JP4686924B2 - Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet - Google Patents

Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet Download PDF

Info

Publication number
JP4686924B2
JP4686924B2 JP2001223744A JP2001223744A JP4686924B2 JP 4686924 B2 JP4686924 B2 JP 4686924B2 JP 2001223744 A JP2001223744 A JP 2001223744A JP 2001223744 A JP2001223744 A JP 2001223744A JP 4686924 B2 JP4686924 B2 JP 4686924B2
Authority
JP
Japan
Prior art keywords
thickness
steel sheet
hot
measuring
rolled steel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2001223744A
Other languages
Japanese (ja)
Other versions
JP2003035530A (en
Inventor
智之 加藤
行弘 岡田
淳 川原
Original Assignee
Jfeスチール株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jfeスチール株式会社 filed Critical Jfeスチール株式会社
Priority to JP2001223744A priority Critical patent/JP4686924B2/en
Publication of JP2003035530A publication Critical patent/JP2003035530A/en
Application granted granted Critical
Publication of JP4686924B2 publication Critical patent/JP4686924B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thickness measurement method, thickness measurement apparatus, and thickness control method for a hot rolled steel sheet.
[0002]
[Prior art]
When manufacturing steel sheets, first perform hot rolling in the hot rolling line, and then perform cold rolling in the cold rolling line or perform refining work (cold) in the refining line. I try to get the final product.
[0003]
In the hot rolling line, the thickness of the steel sheet immediately after hot rolling is measured, and the thickness of the steel sheet to be rolled next is controlled based on the measured thickness. The thickness of the steel sheet in the hot rolling is measured by measuring the temperature of the object to be measured at a high temperature close to 1000 ° C., scattering of moisture and water vapor into the atmosphere by various cooling waters, and scaling from the steel sheet being rolled. And the environment around the measurement site is inferior to the plate thickness measurement, and so on, using a radiation plate thickness meter such as X-rays or γ-rays at the exit of the hot rolling mill. The plate thickness is measured.
[0004]
Plate thickness measurement using radiation such as X-rays or γ-rays utilizes the principle that radiation passes through a steel sheet in a non-contact manner, and the amount of radiation transmitted changes according to the plate thickness. In general, assuming that the output of the radiation sensor when there is no steel plate is I 0 , the output I of the radiation sensor when a steel plate having a thickness of h exists is obtained by the following equation (1).
[0005]
I = I 0 exp (−μh) (1)
However, μ: Linear absorption coefficient of the steel sheet Further, the linear absorption coefficient μ of the steel sheet in the above expression (1) is obtained by the following expression (2).
μ = μ m ρ ............ (2 )
However, mu m: the mass absorption coefficient of the steel sheet [rho: In the plate thickness measurement by the density radiation thickness gauge of the steel sheet, the density of the steel sheet described above [rho, the linear absorption coefficient mu or mass absorption coefficient mu m is not given properly The true plate thickness cannot be measured. Such a density ρ and thickness measuring method of a steel plate using a mass absorption coefficient mu m proper steel sheet, there is a plate thickness measuring method disclosed in Japanese Patent Kokoku 5-15206.
[0006]
This plate thickness measurement method is a method for measuring the plate thickness of a steel plate by radiation.In calculating the plate thickness of the steel plate by calculation, the steel component configuration is analyzed for each measurement target steel plate and preset based on the analysis result. The density and mass absorption coefficient of the steel plate are calculated by the calculated equation, and the plate thickness of the steel plate is measured using the calculation result.
[0007]
In the thickness measuring method, the mass absorption coefficient mu m is expressed by the following equation (3).
[0008]
[Expression 1]
[0009]
However, mu m: the mass absorption coefficient mu mi of the measurement target steel sheet: the mass absorption coefficient of the steel component constituent element i A i: configuration percentage of steel constitutional elements i (%)
Moreover, the steel plate density ρ is expressed by the following equation (4).
[0010]
[Expression 2]
[0011]
Where ρ is the density of the steel sheet to be measured ρ s is the density of pure iron (≈7.86 g / cm 3 )
a i : An influence coefficient on A i , which is determined theoretically or empirically.
[0012]
In the above equation (3), A i is the constituent percentage (%) of the steel component constituent element i, and therefore can be input in advance from the material information providing computer to the hot radiation thickness gauge. In addition, since the mass absorption coefficient μ mi of the steel component constituent element i can also be input in advance to the hot radiation thickness gauge, the experimental value described in the Riken Handbook etc., the mass absorption coefficient μ m of the steel plate to be measured Is obtained by the equation (3).
[0013]
In the above (4), since the [rho s and A i is known, knowing the influence coefficient a i get to A i, the density [rho measurement target steel sheet Motomari, therefore, the plate thickness from the equation (2) h can be calculated backward.
[0014]
[Problems to be solved by the invention]
However, the steel plate thickness measuring method disclosed in the above-mentioned Japanese Patent Publication No. 5-15206 has the following problems. The value of ρ obtained by the above equation (3) cannot be obtained unless the influence coefficients a i for all steel component constituent elements are determined. However, Japanese Patent Publication No. 5-15206 discloses C, Si, Only the coefficient for Mn is shown, and in the case of a steel type that includes components other than these components, it is necessary to determine the coefficient corresponding to that component.
[0015]
Normally, steel is composed of 10 or more components. Therefore, when an influence coefficient a i for each component is sought experimentally using a test piece, each component has a content ratio of 2 levels or more. Since it is necessary to prepare different test pieces, at least 20 kinds of test pieces are required, and much labor is required to determine the influence coefficient a i for each component.
[0016]
Further, when manufacturing a steel sheet containing a new component, a procedure for obtaining the influence coefficient a i again is necessary.
[0017]
The present invention has been made to solve the above-described problems of the prior art, and is a hot-rolled steel sheet thickness measuring method, sheet thickness measuring apparatus, and sheet that can easily determine the a i. The object is to provide a thickness control method.
[0018]
[Means for Solving the Problems]
The method for measuring the thickness of a hot-rolled steel sheet according to the present invention is a method for measuring the thickness of a hot-rolled steel sheet in manufacturing a steel sheet that undergoes a hot-rolling process and a cold-treatment process,
The cold treatment process is equipped with a laser distance meter type thickness gauge and a cold radiation thickness gauge,
The true plate thickness of the steel plate measured by the laser distance meter type thickness gauge, the output of the radiation sensor of the cold radiation plate thickness meter when the steel plate is present, the constituent ratio of each component of the steel plate and the By measuring and calculating the mass absorption coefficient of the steel sheet obtained from the mass absorption coefficient of each constituent component by the number equal to the number of each constituent component, and solving the simultaneous equations based on the measured and calculated data, By calculating the influence coefficient a i related to the composition ratio and inputting the calculated influence coefficient a i into the hot radiation thickness gauge provided for the hot rolling step, the thickness measurement of the hot rolled steel sheet is performed. Is what you do .
[0019]
Moreover, the hot rolled steel sheet thickness measuring apparatus according to the present invention is a hot rolled steel sheet thickness measuring apparatus in steel sheet production through a hot rolling process and a cold processing process,
A laser distance meter thickness gauge and a cold radiation thickness gauge in preparation for the cold treatment process;
The true plate thickness of the steel plate measured by the laser distance meter type thickness gauge, the output of the radiation sensor of the cold radiation plate thickness meter when the steel plate is present, the constituent ratio of each component of the steel plate and the By measuring and calculating the mass absorption coefficient of the steel sheet obtained from the mass absorption coefficient of each constituent component by the number equal to the number of each constituent component, and solving the simultaneous equations based on the measured and calculated data, An influence coefficient computing device for calculating an influence coefficient a i related to the composition ratio ;
A hot radiation thickness meter that measures the thickness of the hot-rolled steel sheet in the hot rolling process using the influence coefficient a i calculated by the influence coefficient computing device .
[0020]
Moreover, the thickness control method of the hot-rolled steel sheet according to the present invention controls the thickness of the hot-rolled steel sheet based on the thickness measured by the thickness measuring device for the hot-rolled steel sheet.
[0021]
In the method for measuring the thickness of a hot-rolled steel sheet according to the present invention, the influence coefficient a i for each component when determining the density of the steel sheet is determined using a cold radiation thickness gauge and a laser distance meter type thickness gauge. Since the measured thickness of the steel sheet in the hot rolling process is measured using the measured radiation output and the actual measured value of the sheet thickness and using the obtained influence coefficient a i , the sheet thickness measurement accuracy in the hot state Will improve.
[0022]
Further, since the plate thickness measurement accuracy is improved, the accuracy of hot plate thickness control based on the measurement value is also improved.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a thickness measuring apparatus for hot rolled steel sheets according to the present invention will be described with reference to FIG. FIG. 1 is an explanatory view showing an embodiment of a thickness measuring apparatus for hot rolled steel sheets according to the present invention. This steel sheet thickness measuring apparatus includes a cold radiation thickness gauge 2 and a laser type thickness gauge 3 that measure the thickness of a steel sheet in the cold refining step 1 of the steel sheet, and a cold radiation thickness gauge. The output of the radiation sensor when there is no steel plate obtained by the total 2 is I 0 , the output I j of the radiation sensor when the steel plate is present, and the plate thickness h j obtained by the laser type plate thickness meter 3 from the influence coefficient calculating unit 4 for calculating the influence factor a i, using the influence coefficient a i sent from the influence coefficients calculation unit 4, measuring the thickness h of the hot rolled steel sheet by hot rolling step 5 It is comprised from the hot radiation plate thickness meter 6 which does. In FIG. 1, reference numeral 7 is a sheet thickness control device (AGC) that controls the thickness h of the hot-rolled steel sheet in the hot rolling process 5, and reference numeral 8 is material information that provides material information (component composition, etc.) of the steel sheet. Provided calculator.
[0024]
Next, a method for measuring the thickness of the hot-rolled steel sheet and controlling the thickness using the above-described hot-rolled steel sheet thickness measuring device will be described.
[1] In the cold treatment step, the cold radiation plate thickness meter 2 measures the output I j of the radiation sensor when the steel plate j is present, and inputs the signal to the influence coefficient calculation device 4.
[2] At the same time, the laser plate thickness meter 3 provided in the vicinity of the cold radiation thickness meter 2 measures the true thickness h j of the steel plate j, and the signal is used as the influence coefficient calculation device 4. To enter.
[3] The component configuration of the plate thickness measurement target steel plate j, the component ratio A ij of each component, and the mass absorption coefficient μ i of each component are input in advance to the influence coefficient calculation device 4 from the material information providing computer 9. Therefore, using these numerical values, the mass absorption coefficient μ j of the steel plate j is calculated based on the following equation (5).
[0025]
[Equation 3]
[0026]
[4] The density ρ j of the steel plate j is measured based on the formula (6) using the measured values I 0 (preliminarily input), I j and h j and μ j calculated based on the formula ( 3 ). Calculate.
ρ j = {1 / (μ j · h j )} × ln (I 0 / I j ) (6)
[5] On the other hand, ρ j is expressed by the following equation (7) based on the above-described equation ( 4 ).
[0027]
[Expression 4]
[0028]
Therefore, using ρ j obtained by equation (6), for the unknown a i ,
The following simultaneous equations (8) to (n) are solved to obtain a i .
[0029]
[Equation 5]
[0030]
Since the number of components used in the steel sheet is about 20 at most, if data of 20 or more steel sheets is accumulated, this simultaneous equation can be solved, and thereafter, it is estimated gradually by regression. Accuracy will improve.
[6] The value of a i obtained by the above simultaneous equations is input from the mass absorption coefficient / density calculation device 4 to the hot radiation plate thickness meter 5, and the thickness of the hot-rolled steel plate is calculated based on the equation (1). Find h.
[7] Furthermore, the thickness h obtained by the hot radiation thickness gauge 5 is fed back to the hot thickness control device (AGC) 7 and the thickness of the steel sheet rolled in the hot rolling process is controlled. I do.
[0031]
FIG. 2 is a diagram showing the distribution of the thickness of a steel sheet to be hot-rolled. (A) shows a case where the true thickness can be measured, and (b) shows a conventional method using a hot radiometer thickness gauge. In the case of measurement, (c) is a case of measurement by the method of the present invention using a hot radiometer thickness gauge.
As shown in FIG. 2A, when the true plate thickness can be measured, a normal distribution as shown by a curve B centered on the average value A is obtained. A range exceeding the upper limit C of the allowable thickness tolerance of the product and a range below the lower limit D of the allowable thickness tolerance of the product are rejected, resulting in a yield loss. In the plate thickness control of the steel plate, the plate thickness control is usually performed to reduce the standard deviation of the normal distribution in order to reduce this loss.
[0032]
In the conventional thickness measuring method that does not measure the true thickness, the average value E slightly deviates from the average value A as shown in FIG. 2 (b). In the case of FIG. Is a normal distribution curve F, and the range below the lower limit D of the allowable sheet thickness tolerance of the product increases, and the loss greatly increases.
When measured by the method of the present invention, the average value G becomes a normal distribution curve H closer to the average value A, as shown in FIG. The yield loss is greatly reduced compared to the conventional method.
[0033]
【The invention's effect】
According to the present invention, since the influence coefficient of the component when obtaining the density of the steel sheet can be easily obtained, the precision of the thickness measurement in the hot rolling can be improved, and the precision of the thickness control is accordingly improved. Yield loss is greatly reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of a thickness measuring apparatus for hot rolled steel sheets according to the present invention.
FIG. 2 is a diagram showing the distribution of the thickness of a steel sheet to be hot-rolled, where (a) shows a true method for measuring the true thickness, and (b) shows a conventional method using a hot radiometer thickness gauge. (C) is a case where it measures by the method of this invention with a hot radiometer thickness gauge.
[Explanation of symbols]
1 Cold refining process 2 Cold radiation thickness gauge 3 Laser-type thickness gauge 4 Influence coefficient calculator 5 Hot rolling process 6 Hot radiation thickness gauge 7 Sheet thickness controller (AGC)
8 Material information provision computer

Claims (3)

  1. A method for measuring the thickness of a hot rolled steel sheet in the production of a steel sheet through a hot rolling process and a cold processing process,
    The cold treatment process is equipped with a laser distance meter type thickness gauge and a cold radiation thickness gauge,
    The true plate thickness of the steel plate measured by the laser distance meter type thickness gauge, the output of the radiation sensor of the cold radiation plate thickness meter when the steel plate is present, the constituent ratio of each component of the steel plate and the By measuring and calculating the mass absorption coefficient of the steel sheet obtained from the mass absorption coefficient of each constituent component by the number equal to the number of each constituent component, and solving the simultaneous equations based on the measured and calculated data, By calculating the influence coefficient a i related to the composition ratio and inputting the calculated influence coefficient a i into the hot radiation thickness gauge provided for the hot rolling step, the thickness measurement of the hot rolled steel sheet is performed. A method for measuring the thickness of a hot-rolled steel sheet, comprising:
  2. A device for measuring the thickness of a hot-rolled steel sheet in the production of a steel sheet that undergoes a hot-rolling process and a cold-treatment process,
    A laser distance meter thickness gauge and a cold radiation thickness gauge in preparation for the cold treatment process;
    The true plate thickness of the steel plate measured by the laser distance meter type thickness gauge, the output of the radiation sensor of the cold radiation plate thickness meter when the steel plate is present, the constituent ratio of each component of the steel plate and the By measuring and calculating the mass absorption coefficient of the steel sheet obtained from the mass absorption coefficient of each constituent component by the number equal to the number of each constituent component, and solving the simultaneous equations based on the measured and calculated data, An influence coefficient computing device for calculating an influence coefficient a i related to the composition ratio ;
    Hot rolling comprising a hot radiation plate thickness meter that measures the thickness of a hot rolled steel sheet in the hot rolling step using the influence coefficient a i calculated by the influence coefficient computing device Steel sheet thickness measuring device.
  3.   A thickness control method for a hot rolled steel sheet, comprising controlling the thickness of the hot rolled steel sheet based on the thickness measured by the thickness measuring device for the hot rolled steel sheet according to claim 2.
JP2001223744A 2001-07-25 2001-07-25 Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet Expired - Fee Related JP4686924B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001223744A JP4686924B2 (en) 2001-07-25 2001-07-25 Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001223744A JP4686924B2 (en) 2001-07-25 2001-07-25 Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet

Publications (2)

Publication Number Publication Date
JP2003035530A JP2003035530A (en) 2003-02-07
JP4686924B2 true JP4686924B2 (en) 2011-05-25

Family

ID=19057024

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001223744A Expired - Fee Related JP4686924B2 (en) 2001-07-25 2001-07-25 Thickness measuring method, thickness measuring device and thickness control method for hot rolled steel sheet

Country Status (1)

Country Link
JP (1) JP4686924B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE502007004215D1 (en) * 2006-12-15 2010-08-05 Fraunhofer Ges Forschung Method and device for thickness measurement
JP5459175B2 (en) * 2010-10-28 2014-04-02 新日鐵住金株式会社 Steel sheet thickness measuring method, sheet thickness calculating device and program

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60164202A (en) * 1984-02-06 1985-08-27 Sumitomo Metal Ind Ltd Thickness measuring method of double layered materials
JPS62194410A (en) * 1986-02-21 1987-08-26 Sumitomo Metal Ind Ltd Measurement of thickness of steel plate
JPH04273010A (en) * 1991-02-28 1992-09-29 Kawasaki Steel Corp Measurement of plate thickness of thick plate

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60164202A (en) * 1984-02-06 1985-08-27 Sumitomo Metal Ind Ltd Thickness measuring method of double layered materials
JPS62194410A (en) * 1986-02-21 1987-08-26 Sumitomo Metal Ind Ltd Measurement of thickness of steel plate
JPH04273010A (en) * 1991-02-28 1992-09-29 Kawasaki Steel Corp Measurement of plate thickness of thick plate

Also Published As

Publication number Publication date
JP2003035530A (en) 2003-02-07

Similar Documents

Publication Publication Date Title
Hartley et al. Measurement of the temperature profile during shear band formation in steels deforming at high strain rates
Beynon et al. Modelling microstructure and its effects during multipass hot rolling
EP2350627B1 (en) Method for detecting defect in material and system for the method
US6013915A (en) Process control by transient thermography
US7617709B2 (en) Apparatus for controlling materials quality in rolling, forging, or leveling process
EP1899085B1 (en) Method and device for optimization of flatness control in the rolling of a strip
CN101590489B (en) Board width controller of hot rolling mill and control method thereof
KR101362300B1 (en) Steel plate quality assurance system
Wang et al. FEM analysis for residual stress prediction in hot rolled steel strip during the run-out table cooling
JP4685777B2 (en) Wedge setting and control method in sheet metal rolling
US20070006625A1 (en) Method and control device for operating a mill train for metal strip
CN100493749C (en) Roughed plate bloom temperature control method in hot-rolled process
Dziallach et al. Sheet metal testing and flow curve determination under multiaxial conditions
CN105203731B (en) A kind of strip steel cross-sectional outling defect local high spot quantization method and device
JP4997263B2 (en) Hot rolling simulation apparatus and rolling history simulation method
JP2005297015A (en) Winding temperature controller
Gorji et al. Modeling of localization and fracture phenomena in strain and stress space for sheet metal forming
US8539804B2 (en) Method and device for controlling a roll gap
DE102011082158A1 (en) Casting, in particular continuous casting
JP4523010B2 (en) Steel plate manufacturing method
JPWO2008012881A1 (en) Material prediction and material control device for rolling line
TWI412411B (en) Method for adjusting flatness and/or roughness of metal strip and lubricant applying device
DE19930173A1 (en) Method and device for the process-optimized setting of parameters of a production process
Lazarescu et al. Analytical and experimental evaluation of the stress-strain curves of sheet metals by hydraulic bulge tests
EP3100802B1 (en) Method, device and program for determining casting state in continuous casting

Legal Events

Date Code Title Description
RD01 Notification of change of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7421

Effective date: 20060921

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20080423

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20100917

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100928

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20101125

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20110118

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20110131

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140225

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees