Method for testing the stiffness of a four-high reversing hot rolling mill

Abstract

A kind of rigidity test method of four-high reversible hot rolling mill, the specific steps of test method are as follows: S1, mill pre-pressing zero adjustment;S2, rigidity test of mill forward rotation;S3, rigidity test of mill reverse rotation;S4, data acquisition;S5, data processing and analysis.The beneficial effects of the present application are: by testing the rigidity difference of both sides when mill forward and reverse rotation, the reasons and rules of rigidity difference are studied, the rigidity of both sides is improved to be consistent, and the rigidity difference is included in the first level automatic control, realizing the leap from artificial judgment and intervention to automation and intelligentization, so as to improve the plate shape, improve product quality and reduce the occurrence of product quality dispute.

Description

TECHNICAL FIELD

[0001] The present application relates to a rigidity testing method, in particular to a rigidity testing method of a four-high reversing hot rolling mill. BACKGROUND

[0002] The rigidity of a rolling mill refers to the rolling force required by a hydraulic cylinder to produce a unit elastic deformation in the longitudinal direction, and its geometric meaning is the slope of the straight line segment of the elastic curve of the rolling mill, which is a key indicator of the precision of the production line equipment, the quality of the product (including size, shape), and the production efficiency of the rolling stability of the production line. It is also the source of a series of key quality indicators of finished products, such as model setting accuracy, stable rolling of steel plates, and plate shape quality. The camber in the plate rolling process has always been a key indicator that restricts production and quality, and currently, the plate shape control in most plate rolling processes mainly relies on the naked eye observation of the plate shape by the operator during different passes and the intervention and adjustment of the two sides of the reduction, but due to the limitations and hysteresis of naked eye observation, the effect of intervention is not ideal, resulting in significant camber in the rolling process of thin gauge steel plates, and reducing the market competitiveness of the enterprise. SUMMARY

[0003] The present application aims to overcome the deficiencies and shortcomings in the prior art, and provides a rigidity testing method of a four-high reversing hot rolling mill, which tests the rigidity difference on both sides of the rolling mill during forward and reverse rotation, studies the causes and rules of the rigidity difference, improves the rigidity on both sides to make it consistent, and at the same time, incorporates the rigidity difference into the first level automatic control, realizes the leap from manual judgment and intervention to automation and intelligence, so as to improve the plate shape, improve the product quality, and reduce the occurrence of product quality disputes.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solution: a rigidity testing method of a four-high reversing hot rolling mill, the specific steps of the testing method are as follows: S1, rolling mill pre-pressing zero adjustment; S2, rolling mill forward rigidity testing; S3, rolling mill reverse rigidity testing; S4, data acquisition; S5, data processing and analysis.

[0005] More specifically, the rolling mill pre-pressing zero adjustment is as follows: before the rigidity testing, first adjust the inclination of the two sides of the rolling mill gap to zero, set the rolling force to zero on the main interface, switch the zero adjustment interface to the zero adjustment state, select "automatic zero adjustment selection" on the zero adjustment interface, click start zero adjustment, and then click stop zero adjustment when the two rollers of the rolling mill are pressed together.

[0006] More specifically, the rolling mill forward rigidity testing is as follows: set the rolling mill to a crawling state, start the rigidity testing, stop loading when the single side rolling force reaches 18000kN, and then restore the gap to zero.

[0007] As more specific of the present application, the rolling mill reverse stiffness test is specifically: click reverse crawl→ start stiffness test→ to one-sided rolling force reaches 18000kN→ stop loading-> when the roll gap returns to zero, query process trend chart→ collect test curve results.

[0008] As more specific of the present application, the data collection is specifically: export the test period rolling force and roll gap corresponding data from the PDA process data collection system, and take the data of one-sided rolling force greater than 7000kN.

[0009] As more specific of the present application, the data processing and analysis is specifically: the slope obtained by linear fitting by using data analysis software is the stiffness of the running rolling mill at this time.

[0010] As more specific of the present application, the rolling mill pre-pressing zero setting is that when the two rolls of the rolling mill are pressed together, the roll gap is displayed as 0 value.

[0011] As more specific of the present application, in the rolling mill forward stiffness test, the creep speed of the rolling mill is set to 10 rad / min, the rolling force is set to be uniformly loaded at a speed of 300kN / s, and when the one-sided rolling force reaches 18000kN, the loading is stopped to the total rolling force of 36000kN, which achieves the purpose of ensuring the safety of the equipment.

[0012] As more specific of the present application, in the data collection, the data of one-sided rolling force greater than 7000kN is taken to remove the influence of the non-linear stage on the test accuracy.

[0013] As more specific of the present application, in the data processing and analysis, at least one of Origin 9.1 and Excel can be selected as the data analysis software.

[0014] After adopting the above technical solution, the present application has the beneficial effects that: by quickly testing the stiffness difference of the two sides of the rolling mill in forward and reverse directions, the reasons and rules of the stiffness difference are studied, the stiffness of the two sides is improved to be consistent, and the stiffness difference is included in the first-level automatic control, so that the manual judgment and intervention are changed to automation and intelligence, thereby improving the plate shape, improving the product quality, and reducing the occurrence of product quality disputes. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0016] Figure 1 is the test curve result graph of the present application.

[0017] Figure 2 is the first test result graph of rough rolling mill rigidity test in the present application.

[0018] Figure 3 is the second test result graph of rough rolling mill rigidity test in the present application.

[0019] Figure 4 is the first test result graph of finishing rolling mill rigidity test in the present application.

[0020] Figure 5 is the second test result graph of finishing rolling mill rigidity test in the present application. DETAILED DESCRIPTION

[0021] Reference Figure 1 The technical solution adopted in the present embodiment is shown in the figure: the precondition for using the method is that the tested rolling mill is a four-roll reversible rolling mill, and the rolling mill is provided with a two-stage automatic control system and a PDA process data acquisition system, and the method is characterized in that the specific steps of the test method are as follows:

[0022] S1, rolling mill pre-pressing zero adjustment: before the rolling rigidity test, first adjust the inclination of the two sides of the rolling mill gap to zero, set the rolling force zero to the main interface picture, switch to the zero adjustment state, select "automatic zero adjustment selection" in the zero adjustment interface, click start zero adjustment, and then click stop zero adjustment when the two rollers of the rolling mill are pressed together (the gap is displayed as 0 value).

[0023] S2, rolling mill forward rotation rigidity test: set the rolling mill to the creeping state (the creeping speed is set to 10 rad / min) → start the rigidity test (set the rolling force to be loaded uniformly at a speed of 300 kN / s) → when the unilateral rolling force reaches 18000 kN (the loading is stopped when the total rolling force of the two sides reaches 36000 kN to ensure the safety of the equipment) → stop loading, and the gap returns to zero.

[0024] S3, rolling mill reverse rotation rigidity test: click reverse creeping → start rigidity test → when the unilateral rolling force reaches 18000 kN → stop loading, and when the gap returns to zero, query the process trend chart → collect the test curve result as Figure 1

[0025] S4, data acquisition: export the corresponding data of rolling force and gap during the test period from the PDA process data acquisition system, and take the data of unilateral rolling force greater than 7000 kN (take the data of unilateral rolling force greater than 7000 kN to remove the influence of the non-linear stage on the test accuracy).

[0026] ​S5, data processing and analysis: using data analysis software (optional Origin9.1, Excel at least one) for linear fitting of the slope is the stiffness of the running mill at this time Figures 2-5 and refer to the following table 1 and table 2:

[0027] Table 1: roughing mill stiffness test results table

[0028]

[0029] Table 2: finishing mill stiffness test results table

[0030] 1st Drive side Roll change side Relative difference 2nd Drive side Roll change side Relative difference Forward rotation 3544 3758 -5.86％ Forward rotation 3559 3811 -6.84％ Reverse rotation 3434 3803 -10.20％ Reverse rotation 3440 3795 -9.81％ Relative difference 3.15％ -1.19％ Relative difference 3.40％ 0.42％

[0031] The above description is only to illustrate the technical solutions of the present application, not to limit, the ordinary skilled in the art of the technical solutions of the present application of other modifications or equivalent replacement, as long as not departing from the spirit and scope of the technical solutions of the present application, should be covered in the scope of the claims of the present application.

Claims

1. A method for testing the rigidity of a four-high reversing hot rolling mill, characterized in that: The specific steps of the test method are as follows: S1, the rolling mill is pre-pressed against zero, specifically: Before the rolling stiffness test, first adjust the inclination intervention on both sides of the roll gap to zero, set the rolling force to zero, switch the main interface picture to the zero state, select "automatic zero selection" in the zero interface, click start zeroing, and then click terminate zeroing when the two rollers of the rolling mill are pressed together; S2, rolling mill positive rotation stiffness test, specifically: The rolling mill is set to the creeping state, start the stiffness test, and stop loading when the unilateral rolling force reaches 18000 kN, and the roll gap returns to zero; S3, rolling mill reverse rotation stiffness test, specifically: Click reverse creep, start the stiffness test, and stop loading when the unilateral rolling force reaches 18000 kN, and the roll gap returns to zero, query the process trend chart, and collect the test curve results; S4, data collection, specifically: Export the corresponding data of rolling force and roll gap during the test period from the PDA process data collection system, and take the data of unilateral rolling force greater than 7000 kN; S5, data processing and analysis, specifically: Use data analysis software to perform linear fitting to obtain the slope, which is the stiffness of the running rolling mill.

2. A method of testing the rigidity of a four-high reversing hot rolling mill according to claim 1, characterized in that: In S1, when the two rollers of the rolling mill are pressed together, the roll gap is displayed as 0 value.

3. A method of testing the rigidity of a four-high reversing hot rolling mill according to claim 1, characterized in that: In S2, the creeping speed of the rolling mill is set to 10 rad / min, the rolling force is set to be loaded uniformly at a speed of 300 kN / s, and when the unilateral rolling force reaches 18000 kN, the loading is stopped at a total rolling force of 36000 kN on both sides, which achieves the purpose of ensuring the safety of the equipment.

4. The method of claim 1, wherein the four-high reversing hot rolling mill is a hot strip mill. In S4, the data of unilateral rolling force greater than 7000 kN is taken to remove the influence of the non-linear stage on the test accuracy.

5. The method of claim 1, wherein the four-high reversing hot rolling mill is a hot strip mill. In S5, at least one of Origin 9.1 and Excel can be used as the data analysis software.

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