A Cold Rolling Strip Ribbing Risk Early Warning Method Based on Hot Rolling Incoming Material Data

Abstract

The present invention relates to a method for warning of the risk of ribbing in cold-rolled strip steel based on hot-rolled incoming material data, including steps such as reading camber data, wedge data, and thickness data, and making judgments according to process requirements. The method for warning of the risk of ribbing in cold-rolled strip steel based on hot-rolled incoming material data provided by the present invention utilizes the data of hot-rolled incoming materials to achieve pre-identification of the risk of ribbing and to react in advance to the risk of ribbing.

Description

Technical Field

[0001] The present invention relates to a method for warning the risk of ribbing in cold-rolled strip based on hot-rolled incoming material data, belonging to the technical field of automatic control. Background Art

[0002] The "ribbing" problem is a very complex problem, facing difficulties such as numerous influencing factors, complex processes, and unclear mechanisms. In terms of technology, both the hot-rolling process and the cold-rolling process may be important factors affecting "ribbing". Among them, in the hot-rolling aspect, the geometric characteristics of the strip after hot-rolling (such as local high points, etc.) are mainly involved. However, for the current pickling-cold rolling tandem mill, there is no complete risk identification and monitoring system for ribbing after rolling that can identify and pre-control risks for hot-rolled incoming material factors. As a result, additional waviness is generated in the strip after rolling, affecting the shape and surface quality of the strip, and even causing product downgrading or scrapping.

[0003] There are still many technical difficulties in the risk identification and pre-control system for ribbing after rolling:

[0004] (1) Due to the information barrier between the hot-rolling and cold-rolling processes, it is difficult for cold rolling to obtain hot-rolling data, and the information in the hot-rolling quality data cannot be fully explored.

[0005] (2) The "ribbing" problem is very complex, and there are many influencing factors for hot-rolled incoming materials. It is difficult to organically combine all the influencing factors of incoming materials.

[0006] Based on the above characteristics, due to the lack of unified management and information exploration of hot-rolled incoming material quality data, and the complex ribbing mechanism, there is no effective risk identification and pre-control means for the ribbing problem after rolling at the present stage. For the coiled strips with ribbing, they can only be processed by downgrading or scrapping.

[0007] If the risk of ribbing is to be identified, the main problem to be solved first is to obtain accurate hot-rolled incoming material quality data with positioning in the length direction. Thickness gauges and other measuring devices are installed on both sides of the outlet of the last finishing mill in the hot strip mill production line to collect a series of quality data of the strip in real time during hot-rolling production. After classifying and archiving the data, the hot-rolling quality data is transmitted to the cold-rolling end through the core switch, optical-electric converter and firewall.

[0008] The ribbing defect refers to a "bulge" phenomenon formed on the surface of the steel coil due to the cumulative local characteristics of the strip during the coiling process. For the ribbing buckling behavior of the strip, according to the different positions of the "ribs" on the surface of the steel coil, the actual situation can be divided into two types: middle ribs and edge ribs. The ribbing area is mainly concentrated in the middle of the strip, and there are 3 - 5 ribs distributed transversely along the strip. The interval between the ribs varies from 20 to 50 mm and exists along the entire length direction. Occasionally, there may also be ribbing at the edges. The direct consequence of ribbing is the generation of local additional waviness on the strip surface after uncoiling, which seriously affects the appearance and service performance of the product. Summary of the Invention

[0009] The technical problem to be solved by the present invention is: to overcome the above-mentioned technical drawbacks and provide a method for warning the risk of ribbing in cold-rolled strip based on hot-rolled incoming material data.

[0010] To solve the above-mentioned technical problem, the technical solution proposed by the present invention is: a method for warning the risk of ribbing in cold-rolled strip based on hot-rolled incoming material data, including the following steps:

[0011] Step 1: Read the full-length hot convexity data measured at the hot-rolled exit of the strip to be cold-rolled. The measurement interval of the full-length hot convexity data is 1 meter; calculate the convexity mean value of the strip after removing the data at the head and tail of 4m in the full-length direction. : ; Select the maximum convexity value and the minimum convexity value in the data after removing the data at the head and tail of 4m in the full-length direction of the strip. and the minimum convexity value ;

[0012] Step 2: Read the full-length wedge data measured at the hot-rolled exit of the strip. The measurement interval of the full-length wedge data is 1 meter; calculate the wedge mean value of the strip after removing the data at the head and tail of 4m in the full-length direction: ;

[0013] Step 3: Read the cross-sectional thickness data measured at the hot-rolled exit of the strip. ; Wherein i is the position in the length direction, j is the position in the width direction, the measurement interval in the length direction is 1m, and the measurement interval in the width direction is 5mm; calculate the thickness difference between adjacent two points in the width direction of the cross-section:

[0014] Step 4: After starting rolling, monitor the convexity data of the strip except for the 4m at the head and tail. The determination condition for the abnormal full-length mean value of the convexity is: ; Wherein, It is the limit of the average convexity specified in the process according to the steel type and specifications of the current strip; the determination condition for the abnormal maximum convexity is: ;

[0015] where C is the limit of the maximum convexity specified in the process according to the steel type and specifications of the current strip; the determination condition for the abnormal minimum convexity is: ; where, is the limit of the minimum convexity specified in the process according to the steel type and specifications of the current strip;

[0016] Step 5: The determination condition for the abnormal average wedge is: ; where, is the limit of the average wedge specified in the process according to the steel type and specifications of the current strip;

[0017] Step 6: The determination condition for the abnormal thickness difference between two adjacent points in the cross-sectional width direction is: ; where, is the limit of the thickness difference between two adjacent points in the cross-sectional width direction specified in the process according to the steel type and specifications of the current strip;

[0018] Step 7: According to the abnormal determinations in Step 4, Step 5, and Step 6, give an early warning when an abnormality occurs..

[0019] A further improvement of the above solution is that in the said Step 1, the measurement position of the full-length hot convexity data is at a position 40 mm from the strip edge in the width direction.

[0020] A further improvement of the above solution is that in the said Step 2, the measurement position of the full-length wedge data is at a position 40 mm from the strip edge in the width direction.

[0021] The cold-rolled strip ribbing risk early warning method based on hot-rolled incoming material data provided by the present invention utilizes the data of hot-rolled incoming materials to realize the pre-identification of ribbing risks and to react in advance to ribbing risks. Specific Embodiments Embodiment

[0022] The cold-rolled strip ribbing risk early warning method based on hot-rolled incoming material data in this embodiment includes the following steps:

[0023] Step 1: Read the full-length hot convexity data measured at the hot-rolled exit of the strip to be cold-rolled , and the measurement interval of the full-length hot convexity data is 1 meter; calculate the average convexity of the strip in the full-length direction after removing the data at the head and tail for 4 m : ; select the maximum convexity value from the data at the head and tail for 4 m removed in the full-length direction of the strip and the minimum camber ;

[0024] Step 2: Read the full-length wedge data measured at the hot rolling exit of the strip , and the measurement interval of the full-length wedge data is 1 m; calculate the average wedge value after removing the data at both ends of 4 m in the full length direction of the strip: ;

[0025] Step 3: Read the cross-sectional thickness data measured at the hot rolling exit of the strip ; where i is the position in the length direction, j is the position in the width direction, the measurement interval in the length direction is 1 m, and the measurement interval in the width direction is 5 mm; calculate the thickness difference between adjacent two points in the width direction of the cross-section:

[0026] Step 4: After starting rolling, monitor the camber data except for the 4 m at both ends of the strip. The determination condition for the abnormal average value of the full-length camber is: ; where, is the limit of the average camber value specified in the process according to the steel grade and specification of the current strip; the determination condition for the abnormal maximum camber is: ;

[0027] where is the limit of the maximum camber value specified in the process according to the steel grade and specification of the current strip; the determination condition for the abnormal minimum camber is: ; where, is the limit of the minimum camber value specified in the process according to the steel grade and specification of the current strip;

[0028] Step 5: The determination condition for the abnormal average wedge value is: ; where, is the limit of the average wedge value specified in the process according to the steel grade and specification of the current strip;

[0029] Step 6: The determination condition for the abnormal thickness difference between adjacent two points in the width direction of the cross-section is: ; where, is the limit of the thickness difference between adjacent two points in the width direction of the cross-section specified in the process according to the steel grade and specification of the current strip;

[0030] Step 7: According to the abnormal determinations in Step 4, Step 5 and Step 6, give an early warning when an abnormality occurs..

[0031] In Step 1, the measurement position of the full-length hot camber data is at a position 40 mm away from the strip edge in the width direction.

[0032] In Step 2, the measuring position of the full-length wedge data is at a position 40 mm from the strip edge in the width direction.

[0033] Taking actual production as an example for illustration.

[0034] Basic information of the steel coil: the length is 1200 m, the width is 1000 mm, and the abnormal judgment limits for the various indexes specified for the steel grade of this coil of steel according to the relevant process are: is 30 ; is 40 ; is 20 ; is 30 , is 12 .

[0035] Obtain the full-length camber data and wedge data in the length direction of the hot-rolled incoming material from the hot-rolled data acquisition and storage platform, and calculate that the average value of the full-length camber = 28.5632, the maximum camber value = 42.6658 at 21 m from the strip head, the minimum camber value = 16.6223 at 106 m from the strip tail, and the average value of the full-length wedge = -6.39436.

[0036] Take the cross-sectional thickness data, as shown in the following subscripts (only part of the data is shown):

[0037]

[0038] Calculate the thickness difference data between two adjacent points in the cross-section, as shown in the following table (only part of the data is shown):

[0039]

[0040] Make a judgment according to Step 4 and Step 5, and the judgment results are shown in the following table:

[0041]

[0042] Make a judgment according to Step 6, and the judgment results are shown in the following table:

[0043]

[0044] Based on the above judgment results, the maximum camber value exceeds the limit, and the exceeding position is at 21 m from the head; the thickness difference between two adjacent points in the cross-section exceeds the limit, and the exceeding position is at 83 m from the head; that is, there is a risk of ribbing at the positions 21 m from the head and 83 m.

[0045] The present invention is not limited to the above embodiments. Any technical solution formed by equivalent replacement falls within the protection scope required by the present invention.

Claims

1. A method for early warning of the risk of ribbing in cold-rolled strip steel based on hot-rolled incoming material data, characterized in that, it includes the following steps: Step 1: Read the full-length hot convexity data measured at the hot rolling exit of the strip to be cold rolled , the measurement interval of the full-length hot convexity data is 1 m; calculate the convexity mean value of the strip data after removing the head and tail 4 m data in the full-length direction : ; Select the maximum value of the crown in the data obtained by removing the head and tail 4 m in the entire length direction of the strip steel and the minimum value of the crown ; Step 2: Read the full-length wedge data measured at the hot rolling exit of the strip steel , the measurement interval of the full-length wedge data is 1 m; calculate the wedge mean value of the strip steel after removing the data at both ends for 4 m in the full-length direction: ; Step 3: Read the cross-sectional thickness data measured at the hot rolling exit of the strip steel ; where i is the position in the length direction, j is the position in the width direction, the measurement interval in the length direction is 1 m, and the measurement interval in the width direction is 5 mm; calculate the thickness difference between two adjacent points in the width direction of the cross section: Step 4: After starting rolling, monitor the crown data except for the head and tail 4 m of the strip. The determination condition for the abnormal overall mean value of the crown is: ; where is the limit of the mean crown value specified in the process according to the steel grade and specifications of the current strip. The determination condition for the abnormal maximum crown value is: ; Among which C is the limit of the maximum camber value specified in the process according to the steel grade and specification of the strip steel; the determination condition for the abnormal minimum camber value is: ; among which, is the limit of the minimum camber value specified in the process according to the steel grade and specification of the current strip steel; Step 5: The determination condition for the wedge mean anomaly is as follows: ; where is the limit of the wedge mean specified in the process according to the steel type and specifications of the current strip. Step 6: The determination condition for the abnormal thickness difference between two adjacent points in the cross-sectional width direction is: ; where is the limit of the thickness difference between two adjacent points in the cross-sectional width direction specified in the process according to the steel type and specification of the current strip. Step 7: According to the abnormality judgments in Step 4, Step 5 and Step 6, give an early warning when an abnormality occurs.

2. The method for early warning of the risk of ribbing in cold-rolled strip steel based on hot-rolled incoming material data according to Claim 1, characterized in that: In the said Step 1, the measuring position of the full-length hot convexity data is at a position 40 mm away from the strip edge in the width direction.

3. The method for early warning of the risk of ribbing in cold-rolled strip steel based on hot-rolled incoming material data according to Claim 1, characterized in that: In the said Step 2, the measuring position of the full-length wedge data is at a position 40 mm away from the strip edge in the width direction.

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