Calibration and self-checking tool and method under continuous casting soft reduction

Abstract

The invention relates to a continuous casting soft reduction calibration and self-verification tool and method, and belongs to the field of continuous casting withdrawal and straightening machine roll gap calibration and verification. The roller spacing of the withdrawal and straightening machine can be quickly and accurately calibrated, and the accuracy of the roller spacing can be verified, so that calibration and self-verification can be completed within limited time. The calibration and verification tool is a chained dummy bar at least comprising two standard blocks, and the construction mode of the calibration and verification tool is that the standard block A is located at the foremost end of the dummy bar, the standard block B is arranged behind the standard block A, the standard block A is used for calibrating the roller spacing during calibration, and the standard block B is used for verifying the calibration accuracy. According to the continuous casting soft reduction calibration and self-checking tool and method, the two standard blocks are used for calibrating and checking the roller spacing of the withdrawal and straightening machine, calibration and checking are completed at a time, and the defect that soft reduction process execution deviation is caused by inaccurate calibration due to the influences of the clearance of the withdrawal and straightening machine, the straightening area, errors in the calibration process and the like is overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of continuous casting light pressure reduction, and more specifically relates to a tool and method for roll gap calibration and self-checking of a continuous casting light pressure reduction straightening machine. Background Art

[0002] Modern iron and steel metallurgy generally adopts continuous casting process, which has very high quality requirements for continuous casting billets. The use of continuous casting light reduction plays a certain role in improving the center segregation and center looseness of continuous casting billets, especially in the production of large-section continuous casting billets. Light reduction has become one of the indispensable processes. One of the problems in the application of continuous casting light reduction is that the calibrated roll gap of the light reduction straightening machine will drift with the progress of production and the passage of time, which will cause deviations in the execution of the light reduction process and lead to unstable production quality of light reduction billets. Therefore, during the implementation of light reduction, it is necessary to periodically recalibrate the roll gap of the straightening machine. At present, there are two main calibration methods for continuous casting light reduction: cold calibration and hot calibration. Cold calibration uses standard blocks to calibrate when the machine is shut down. Hot calibration uses continuous casting billets for calibration during the straightening process. In actual operation, hot calibration usually leads to inaccurate calibration due to billet bulging and thickness differences of the incoming billets themselves. At the same time, due to the characteristics of the steel grade, recalibration is required at the beginning of each casting, which is not only time-consuming and labor-intensive, but also affects the yield of the billets. Cold calibration is carried out during production breaks or maintenance, and time is limited. Since the calibration will not be performed again after the shutdown, the accuracy of the calibration must be guaranteed.

[0003] The patent application with Chinese patent publication number CN106041010A, published on October 26, 2016, discloses a calibration method for light pressure reduction of large square billets to calibrate the roll gap of the straightening machine, and then to inspect and recalibrate the light pressure reduction system through hot billet verification. This method can achieve calibration through the cold calibration method, but it needs to be recalibrated with hot billets, that is, the accuracy of the calibration cannot be confirmed before formal production. There is a hidden danger of unqualified production quality for the first production of billets after calibration, and if the calibration is found to be inaccurate during the hot billet calibration, it is impossible to stop the machine in time for recalibration.

[0004] The patent application with Chinese patent publication number CN 104416135 A was published on March 18, 2015, and discloses a method for calibration of light reduction in continuous casting of square billets. By selecting a standard dummy rod as a calibrator, multiple chain links are used to calibrate the straightening machine and a two-point linear correction algorithm is used to determine the correction and compensation through the linear function relationship between pressure and thickness. The calibration of this method is simple, but due to the existence of a straightening area, starting multiple straightening machines at one time easily leads to uncertainty in the contact surface between the straightening machine and the dummy rod in the straightening area, and there is also a lack of re-verification before production. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a tool and method for calibration and self-verification of continuous casting light reduction. The tool is used to calibrate and verify the roller spacing of each straightening machine. The tool is a calibration dummy rod comprising at least two standard blocks (standard block A and standard block B). In terms of structure, the dummy rod comprises a plurality of chain blocks, which are arranged continuously. Adjacent chain blocks are connected by chain rods. Two standard blocks are included in the plurality of chain blocks. In terms of arrangement order, standard block A is located at the front of the plurality of chain blocks, and standard block B is located in the second position immediately following standard block A. During calibration, the roller gap of the straightening machine is first calibrated by standard block A, and then the calibrated roller gap is verified by standard block B. The accuracy of the calibration is judged so that the calibration and verification of the roller gap can be completed within a limited time, thereby ensuring the stable execution of the light reduction process.

[0006] In order to achieve the above object, the technical solution provided by the present invention is:

[0007] A tool and method for continuous casting light reduction calibration and self-verification, wherein the calibration and verification tool is a calibration dummy rod comprising at least two standard blocks, and the construction method is as follows: the standard block A is located at the front end of the dummy rod, and the standard block B is arranged behind the standard block A, the thickness of the standard block A is a, and the thickness of the standard block B is b.

[0008] The calibration and verification method is as follows: before calibration, the calibration dummy rod is sent from the last straightening machine to the first straightening machine in the opposite direction of the billet drawing, and the transportation is stopped when the standard block B is located at the center of the two rollers of the first straightening machine. The second straightening machine and the first straightening machine are pressed down successively with a constant pressure. After the pressure is stable, the compensation coefficient is modified to calibrate the roller spacing of the first straightening machine to b; the first and second straightening machines are lifted, and the dummy rod is transported along the billet drawing direction until the standard block A is located between the two rollers of the first straightening machine. Stop conveying when it reaches the center, and press down the second straightening machine and the first straightening machine successively with a constant pressure. After the pressure stabilizes, record the roller spacing of the first straightening machine as D1; ​​compare the roller spacing D1 of the first straightening machine with the a value. If ︱D1-a︱≤error value S, the calibration and verification of the first straightening machine are completed, lift the first and second straightening machines, convey the guide rod backwards and repeat the above steps to calibrate and verify the subsequent straightening machines; if ︱A-Bx︱>error value, the system reports an error, find the cause and recalibrate.

[0009] Preferably, the standard block A and the standard block B are integrally formed of a rigid material, and are milled and polished to obtain a component with a maximum deviation of ≤0.1 mm.

[0010] Preferably, the standard block B is spaced apart from the standard block A by a distance, and the distance is equal to the center distance between two adjacent tensioning and straightening machines.

[0011] Preferably, the error value S is 0.1 mm.

[0012] Preferably, the thickness a of the standard block A and the thickness b of the standard block B can be designed to be equal or unequal (a is greater than or equal to b, and the thickness of the chain block behind the standard block B is consistent with that of the standard block B.

[0013] Preferably, the calibration dummy bar is a chain dummy bar.

[0014] Preferably, the pressing pressure of the tension and leveling machine is 200-400 kN.

[0015] Preferably, the calibration tool and method are applicable to a target casting speed of 0.4-1.2 m / min and a casting thickness of 300-500 mm of a continuous casting machine.

[0016] The tool and method for continuous casting light pressure calibration and self-calibration of the present invention and the prior art have the following significant advantages:

[0017] (1) The tool is preferably calibrated and checked using an integrally formed standard block, which has a strong ability to remain undeformed under pressure, has higher machining accuracy than the calibration dummy bar, and is more accurate in calibration.

[0018] (2) The tool uses two standard blocks for cold calibration and verification of light pressure reduction. The roll gap (roller spacing) of the light pressure reduction straightening machine can be accurately calibrated and verified before production, thereby improving the implementation accuracy of light pressure reduction and ensuring the quality of the casting.

[0019] (3) The distance between the two standard blocks in the tool is equal to the center distance between the two adjacent straightening machines, so that the calibration of the n+1 roller and the verification of the n roller can be carried out simultaneously, improving efficiency and saving time.

[0020] (4) The tool and method for continuous casting light pressure calibration and self-calibration of the present invention adopts a pressure of 200-400 kN for cold calibration. Practice has proved that this pressure value can eliminate the gap of the straightening machine and has strong repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a tool for continuous casting light reduction calibration and self-calibration in an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the state of the tool in the roller gap of the tensioning and straightening machine in an embodiment of the present invention;

[0023] In the figure, 1-standard block A; 2-standard block B. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with examples. The examples are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0025] Figure 1 The tool and method for calibration and self-checking of continuous casting light pressure reduction of the present invention shown in the figure adopts a calibration dummy rod containing at least two standard blocks. In particular, the dummy steel is chain-type, consisting of chain blocks and chain links, adjacent chain blocks are connected by chain links, and the chain blocks contain standard blocks A and standard blocks B. Its construction method is that standard block A is located at the front end of the dummy rod, standard block B is arranged behind standard block A, the spacing between standard block A and standard block B is equal to the center distance of two adjacent straightening machines, the thickness of standard block A is a, the thickness of standard block B is b, the thickness of the two standard blocks can be equal or unequal, a is greater than or equal to b, and the thickness of the chain block behind standard block B is consistent with the thickness of standard block B. The calibration and verification method of the straightening machine using the tool is as follows: before calibration, the calibration guide rod is sent from the last straightening machine to the first straightening machine in the opposite direction of the billet drawing, and the conveying is stopped when the standard block B is located at the center of the two rollers of the first straightening machine, and the second straightening machine and the first straightening machine are pressed down successively with a constant pressure. After the pressure stabilizes, the straightening machine indication X1 is recorded, and the compensation coefficient is modified to calibrate the roller spacing of the first straightening machine to b; the first and second straightening machines are lifted, and the guide rod is conveyed along the billet drawing direction until the standard block A is located at the center of the two rollers of the first straightening machine, and the conveying is stopped. At this time, the standard block B is located at the center of the two rollers of the second straightening machine, and the second straightening machine and the first straightening machine are pressed down successively with a constant pressure. After the pressure stabilizes, record the roller spacing of the 1st and 2nd straightening machines as D1 and X2 respectively; modify the compensation coefficient to calibrate the roller spacing of the 2nd straightening machine to b, and the calibration of the 2nd straightening machine is completed; compare the roller spacing D1 of the 1st straightening machine with a value, if ︱D1-a︱≤error value S, the calibration of the 1st straightening machine is completed, lift the 1st and 2nd straightening machines, transport the ingot rod backward and repeat the above steps to calibrate the n+1th roller and calibrate the nth roller, until all straightening machines are calibrated and calibrated; if the error value is greater than S, the system reports an error, and the staff will find the cause and recalibrate. This light pressure calibration tool and method are suitable for the target pulling speed of the continuous casting machine of 0.4~1.2m / min and the thickness of the ingot is 300~500mm.

[0026] Table 1

[0027] Straightening machine number 1# 2# 3# 4# 5# 6# 7# 8# 9# Before calibration / mm 399.4 399.6 399.4 399.0 399.6 399.7 399.9 399.8 399.2 Calibration value / mm 400.0 400.0 400.0 400.0 400.0 400.0 400.0 400.0 400.0 Check value / mm 400.0 400.1 400.0 400.1 399.9 400.0 400.0 400.0 400.0

[0028] Example 2

[0029] The present embodiment provides a tool and method for continuous casting light pressure calibration and self-calibration. The calibration and calibration tool used is a calibration dummy bar containing two standard blocks. The dummy bar is chain-type and is constructed in such a way that the standard block A is located at the front end of the dummy bar, and the standard block B is arranged behind the standard block A. The spacing between the standard block A and the standard block B is equal to the center distance between two adjacent straightening machines. In the present embodiment, the spacing is 1.2 m. The thickness of the two standard blocks is equal to 390.0 mm. The calibration and verification method is as follows: before calibration, the dummy rod is sent from the last straightening machine to the first straightening machine in the opposite direction of the billet drawing, and the conveying is stopped when the standard block B is located at the center of the two rollers of the first straightening machine. The second straightening machine and the first straightening machine are pressed down successively with a constant pressure value of 200kN. After the pressure is stable, the reading of the straightening machine is recorded as 390.2mm, and the compensation coefficient is modified to calibrate the roller spacing of the first straightening machine to 390.0mm; lift the first and second straightening machines, and place the dummy rod. The rod is transported along the direction of billet drawing until the standard block A is located at the center of the two rollers of the first straightening machine. The standard block B is located at the center of the two rollers of the second straightening machine. The second straightening machine and the first straightening machine are pressed down successively with a constant pressure value of 200kN. After the pressure stabilizes, the roller spacings of the first and second straightening machines are recorded as 390.0mm and 389.6mm respectively. The compensation coefficient is modified to calibrate the roller spacing of the second straightening machine to 390.0mm, and the roller spacing of the second straightening machine is calibrated to 389.6mm. The calibration of the machine is completed; compare the roller spacing D1 of the first straightening machine with the a value, |D1-a|≤error value S, the calibration of the first straightening machine is completed, lift the first and second straightening machines, transport the ingot rod backward and repeat the above steps to calibrate the n+1th roller and calibrate the nth roller, until all 9 straightening machines are calibrated and calibrated. The data after calibration are shown in Table 2. This light pressure calibration tool and method are suitable for the target pulling speed of the continuous casting machine of 0.4m / min and the billet thickness of 400mm.

[0030] Table 2

[0031] Straightening machine number 1# 2# 3# 4# 5# 6# 7# 8# 9# Before calibration / mm 390.2 389.6 390.0 389.4 389.6 390.1 390.2 390.2 390.1 Calibration value / mm 390.0 390.0 390.0 390.0 390.0 390.0 390.0 390.0 390.0 Check value / mm 390.0 390.0 390.0 390.1 390.0 390.0 389.9 390.0 390.0

[0032] Example 3

[0033] The present embodiment provides a tool and method for continuous casting light pressure calibration and self-calibration. The calibration and calibration tool used is a calibration dummy bar including two standard blocks. The dummy bar is chain-type and is constructed in such a way that the standard block A is located at the front end of the dummy bar, and the standard block B is arranged behind the standard block A. The spacing between the standard block A and the standard block B is equal to the center distance between two adjacent straightening machines. In the present embodiment, the spacing is 1.2 m. The thicknesses of the two standard blocks are not equal. The thickness a of the standard block A is 400.0 mm. The thickness b of the standard block B is 390.0 mm. The calibration and verification method is as follows: before calibration, the calibration dummy rod is sent from the last straightening machine to the first straightening machine in the opposite direction of the billet drawing, and the standard block B is stopped when it is located at the center of the two rollers of the first straightening machine. The second straightening machine and the first straightening machine are pressed down successively with a constant pressure value of 300 kN. After the pressure is stable, the reading of the straightening machine is recorded as 390.2 mm, and the compensation coefficient is modified to calibrate the roller spacing of the first straightening machine to 390.0 mm. Lift the 1st and 2nd straightening machines, and convey the dummy rod along the direction of billet drawing until the standard block A is located at the center of the two rollers of the 1st straightening machine. Stop conveying. At this time, the standard block B is located at the center of the two rollers of the 2nd straightening machine. Press down the 2nd straightening machine and the 1st straightening machine successively with a constant pressure value of 300kN. After the pressure stabilizes, record the roller spacing of the 1st and 2nd straightening machines as 390.0mm and 390.2mm respectively; modify the compensation coefficient to calibrate the roller spacing of the 2nd straightening machine to 390.0m m, the calibration of the second straightening machine is completed; compare the roller spacing D1 of the first straightening machine with the a value, ︱D1-a︱≤error value S, the verification of the first straightening machine is completed, lift the first and second straightening machines, transport the ingot rod backward and repeat the above steps to calibrate the n+1th roller and verify the nth roller, until all 9 straightening machines are calibrated and verified. The data after the calibration is shown in Table 3. The light pressure calibration tool and method are suitable for the target pulling speed of the continuous casting machine of 0.4m / min and the ingot thickness of 400mm.

[0034] Table 3

[0035] Straightening machine number 1# 2# 3# 4# 5# 6# 7# 8# 9# Before calibration / mm 390.2 390.2 390.0 389.4 389.6 390.1 390.2 390.2 390.1 Calibration value / mm 390.0 390.0 390.0 390.0 390.0 390.0 390.0 390.0 390.0 Check value / mm 400.0 400.0 399.9 400.1 400.0 400.0 400.0 400.0 400.0

Claims

1. A tool for continuous casting soft reduction calibration and self-calibration, characterized by: It is a chain-type dummy rod, comprising a plurality of chain blocks and a plurality of chain rods, wherein the chain blocks are arranged continuously, and adjacent chain blocks are connected by the chain rods, and the plurality of chain blocks include a standard block A and a standard block B, wherein the standard block A is located at the front end, and the standard block B is located behind the standard block A.

2. The tool according to claim 1, characterized in that: The thickness of the standard block A is a, the thickness of the standard block B is b, a is greater than or equal to b, and the thickness of the chain block after the standard block B is consistent with the thickness of the standard block B.

3. The tool according to claim 1, characterized in that: The distance between the standard block A and the standard block B is equal to the center distance between two rollers of two adjacent straightening machines.

4. A method for continuous casting soft reduction calibration and self-calibration using the tool described in any one of claims 1 to 3, characterized in that: include, Step 1: Before calibration, send the dummy rod from the last straightening machine at the end to the first straightening machine at the front end in the opposite direction of the billet drawing, and stop the conveying when the standard block B is located at the center of the two rollers of the first straightening machine. Press down the second straightening machine and the first straightening machine successively with a constant pressure. After the pressure is stable, record the readings of the straightening machine, modify the compensation coefficient and calibrate the roller spacing of the first straightening machine to b; Step 2: lift the first and second straightening machines, and convey the dummy rod along the direction of billet drawing until the standard block A is located at the center of the two rollers of the first straightening machine, then stop conveying, and successively press down the second straightening machine and the first straightening machine with a constant pressure. After the pressure is stable, record the roller spacing of the first straightening machine as D1; Step 3: Compare the roller spacing D1 of the first straightening machine with the a value. If |D1-a|≤error value S, the calibration and verification of the first straightening machine is completed. Lift the first and second straightening machines, transport the guide rod backwards and repeat steps 1 and 2 to calibrate and verify the roller spacing of subsequent straightening machines in turn. Otherwise, the system reports an error, find the cause and recalibrate.

5. The method according to claim 4, characterized in that: include, Step 1: Before calibration, send the dummy rod from the last straightening machine at the end to the first straightening machine at the front end in the opposite direction of the billet drawing, and stop the conveying when the standard block B is located at the center of the two rollers of the first straightening machine. Press down the second straightening machine and the first straightening machine successively with a constant pressure. After the pressure is stable, record the roller spacing of the first straightening machine as X1, modify the compensation coefficient and calibrate the roller spacing of the first straightening machine as b. The calibration of the first straightening machine is completed. Step 2: lift the first and second straightening machines, and convey the dummy rod along the direction of billet drawing until the standard block A is located at the center of the two rollers of the first straightening machine, and the standard block B is located at the center of the two rollers of the second straightening machine. Stop conveying, and press down the second straightening machine and the first straightening machine successively with a constant pressure. After the pressure is stable, record the roller spacing of the first straightening machine as D1, and the roller spacing of the second straightening machine as X2. Modify the compensation coefficient and calibrate the roller spacing of the second straightening machine as b. The calibration of the second straightening machine is completed. Step 3: Compare the roller spacing D1 of the first straightening machine with the a value. If |D1-a|≤error value S, the calibration of the first straightening machine is completed, lift the first and second straightening machines, transport the guide rod backwards and repeat steps 1 and 2 to calibrate the roller spacing of the n+1 straightening machine and calibrate the roller spacing of the nth straightening machine; otherwise, the system reports an error, find the cause and recalibrate.

6. The method according to claim 4, characterized in that: The error value S is 0.1 mm.

7. The method according to claim 4, characterized in that: The pressing pressure of the tension and leveling machine is 200-400 kN.

8. The method according to claim 4, characterized in that: The method is suitable for a continuous casting machine with a target casting speed of 0.4 to 1.2 m / min and a casting thickness of 300 to 500 mm.

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