WO2012025266A1 - Method for determining wear on a roll for rolling metal stock - Google Patents

Abstract

In order to determine wear (d) on a roll (3) for rolling metal stock (1) a volume temperature distribution (VT) of the roll (3) is updated with reference to a heat flow distribution (WT) occurring on the surface of the roll (3) by means of a temperature model of the roll (3). The volume temperature distribution (VT) is spatially resolved at least in the axial direction and in the radial direction of the roll (3). The heat flow distribution (WT) is spatially resolved in the axial direction and in the tangential direction of the roll (3). The wear (d) on the roll (3) is determined by means of a wear model (11). Within the context of the wear model (11) at least one upper surface temperature (T") which occurs at specific points on the surface of the roll (3) is determined with reference to the updated volume temperature distribution (VT) and/or the heat flow distribution (WT) while the respective point is in contact with the metal stock (1). The wear (d) on the roll (3) is determined taking account of the upper surface temperature (T") of the roll (3).

Description

description

Determination procedure for wear of a roll for rolling of rolling stock

The present invention relates to a determination method for a wear of a roll for rolling of rolling stock.

The present invention further relates to a computer program which comprises machine code which can be processed directly by a computer and whose execution by the computer causes the computer to carry out such a determination ^method . The present invention further relates to a computer which is designed such that it carries out such Ermitt ^¬ treatment method.

The present invention further relates to a rolling mill for rolling of rolling stock, which is equipped with such a computer.

When rolling metals occurs on the rollers wear. The extent to which wear occurs depends on various parameters. For example, the amount of wear on the type of rolls (working roll, supporting ^¬ stripper, ...), the type of rolling (cold-rolling or Warmwal ^¬ zen), the arrangement of the rolls in the rolling mill is dependent (first, second, third rolling stand of the rolling mill etc.), the material of the rolling stock (steel, aluminum, copper, ...), the material of

Rolls (cast iron, cast steel, high-speed steel, ...) etc. from.

The wear has an impact on the quality of the rolled stock. In particular, the wear caused by entspre ^¬-reaching rake corrections must - for the flat rolling optionally also in terms of profile and flatness - into account are ^¬ Strengthens compensated and, if possible. Furthermore, sen to switch the rollers from time to time and nachgeschlif ^¬ fen.

A direct measurement of the roller wear is only possible if the relevant roller is removed from the rolling stand and can be measured. In the current rolling process, a direct measurement of the roll wear is, however, not mög ^¬ Lich. It is known, however, to detect process variables of the rolling process and the roll wear counted by means of a Ver ^¬ schleißmodells in real time. By means of the Ver ^¬ schleißmodells is determined depending on the rolled distance of the rolling stock, the rolling force course of this route, etc., the wear of the respective roller. The Ver ^¬ schleißmodell shows the determined wear other STEU ^¬ erungssystemen available, for example for correction of the corresponding job.

It is also known to carry out similar calculations offline. The process variables used in this case may be, for example, model-based predicted expected quantities

As a rule, the determination of the wear takes place according to the relationship d = c Φ -a · / (1)

Here d is the expected wear, c a constant coefficient of wear, Φ the pressure distribution in the nip, the contact angle and 1 the rolled length.

The wear coefficient c is set appropriately. It may depend on the above parameters.

When rolling a thermal Bal ^¬ ligkeit must be determined as part of the determination of variables for profile and flatness actuators. This is done in the prior art in that, during operation, a volume temperature distribution of the roller is continuously determined on the basis of a Surface of the roll occurring heat flow distribution is updated by means of a temperature model of the roller. The vo ^¬ lumentemperaturverteilung is here spatially resolved at least in the axial direction and in the radial direction of the roller, the heat flow distribution in the axial direction and in the tangential direction of the roller.

The terms "axial direction", "radial direction" and "tangential direction" are always referenced above and also to the axis of rotation of the roller The axial direction is parallel to the axis of rotation The radial direction is orthogonal to the axis of rotation The tangential direction is at a constant distance from the axis of rotation about the rotational axis. Rein is exemplified with respect to the procedure of Stan ^¬ of the art in the technical paper "An investigation into the control of thermal camber by spray cooling When hot ROL ling aluminum" by PA Atack et al. , Modeling of metal rolling processes Symposium 7, cooling in rolling mills, June 7, 1995 in London. The determination of the thermal crown as part of said Fachaufsat ^¬ zes using a volumetric temperature distribution which is not spatially resolved in the tangential direction. The heat ^¬ flux distribution is averaged in the tangential direction. Using the averaged heat flux distribution, the volume temperature distribution is updated and tracked.

From the article "Increasing work-roll life by improved roll-cooling practice" by PG Stevens et al., Journal of The Iron and Steel Institute, January 1971, pages 1 to 11, it is known that the wear of rolls and a thermal As a first approximation, the thermal wear component is determined by various rolling and rolling parameters as well as by the variables "maximum surface temperature", "minimum surface temperature" and "temperature inside the roller". The object of the present invention is to provide opportunities to determine the wear of the roller in a reliable model-based manner. The object is achieved by a preliminary investigation with the features of claim 1. Advantageous embodiments of the investigation are subject of the dependent claims 2 to 13. An ^¬ According to the invention, to design an investigation of the type mentioned in the introduction,

 that a volume temperature distribution of the roll is updated by means of a heat flow distribution occurring at the surface of the roll by means of a temperature model of the roll,

 that the volume temperature distribution is spatially resolved at least in the axial direction and in the radial direction of the roller,

the heat flow distribution is spatially resolved in the axial direction and in the tangential direction of the roll,

- that the wear of the roll is determined by a Verschleißmo ^¬ dells,

 - that in the context of the wear model

 - Based on the updated volume temperature distribution and / or the heat flow distribution at least an upper surface temperature is determined, which occurs at certain points of the surface of the roller, while the respective point is in contact with the rolling stock, and

- The wear of the roller is determined taking into account the upper surface temperature of the roller.

To using data from the temperature model, so the aktuali ^¬ terraced volume temperature distribution and to determine the upper surface temperature of the heat flux distribution, there are two possibilities.

On the one hand, it is possible that the volume ^{temperature distribution} in the tangential direction of the roll is not spatially resolved. In this case, the updated volume temperature Distribution a spatially resolved average ^¬ surface temperature distribution in the axial direction, which is characteristic of an average surface temperature of the roller. In this case, the upper surface temperature can be determined by

- that based on the rolling of the rolling stock related by the roller process variables in the axial direction in a spatially resolved respective contact times are determined, which are for charac ^¬ teristic how long the respective point of the roller currency rend one revolution of the roller with the rolling stock is in contact, and

- That the upper surface temperature on the basis of the average surface temperature distribution of the roller, that part of the heat flow distribution, which occurs during the contact of the roller with the rolling stock, and the Kon ^¬ tact times is determined.

On the other hand, it is possible that the volume ^{temperature distribution is} also spatially resolved in the tangential direction of the roll. In this case, it is possible to determine the top surface tempera ^¬ ture solely on the basis of the updated volume temperature distribution.

The wear preferably comprises a thermal wear component. The determination of the thermal wear component can be carried out, for example, by using the upper surface temperature and at least one further surface temperature of the roller related to the surface of the roller. As an alternative to drawing on the further surface temperature related to the surface of the roll, an internal temperature distribution given inside the roll can be used.

The wear preferably further comprises an abrasive wear portion. The determination of the abrasive wear component is preferably carried out using a Oberflä ^¬ chenhärte the roller. The surface hardness of the roll in this case becomes using the upper surface temperature the roller determined. The determination of the abrasive wear ^¬ share can be done with the additional use of a temperature and / or the material composition of the rolling stock.

It is possible that the heat flow distribution is given as such. Preferably, however, the Wärmeflussvertei ^¬ lung is determined based on the rolling of the rolling material by the roller-related process variables and a plane defined by the not yet actuaries ized volumetric temperature distribution initial surface temperature distribution of the roll.

It is possible that the process variables are (at least partially) model-based expected expected quantities. Alternatively, it is possible that the process variables are (at least partially) actual variables which are detected during rolling of the rolling stock by the roll. Also mixed forms are possible. For example, based on actual variables recorded during rolling, a first wear value can be determined, which is currently expected. Based on the currently expected wear value can then be based on expected future kor ^¬ respondierender process variables to forecast the wear occurring later. The determination process can be performed in real time during rolling of the rolling stock by the roll. Alternatively, it may be prior to the rolling of the rolling material by the roller out ^¬ leads. An execution after rolling of the rolling stock by the roller is possible.

It is possible to determine the wear only and output, for example, to an operator of the mill. Preferably, however, the determined wear is taken into account as part of the determination of manipulated variables, which influence the rolling of the rolling stock.

The inventive object is also achieved by a Compu ^¬ terprogramm of the type mentioned. The computer- Program is designed in this case such that the computer performs a determination process with all steps of a determination method according to the invention.

The object is further achieved by a computer which is designed such that it performs such Betriebsver ^¬ drive.

The object is further achieved by a rolling mill for rolling flat rolling stock, which is equipped with such a computer.

Further advantages and details emerge from the following description of exemplary embodiments in conjunction with the drawings. In a schematic representation:

1 shows schematically a rolling mill for rolling a

 rolling stock,

 2 shows a flow chart,

 3 shows a possible volume temperature distribution,

4 shows a slice of a further possible volume temperature distribution,

 5 shows surface temperature distributions,

 6 and 7 flow charts,

 FIGS. 8 and 9 formulas,

 10 is a flowchart,

 11 shows a formula and

FIGS. 12 to 14 are flowcharts. The present invention will be explained in more detail below in connection with the rolling of a flat rolled stock 1. This embodiment represents by far the most common application of the present invention. In principle, however, the present invention is applicable to any rolling stock 1, for example rod-shaped rolling, tubular rolling or profiled rolling. According to FIG. 1, a rolling mill for rolling the flat rolling stock 1 has a plurality of rolling stands 2. The rolling stands 2 are run through by the flat rolling stock 1 in succession. Each rolling stand 2 of the rolling mill has rollers 3. The rollers 3 comprise at least work rolls, often more Wal ^¬ zen, for example, support rolls or - in addition to back-up rolls - intermediate rolls.

The number of rolling mills 2 of the rolling mill shown is purely exemplary. Minimal is only a single stand 2 available. Furthermore, it is not mandatory that a tape ^¬ running direction x, as shown in Figure 1, is always the same. Alternatively, a reversing rolling could take place, in particular if the rolling mill has only one single rolling stand 2 or only two rolling stands 2.

The flat rolled stock 1, which is rolled in the rolling mill, is a strip as shown in FIG. Alternatively, however, it may be another flat rolled stock 1, for example a plate or a heavy plate.

The rolling mill is equipped with a computer 4. The computer 4 is designed as a control computer that controls the rolling mill. The computer 4 is therefore subsequently - at least in the rule - referred to as the control computer 4. In principle could ^¬ te it, however, be at the computer 4 to another computer, which does not control the mill, but is otherwise connected to the mill or is not even connected to the rolling mill.

The control computer 4 is usually designed as a software programmable device. The operation of the control computer ^¬ 4 is determined by a computer program 5 which is the control computer 4 via a computer-computer connection (not shown) or a storage medium 6 is supplied. Also, the storage medium 6, the computer program 5 in machine-readable form - usually in electronic form - stored. The storage medium 6 is shown in FIG. 1 as a USB Memory stick trained. However, this embodiment is purely exemplary. Any other configurations of the storage medium 6 are possible, for example as a CD-ROM or as an SD memory card.

The control computer 4 is programmed with the computer program 5. The computer program 5 includes machine code 7, which is directly executable by the control computer 4. The execution of the machine code 7 determines the mode of action of the control computer 4. The execution of the machine code 7 by the control computer 4 causes the control computer 4 to carry out a determination process, which will be explained in more detail below in conjunction with FIG. The programming of the STEU ^¬ errechners 4 with the computer program 5 causes the corresponding configuration of the control computer. 4

The present invention is in principle applicable to all rolls 3 of the rolling stands 2. Of particular importance is the application in the work rolls of the rolling stands 2. The present invention will be further explained below in connection with the upper work roll 3 of the third rolling mill 2 shown in FIG. However, this definition is purely arbitrary. The present invention is applicable in an analogous manner to each other ^¬ de roller 3 of each rolling mill. 2

According to FIG. 2, in a step S 1, the control computer 4 initially ^initiates initialization of a volume temperature distribution V T of the roller 3 under consideration. In step S1, each node of the volume temperature distribution - see, for example, the points shown in FIG. 3 - of the roller 3 under consideration is initialized with an initial temperature. For example, the initial temperature may be the same for all nodes and corresponding to the ambient temperature, ie between 0 ° C and 40 ° C, for example.

The nodes of the volume of temperature distribution VT, as illustrated in FIG 3, may be arranged such that the volume ^¬ temperature distribution VT namely (in the axial direction that is in Rieh- tung the axis of rotation of the roller 3) and (in the radial direction that is a direction that is orthogonal to the axis of rotation of the roller 3) is spatially resolved, in the tangential direction (that is, ei ^¬ nem radial distance about the rotational axis of the roller 3 around) but not JE is spatially resolved. Alternatively, the volume temperature distribution VT may be spatially resolved in all three directions (axial, radial, tangential). FIG. 4 shows purely by way of example a pane of such a three-dimensionally spatially resolved volume temperature distribution VT of the roll 3.

FIG 4 shows in addition a backup roll 8 and the Mo ^¬ model- ling and the flat rolling stock 1 and its Modellie ^¬ tion. The modeling of the back-up roll 8 and the flat rolled stock 1 are of subordinate importance in the context of the present invention. Of importance, however, are the heat fluxes j, which are essentially determined by the contact of the considered roll 3 with the flat rolled stock 1, the cooling by cooling devices 9 and, if present, the contact with the support roll 8. To a lesser extent, there is still a heat flux through radiation. However, this heat flow can usually be neglected.

The heat flows j define as a whole a heat flux distribution ^¬ WT, the processing in the axial direction and Tangentialrich- is spatially resolved. Even in the case of a non-spatially resolved in tangential direction ^¬ volume temperature distribution VT heat flux distribution WT is spatially resolved in tangential direction. This is for example characterized ^¬ is indicated in FIG 3, that one of the axial zones of the lung Volumentemperaturvertei- VT is divided on its surface in a tangential direction into individual fields 10th For each individual field 10, a separate heat flow j can be specified.

The spatial resolution of the volume temperature distribution VT need not be uniform everywhere. Thus ^¬ train to the radial resolution is, for example, Be possible to provide a finer resolution in the vicinity of the surface of the roll 3 as in the vicinity of the axis of rotation of the roller 3. If the Volumentempera- VT is also spatially resolved in the tangential direction, the spatial resolution in the tangential direction can become increasingly coarse in a similar way as one approaches the axis of rotation of the roller 3. An example: In the three outermost layers (= rings) of the volume temperature distribution VT there is a spatial resolution of 64 elements in the tangential direction. In the next three layers there is a spatial resolution in the tangential direction of 32 elements each. In the next three layers, there is a tangential Ortsauflö- solution of 16 elements each, etc .. The spatial resolution and said the number of layers for which this applies Ortsauflö ^¬ solution respectively, can of course be varied as required. If the volume temperature distribution VT is also spatially resolved in the tangential direction in addition to the axial and radial directions, the surface temperature distribution, ie the temperature in the radially outermost layer of the roller 3, is available as a two-dimensional spatially resolved function, ie the respective local surface temperature is a function both the axial position z as well as the tangential position φ. When the bulk temperature distribution VT is not spatially resolved in the tangential direction, the surface Tempe ^¬ raturverteilung is such only in the axial direction spatial resolution function. The surface temperature distribution T "in this case corresponds to the average surface temperature distribution T" of the roller 3 as a function of its axial position z. The roller 3 is not in thermal equilibrium during rolling operation. The volume temperature distribution VT must therefore be continuously updated. In order to update the volume temperature distribution VT, the volume temperature distribution VT itself is required, on the one hand, and the heat flux distribution WT, which occurs on the surface of the roller 3, on the other hand. Thus, the individual heat flows j (z, φ) be ^¬ forces, which are applied to φ of the roller 3 at a certain axial position z and tangential position or on the upper surface of the roller 3 at this point flow out of her. In the context of the present invention, it is not sufficient in this case if the heat flows j are tangent in the tangential direction. Rather, it is required that the heat flux distribution WT be spatially resolved both in the axial direction and in the tangential direction.

It is possible to define the heat flow distribution WT as such and to specify the control computer 4. However, the steps S2 to S4 shown in FIG. 2 are preferably present.

In step S2, the control computer 4 receives process variables I. The process variables I are related to the rolling of the rolling stock 1 by the roller 3. It is in the process ^¬ sizes I on the one parameter, such as a slurry ^¬ te of the rolling stock 1, the "chemistry" of the rolling stock 1 (ie, its material composition) and the diameter of the roll 3. On the other hand is variable such as the temperature T of the rolling stock 1, the rolling speed v, the rolling force F, the rolling speed n, etc.

In a step S3, the control computer 4 determines the surface temperature distribution on the basis of the volume temperature distribution VT. The surface temperature distribution is - depending on whether the volume temperature distribution VT is spatially resolved in the tangential direction or not - spatially resolved only in the axial direction or both in the axial direction and in the tangential direction. In the case of a cylindrical roll 3 for rolling flat rolled stock 1, the step S3 consists, for example, essentially of a selection of the radially outermost layer of the volume temperature distribution VT. The temperature determined for the radially outermost layer corresponds, in the case where the volume temperature distribution VT is not spatially resolved in the tangential direction, to the average spatially resolved average temperature in the axial direction. An example of such a temperature profile is shown in FIG. In a step S4, the control computer 4 determines the heat flow distribution W based on the process variables I and the surface temperature distribution of the step S3. The heat flow distribution WT is, as already mentioned, spatially resolved both in the axial direction and in the tangential direction.

In a step S5, the control computer 4 updates the volume temperature distribution VT on the basis of the heat flow distribution WT and the volume temperature distribution VT by means of a temperature model of the roll 3. If the volume temperature distribution VT (also) is spatially resolved in the tangential direction, a release of a three-dimensional heat equation takes place in step S5. When the temperature distribution volume VT is not spatially resolved in the tangential direction, the sum of the heat ^¬ streams j (z, cp) detected at the respective axial position z for each axial zone initially in tangential direction. Then, a two-dimensional heat equation is solved. Both approaches are known and familiar to those skilled in the art. The updating of the volume VT temperature distribution of the roll 3 is done in the prior art to the thermal crown it to transmit at a roller 3 for rolling flat rolling stock 1 ^¬. This is also possible within the scope of the present invention and is optionally carried out in a step S6. However, the determination of the thermal crowning is not a core subject of the present invention.

In a step S7, the control computer 4 determines at least one upper surface temperature T ". The control computer 4 preferably determines the upper surface temperature T" such that it is spatially resolved in the axial direction. In this case - see FIG. 5 - a respective upper temperature is determined for the respective axial position z, which occurs at the points of the roller 3 determined by the respective axial position z, while the respective points are in contact with the rolling stock 3. The upper surface temperature T "thus gives - possibly for the respective axial position z - the maximum temperature on the roll 3. Alternatively, a corresponding temperature can be specified which is slightly lower.

Here are just dealing with the case that the upper surface temperature T "is a spatially resolved axial distribution. This leads to better results. However, it is in principle sufficient to use a single upper Oberflä ^¬ chentemperatur, for example in the roll center.

It is possible for the control computer 4 to determine the upper surface temperature distribution T "exclusively on the basis of the updated volume temperature distribution VT. This will be explained in more detail later in conjunction with FIG

Surface temperature distribution T "determined on the basis of the updated volume temperature distribution VT and the heat flow distribution WT .This will be explained in more detail later in connection with FIG.

In a step S8, the control computer 5 determined by ei ^¬ nes wear model 11 wear d of the roller 3. The control computer 4 determines the wear d as part of step S8 taking into account the ermit- in step S7 telten upper surface temperature distribution T ".

In a step S9, the control computer 4 takes further measure took ^¬. For example, in the course of step S9, the control computer 4 can output the determined wear d to an operator 12 of the rolling mill. It is also possible for the control computer 4, as shown in FIG. 2, to take into account the determined wear d as part of the determination of manipulated variables S, which influence the rolling of the rolling stock 1. The determined manipulated variables S can act on the rolling stand 2 in which the roller 3 is installed. Alter ^¬ natively or additionally, the determined manipulated variables S act on other facilities of the rolling mill, for example other rolling stands 2. Other measures are also possible. This will be explained in more detail below.

In a step S10, the control computer 4 checks whether it should terminate the determination process. Depending on the result of the test of step S10, the control computer 4 is used

Step S2 back or not.

If the volume temperature distribution VT is also spatially resolved in the tangential direction, the determination of the upper

Surface temperature distribution T "can be determined exclusively on the basis of the volume temperature distribution VT This will be explained in more detail below in conjunction with FIG 6. According to FIG 6, the control computer 4 selects in one step

Sil an axial position z. In a step S12, the control computer 4 selects for the selected axial position z the radially outermost elements of the volume temperature distribution VT. In a step S13, the control computer 4 determines - as beispiels- - the highest temperature occurs in the VT, in step S12 se lected ^¬ elements of the volume distribution of temperature. Alternatively, the control computer 4 can determine, for example, the average value of those local temperatures which occur between the beginning of the contact of the roller 3 with the rolling stock 1 and the end of the contact of the roller 3 with the rolling stock 1. Other approaches are possible. It is crucial that the determined temperature is at least close to the maximum temperature. In a step S14, the control computer 4 assigns the temperature ascertained in step S13 to the upper surface temperature profile T "as the corresponding temperature value for the selected axial position Z. In a step S15, the control computer 4 checks whether it already has the corresponding temperature for all axial positions z conducted ^¬ turermittlung. If this is not the case, the control computer is 4 to step Sil back, in which he z se ^¬ lected another, not previously treated axial position. Otherwise, the procedure of FIG 6 is completed ^¬ det. If the volume of distribution of temperature VT is not spatially resolved in Tangentialrich- tung, need to determine the obe ^¬ ren surface temperature distribution T "both the volume of distribution of temperature VT and the heat flux distribution WT HE will range covered. This will be explained in conjunction with FIG. 7

According to FIG. 7, steps S12 and S13 of FIG. 6 are replaced by steps S21 to S24. The steps Sil, S14 and S15 of FIG. 6 are maintained.

In step S21, the control computer 4 determines a contact angle for the selected axial position z. The contact angle corresponds to the angle, over which the roller 3 is in contact with the rolling stock 1 at the selected axial position z - see explanation 4. The determination of the contact ^¬ angle is carried out as a function of process variables as in ^¬ example, the diameter of the roller 3, the reduction, the Walzgutabmessungen etc ..

In step S22, the control computer 4 - preferably based on the relationship t = al ω (2) determines a corresponding contact time t. ω is the Winkelge ^¬ speed of the roller 3. The contact time t thus corresponds to the time during which is a z axial position at this point befindlicher the roller 3 during one rotation of the roller 3 with the rolling stock 1 is in contact.

In step S23, the control computer 4 determines at least one heat flow j, which occurs during the contact of the roller 3 with the rolling stock 1. For example, the control computer 4, the maximum, minimum, average or some other value of the heat flows occurring during this time he j ^¬ means. In step S24, the control computer 4 determines for the selected axial position z the upper surface temperature occurring at this axial position z, ie the corresponding value of the upper surface temperature distribution T.sub.n.The control computer 4 determines the upper surface temperature from the average surface temperature valid for the selected axial position z For example, the control computer 4 may set the upper surface temperature for the selected axial position z as shown in FIG. 8 by the relationship of the contact time t obtained in step S22 and the heat flux j determined in step S23

aufweisen, p, λ und c_p sind die Dichte, die Wärmeleitfähigkeit und die Wärmekapazität des Materials der Walze 3. Der Term maxcp (j ( z, cp) ) entspricht dem im Schritt S23 ermittelten Wärmefluss für den Fall, dass der maximal auftretende Wärme- fluss j herangezogen wird. T k (z) = T '(z) + k- max ^ (j (z, φ)) ■ ^ {z), k is an adaptation factor in the above relationship

p, λ and c _p are the density, the thermal conductivity and the heat capacity of the material of the roller 3. The term maxcp (j (z, cp)) corresponds to the heat flow determined in step S23 in the event that the maximum occurring heat - River j is used.

For the implementation of step S8 of FIG. 2, that is to say the determination of the wear d, various possibilities also exist. These will be explained in more detail below in connection with FIGS. 9 to 11.

The wear d usually includes a thermal wear component dT. The thermal wear component dT can, for example, according to FIG 9 based on the relationship dT (z) = dT (e _P (T "(z), TZ (z)), R, l) (5) be determined. Here, ε _{Ρ is} the plastic strain of the surface of the roller 3 which occurs during a single revolution of the roller 3. The thermal wear dT is proportional We ^¬ sentlichen for plastic elongation _ε Ρ proportional to the rolled length 1 and inversely proportional to the Ra ^¬ dius R of the roll 3. The radius R may alternatively abge ^¬ plattete or unloaded radius of the roll Be 3.

The determination of the plastic strain ε _Ρ is based on the corresponding upper surface temperature T "(z) and a further temperature TZ, this preferably spatially resolved in the axial direction, ie for the respective axial position z. Here too - analogous to the upper surface temperature T" - only the case is treated that the further temperature TZ is spatially resolved in the axial direction.

The (at least one) further temperature TZ may be a temperature related to the surface of the roll 3. It may, for example, the average temperature T "(z) at the corresponding axial position act z. Preferably, it is a minimum at the respective Axialposi ^¬ tion z on the surface of the reel 3 occurring temperature. Alternatively, it is in the further Temperature TZ act at a temperature that occurs at the relevant axial position z inside the roller 3. Here, alternatively, a temperature from a relatively near-edge layer or a temperature from the core of the roller 3 can be used.

A temperature at the surface of the roller 3 is preferably used when the volume temperature distribution VT is also spatially resolved in the tangential direction. However, the pre ^¬ hens as is possible even when the bulk temperature distribution VT is not spatially resolved in the tangential direction. A use of a temperature occurring inside the roller 3 is likewise possible in both cases.

The determination of the plastic strain ε _Ρ on the basis of the two temperatures is generally known to experts and, for example, As in the aforementioned technical paper by PG Stevens et al. explained in more detail.

The wear also often includes an abrasive wear component dA. The abrasive wear component dA is in

State of the art often in accordance with the aforementioned Bezie ^¬ hung d = c - (j) - a - l ^ determined. Optionally, a thermal dependency may indirectly be taken into account in this respect. In this case, the wear coefficient c is not a constant, but proportional to the root of the contact time t.

Although the latter procedure leads to a verb ^¬ provement to a determination of the abrasive wear component dA over the prior art. The procedure is not yet optimal. To significantly better results-Nissen performs a procedure as will be explained below in connection with FIG Ver ^¬ 10 in more detail.

According to FIG. 10, the control computer 4 determines the thermal wear component dT in a step S31. The determination of the thermal wear component dT, for example, so he follow ^¬ , as already explained above.

In a step S32, the control computer 4 determines a surface hardness H of the roller 3, if necessary spatially resolved in the axial direction. The surface hardness H is determined on the one hand as a function of the material properties of the surface of the roller 3 and on the other hand as a function of the upper surface temperature distribution T. In a step S33, the control computer 4 determines the abrasive wear component dA using the surface hardness H of the roller 3 determined in step S32. In a step S34, the control computer 4 determines the wear d by sum. of the thermal wear component dT and the abrasive wear component dA.

To determine the abrasive wear component dA (= step S33), the control computer 4 can, for example, according to FIG 11 ei ^¬ ne functional relationship use, in which the Oberflä ^¬ chenhärte H, the rolled length 1 and the contact angle received. In which Determined ^¬ development of the abrasive wear component dA is preferably as shown in FIG 11, additionally, the Tempe ^¬ temperature T and / or the material composition of the rolling material 1 a. For example, as shown in FIG. 11, the control computer 4 can determine a maximum yield stress o on the basis of the temperature T and the material composition of the rolling stock 1 and the yield stress o according to the relationship dA = (a (T), H (T "( z considered)) l, a) ₍₇₎ in the determination of the abrasive wear component dA. the abrasive wear component dA is in this case proportional to the yield stress o, the rolled length 1 and the contact angle and inversely proportional to the ermit ^¬ telten surface hardness H. Also, the temperature T and / or the "chemistry" of the rolling stock 1 can be taken into account in the context of Zundermo ^¬ dellen, the result has influence on the modeling of the abrasive Verschließanteils dA.

As already mentioned, the determination of the heat flow distribution WT preferably takes place on the basis of process variables I related to the rolling of the rolled stock 1 by the roll 3, in cooperation with the initial surface temperature distribution T " I model-based are expected expected quantities, which are supplied to the computer 4 from the outside, see FIG 1. Alternatively, it is possible that the process variables I actual sizes that are detected during the rolling of the rolling stock 1 by the roller 3, see also FIG. 1. Mixed forms are also possible. For example, it is possible for the control computer 4 to predefine ^{modeled ¬} expected expected process variables I up to a point in the future. In this case, can be expected for the past captured actual values and forecasts for the future expected wear are created d starting from the so determined wear d, based on the forward-looking expected Prozessgrö ^¬ KISSING I. This is described in detail in time ^¬ equal filed with this application application "operating method for a rolling mill for rolling flat rolling with rolling wear forecast" (internal docket: 201013425). Described in detail rough be discuss the procedure below in connection with FIG 12 ^¬ tert.

According to FIG. 12, the control computer 4 initializes in one

Step S41, the volume temperature distribution VT. The step S41 corresponds to the step Sl of FIG. 2. In a step S42, the control computer 4 accepts (or determines) the schedule data SP. The stitch plan data SP define - among other things - the mentioned model-supported, expected future process variables I. The

Step S42 corresponds to a partial embodiment of step S2 of FIG. 2.

In a step S43, the control computer 4 receives actual variables of the rolling process which describe the rolling of the rolling stock 1 by the roller 3 under consideration. Step S43 corresponds to a further partial embodiment of step S2 of FIG. 2.

In a step S44, the control computer 4 uses the actual variables of step S43 to determine an actual crowning and the current wear d. The step S44 corresponds Wesentli ^¬ chen a summary of the steps S3 to S8 of Figure 2, based on the exploitation of the actual values of the step S43. In a step S45, the control computer 4 calculates the adjustment ^¬ sizes S, which influence the rolling of the rolling stock. 1 The manipulated variables S, as already mentioned, acting on the look ^¬ te roller 3 and / or to other rollers 3 on the other rolling stands. 2

It is possible for the control computer 4 to carry out the procedure of FIG. 12 in real time during the rolling of the rolling stock 1. In this case, there is a step S46, in which the control computer 4 controls the rolling mill in accordance with the determined manipulated variables S. Alternatively, of course, the control computer 4, the procedure of FIG 12 also after rolling of the rolling stock 1 run. In this case, step S46 may be omitted.

In a step S47, the control computer 4 determines a prognosis for the thermal crowning and the wear d. The step S47 corresponds essentially to an implementation of the step S44, but in contrast to the step S44, not the detected actual variables of the rolling process are evaluated, but the stitch plan data SP. In a step S48, further measures can be taken depending on the expected future wear d determined in step S47. For example, a roll change can be initiated. The determined wear ^forecast can also be output, for example, to the operator 12 of the rolling mill.

In a step S49, the control computer 4 checks whether the pre ^¬ hens example of FIG should be terminated 12th Depending on the result of the test of step S49, the control computer 4 proceeds to a step S50 or terminates the procedure of FIG. 12.

In step S50, the control computer 4 checks whether it has specified further stitch plan data SP or has been determined by it. Depending on the result of the check of step S50, the control computer 4 returns to step S42 or step S43. Was above essentially a procedure erläu ^¬ tert that is performed in real time during the rolling of the rolling material 1 by the roller. 3 However, this is not mandatory. As already mentioned, the superiors may hens as performed after rolling the rolling stock 1 ^¬ to. In this case, according to FIG 13, the steps S42 and S45 to S48 and the step S50 omitted. Instead, a step S51 is present, in which the respectively determined Ver ^¬ wear d - optionally broken down by thermal wear and abrasive wear dT dA - is issued to the operator 12 of the mill.

It is also possible to so ^¬ fit the procedure of FIG 12, to ze before rolling of the rolling material 1 by the whale is executed. 3 In this case, steps S43 to S46 may be omitted. The step S47 wei ^¬ terhin preferably steps S56 and S57 are arranged downstream in this case. In step S56, the control computer 4 determines based on the in

In step S47, wear d determines the required manipulated variables S. In step S57, the control computer 4 stores the manipulated variables S, so that they are available for later activation of the rolling mill. Step S48 may still be present. Alternatively, it can be omitted. It may alternatively be upstream or downstream of steps S56 and S57.

The present invention has many advantages. Insbeson ^¬ particular, the roll life, ie the time between installation and removal of the rollers 3, are optimized. Also, often the quality of rolled rolled stock 1 can be optimized.

The above description is only for explanation of the present invention. The scope of the present invention, however, is intended to be determined solely by the appended claims.

Claims

claims 1. Determination method for wear (d) of a roll (3) for rolling rolling stock (1), wherein a volume temperature distribution (VT) of the roll (3) is updated by means of a temperature model of the roll (3) on the basis of a heat flow distribution (WZ) occurring on the surface of the roll (3),  - wherein the volume temperature distribution (VT) at least in  Axial direction and in the radial direction of the roller (3) is spatially resolved,  wherein the heat flow distribution (WT) is spatially resolved in the axial direction and in the tangential direction of the roller (3),  wherein the wear (d) of the roller (3) is determined by means of a wear model (11),  - wherein in the context of the wear model (11)  - Based on the updated volume temperature distribution (VT) and / or the heat flow distribution (WT) at least an upper surface temperature (T ") is determined, which at certain points of the surface of the roller (3) occurs while the respective point is in contact with the roll ^¬ well (1), and  - The wear (d) of the roller (3) is determined taking into account the upper surface temperature (T ") of the roller (3). 2. Investigation process according to claim 1, characterized,  that the volume temperature distribution (VT) in the tangential direction of the roller (3) is not spatially resolved,  the updated volume temperature distribution (VT) defines an axially resolved average surface temperature distribution (') which is characteristic of an average surface temperature of the roller (3), in that spatially resolved respective contact times (t) are determined in the axial direction by means of process variables (I) related to the rolling of the rolled stock (1) by the roll (3), which are characteristic of how long the respective point of the roller (3) during a rotation of the roller (3) with the rolling stock (1) is in contact, and - That the upper surface temperature (T ") on the basis of the average surface temperature (') of the roller (3), that part of the heat flow distribution (WT), which occurs during the contact of the roller (3) with the rolling stock (1), and the contact times (t) is determined. 3. Investigation process according to claim 1, characterized, in that the volume temperature distribution (VT) is also spatially resolved in the tangential direction of the roller (3) and that the upper surface temperature (T ") is determined exclusively on the basis of the updated volume temperature distribution (VT). 4. The investigative procedure according to claim 1, 2 or 3, characterized, that the wear (d) comprises a proportion of thermal wear (dT) and that the determination of the thermal wear component (dT) using the upper surface temperature (T ") and at least one further, on the surface of the roller (3) surface temperature (') the roller (3) takes place. 5. The investigative process according to claim 1, 2 or 3, characterized, in that the wear (d) comprises a proportion of thermal wear (dT) and that the determination of the thermal wear proportion (dT) is made using the upper surface temperature (T ") of the roller (3) and an internal temperature inside the roller (3) he follows. 6. Investigative procedure according to one of the above claims, characterized in that the wear (d) comprises an abrasive wear component (dA), that the determination of the abrasive wear component (dA) using a surface hardness (H) of the roller (3) and that the surface hardness (H) of the roller (3) is determined using the upper surface temperature (T ") of the roller (3). 7. investigation according to claim 6, characterized, that the determination of the abrasive wear component (dA) un ^¬ ter additional use of a temperature is (T) and / or the material composition of the rolled stock (1). 8. Investigative procedure according to one of the above claims, characterized that the heat flux distribution (WT) based on the rolling of the rolling stock (1) by the roller (3) related process variables (I) and a plane defined by the not yet updated Volumentem ^¬ peraturverteilung (VT) initial surface temperature distribution ( ') of the roll (3) is determined. 9. investigation according to claim 8, characterized, the process variables (I) are expected quantities determined at least partially model-supported. 10. investigation according to claim 8 or 9, characterized, that the process variables (I) are at least partially actual values that are detected during the rolling of the rolling stock (1) by the Wal ^¬ ze (3). 11. The investigative procedure according to claim 8, 9 or 10, characterized, that it is carried out in real time during the rolling of the rolling stock (1) by the roller (3). 12. An investigation according to claim 8 or 9, characterized, that it is performed by the roller (3) before rolling the rolling stock (1). 13. Investigation procedure according to one of the above claims, characterized that the determined wear (d) is taken into account in the context of the determination of manipulated variables (S), which influence the rolling of the rolling stock (1). 14. computer program, the machine code (7), which is directly abarbeitbar of a computer (4) and its processing by the computer (4) causes the computer (4) a determination process with all the steps of a determination method according to one of the above claims performs. 15. calculator, characterized, that the computer is designed such that it performs a determined ^¬ procedure with all the steps of a preliminary investigation of any of claims 1 to 13. 16. Rolling mill for rolling rolling stock (1), characterized, the rolling mill is equipped with a computer (4) according to claim 15.