JP2007262502A - Method and apparatus for controlling alloying degree by alloying furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for controlling alloying degree by an alloying furnace, which allows easy adjustment of parameters and has high accuracy in the estimation of the output of the alloying furnace. <P>SOLUTION: The method for controlling the alloying degree by the alloying furnace includes: a database creating process for storing performance data of input items and output items as a database; a request point data inputting process for inputting, as request point data, the data of the input items of a steel sheet to be plated being coated from now; a neighbor data selection process comprising calculating the distance between all data in the database and the request point data and selecting one or more data as neighbor data in the order of shorter calculated distance; an alloying furnace output determination process for determining the output of the alloying furnace for the steel sheet to be plated being coated from now based on the selected neighbor data; and a database updating process for adding new performance data to the database or renewing the database every time when coating is performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention automatically controls the degree of alloying in the plating layer to an alloying furnace output suitable for the target degree of alloying when the alloying treatment of the hot dip galvanized steel sheet is performed in the alloying furnace. The present invention relates to an alloying degree control method and apparatus using an alloying furnace.

  The hot dip galvanized steel sheet is immersed in a hot dip galvanizing bath, and after adjusting excess zinc adhering to the surface of the steel sheet to an appropriate amount of adhesion using the squeezing device, the steel sheet is immediately heated in an alloying furnace, It is performed by rapidly cooling after holding and diffusing iron from the steel sheet to the adhered zinc layer. However, when the heating temperature of the induction heating zone in the alloying furnace is not appropriate, the quality characteristic of the plating is lost, and therefore the induction heating zone is required to be controlled with high accuracy. For this reason, conventionally, various techniques for controlling the temperature of the induction heating zone with higher accuracy have been disclosed.

  For example, in Patent Document 1, based on the principle of induction heating, from the target values of the plate thickness, the plate width and the composition of the steel plate, the moving speed, the plate temperature, and the coating amount of the hot dip galvanized layer, the amount of power to be applied Po Is calculated with a power calculation unit and the characteristics of the alloying process are taken into account, and the amount of hot-dip galvanized layer, the temperature of the hot-dip galvanizing bath, the temperature of the induction galvanizing bath, the induction heating type alloying furnace Is obtained by calculating the power correction value ΔP with the power correction amount calculation device and the power calculation device with the correction value ΔP from the actual values of the moving speed and plate temperature of each steel plate. A technique is disclosed in which the electric power P is input to the induction heating coil.

  In Patent Document 2, hot galvanizing is performed on a steel strip that is continuously conveyed, adjusted to a predetermined plating adhesion amount, and then alloyed in an induction heating alloying furnace, the alloying power is changed to the steel type, plate A technique of controlling to a value obtained from the following equation which is a function of thickness, sheet width, line speed, adhesion amount, and degree of alloying is disclosed.

Alloying furnace power (kW) = a0 x plate thickness ^a1 x plate width ^a2 x line speed ^a3 x deposition amount ^a4 x alloying degree ^a5 (however, a0 to ^a5 are constants given for each steel type)
Furthermore, in patent document 3, in the alloying control of the hot-dip galvanization equipment which has an induction heating apparatus which heats a galvanized steel plate, a tropical zone, and a cooling zone one by one, the preset target plate temperature of the induction heating apparatus exit side and A required heat amount in the induction heating device is calculated on the basis of the plate passing condition, and a power command setter is provided for instructing the input power amount to the induction heating device by adding the heating coil efficiency to the required heating amount, A plate thermometer is installed in the vicinity of the exit side and furnace thermometers are installed at multiple locations in the tropical region, and the temperature of the induction heating device exit side is calculated using the measured results of the plate thermometer and the furnace thermometer. Has been disclosed that corrects the target plate temperature of the power command setter based on the value calculated by the plate temperature correction calculator and corrects the amount of power input to the induction heating device. Yes.
JP-A-6-330276 JP-A-8-269669 JP 2004-137514 A

  However, the techniques disclosed in the above-mentioned patent documents control the degree of alloying using physical model formulas and empirical rule model formulas including several parameters. However, when the number of parameters is increased, it is difficult to adjust the parameters in order to obtain a model for accurately estimating the power of the alloying furnace.

  Conversely, if the number of parameters is reduced or a simple linear model is used, the nonlinear part of the model cannot be expressed, which results in a model error, and the alloying furnace output estimation accuracy deteriorates. There is also.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an alloying degree control method and apparatus using an alloying furnace, which is easy to adjust parameters and has a high alloying furnace output estimation accuracy.

In the invention according to claim 1 of the present invention, the hot dip galvanizing is applied to the steel plate to be plated, and after adjusting to a predetermined coating amount, the alloying degree of the steel plate to be plated is set in the alloying furnace. In a method for controlling the degree of alloying by an alloying furnace to be controlled, a database creation step for storing actual data of input items and output items as a database, and data of the input items of the steel sheet to be coated are input as required point data. Request point data input process,
Performing a distance calculation between all the data in the database and the requested point data, and selecting one or a plurality of data as neighboring data in order of the calculated distance being short,
Based on the selected neighborhood data, an alloying furnace output determination process for determining the output of the alloying furnace for the steel sheet to be coated from now on, and new performance data each time coating is performed are stored in the database. A method for controlling the degree of alloying by an alloying furnace, comprising: a database updating step for adding or updating.

  Further, the invention according to claim 2 of the present invention is the alloying degree control method by the alloying furnace according to claim 1, wherein, in the database creation step, the result data of the input items is the alloying degree of the steel sheet to be plated, Plate thickness, plate width, steel plate conveyance speed, wiping nozzle height from zinc bath surface, distance between wiping nozzle and steel plate, wiping nozzle gas pressure, zinc bath temperature, zinc adhesion amount, induction heating zone entry side plate temperature Or a combination of them, and the result data of the output item is an alloying furnace output, and is an alloying degree control method by an alloying furnace.

  The invention according to claim 3 of the present invention is the alloying degree control method using the alloying furnace according to claim 1 or claim 2, wherein in the alloying furnace output determining step, multiple regression is performed from the selected neighborhood data. Alloying by an alloying furnace is characterized in that a model is created and the output of the alloying furnace for a steel sheet to be coated is determined by substituting the required point data into the created multiple regression model This is a degree control method.

  Further, the invention according to claim 4 of the present invention is the alloying degree control method by the alloying furnace according to claim 1 or 2, wherein in the alloying furnace output determining step, the output item of the selected neighborhood data is output. An alloying degree control method using an alloying furnace is characterized in that the output of the alloying furnace for a steel sheet to be coated is determined by averaging the actual values of the alloying furnace output.

  Furthermore, the invention according to claim 5 of the present invention stores actual data of input items and output items in an alloying furnace for alloying after subjecting a steel plate to be plated to hot dip galvanization and adjusting to a predetermined coating amount. An alloying degree control device having functions of database, proximity data selection close to the input item data of the steel sheet to be coated, and alloying furnace output determination, and using the determined alloying furnace output as a set value, an alloy An alloying degree control device using an alloying furnace, comprising: an alloying furnace control device that controls the output of the forming furnace.

  In the present invention, various performance data is used as input items, alloying furnace output is stored as a database as output items, the vicinity of the required point is selected for the material to be coated, and the selected neighborhood data is used. The local model is created, the average value of the neighboring data is taken, or the actual data with the highest similarity is selected, so the error due to the nonlinearity of the model is reduced and the alloying furnace output estimation accuracy is achieved Alloying degree control can be realized. In addition, every time a request point is generated, the neighborhood of the request point is selected again, so that there is an effect that no parameter adjustment is necessary.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be specifically described below using mathematical expressions and drawings. FIG. 1 is a diagram showing a schematic configuration of an alloying furnace and a control apparatus to which the present invention is applied. In the figure, 1 is a steel plate, 2 is a zinc pot, 3 is a wiping nozzle, 4 is an alloying furnace, 5 is a first cooling zone, 6 is a second cooling zone, 7 is a third cooling zone, and 8 is a water quench. , 9 is an alloying degree meter, 10 is an alloying degree control device, 11 is an alloying furnace control device, and 12 is a process computer.

  The plated steel sheet 1 continuously conveyed to the zinc pot 2 is immersed in a hot dip galvanizing bath to form a plated layer on the surface of the plated steel sheet 1, and then a desired plated layer thickness by the wiping nozzle 3. In addition, the alloying treatment is performed in which the iron is diffused in the plating layer by heating in the alloying furnace 4 to generate the Fe—Zn alloy layer. The alloying furnace to which the present invention is applied may be any heating type furnace as long as it can heat the steel sheet to be plated. The following description will be made by taking an example of a high frequency induction heating type alloying furnace.

  The plated steel sheet 1 exiting the alloying furnace 4 passes through the first cooling zone 5, the second cooling zone 6, the third cooling zone 7, and the water quench 8, and its alloy layer is measured by an alloying degree meter 9. The degree of alloying is measured.

  The alloying degree control device 10 has functions such as a database, neighborhood data selection, and alloying furnace output determination described later. It should be noted that functions other than the alloying furnace output determination are integrated in the alloying degree control device 10 after being realized by respective separate devices even if they are incorporated in the alloying degree control device 10 as shown in the figure. It may be a thing.

From the process computer 12, information such as the target alloying degree, plate thickness, plate width, steel plate conveyance speed, induction heating inlet side plate temperature and the like as setting information, and information from the zinc bath surface of the wiping nozzle as the actual information are set. Information such as the distance between the wiping nozzle and the steel sheet, the wiping nozzle gas pressure, and the degree of alloying is provided to the degree of alloying control device 10. The alloying furnace output determined by the alloying degree control device 10 (for example, induction heating zone set voltage in the case of induction heating) is sent to the alloying furnace control device 11 as a set value.

  FIG. 2 is a conceptual diagram showing the relationship between predicted request points and request point neighborhood data in the database (past data having a high degree of similarity with the request points). This figure shows the predicted required points, ie, the data of the material to be coated and the data in the database, plotted in three dimensions, for example, induction heating zone set voltage, plate thickness, and plate width, and is selected close to the required point. Data and other data are schematically shown.

  FIG. 3 is a flowchart showing an example of the processing procedure of the present invention. The procedure will be described according to the figure.

(1) Database creation process (Step01)
In the conceptual diagram of FIG. 2, the output item is the induction heating zone set voltage and the input item is expressed only by two items of the plate thickness and the plate width. However, more items may be selected as the input item. . For example, [degree of alloying, plate thickness, plate width, steel plate transport speed, wiping nozzle height from zinc bath surface, distance between wiping nozzle and steel plate, wiping nozzle gas pressure, induction heating zone inlet side plate temperature], etc. Select.

As the induction heating inlet side plate temperature, a measured value by a sensor may be used, or a set value or the like may be used. In the following description, the input item and the output item are expressed as X = [G, D, W, LS, N _h , N _D , N _p , T _IHS ] and Y = W _G shown below for convenience.

X = [G, D, W, LS, N _h , N _D , N _p , T _IHS ] = [x1 x2 x3 x4 x5 x6 x7 x8]
here,
· G: · Fe content was measured by alloying meter D: thickness · W: strip width · LS: conveying speed · N _h of the steel sheet: Height · N _D from the zinc bath surface of the wiping nozzle: wiping nozzle distance · N _p of the steel sheet: wiping nozzle gas pressure · T _IHS: the induction heating zone entry side temperature Figure 1 Fe content control apparatus 10 shown in, the past performance data for the output item Y and the input item X Stored as a database of data size N points.

  Next, when the material passing through the alloying furnace approaches the alloying furnace, the alloying furnace output for converging the degree of alloying of the material to the target value is calculated in the alloying degree control device.

(2) Request point data input process (Step02)
Collect the required point (input material to be coated) data. The request point Q is expressed as follows.

Q = [G, D, W, LS, N _h , N _D , N _p , T _IHS ] = [q1 q2 q3 q4 q5 q6 q7 q8]
here,
· G: target Fe content & D: thickness, W: strip width-LS: conveying speed, N _h of the steel sheet: Height - N _D from the zinc bath surface of the wiping nozzle: the distance between the wiping nozzle and the steel sheet, N _p : Wiping nozzle gas pressure · T _IHS : Induction heating zone inlet side plate temperature (3) Neighborhood data selection process (Step03)
a) Data editing in the database The input variable vector X = [x1 x2 x3 x4 x5 x6 x7 x8] to be all points in the database is normalized.

  Assuming that xp ′ is a normalized value of each component of the input variable vector X for N points in the whole database, it can be expressed as follows.

b) For the distance calculation input variable vector X with respect to the request point Q, the inter-input variable weighting corresponding to the influence on the output Y is performed. The inter-input variable weight W is expressed as follows.

The weighted distance D between the request point Q and each input variable X in the database can be expressed as follows.

Here, Euclidean distance is shown as an example of distance calculation, but other distance calculation may be used.

c) Selection of neighboring data The distances obtained in the above b) are arranged in ascending order, and k pieces of data are selected in ascending order.

(4) Alloying furnace power determination process (Step 04)
a) The decision neighborhood data by the multiple regression model is set as follows.

Then, the multiple regression equation and the coefficient vector are obtained as follows.

The value obtained by substituting the required point data into the multiple regression equation thus obtained is the alloying furnace output for the required point Q.

b) Determination by weighted average Place nearby output data as follows.

The weighted average according to the weighting factor and the distance from the request point can be expressed as follows.

The weighted average value thus obtained is the alloying furnace output for the required point Q.

c) Determination by nearest neighbor data Among the k data obtained in the above (3) c), the alloying furnace output of the first data, that is, the data with the shortest distance is used. This is the same even when k = 1 in the above (3) c).

(5) Database update process (Step 05)
Each time rolling is performed, the database is added or updated by the method (1). In this way, a more accurate alloying furnace output set value can be obtained.

FIG. 4 is a diagram illustrating an embodiment. It is a control result to which the database type model of the present invention is applied, and it can be confirmed that there is little variation in data even when compared with the actual value, and that they are in good agreement.

It is a figure which shows the structure outline | summary of the alloying furnace and control apparatus to which this invention is applied. It is a conceptual diagram which shows the relationship between a prediction request | requirement point and the request | requirement point vicinity data in a database. It is a flowchart which shows the example of the process sequence of this invention. It is a figure which shows an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate 2 Zinc pot 3 Wiping nozzle 4 Alloying furnace 5 1st cooling zone 6 2nd cooling zone 7 3rd cooling zone 8 Water quench 9 Alloying degree meter 10 Alloying degree controller 11 Alloying furnace controller 12 Process computer

Claims (5)

A method for controlling the degree of alloying by an alloying furnace for controlling the degree of alloying of the steel sheet to be plated when the steel sheet to be plated is subjected to hot dip galvanization and adjusted to a predetermined coating amount and then alloyed in an alloying furnace. In
A database creation process for storing the actual data of input items and output items as a database;
A required point data input process for inputting the data of the input items of the steel sheet to be coated from now on as required point data,
Performing a distance calculation between all the data in the database and the requested point data, and selecting one or a plurality of data as neighboring data in order of the calculated distance being short,
An alloying furnace output determining step for determining the output of the alloying furnace for the steel sheet to be coated from now on, based on the selected neighborhood data;
A method for controlling the degree of alloying by an alloying furnace, comprising: a database update step of adding or updating new performance data to the database each time coating is performed. In the alloying degree control method by the alloying furnace according to claim 1,
In the database creation step,
The actual data of the input items are the degree of alloying of the steel plate to be plated, the plate thickness, the plate width, the conveyance speed of the steel plate, the height of the wiping nozzle from the zinc bath surface, the distance between the wiping nozzle and the steel plate, the wiping nozzle gas pressure, One of zinc bath temperature, zinc adhesion amount, induction heating zone entrance side plate temperature, or a combination thereof,
An alloying degree control method using an alloying furnace, wherein the output data of the output item is an alloying furnace output. In the alloying degree control method by the alloying furnace according to claim 1 or 2,
In the alloying furnace output determination step,
A multiple regression model is created from the selected neighborhood data, and the required point data is substituted into the created multiple regression model to determine the output of the alloying furnace for the steel sheet to be coated from now on An alloying degree control method using an alloying furnace. In the alloying degree control method by the alloying furnace according to claim 1 or 2,
In the alloying furnace output determination step,
According to the alloying furnace, which determines the output of the alloying furnace for the steel sheet to be coated from now on by averaging the actual values of the alloying furnace output which is the output item of the selected neighborhood data Alloying degree control method. In an alloying furnace for alloying after subjecting the steel plate to be plated to hot dip galvanization and adjusting to a predetermined coating amount,
A database for storing actual data of input items and output items, proximity data selection close to the input item data of the steel sheet to be coated from now on, and an alloying degree control device having a function of determining an alloying furnace output,
An alloying degree control device using an alloying furnace, comprising: an alloying furnace control device that controls the output of the alloying furnace using the determined alloying furnace output as a set value.