section allowed. This can be followed by further post-treatments such as cooling and tempering, which allow a further change in the structural properties. Thus, a possibility has been found, a near net deformation to combine flat profiles produced from steel materials in the warm state with a targeted microstructure adjustment with regard to material parameters to be set, which minimizes the after-treatment of flat profiles produced in this way.

It is particularly advantageous if the heating of the starting material in the heating station is at a temperature above the A ₃ temperature of the γ mixed crystal (austenite). As a result, a variety of microstructures can be produced from an austenitized structure as a starting structure before rolling the starting material, which correspond to the various properties of the steel material required for the typical applications of the flat profiles and thus enable a wide field of application of correspondingly produced flat profiles.

Another embodiment of the method according to the invention provides that the heating of the starting material in the heating station to a temperature in the region of the α / γ mixed crystal (ferrite / austenite) takes place. As a result, it is possible in particular to set an advantageous starting structure for the subsequent rolling, in particular for steels of lower carbon content.

It is also conceivable in another embodiment that the heating of the starting material takes place in the heating station to a temperature close to the A ₁ point. As a result, other processes of structural transformation during the rolling of the starting material can be triggered again, which leads to a further spectrum of structural formation of the rolled and possibly post-treated flat profile.

Of significant advantage for carrying out the method is when used as a starting material round or oval wire. Under round wire in this context, not only wire with a circular cross-section understood, for example, can be made by rolling or drawing technology, but generally wire any cross-section, which is suitable for deformation by rolling technical means towards a flat profile. Corresponding Ovaldrähte here have an oval cross-section. In this case, the free expansion of the round wire or oval wire is usually utilized in a rolling process, on the one hand to cause required property changes in terms of the geometry of the flat profile and on the other hand to cause the required microstructural properties and thus the material properties of the finished flat profile. Such round wire or Oval wire is a commercially available starting material and can be obtained commercially in a wide variety of compositions and alloys, whereby the costs for such round wire or oval wire are relatively favorable.

It is conceivable here that the round wire or oval wire runs through the process as windable starting material. As a result, a quasi-continuous processing of the usually supplied on rings round wire or Ovaldrahtes is possible, which can also be further processed as a wound coil of the finished flat profile as windable finished material. It is also conceivable in another embodiment that the round wire or oval wire as a rod-like starting material passes through the process, wherein the rod-like starting material accordingly also rod-like flat profiles results.

It is advantageous if unalloyed or low-alloyed carbon steels are used as the starting material. Such unalloyed or low-alloyed carbon steels form the starting material for the production of many different components and components and offer a wide range of application areas for the use of flat profiles produced according to the invention.

It is conceivable here that the heating of the starting material takes place in the heating station to a temperature above the A ₃ point. Such a temperature of the starting material is clearly in the range of austenite for the steels usually used in this case, so that the austenitizing occurring structural changes form the basis for a number of conventional changes in material properties with respect to the material properties of the flat profiles to be achieved.

A first embodiment of the method according to the invention can be seen therein, when the cooling in the cooling station cools the starting material before rolling to a temperature for setting an austenite microstructure only slightly above the A ₃ temperature of about 800 ° C. As a result, the rolling process itself is made in the form of austenite microstructure even in the expression of the microstructure of the starting material, which can still proceed correspondingly simple diffusion processes and the influence of the intended microstructural changes can be made controlled.

For this purpose, in a further advantageous embodiment of this embodiment of the method, after the rolling of the flat profile in the temperature range of the austenite microstructure, a cooling of the austenite microstructure for conversion into a sorbitol structure is then carried out directly afterwards. This sorbitol structure is very fine-lamellar and offers the best conditions for certain applications of such flat profiles.

Another embodiment of the method according to the invention can be seen in that the cooling in the cooling station, the pre-material before rolling to a temperature for setting a Patentiergefüges, e.g. for a steel C75 between 400-550 ° C cools. Such a patenting structure is formed from a fine-grained pearlite and is particularly well suited e.g. for further cold drawing corresponding flat profiles or for applications of flat profiles, where high tensile strengths must be combined with good toughness of the materials. A correspondingly slow cooling of the patenting structure from the pearlite stage usually follows the rolling process. The formation of a Patentiergefüges (the same applies to the below-mentioned bainite and austenite) takes place in each material relevant here due to its composition at a different temperature, but this is known and characteristic of each material. The relationships between the structure characteristics and the respective temperatures and process control of the different materials can be read off from so-called time-temperature conversion diagrams (so-called ZTU diagrams). Therefore, below the temperature for setting a Patentiergefüges (respectively a bainite or austenite) a although for each relevant material different, but with specification of a corresponding material but unique temperature understood for the purely exemplary of a steel C75 also concrete values are indicated. Otherwise, the person skilled in the art knows for each material relevant here which temperatures he has to set for setting a patenting structure or a bainite structure or an austenitic structure.

A further embodiment of the method according to the invention can be seen therein, when the cooling in the cooling station, the starting material before rolling to a temperature for setting a Bainitgefüges, eg for a steel C75 between 275-370 ° C cools. Here, the starting material is still cooled in contrast to the setting of a Patentiergefüges until the rolling of the starting material is carried out in a structural state of the intermediate bainite in which due to the low temperature diffusion processes are largely prevented and by folding over austenite in the material α-grid areas form. This then separates fine-grained cementite with the beneficial effects on the microstructural properties.

An alternative embodiment of the method according to the invention can be seen in that the cooling in the cooling station, the pre-material before rolling to a temperature for adjusting a supercooled austenite microstructure, e.g. for a steel C75 between 220-280 ° C cools. By correspondingly rapid cooling of the structure of the austenite otherwise running conversion processes are delayed or can not or not significantly occur, so that the rolling of such a rapidly cooled, supercooled Austenitgefüges offers the possibility largely or exclusively to a martensite with the known To make needle-like hardened structure, whereby correspondingly high-strength materials are produced, with which in another embodiment, for example also directly afterwards a tempering treatment can be performed with a cooling of the flat profile before winding. By tempering the material is changed again in terms of hardness and toughness and thus achieves high hardness with good mechanical strength properties.

However, it is conceivable in a rolling of the starting material as supercooled austenite, that after the rolling of Flachprofiles directly followed by a tempering without quenching the supercooled Austenitgefüges, but with a tempering treatment possibly to form a bainite and a tempering treatment with a cooling of the flat profile before winding is performed , In this case, instead of the above-described martensite formation, the intermediate-layer structure bainite is produced which also has the properties already advantageous above.

Furthermore, it would also be conceivable, without generating undercooled austenite directly to roll as described above in the austenite phase, deter after the rolling of the flat profile in the temperature range of the austenite microstructure for martensite, but then immediately perform a tempering treatment and cooling of the flat profile before winding. Hereby a tempered Martensitgefüge is produced, which also has the advantages already mentioned.

An advantage of all these different process guides is when the starting material is held during the rolling process at least on the set after cooling of the starting material in the cooling station temperature. As a result, the structure does not change during rolling or not too strong, so that the rolling alone causes no structural changes. For this purpose, depending on the configuration of the rolling process, heat may have to be removed from the rolling zone, for example in view of the deformation work introduced into the starting material and the resulting temperature change of the starting material, e.g. at high degrees of transformation, or e.g. at low conversions, the starting material e.g. be maintained by heating the rollers at the desired temperature by supplying heat.

Furthermore, it is conceivable that depending on the choice of process to be carried out, the starting material is subjected to the near-net edge flat profile of further cooling, in particular a rapid cooling after the rolling technical forming. For this purpose, the material which is already present as a flat profile may be e.g. a water cooling or the like. Well-known cooling methods are subjected.

It can also be useful if the rapid cooling cools the rolled flat profile at least below the temperature limit for the course of oxidation processes on the surface of the flat profiles and thus ensures that Verzunderungsvorgänge or the like. No longer or no longer can proceed to an inadmissible extent.

It is advantageous if the cooling of the starting material takes place after passing through the heating station and before rolling in a tempered metal bath. Such tempered metal baths are basically known and tested and provide the Possibility of tempering continuous metal strips precisely and precisely and also to maintain them at a predetermined temperature in order to allow corresponding compensating processes to take place without exposing the surfaces of the metal strips to unacceptable oxidation.

Here, in a further embodiment, it can also be thought that the starting material for cooling the starting material after passing through the heating station remains a predetermined time in the tempered metal bath, in particular the tempered metal bath passes through a predetermined time to the already mentioned compensating processes for controlling the temperature of the entire cross section of the starting material.

It is furthermore advantageous if the heating of the primary material takes place by means of inductive heating and / or conductive heating and / or by means of liquid metal baths. Of course, other, not discussed in detail heating methods are conceivable, which are known and customary in metallurgy.

An improvement in the surface of the flat profile can be achieved if the heating of the starting material is carried out under inert gas. As a result, occurring during the heating of the starting material oxidation processes are prevented, which then of course not propagate through the whole process control and thus can cause any later deviations or surface defects.

It is also conceivable that a homogenizing device for temperature compensation within the heated starting material is passed through between heating station and cooling station, wherein in a further embodiment, the homogenization of the temperature within the heated starting material after passing through the heating station under protective gas influence can be performed.

The invention further relates to a device for carrying out a method according to claim 1, wherein the device in the passage direction of the starting material, a winding / withdrawal device for the unwinding of the windable material or a feed device for the rod-shaped starting material, a heating station, a cooling station for Setting a rolling temperature, a, Rolling station, a cooling line and a winding / withdrawal device for winding the windable flat profile or a discharge device for the rod-shaped flat profile. This basic configuration of the device makes it possible to carry out the basic process variants in which, after heating, a targeted cooling of the starting material is carried out to a temperature which permits rolling of the starting material with a structure either as austenitic structure, as patenting structure, as bainite structure or as undercooled austenite. Here, depending on the gradient of the cooling and the cooling time, the corresponding structure can be adjusted. Further aftertreatments or intermediate processes can be carried out by interposing or connecting additional accessory device components, such as, for example, the heat treatment processes subsequent to rolling, such as during tempering or else tempering operations, such as holding the starting material at a specific temperature over a defined period of time, in order to allow compensation processes within the material to be able to.

It is advantageous if the rolling station has at least one rolling device, preferably a plurality of rolling devices connected in series. As a result, a careful transformation of the starting material during rolling can be achieved by targeted design and also sequential arrangement of several rolling devices.

It is also conceivable that in the region of the at least one rolling device, a temperature monitoring for detecting the temperature of the starting material before / and / or after rolling is arranged, with the e.g. in terms of microstructure, detected impermissible temperature changes during rolling and e.g. can be turned off by targeted heat input into the rollers, for example by tempering the rollers.

For the targeted heating of the starting material, it is advantageous if, for the heating of the starting material by means of conductive heating current-carrying contact rollers are arranged in the inlet region of the device for the starting material. Such, basically known conductive heating of the starting material allows a well controllable heating and thus structural transformation of the starting material.

A particularly favorable cooling of the starting material can be realized if the cooling station has a tempered metal bath for setting a rolling temperature. Such a tempered, such as a metal bath of a lead-bismuth alloy, is already widely used and is therefore known and tested in terms of its behavior. However, it is also possible to ensure a reliable temperature control of the primary material while simultaneously preventing oxidation processes on the surface of the primary material even with relatively longer throughput times of the primary material through such a metal bath.

It is conceivable here that the tempered metal bath is arranged before and after the rolling station. Depending on the process, the heating temperature in the heating station can be rolled directly out of the austenite phase with appropriate tuning, so that the metal bath then takes the tempering of the rolled flat profile for the formation of bainitic interstitial structure. In other cases, the metal bath is used for targeted cooling of the starting material to the rolling temperature and must of course then be placed in front of the rolling station. In this case, in a further embodiment, the tempered metal bath having a winding and / or deflection, over which the starting material is guided during the residence time in the temperature-controlled metal bath. The winding or deflection can also take over buffer function for downstream device stations.

For certain variants of the process control, it is advantageous if, in the cooling section, water cooling cools the flat profile with a high temperature gradient. As a result, microstructures achieved after rolling are virtually frozen by the rapid cooling and are retained even at lower temperatures.

In the context of the aftertreatment of rolled flat profiles, it is advantageous if a further conductive heating station is provided for heating the flat profile for a subsequent rolling subsequent annealing, in which then, for example, the heating can be done again under inert gas. Also, for example, for cooling the flat profile in the context of a subsequent rolling subsequent annealing a further cooling section can be provided.

Such a flat profile advantageously has essentially a rectangular cross-section or a cross-section close to the rectangular, wherein very different configurations of the edge region can be adjusted depending on the later use of the flat profile.

It is advantageous if typical carbon steels, in particular carbon steels having a carbon content of between 0.10 and 1.35%, in particular also C 10 to Ck 101/125 Cr 1, can be processed. Such flat profile are preferably in dimensions between a thickness of 0.5 - 5 mm and a width of 4 - 25 mm processable.

A particularly preferred embodiment of a corresponding device is shown in the drawing.

Figur 1 -

eine schematische Darstellung des prinzipiellen Aufbaus einer Vorrichtung zur Durchführung eines Verfahrens zum Warmwalzen von Walzdrähten mit den wichtigsten Vorrichtungsbestandteilen,

Figur 2 -

ein kontinuierliches Zeit-Temperatur-Umwandlungsschaubild für die Durchführung des Verfahrens gemäß Figur 1,

Figur 3 -

eine schematische Darstellung des prinzipiellen Aufbaus einer Vorrichtung gemäß Anspruch 26 zur Durchführung des erfindungsgemäßen Verfahrens mit einer Abkühlung des Vormaterials vor dem walzen zur Herstellung von Patentiergefüge, Bainitgefüge oder einem unterkühlten Austenitgefüge,

Figur 4 -

ein isothermes Zeit-Temperatur-Umwandlungsschaubild für die Durchführung des Verfahrens gemäß Figur 3 mit der Angabe der jeweiligen Verfahrensführung zur Herstellung von Patentiergefüge, Bainitgefüge oder einem unterkühlten Austenitgefüge,

Figur 5 -

eine modifizierte Vorrichtung gemäß Figur 3 zur nach dem Walzen durchgeführten Wärmebehandlung eines unterkühlten Austenitgefüges,

Figur 6 -

eine modifizierte Vorrichtung gemäß Figur 3 zur nach dem Walzen durchgeführten Wärmebehandlung eines Austenitgefüges ohne Kühleinrichtung vor dem Walzen,

Figur 7 -

eine modifizierte Vorrichtung gemäß Figur 3 mit Kühleinrichtung vor der Walzstation und Einrichtungen zur nach dem Walzen durchgeführten Wärmebehandlung,

Figur 8 -

eine modifizierte Vorrichtung gemäß Figur 7 mit Kühleinrichtung nach der Walzstation und Einrichtungen zur nach dem Walzen durchgeführten Wärmebehandlung.

Show it:

FIG. 1 -

a schematic representation of the basic structure of an apparatus for carrying out a method for hot rolling of wire rods with the main device components,

FIG. 2 -

a continuous time-temperature conversion diagram for carrying out the method according to FIG. 1 .

FIG. 3 -

a schematic representation of the basic structure of a device according to claim 26 for carrying out the method according to the invention with a cooling of the starting material before rolling for the production of Patentiergefüge, bainite or a supercooled austenite microstructure,

FIG. 4 -

an isothermal time-temperature conversion diagram for carrying out the method according to FIG. 3 indicating the respective procedure for the production of patented structure, bainite structure or a supercooled austenitic structure,

FIG. 5 -

a modified device according to FIG. 3 for the heat treatment of a supercooled austenite structure after rolling,

FIG. 6 -

a modified device according to FIG. 3 for the heat treatment of an austenitic structure without a cooling device before rolling, after rolling,

FIG. 7 -

a modified device according to FIG. 3 with cooling equipment in front of the rolling mill and means for post-rolling heat treatment,

FIG. 8 -

a modified device according to FIG. 7 with cooling device after the rolling station and means for after-rolling heat treatment.

In the FIG. 1 is shown in a very schematic representation of the structure of an apparatus for performing a method for hot rolling of wire rod to flat profiles. This is a device for carrying out a process without special means for cooling the starting material before rolling.

A flat profile 18 should be understood to mean steel material whose width corresponds to a maximum of 10 to 20 times its thickness and which is usually used as a structural basis for mainly mechanically loaded components such as springs, piston rings or the like as well as saw blades or other highly stressed workpieces. The dimensions of such flat profiles, in contrast to otherwise produced rolled strip rather low, and is typically in the range of up to 30 millimeters in width and 5 millimeters in thickness. The starting material 17 is usually supplied as a round wire rod of the system 1, but may of course have other cross sections as a starting material for rolling in a rolling device 7.

The starting material 17 is in Appendix 1 of a reel with a coil outlet 2 via a caterpillar take-off 3 and a straightening device 4 in a device 5 for conductive conductive heating of the starting material 17, wherein the conductive device 5 has current-carrying contact rollers 16, which bring about the coupling of the current in the starting material 17 along the conductive device 5, a heating of the starting material 17. This heating takes place predominantly in a protective gas channel 6, which prevents the formation of oxidation products on the surface of the preliminary material 17 during the heating. Following the second pair of contact rollers 16 is also a channel-like and possibly flooded with inert gas channel 12 is provided as a compensation zone, within which the starting material 17 is evenly heated by balancing processes in the interior and thus before entering the rolling device 7 a uniform temperature profile within 17 of the starting material. Within this compensation zone 12, the temperature of the starting material 17 drops from the resulting, for example, in the heating between the contact rollers 16 end temperature of z. B. 1020 ° Celsius to a lower temperature, so that within the compensation zone 12, a cooling of the starting material 17 to a temperature eg just above the A ₃ temperature occurs. With this temperature, which is monitored, for example, before or after the rolling device 7 by an approximately per Strahlungspyrometer temperature measurement 8, the starting material 17 enters the rolling device 7 and is there in one or more stitches (shown is simplified only a rolling device 7, but it can also be several such rolling devices 7 are connected in series) rolled to the flat profile 18, which is then cooled by means of a cooling section 9 with here, for example two blast chillers 10 and abandoned via a caterpillar take-off 3 a reel 11 and wound there to form a coil. The starting material 17 thus passes through the plant 1 in the direction of passage 19 and is supplied to the plant 1 as a coiled coil, for example, a round wire rod and wound up as a coil of a flat profile 18 completed.

Such a rolling line 1 executes a method that according to the FIG. 2 in a representation in a continuous time-temperature conversion diagram for a steel C 75 illustrated for producing bainite according to the temperature guide along the line 13. Here, the starting material 17 is rolled at a temperature of just below 800 ° C and then cooled along the line 13. The resulting sorbitol structure provides for the corresponding The disadvantage of this procedure is that by cooling only in the compensation zone 12, the temperature of the semi-finished material 17 is relatively expensive einzugelegeln, also can not reduce the temperature to values that would be useful for other process management.

It will therefore be an evolution of the in the FIG. 1 Annex 1 so far proposed that according to FIG. 3 the system 1 is modified in that before the rolling device 7, a cooling device 14 z. B. consisting of a metal bath, such as a lead-bismuth metal bath, is preceded, in which a targeted cooling of the precursor 17 is made prior to entering the rolling device 7, so that the structure of the starting material 17 when entering the rolling device 7 exactly corresponds to defined conditions and therefore the deformation of the starting material 17 to the flat profile 18, possibly in conjunction with subsequent treatment operations further described later, the desired structure of the flat profile 18 and the required cross-sectional dimensions and cross-sectional shapes. Otherwise corresponds to the plant 1 of FIG. 3 essentially the attachment 1 of FIG. 1 , so that only the existing differences should be discussed further.

The heating in the conductive device 5 can in this case take place in two or more stages, with a number of contact rollers 16 are arranged one behind the other, so that the heating multi-stage, possibly even using different currents and thus different temperature gradients in the heating can be made. This usually causes a much better controllable heating of the starting material 17, moreover, 5 occur during the passage through the conductive device corresponding compensating processes, so that the starting material 17 at the end of the run through the conductive device 5 very evenly on the specified Temperature of 1020 ° Celsius is present.

The metal bath 14 has for the passage of the starting material 17, a winding device 15 in the form of rollers of z. B. one meter in diameter, on which the starting material 17 is wrapped several times and thus over a predetermined time within the metal bath 14 as it passes through the metal bath 14 remains. The metal bath 14 is so tempered that the desired starting temperature for the rolling of the starting material 17 in the rolling device 7 within the Vormaterials 17 sets and thus within the Vormaterials 17 can form the exact structure that for rolling within the rolling device 7 for the Achieving the final structure is needed. In order to prevent impermissible surface changes of the starting material 17 after exiting the conductive device 5 and the passage through the metal bath 14, protective gas channels 6 are also arranged before and after the metal bath, so that the starting material 17 is almost completely heated under inert gas atmosphere and tempered.

After rolling in the rolling device 7, the flat profile 18 is cooled by a water cooler or the like via a high-speed cooler 10 and, as already described FIG. 1 described wrapped.

In the FIG. 4 For example, various conceivable procedures along the line 13 ', 13 ", 13'" are recorded in an isothermal time-temperature conversion graph for a steel C 75 indicating the different end structures of the flat profile 18 to be adjusted in the mill 7 after rolling. If, for example, the temperature of the primary material within the cooling device 14 is reduced to about 500 ° C. and then rolled, a so-called patenting structure can be set for this steel according to line 13 ', which enables a particularly high toughness at very high tensile strength values. If, on the other hand, cooling is continued in the cooling device 14 to values of approximately 350 ° C., a so-called interstep structure in the form of a bainite structure according to line 13 "results during rolling, and a particularly interesting option for producing flat profiles 18 is cooling in the cooling device 14 to be carried out so fast that according to the line 13 '"comes in the range below 300 degrees Celsius of the supercooled austenite for rolling in the rolling device 7 and then can perform a martensite hardening of this supercooled Austenites by appropriate treatment.

Thus, by the involvement of a cooling device 14 before rolling in the rolling device 7, the possibility created on a system 1 a very different To process type of materials to flat profiles 18 and in each case the optimal process management according to the lines 13 ', 13 ", 13'" in the FIG. 4 to be able to drive.

A modification of the for the FIG. 3 described plant for rolling supercooled austenite as a structure of the starting material 18 shows the FIG. 5 , in which until rolling in the rolling device 7 for the FIG. 3 As stated above. After the rapid cooling 10 after rolling in the rolling device 7, a further conductive device 5 'is arranged, which serves for re-heating of the flat profile 18 for a compensation of the structure of the flat profile 18, which is also heated again conductively and cooled in a subsequent rapid cooling 10 , As a result, a wide control of the properties of the precursor material 17 rolled as a supercooled austenite can be achieved.

In the FIG. 6 a further modification of Appendix 1 is shown, in accordance with line 3 in the FIG. 4 the rolling takes place without a separate cooling device and only after a certain cooling in the compensation zone 12, and thus the rolling in the rolling device 7 in the austenite region of the microstructure of the starting material 17 is carried out. This thus rolled and cooled in the cooling device 10 flat profile 18 is then as already above for FIG. 5 described by tempering operations in a conductive device 5 'annealed and thus changed once again in its properties.

According to the FIGS. 7 and 8th are again two variants of Appendix 1 according to the FIG. 5 shown, in which the cooling device 14 before and alternatively a cooling device 20 is arranged after the rolling device 7, so that the temperature control of the Vormaterials 17 in the area of the rolling device 7 selectively changed, for example, after rolling in the rolling device 7 by tempering the resulting flat profile 18 further can be. The cooling device 20 according to the FIG. 8 can be used for about correspondingly slow or targeted tempering of the flat profile 18 after rolling to supply the present after rolling structure of the flat profile 18 of a targeted change, without directly perform too fast cooling of the flat profile 18.

Part number list

1

- rolling line / plant

2

- Coil drain

3

- Caterpillar take-off

4

- straightening device

5, 5 '

- conductive heating

6

- Protective gas channel

7

- rolling device

8th

- Temperature measurement

9

- Cooling section

10

- Water cooling

11

- coiler

12

- equalization zone

13-13 ' "

- Temperature control for process variants

14

- cooling station / metal bath

15

- Winding device

16

- contact roles

17

- starting material

18

- flat profile

19

- Continuous feedstock

20

- Cooling device

Claims (37)

1. Method for deformation of semi-finished material (17) in wire or rod form, by means of rolling technology, particularly for rolling of flat profiles (18) from rolled wire, in which heating of the semi-finished material (17) to a desired temperature takes place in a heating station (5), the semi-finished material (17) is deformed in at least one rolling process (7), and subsequently cooled,
   characterized in that
   after heating of the semi-finished material (17) by means of inductive heating and/or by means of conductive heating and/or by means of liquid metal baths in the heating station (5), the semi-finished material (17) is cooled to a rolling temperature that can be pre-determined, in a cooling station (14) for setting of a predetermined microstructure, deformed by a rolling process into a flat profile (18) at this rolling temperature, close to the final dimensions, and subsequently is cooled and/or post-treated in accordance with the microstructure properties that are to be set.
2. Method according to claim 1, characterized in that the heating of the semi-finished material (17) takes place, in the heating station (5), to a temperature above the A₃ temperature of the γ mixed crystal (austenite).
3. Method according to claim 1, characterized in that the heating of the semi-finished material (17) takes place, in the heating station (5), to a temperature in the range of the α/γ mixed crystal (ferrite/austenite).
4. Method according to claim 1, characterized in that the heating of the semi-finished material (17) takes place in the heating station (5), to a temperature in the range just below the A₁ point.
5. Method according to one of the preceding claims, characterized in that round wire or oval wire is used as the semi-finished material (17).
6. Method according to claim 5, characterized in that the round wire or oval wire runs through the process as a semi-finished material (17) that can be wound up.
7. Method according to claim 5, characterized in that the round wire or oval wire runs through the process as a rod-like semi-finished material (17).
8. Method according to one of the preceding claims, characterized in that unalloyed or low-alloyed carbon steels are used as the semi-finished material (17).
9. Method according to one of the preceding claims, characterized in that cooling in the cooling zone or in the cooling station (14) cools the semi-finished material (17), before rolling (7), to a temperature for setting an austenite microstructure, of only slightly above the A₃ temperature, for C 75 to a temperature of about 800 °C.
10. Method according to one of claims 1 to 8, characterized in that cooling in the cooling zone or in the cooling station (14) cools the semi-finished material (17), before rolling (7), to a temperature for setting a patenting microstructure, for C 75 to a temperature between 400-550 °C.
11. Method according to one of claims 1 to 8, characterized in that cooling in the cooling zone or in the cooling station (14) cools the semi-finished material (17), before rolling (7), to a temperature for setting a bainite microstructure, for C 75 to a temperature between 275-370 °C.
12. Method according to one of claims 1 to 8, characterized in that cooling in the cooling zone or in the cooling station (14) cools the semi-finished material (17), before rolling (7), to a temperature for setting an undercooled austenite microstructure, for C 75 to a temperature between 220-280 °C.
13. Method according to one of the preceding claims, characterized in that the semi-finished material (17) is held at least at the temperature set in the cooling zone or in the cooling station (14), after cooling of the semi-finished material (17), during the rolling process (7).
14. Method according to one of the preceding claims, characterized in that the semi-finished material (17) is subjected to further cooling (9, 10), particularly rapid cooling (10), after the deformation (7) by means of roller technology to produce a flat profile (18) close to the final dimensions.
15. Method according to one of the preceding claims, characterized in that the rapid cooling (10) cools the rolled flat profile (18) at least below the temperature limit for the occurrence of oxidation processes at the surface of the flat profile (18).
16. Method according to claim 9, characterized in that after rolling (7) of the flat profile (17) in the temperature range of the austenite microstructure, immediately afterward, cooling of the austenite microstructure for conversion to a sorbite microstructure is carried out.
17. Method according to claim 12, characterized in that after rolling (7) of the flat profile (17) in the temperature range of the undercooled austenite microstructure, and after cooling in a cooling segment (9, 10) with quenching of the undercooled austenite microstructure for conversion into a martensite microstructure, immediately afterward, an annealing treatment with cooling of the flat profile (18) before it is wound up is carried out.
18. Method according to claim 12, characterized in that after rolling (7) of the flat profile (18) in the temperature range of the undercooled austenite microstructure, immediately afterward, a tempering treatment without quenching of the undercooled austenite microstructure, but with an annealing treatment for forming a bainite microstructure, and an annealing treatment with cooling of the flat profile (18) before it is wound up (11) is carried out.
19. Method according to claim 12, characterized in that after rolling (7) of the flat profile (18) in the temperature range of the austenite microstructure, quenching of the austenite microstructure for conversion into a martensite microstructure is carried out, and afterward, an annealing treatment with cooling of the flat profile (18) before it is wound up (11) is carried out.
20. Method according to one of the preceding claims, characterized in that he cooling of the semi-finished material (17) takes place after it has passed through the heating station (5) and before rolling (7), in a tempered metal bath (14).
21. Method according to claim 20, characterized in that for cooling of the semi-finished material (17) after it has passed through the heating station (5), the semi-finished material (17) remains in the tempered metal bath (14) for a period of time that can be pre-determined, in particular, it passes through the tempered metal bath (14) during a period of time that can be pre-determined.
22. Method according to one of the preceding claims, characterized in that the heating (5) of the semi-finished material (15) takes place by means of inductive heating and/or conductive heating (16) and/or by means of liquid metal baths.
23. Method according to one of the preceding claims, characterized in that the heating (5) of the semi-finished material (1) is carried out under the influence of inert gas (6).
24. Method according to one of the preceding claims, characterized in that a uniformization device (12) for temperature equalization within the heated semi-finished material (17) is run through between heating station (5) and cooling zone or cooling station (14).
25. Method according to claim 24, characterized in that the uniformization of the temperature within the heated semi-finished material (17) is carried out after it has passed through the heating station (5), under the influence of inert gas (12).
26. Device (1) for carrying out a method according to claim 1, characterized in that the device (1) has, in the pass-through direction of the semi-finished material (17), a winding/take-off device (2, 3) for unwinding the semi-finished material (17), which can be wound up, or a feed device for the semi-finished material in rod form, a heating station (5), a cooling zone or cooling station (14) for setting a rolling temperature, a rolling station (7), a cooling segment (9, 10), and a winding/take-off device (11) for winding up the flat profile (18) that can be wound up, or a removal device for the flat profile in rod form.
27. Device (1) according to claim 26, characterized in that the rolling station (7) has at least one rolling device, preferably several rolling devices switched one behind the other.
28. Device (1) according to one of claims 26 or 27, characterized in that a temperature monitoring device (8) for detecting the temperature of the semi-finished material (17) before and/or after rolling is disposed in the region of the at least one rolling device (7).
29. Device (1) according to one of claims 26 to 28, characterized in that contact rollers (16) through which current flows are disposed in the intake region of the device (1) for the semi-finished material (17), for heating the semi-finished material (17) by means of conductive heating.
30. Device (1) according to one of claims 26 to 29, characterized in that the tempered metal bath (14) is a metal bath of a lead/bismuth alloy.
31. Device (1) according to claim 30, characterized in that the tempered metal bath (14) is disposed ahead of the rolling station (7).
32. Device (1) according to one of claims 30 to 31, characterized in that the tempered metal bath (14) has a winding device and/or deflection device (15), over which the semi-finished material (17) can be guided during the dwell time in the tempered metal bath (14).
33. Device (1) according to claim 30, characterized in that a tempered metal bath (20) is disposed behind the rolling station (7).
34. Device (1) according to one of claims 27 to 33, characterized in that water cooling (10) cools the flat profile (18) in the cooling segment (9, 10), at high temperature gradients.
35. Device (1) according to one of claims 27 to 34, characterized in that another conductive heating station (5') can be provided, for heating the flat profile (18), for tempering that takes place after rolling (7).
36. Device (1) according to claim 35, characterized in that the heating (5') of the flat profite (18) takes place for tempering under the influence of inert gas (6).
37. Device (1) according to one of claims 27 to 36, characterized in that another cooling segment (10) can be provided, for cooling the flat profile (18) within the framework of tempering that takes place after rolling (7).

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