MXPA01002834A - Combined regulating system for producing particular product characteristics in the rolling of austentic, mixed austentic and ferritic and ferritic steel qualities - Google Patents

Abstract

The invention relates to a combined regulating system for producing defined product characteristics in the rolling of austentic, mixed austentic and ferritic and ferritic steel qualities, using a measuring method to determine the roll gap of a roll pair by detecting the absolute position of the work and back-up rolls on the side facing away from the roll gap by optical position measurement. The upper edge of the top roll or the lower edge of the bottom roll is detected relative to the absolute position of the rolls, in segments over the barrel length, by means of adjacent sensors situated along the roll. The measuring results are incorporated in a suitable regulating operation that influences the geometry of the roll gap and rolled stock using a model that takes into account the influences of the deflecting and roll adjusting systems, the deflection of the rolls, flattening between the rolls, flattening between the work roll and the rolled stock and the wear and thermal crowning of the rolls. In addition to the necessary absolute thickness, the regulating operation ensures that the necessary thickness profile and the flatness criteria are produced.

Description

COMBINED REGULATION SYSTEM TO PRODUCE SPECIFIC CHARACTERISTICS OF A PRODUCT, IN THE LAMINATE OF QUALITIES OF AUSTENIC, AUSTENITIC AND FERRITIC OR MIXED AND FERRITICAL STEEL DESCRIPTION OF THE INVENTION The invention relates to a combined regulation system for the rolling of steel grades to produce certain properties of the product in the austenitic, combined austenitic-ferritic and ferritic ranges by the use of a measuring process to determine the separation between cylinders of a pair of working cylinders by detecting the absolute position of the support or work cylinders by the side in each case remote from the slot between cylinders by optical measurement of the position. For thickness regulation, the Gaugemeter process has been used for many years. In the case of the Gaugemeter process (Fig. 3), it is assumed that the resistance of the material to be laminated (Cmat) has a linear characteristic within the working area of the laminator frame, that is, a greater or lesser rolling force is a measure of a greater or lesser decrease in the thickness of the pass in the indentation between cylinders if the compensation of the temperature at the point of operation A refinement represents what is known as the OGC process that allows a more precise regulation of the thickness. In this process, the deviation is measured by the position transmitters that correlate directly with the gap between the cylinders, so that a value corresponding to the thickness of the material to be laminated is obtained. In the case of a four or six-fold rolling mill, this can be the direct measurement of the elevation or change of position of the support cylinder. An analogous measuring system is described in German patent 42 03 469. Taking into account the felxiones of the cylinders, the crushing between the cylinders, the crushing between the cylinder and the material to be laminated as well as the basic facet, wear and the thermal bulge of the cylinders can be obtained a more precise regulation of the thickness with this system than hitherto according to the Gaugemeter principle. However, with the known system it is not possible to regulate the profile, the flatness and the contour, for this purpose numerous different systems and processes are known, such as: working cylinders with a certain basic facet (symmetric / asymmetric) displacement of the working cylinders in the axial direction bending of the working cylinders in vertical direction - grinding of the working cylinders during the process of rolling work cylinders with certain angular position with respect to the direction of rolling (crossing) - cooling controlled working cylinders - support cylinders with a certain cylinder profile. To regulate the temperatures of the cylinders, an additional regulator circuit is required. Controlling a certain temperature of the cylinders is an important precondition for obtaining a certain structure and therefore obtaining the desired mechanical properties of the material to be laminated. Thus, for example, in a continuous rolling mill the final rolling temperature is adjusted to the desired value by regulating the rolling speed as well as the cooling between frames in the case of a pre-established distribution of the thickness reduction to the pass .

Until now, the regulation of thickness, temperature and profile, flatness and contour are separate regulating circuits. These individual control circuits have an unfavorable influence on one another and - depending on the pre-established priorities - certain target values are not achieved optimally. Precisely when laminating some qualities of steel in the temperature range below the austenitic range are great problems to regulate, for example, the thickness; and is that, as already mentioned in the above, the Gaugemeter process is based on a force characteristic of linear rolling. But it is known that below the austenitic range in various steels there is a characteristic of plastic stress that in this temperature range does not have a linear development (Fig. 4). Therefore, in this range the decrease in the rolling force does not always mean a smaller decrease in the thickness of the pass in the gap between cylinders, that is to say that the relation between rolling force and variation of the thickness is no longer unequivocally given. Even in the case of what is known as "Fiying Gauge Change" (Fig. 5), in which the output thickness varies within a shortest possible time interval, the Gaugemeter process can not be used, since vary some magnitudes of influence that determine the process of rolling (for example speed of the cylinders, strength of rolling, thickness of exit), which can not be duplicated with precision by means of the Gaugemeter process. Also when laminating in a stranding and thin strip rolling plant, only the Gaugemeter process operates in a limited way. And is that due to the casting process can vary in thickness and temperature in the material to be rolled that exceed the range of operation of a conventional Gaugemeter regulation. It is true that in this case the process presented in patent DE 4203469 C2 can be used, but only the ends of the tables are used for the measurement, which, however, is not an accurate measurement of the shape of the cylinder in by virtue of the fact that, in the form of the cylinder along the table, it is influenced - among other previously mentioned systems - by means of a controllable cooling of the cylinder as well as a controllable lubrication of the slot between cylinders. The task of the present invention is to employ a combined system and regulation process for laminating steel grades to various temperature ranges in a reversion mill with at least one horizontal frame or a continuous mill with at least one two horizontal frames with which certain properties of the product are automatically obtained in terms of geometrical and mechanical characteristics. For the solution of the problem, it is proposed - from the state of the art, that it is known as OGC - a regulating system which, in relation to the absolute position of the cylinders measured, detects by means of sensors arranged adjacent to each other along the cylinder in each case segments along the length of the table the upper edge of the upper cylinder and the lower edge of the lower cylinder, that the results of the measurement intervene in an adequate regulation that influences the separation of the cylinders and the geometry of the material when rolling by means of a model that in addition to the influences of the systems of flexion and adjustment of the cylinders takes into account the flexions of the cylinders, the crushing between the cylinders, the crushing between the working cylinder and the material to be laminated as well as the wear and the thermal bulge of the cylinders, which in addition to the required absolute thickness produces the thickness profile and the criteria of required flatness. The refinements of the regulating system according to the invention are defined in the dependent claims. The invention is described below based on the example of a continuous rolling mill. They show: fig. 1 the schematic view of a rolling mill with three frames, fig. 2 the schematic view of a set of cylinders with the regulating system according to the invention, fig. 3 a known gaugemeter diagram, fig. 4 the plastic strain curve of an ULC steel, and fig. 5 a graphic representation of the Fiying Gauge Change. This rolling mill (see Fig. 1) consists of at least three horizontal frames 2 to 3 arranged one after another (quadruples and / or sextuples), which are equipped in each case with hydraulic adjusters. In work cylinders, a device 5 is provided on the input side and on the output side, with which it can be influenced without contact or with contact in the shape of the cylinder along the width and at controlled intensity by means of a refrigerant and / or heating medium. On the input side there are supply systems 7 below and above the doctor blades 6 through which a lubricant is injected onto the cylinder or into the groove between cylinders in a controllable manner across the width. In front and behind the laminator train and between the racks there may be devices 9 with which you can influence without contact or with contact in the temperature of the material to be laminated along the width and with controlled intensity by means of a cooling and / or heating means. The last and possibly also the penultimate frame is equipped with what is known as the OGCC system 8 according to the invention. A temperature measuring point 10 is arranged before each frame, with which the temperature of the material to be laminated along the width and / or points is measured. Behind the last frame a measuring station 11 is installed which captures both the profile of temperature and thickness as well as the width, flatness and quality of the surface. The material 1 to be laminated enters the first frame and leaves the train by the last frame 3. the rolling temperature in the passes can be found in the austenitic, combined austenitic-ferritic and / or ferritic range. In addition to the speed regulation, for a run scheme with defined decreases it is possible to adjust the respectively required temperatures of the material to be laminated by the systems 5, 7 influencing the laminate as well as by the systems 9 that influence the material be laminated, which have as their purpose the mechanical properties required. Simultaneously it is also possible to influence the form of the gap between cylinders with the systems 5, 7 together with the mechanical adjustment systems, which is detected with the system 8 as a measuring element, so that suitable regulations can intervene which, in addition to the required absolute thickness, have as their goal the profile of thickness and the criterion of required flatness. The essential measurement system is the regulation system (OGCC = Optical Gauge &Crown Control) shown in fig. 2. On the upper side of the upper support cylinder 22 and / or on the lower side of the lower support cylinder, several sensors 24 are arranged along the length of the table, which measure the real shape of the profile by segments. These sensors are mounted on a support. Because this support carves on sliding shoes on the cylinder the distance to the cylinder is kept constant. In this way it is possible to use sensors that have a high resolution and a reduced measuring range; for example, sensors that measure the distance with respect to the cylinder according to the principle of induction. Simultaneously, a defined measuring edge 23 is placed on these sliding shoes, which serves for the optical measurement of the position. That is to say that by means of the optical measurement of the position (edge 23 of measurement) the absolute position of the support cylinders is captured and in relation to it the upper edge and the edge bottom of the support cylinders along the table with the sensors (24). These measurement results are transferred to a shape that describes the geometry of the gap between cylinders and the material to be laminated through a model that in addition to the influences of the systems of flexion and adjustment of cylinders also takes into account the bends of the cylinders 21, 22, the crushing between the cylinders 21, 22, the crushing between the working cylinder 21 and the material 25 to be laminated as well as the wear and thermal bulging of the cylinders 21, 22. That is to say that the Measured values checked with the sensors provide an image of the material to be laminated that is in the gap between the cylinders. By means of computer control, it is intervened in a suitable regulation that influences the separation of the cylinders and the geometry of the material to be laminated and that, in addition to the required absolute thickness, provides the thickness profile and the requisite flatness criteria.

Claims (8)

1. CLAIMS 1. Combined regulation system for the rolling of steel grades to produce certain properties of the product in the austenitic, combined austenitic-ferritic and ferritic ranges by using a measuring process to determine the separation between cylinders of a pair of cylinders of work by capturing the absolute position of the working cylinders or support on the surface in each case away from the gap between cylinders by an optical measurement of the position, characterized because in relation to the absolute position of the cylinders measured, detects by means of sensors disposed adjacent along the cylinder in each case by segments along the length of the table the upper edge of the upper cylinder and the lower edge of the lower cylinder, that the results of the measurement intervene in a suitable regulation that influences in the separation of the cylinders and the geometry of the material laminar by a model that in addition to the influences of the systems of flexion and adjustment of the cylinders takes into account the flexions of the cylinders, the crushing between the cylinders, the crushing between the working cylinder and the material to be laminated as well as the wear and thermal bulge of the cylinders, which in addition to the absolute thickness required provides the thickness profile and the required flatness criteria. Combined regulation system according to claim 1, characterized in that for a suitable regulation of the separation between cylinders and the geometry of the material to be laminated, a device is provided on the input and output side of the work rolls. which can be influenced without contact or with contact in the shape of the cylinders along the width and with controllable intensity by means of a cooling and / or heating means. Combined regulation system according to claim 1 and 2, characterized in that on the input side there are systems that supply liquid to the scrapers that attack from below and above in the working cylinders, through which it is injected a lubricant on the cylinder or in the groove between cylinders in a controllable way across the width. Combined regulation system according to claim 2, characterized in that the devices for influencing, without contact or contact, the temperature of the material to be laminated are provided in front of and behind the mill train and between the frames. 5. Combined regulation system according to claim 1 to 4, characterized in that the at least A frame is equipped with the regulation system according to the invention. Combined regulation system according to claim 1 to 5, characterized in that a temperature measurement site is arranged in front of each frame, with which the temperature of the material to be laminated across the width and / or in a point-specific manner is measured. . Combined regulation system according to claim 1 to 6, characterized in that behind the last frame a measuring station is installed which detects both the temperature and thickness profile as well as the width, flatness and quality of the surface. Combined regulation system according to claim 1 to 7, characterized in that the material entering the rolling process is cast tape. SUMMARY The invention relates to a combined regulation system for the rolling of steel grades to produce certain properties of the product in the austenitic, combined austenitic-ferritic and ferritic ranges by employing a measuring process to determine the separation between cylinders of a pair of cylinders by capturing the absolute position of the support or work cylinders by the side in each case away from the indentation between cylinders by optical measurement of the position. For this, in relation to the absolute position of the measured cylinders, the upper edge of the upper cylinder and the lower edge of the lower cylinder are detected by segments in each case along the length of the table by means of sensors arranged adjacent to the cylinder. . The results of the measurement intervene in a suitable regulation that influences the separation of the cylinders and the geometry of the material when laminating by means of a model that in addition to the influences of the systems of flexion and adjustment of the cylinders takes into account the flexions of the cylinders, the crushing between the cylinders, the crushing between the working cylinder and the material to be laminated, as well as the wear and thermal bulge of the cylinders, which in addition to the required absolute thickness produces the thickness profile and the required flatness criteria. Figure 1