JP4736440B2 - Apparatus and method for measuring surface treatment film adhesion amount of metal strip - Google Patents

Description

  The present invention relates to an apparatus and method for measuring the amount of a surface treatment coating such as a chemical conversion coating or an organic-inorganic composite coating applied to a metal strip such as a galvanized steel sheet online by fluorescent X-ray analysis. More specifically, the present invention relates to an apparatus and a method for measuring an element having an atomic number smaller than Ca (hereinafter referred to as a light element) in the surface treatment film online by fluorescent X-ray analysis.

  Chromate treatment of galvanized steel sheet is widely used as an inexpensive rust prevention treatment method that suppresses white rust of zinc, and in recent years, high-quality chromate treatment with additional characteristics such as fingerprint resistance and weldability has also been performed. ing. The chromium adhesion amount of the chromate treatment affects the properties such as corrosion resistance, fingerprint resistance and weldability of the plated steel sheet. Therefore, for the quality control of the product, the chromium adhesion amount needs to be managed within a predetermined range so that the required characteristics can be expressed.

  Conventionally, the amount of chromium deposited is obtained by taking a sample piece from a plated steel plate and measuring the fluorescent X-ray intensity of Cr in the film using a fluorescent X-ray analyzer offline or by chemically dissolving the film on the sample piece. It was requested by chemical analysis. However, with this method, the amount of adhesion obtained is only a value that represents only a small part of the total length of the steel sheet, and the analysis takes a long time, so the obtained measurement results cannot be fed back during operation. There is a problem that the amount of adhesion cannot be strictly controlled. In order to improve this problem, in recent years, an X-ray fluorescence analyzer has been arranged in the line, and the amount of Cr deposited in the film has been directly obtained online (see, for example, Patent Document 1).

  Since the chromate treatment solution contains hexavalent chromium, the use of wastewater treatment with a completely closed system during chromate treatment and the development of coating-type chromate treatment technology that does not require a water-washing process have been conducted as environmental measures. . In addition, regarding hexavalent chromium contained in a minute amount in the chromate film, development of an organic composite coated steel sheet that prevents elution of chromium, and examination of poor coating-type chromate film have been carried out.

  On the other hand, in view of environmental measures, a chromium-free chemical conversion treated steel sheet that does not use hexavalent chromium has been developed. For example, Patent Documents 2 and 3 describe phosphorous containing oxide in the lower layer instead of a chromate film. An organic composite coated steel sheet is proposed in which an acid and / or phosphoric acid compound film is formed, and an organic composite coating made of a resin film is formed on the upper layer.

The lower layer film of the organic composite-coated steel sheet proposed in Patent Documents 2 and 3 contains phosphoric acid and / or phosphate, and light element P (phosphorus) is used as the main constituent element of the film. The organic composite-coated steel sheet according to this proposal has characteristics that can be sufficiently substituted for a conventional chromate-treated steel sheet. There is a fluorescent X-ray analysis method as a method capable of quickly performing a film component analysis. However, since characteristic X-rays of light elements such as P are attenuated in the atmosphere, fluorescent X-ray analysis has not been performed online. For this reason, analysis of the P adhesion amount is unavoidable, and there is a problem that there is a time delay until the analysis sample collection timing in the processing line and the analysis result are obtained, and strict adhesion amount control cannot be performed. is there.
Japanese Patent Laid-Open No. 5-264811 JP 2001-11645 A JP 2001-11656 A

  An object of the present invention is to provide an X-ray fluorescence analyzer for the amount of light elements contained in a surface treatment film containing a light element such as P formed on the surface of a metal strip such as a zinc-based plated steel sheet. It is providing the adhesion amount measuring apparatus and measuring method which can be analyzed on-line using the.

  Means of the present invention for solving the above problems are as follows.

  A first invention is an apparatus for measuring a coating amount of a traveling metal strip having a film formed on the surface thereof, which is disposed in the vicinity of the traveling metal strip and irradiates the surface of the metal strip with X-rays. A fluorescent X-ray measuring head for detecting excited and emitted fluorescent X-rays, a support device for reciprocally supporting the fluorescent X-ray measuring head in the metal band width direction, and the fluorescent X-ray measuring head A shape sensor that is disposed upstream of the metal band traveling direction and detects the shape of the metal band, and when the shape of the metal band detected by the shape sensor exceeds a threshold value, the fluorescent X-ray measurement head is moved in the metal band width direction. And a retracting device that retracts in a direction away from the end or away from the plate surface.

  A second invention is the adhesion amount measuring apparatus according to the first invention, wherein the shape sensor is a contact detection sensor for detecting contact with a metal strip.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the contact detection part of the contact detection sensor with the metal band is constituted by a wire disposed with a predetermined distance from the metal band and tensioned in the metal band width direction. It is the adhesion amount measuring device characterized by being made.

  A fourth invention is the adhesion amount measuring apparatus according to any one of the first to third inventions, wherein the fluorescent X-ray measurement head is arranged so that a distance from the metal band is 10 mm or less.

  A fifth invention is the adhesion amount measuring apparatus according to any one of the first to fourth inventions, wherein the threshold value of the shape is the same value as the distance between the fluorescent X-ray measurement head and the metal strip.

  A sixth invention is a method for measuring the amount of coating on a traveling metal strip having a coating formed on the surface thereof, wherein the surface of the metallic strip is irradiated with X-rays in the vicinity of the traveling metal strip and excited. A fluorescent X-ray measurement head for detecting emitted fluorescent X-rays is arranged to measure the fluorescent X-rays of the elements of the surface treatment film formed on the surface of the metal band, and the metal band of the fluorescent X-ray measurement head When the shape of the metal band is detected by a shape sensor arranged upstream in the traveling direction, and the detected shape of the metal band exceeds a threshold value, the fluorescent X-ray measurement head is moved outside the end of the metal band width direction or It is an adhesion amount measuring method characterized by retracting in a direction away from the plate surface.

  According to a seventh aspect, in the sixth aspect, the fluorescent X-ray measurement head is disposed at a distance of 10 mm or less from the metal band, and the shape sensor is at least the predetermined distance from the traveling metal band. When the amount of strain is detected, the X-ray fluorescence measurement head is retracted in a direction away from the end of the metal band width direction or away from the plate surface.

  An eighth invention is the adhesion amount measuring method according to the sixth or seventh invention, wherein the measurement element is an element (including Ca) having an atomic number smaller than Ca.

  According to the present invention, it becomes possible to perform on-line analysis of the adhesion amount of a surface treatment film containing a light element such as P, and appropriate adhesion amount control can be quickly performed by feeding back the obtained measurement results. Will be able to. In addition, it is possible to easily grasp not only a small part of the entire length of the metal strip but also the coating amount variation in the longitudinal direction.

  On-line analysis using a fluorescent X-ray analyzer has already been put into practical use in, for example, Cr analysis in a chromate-treated film formed on a zinc-based plated steel sheet. In the analysis using the fluorescent X-ray analyzer, the surface of the plated steel plate is irradiated with X-rays from the X-ray generator, and the fluorescent X-rays generated from the plated surface are detected by the X-ray detector through the spectral crystal. At that time, in order to prevent absorption of X-rays by air, the atmosphere is set in a vacuum state. In the on-line analysis, the distance between the steel plate and the fluorescent X-ray measurement head is about 30 mm. In such on-line analysis, since the fluorescent X-rays generated in light elements are attenuated in the atmosphere, it has been difficult to perform on-line analysis of light elements such as P so far.

  The present inventors use a fluorescent X-ray analyzer to attach P to a film having P (phosphorus) of the organic composite coated steel sheet described in Patent Document 2 and Patent Document 3 described above as a main constituent element of the film. We investigated the possibility of online analysis of quantity and the accuracy of analysis. As a result, as an X-ray fluorescence analyzer, an X-ray generator for injecting X-rays into the plated steel sheet and the L-series and K-series fluorescence X-ray intensities coming out from the plated steel sheet side in the fluorescent X-ray measuring head. An optical system having a semiconductor detector to be measured, and filling part or all of the X-ray incident / exit optical path of the optical system including the inside of the fluorescent X-ray measurement head with a gas having a small X-ray absorption, The fluorescent X-ray measurement head is placed close to the plated steel plate with a predetermined distance of 10 mm or less, so that on-line analysis of the P deposition amount can be performed with sufficient analysis accuracy to be used for operation management in actual operation. I found out. The present invention is based on this finding.

  Hereinafter, embodiments of the present invention will be described in detail. In the following embodiments of the present invention, the metal strip will be described with a galvanized steel sheet in mind.

  FIG. 1 is a schematic side view showing a main part of a continuous electroplating line for steel sheets provided with an adhesion amount measuring apparatus according to an embodiment of the present invention. In the present embodiment, a contact sensor is installed as the shape sensor, and the shape measuring head is retracted outward from the end portion in the steel plate width direction.

  In FIG. 1, 1 is a steel plate, 2 is a rewinding device, 3 is an entry side looper, 4 is an electroplating section, 5 is a coating section, 6 is a shape detection unit (shape sensor), 7 is an adhesion amount measurement unit, and 8 is An exit side looper 9 is a winding device.

  The electroplating section 4 includes a pretreatment portion that performs pickling after alkali degreasing, a plating portion that performs electrogalvanization, and a posttreatment portion that performs posttreatment. The painting section 5 includes a first painting part 5a and a second painting part 5b. The 1st coating part 5a is equipped with the oven 23a which heat-drys the apply | coating application liquid, and then cools it after 3 roll type roll coaters 21a and 22a which apply | coat an application liquid to each of the front and back of the steel plate 1. FIG. The second coating unit 5b includes two-roll type roll coaters 21b and 22b that apply the coating liquid to the front and back surfaces of the steel sheet 1, and an oven 23b that heats and drys the applied coating liquid and then cools it.

  The adhesion amount measuring unit 7 is disposed downstream of the second coating unit 5b with respect to the sheet passing direction, and the shape detection unit 6 is disposed between the first coating unit 5a and the second coating unit 5b. .

  2 and 3 are diagrams showing a main part of the adhesion amount measuring unit 7, FIG. 2 is a schematic side view, and FIG. 3 is a view taken along arrow AA in FIG.

  As shown in FIG. 2, support rolls 33 a and 33 b are arranged on the opposite side of the steel plate 1 between the deflector rolls 31 and 32 so as to push the steel plate 1 forward from the pass line. The pressing amount of the support rolls 33a and 33b is set to an appropriate pressing amount that can prevent C warpage of the steel sheet with the roll. Fluorescent X-ray measurement heads (hereinafter referred to as measurement heads) 34a and 34b are arranged on the opposite side of the support rolls 33a and 33b with the steel plate 1 sandwiched between them and at a predetermined interval. From the viewpoint of ensuring the detection accuracy of fluorescent X-rays radiated from light elements in the surface treatment film formed on the plating surface, the measurement heads 34a and 34b are arranged close to each other with a predetermined interval of 10 mm or less from the steel plate. The The predetermined interval is more preferably 7 mm or less.

  The measurement head 34a is provided with a carriage 36a having a driving device 35a in the lower portion thereof, and is movable on a rail 37a installed in the steel plate width direction by driving the driving device 35a. Similarly, the measurement head 34b is provided with a carriage 36b having a driving device 35b in the lower portion thereof, and is movable on a rail 37b installed in the steel plate width direction by driving the driving device 35b. Reference numerals 38a and 38b denote gas supply pipes and control wiring conveyors, which drive signals to the X-ray generator and wiring for transmitting / receiving signals from the X-ray detector, and drive mechanisms 35a and 35b. Wiring and the like are arranged for this purpose. In FIG. 3, 34 a ′, 34 a ″ and 34 b ′, 34 b ″ indicated by a two-dot difference line indicate the forward limit position and the backward limit position of the measurement heads 34 a, 34 b, respectively.

  FIG. 4 is a schematic diagram for explaining a main part of the adhesion amount detection unit 7. The fluorescent X-ray measurement head 11 is arranged at a required distance from the plated steel plate 1, and a pipe for supplying helium gas from the gas supply device 17 into the head 11 is connected to the measurement head 11. Helium gas has little absorption with respect to L-series fluorescent X-rays, and X-ray attenuation in the optical path is small. In addition, as long as attenuation | damping of the X-ray in an optical path is small, other gas may be sufficient, for example, nitrogen gas may be sufficient.

  The fluorescent X-ray measurement head 11 is formed in a box shape, and an opening is formed in a portion that becomes an X-ray incident optical path and a fluorescent X-ray emission optical path from the plated steel sheet 1 side.

  An optical system 12 is disposed in the fluorescent X-ray measurement head 11. The optical system 12 includes an X-ray generator 13 and a semiconductor detector 14, and an X-ray incident optical path generated from the X-ray generator 13 and an X-ray emitted from the plated steel plate side by the incidence of the X-ray. Gas passages 15 and 16 are provided so that a part or all of the emission optical path of the gas is filled with helium gas, and L-series fluorescent X-rays and K-series fluorescent X-rays from the plating film 2 are measured by the semiconductor detector 14.

  The L-series fluorescence X-ray intensity and the K-series fluorescence X-ray intensity measured by the semiconductor detector 14 are sent to the adhesion amount processing calculation unit 53, respectively.

  The adhesion amount processing calculation unit 53 takes in the L-series fluorescence X-ray intensity and the K-series fluorescence X-ray intensity, and obtains the film adhesion amount based on the calibration curve method. Here, the calibration curve method means that an X-ray is incident at a predetermined incident angle that is set in advance as a measurement condition, and an analysis target element that is obtained by this X-ray incidence and is measured at a predetermined measurement angle that is also set as the measurement condition. A calibration curve for the fluorescent X-ray intensity of the L series is obtained and stored with the coating amount on a known plated steel sheet as a parameter. Similarly, a calibration curve of K-series fluorescence X-ray intensity is obtained and stored as a parameter of the coating amount under the measurement conditions.

  In this state, the L-series fluorescence X-ray intensity and the K-series fluorescence X-ray intensity from the semiconductor detector 14 are taken in, and the amount of light elements attached to the film to be measured is determined based on the taken-in X-ray intensity and the calibration curve. Ask.

FIG. 5 is a graph showing the phosphorous that forms a film in Example 1 on a galvanized steel sheet having a phosphoric acid-containing film on the plating surface under the same conditions as when the analyzer is used online. The result of investigating the relationship between the P adhesion amount of the acid-containing film and the fluorescent X-ray intensity (L series) of P is shown. The interval between the fluorescent X-ray measurement head and the plated steel sheet is 5 mm. A good correlation is observed between the P adhesion amount and the P intensity. Assuming that the P adhesion amount is x (mn / m ² ) and the fluorescent X-ray intensity of P detected by the semiconductor detection device is y (kcps), the relational expression between them is expressed as y = 0.000x + 0.2785. Using this relationship, the P adhesion amount can be obtained by measuring the P intensity online.

FIG. 6 shows the relationship between the Si adhesion amount and the fluorescent X-ray intensity (L series) of Si for a galvanized steel sheet having a Si-containing coating formed on the plating surface in the same manner as described above, using the analyzer of FIG. The survey results are shown. A good correlation is also observed between the Si adhesion amount and the Si strength. Assuming that the Si adhesion amount x (mg / m ² ) and the fluorescence X-ray intensity of Si detected by the semiconductor detection device are y (kcps), the relational expression between them is expressed as y = 0.2607x + 0.0212. Using this relationship, the Si adhesion amount can be obtained by measuring the Si intensity online.

  When the film is a multi-layer structure film and the amount of adhesion of the first layer is analyzed, the relationship as described above may be obtained for the element to be analyzed for the one layer in the steel sheet of the multi-layer structure film.

  In the present invention, the measuring head 11 is arranged close to the steel plate 1 with a predetermined interval of 10 mm or less, more preferably 7 mm or less. The steel plate shape during traveling cannot always be said to be stable and flat, and locally, the values of the steel plate shape such as medium elongation and ear waves may be equal to or greater than the predetermined interval. When such a steel plate having an inferior shape passes through the adhesion amount detection unit 7, there is a risk of contact with the measuring head 11 and damage. Therefore, when there is a portion with a poor steel plate shape, it is indispensable to prevent the apparatus from being damaged by reliably retracting the measuring head 11 outside the steel plate passage portion before the portion passes through the adhesion amount detection unit. is there. In the present invention, from such a viewpoint, a shape sensor that detects the shape of the steel sheet is provided upstream of the adhesion amount detection unit 7 and a retracting means that retracts the measuring head 11 to the outside of the steel plate passage portion. When the shape sensor detects that the steel plate shape is equal to or greater than a predetermined threshold, the retraction means retracts the measuring head 11 to the outside of the steel plate passage portion. By providing such an apparatus, online analysis of light elements can be stably performed for the first time.

  As the shape sensor for detecting the steel plate shape, a non-contact type sensor for detecting the steel plate shape without contact between the sensor and the steel plate, or a contact type sensor for detecting the steel plate shape by bringing the sensor into contact with the steel plate can be adopted. . The shape sensor is preferably one that can detect the maximum value (maximum strain) of the shape in the width direction of the steel sheet.

  In the present embodiment, a non-contact shape sensor capable of detecting the maximum value of strain in the steel plate width direction is installed in FIG. FIG. 7 is a schematic view showing a main part of the shape detection unit (contact type shape sensor) 6. The shape sensor is a position where the plated steel sheet 1 is wound around the deflector roll 41, extends in the axial direction of the deflector roll 41, is parallel to the steel sheet surface, and is spaced apart from the steel sheet surface by a predetermined distance. A wire 43 extending from the outer side of one end to the outer side of the other end, a power supply device 44 for energizing the wire 43, and an ammeter 45 for measuring the current flowing through the wire 43. The distance between the wire 43 and the plated steel sheet 1 is the same as the distance between the measurement heads 34 a and 34 b and the plated steel sheet 1. When the wire 43 and the plated steel plate 1 come into contact with each other, the current value detected by the ammeter 45 changes. If the amount of change in current is greater than or equal to a certain threshold value, it is determined that the shape of the steel sheet is defective.

  FIG. 8 is a flowchart for explaining a control system of the adhesion amount measuring apparatus according to the embodiment of the present invention. In FIG. 8, 51 is a shape calculation unit, 52 is a drive device control unit, 53 is an adhesion amount processing calculation unit, 54 is a centralized control panel, and 55 is an alarm device.

  In the adhesion amount processing calculation unit 53, the relationship between the fluorescent X-ray intensity of the light element to be measured and the amount of film adhesion, which has been obtained by examining the surface treatment film applied and formed in the first coating part, for example, the measurement object When the light element is P, the relationship between the strength of P and the adhesion amount as shown in FIG. 5 is inputted and stored. Further, an upper limit or a lower limit threshold of the adhesion amount is set as necessary. In the measurement heads 34 a and 34 b, the plated steel plate is irradiated with X-rays from the X-ray generator 13, and the generated fluorescent X-ray intensity is detected by the semiconductor detector 14. The detected X-ray intensity is sent to the adhesion amount processing calculation unit 53.

  The measuring heads 34a and 34b can run in the width direction of the steel plate. Usually, the measuring heads 34a and 34b are repeatedly traversed at a constant speed over the entire width in the steel sheet width direction, and the amount of adhesion in the steel sheet width direction is measured. The measuring heads 34a and 34b are traversed in three positions in the steel sheet width direction (center And a method of measuring the amount of adhesion at the position by placing the measuring heads 34a and 34b at the center in the width direction of the steel sheet. Take one of the measurements.

  The adhesion amount processing calculation unit 53 processes the X-ray intensity signal sent from the measurement heads 34a and 34b, and calculates and obtains the film adhesion amount based on the relationship between the stored X-ray intensity and the adhesion amount. . The obtained adhesion amount is output to the centralized control panel 54 and displayed. Further, when the determined adhesion amount is out of the upper threshold value or the lower threshold value, a signal is sent to the alarm device 55 to notify the operator by voice and / or an indicator lamp that the adhesion amount is out of the threshold range.

  The current value measured by the ammeter 45 of the shape sensor 6 is sent to the shape calculation unit 51. The shape calculation unit 51 determines whether or not the current value is equal to or greater than a predetermined threshold value. When the current value falls below the threshold value, the shape calculation unit 51 determines that the wire 43 and the steel plate 1 are in contact with each other, and the determination result is determined by the drive device control unit 52. Output to. The driving device controller 52 drives the driving devices 35a and 35b to move the measuring heads 34a and 34b to the retreating limits 34a "and 34b" outside the steel plate ends. The steel plate shape threshold for retracting the measuring heads 34a, 34b is set to the same value as the distance between the steel plate and the measuring head. Further, a signal is sent to the alarm device 55 to notify the operator of the retracting of the measuring heads 34a, 34b to the retracting limit by voice and / or an indicator lamp. When it is confirmed that the shape sensor and the steel plate are not in contact, the investigator restarts the adhesion amount measurement.

  The distance between the shape sensor 6 and the adhesion amount measuring unit 7 in the sheet passing direction is the response time required for the driving devices 35a, 35b to move the measuring heads 34a, 34b to the respective retraction limits 34a ", 34b". In consideration of the traveling speed of the steel plate, the measurement heads 34a, 34b can be moved to the retraction limits 34a ", 34b" before the defective shape portion detected by the shape sensor 6 reaches the adhesion amount measuring unit 7. Set to Since the steel plate traveling speed changes corresponding to the processing capability of the plating section and the processing capability of the coating section, tracking of the traveling position of the defective shape portion is performed, and the timing for retracting the measuring heads 34a and 34b is determined based on the tracking information. It is advantageous to do so. If the above conditions are satisfied and a steel plate shape defect is generated after passing through the shape detection unit 6, the arrangement location of the shape detection unit 6 is not particularly limited. In the above-described embodiment, the shape sensor 6 is provided upstream of the second coating portion, but may be provided downstream of the second coating portion.

  In the embodiment of the invention described above, the shape sensor is a contact sensor, but the shape sensor may be a non-contact sensor. As a non-contact type sensor, at the position where the steel plate is wound around the deflector roll, toward the other end side of the steel plate in parallel with the steel plate surface, close to the steel plate, outside one end portion of the steel plate A projector that irradiates laser light and a light receiver using a CCD camera that receives the laser light are arranged outside the other end of the steel plate. Based on the amount of light received by the light receiver, the shape of the steel plate (from the reference pass line) The amount of displacement of the steel plate) can be measured.

  In addition, the measuring head was retracted to the outside of the end in the width direction of the steel plate, but the measuring head was separated from the plate surface in a direction perpendicular to the steel plate surface, or diagonally above or diagonally below the steel plate running direction with respect to the steel plate surface. A retraction method of moving in the direction may be used.

  FIG. 9 is a configuration example of an apparatus for retracting the measuring head 11 in a direction perpendicular to the steel plate surface. On the carriage 36, a sliding member 61 that holds the measuring head 11 so as to be slidable in a direction perpendicular to the steel plate surface, a driving device 62 that incorporates a motor and a gear mechanism for moving the measuring head 11 forward or backward in a direction perpendicular to the steel plate surface. Is arranged. The advance position of the measuring head 11 is a predetermined position for performing film analysis. The retracted position of the measuring head 11 is an appropriate position at which contact between the measuring head 11 and the steel plate can be avoided when the shape of the steel plate is poor. At the time of film adhesion amount analysis, the measuring head 11 is disposed at the forward position, and when the shape sensor 6 detects a shape failure of the steel sheet, the driving device 62 is driven based on a command from the driving device control unit to measure the measuring head. 11, the shaft 63 connected to 11 is retracted, and the measuring head 11 is moved to the retracted position. In this apparatus, the time for retracting the measuring head 11 or the time for retracting and returning the measuring head 11 to the measurement position can be shortened, and therefore, there is an advantage that the length of the steel plate that cannot perform the coating amount analysis can be shortened. If necessary, a method of comparing the measuring head to the outside of the end portion in the width direction of the plated steel plate and a method of retracting in the direction away from the plate surface may be used in combination.

  According to the present invention, it is possible to perform on-line analysis of the amount of coating containing a light element such as P and Si using a fluorescent X-ray analyzer. The amount of adhesion can be measured quickly while the steel plate is running, and the amount of adhesion can be controlled more strictly and quickly than in the past by feeding back the measurement result to the painting process.

  Increasing the coating speed tends to increase the amount of adhesion. Therefore, until now, from the viewpoint of preventing the occurrence of out of the adhesion amount range, the coating speed has been set to be low, but according to the present invention, it is possible to strictly control the adhesion amount. It can be increased and contributes to the improvement of productivity.

Examples of the present invention will be described. In the electrogalvanizing line of FIG. 1, electrogalvanizing was performed on a steel sheet having a thickness of 0.4 to 2.3 mm × width of 910 to 1880 mm, and then, in the first coating portion, the first phosphoric acid: 0.0. A treatment liquid of pH 3 containing 01 mol / l, colloidal silica: 0.01 mol / l, and Mg: 0.01 mol / l was applied, followed by baking treatment, and the target range of P adhesion amount was 45 to 65 mg. A surface-treated steel sheet having a phosphoric acid-containing film of / m ² was produced, and the P adhesion amount of the film formed by an off-line fluorescent X-ray analyzer was measured.

In the method of the present invention, the measuring head 11 of the on-line analyzer and the wire 43 of the shape sensor 6 are arranged at positions where the distance to the steel sheet having a maximum charging thickness (plate thickness 2.3 mm) is 5 mm, and within the line. Based on the P adhesion amount detected by the arranged analyzer, the application conditions such as the rotation speed of each roll and the coating liquid concentration were adjusted so that the P adhesion amount was in the range of 45 to 65 mg / m ² . The relationship shown in FIG. 1 was used for the relationship between the fluorescent X-ray intensity of P and the adhesion amount of P.

  In the conventional method in which the P deposition amount is adjusted based on the measurement result of the P deposition amount with an offline X-ray fluorescence spectrometer, the occurrence rate of the P deposition amount outside the target range was 0.5%. The P adhesion amount did not deviate from the target range. Further, in the method of the present invention, even if there is a defective shape portion of the steel plate, the shape sensor 6 detects the defective shape of the steel plate and retracts the measuring head 11 to the outside of the end portion of the steel plate. Did not occur.

  INDUSTRIAL APPLICABILITY The present invention can be used as an apparatus for online analysis of a coating amount containing a light element such as P and Si, and a method for online analysis using a fluorescent X-ray analyzer.

It is a schematic side view which shows the principal part of the continuous electroplating line of the steel plate provided with the adhesion amount measuring apparatus which concerns on embodiment of this invention. It is a schematic side view of the principal part of an adhesion amount measurement part. It is an AA arrow line view of FIG. It is the schematic explaining the principal part of the adhesion amount detection part 7 of the adhesion amount measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the relationship between the amount of P adhesion, and a fluorescent X ray intensity when the space | interval of the fluorescent X ray measuring head and plated steel plate of the fluorescent X ray analyzer which concerns on embodiment of this invention is 5 mm. It is a figure which shows the relationship between the amount of Si adhesion, and fluorescent X-ray intensity when the space | interval of the fluorescent X-ray measuring head of the fluorescent X-ray analyzer which concerns on embodiment of this invention and a plated steel plate is 5 mm. It is the schematic which shows the principal part of a shape detection part. It is a flowchart explaining the control method of the adhesion amount measuring apparatus which concerns on embodiment of this invention. It is a schematic plan view which shows the example of a principal part structure of the apparatus which retracts a measuring head in the orthogonal direction of a steel plate surface.

Explanation of symbols

1 Steel plate (plated steel plate)
2 Rewinding device 3 Incoming looper 4 Electroplating unit 5 Coating unit 6 Shape detection unit (shape sensor)
7 Adhering Amount Measurement Unit 8 Outlet Looper 9 Winding Device 11 Fluorescent X-ray Measurement Head (Measurement Head)
DESCRIPTION OF SYMBOLS 12 Optical system 13 X-ray generator 14 Semiconductor detector 15, 16 Gas passage 17 Gas supply apparatus 31, 32 Deflector roll 33a, 33b Support roll 34a, 34b Fluorescence X-ray measuring head 35a, 35b Drive apparatus 36a, 36b Cart 37a, 37b Rails 38a, 38b Conveyor 41 Deflector roll 42 Support device 43 Wire 44 Power supply device 45 Ammeter 46 Wire rod fixing device 51 Shape calculation 52 Drive device control unit 53 Adhesion amount processing calculation unit (signal processing / analysis device)
54 Central control panel 55 Alarm device 61 Sliding member 62 Drive device 63 Axis

Claims (4)

A coating amount measuring device for a running metal strip having a film containing an element having an atomic number smaller than Ca (including Ca) formed on the surface thereof, disposed near the running metal strip, A fluorescent X-ray measuring head for irradiating the surface of the metal band with X-rays to detect the excited / radiated fluorescent X-ray, and a support device for supporting the fluorescent X-ray measuring head in a reciprocating manner in the metal band width direction; , Extending from the outer side of one end in the width direction of the metal band to the outer side of the other end at the position where the metal band upstream of the traveling direction of the metal band of the fluorescent X-ray measurement head is wound around the deflector roll A wire stretched by tension is arranged in parallel with the metal band surface and spaced from the metal band, and the contact between the wire and the metal band is detected to detect the maximum strain in the metal band width direction. It is detected and shape sensor for detecting the contact said shape sensor is該線material and the metal bands The X-ray fluorescence measurement head and a retracting device for retracting to a position that can avoid contact with the direction of the metal plate away from the metal strip widthwise end outer side or plate surface, the fluorescent X-ray measurement head and An optical system having an X-ray generator for injecting X-rays into the metal band and a semiconductor detector for measuring L-series and K-series fluorescence X-ray intensity emitted from the metal band side, The X-ray entrance / exit optical path including the inside of the fluorescent X-ray measuring head is partially or entirely filled with a gas having a small X-ray absorption, and the fluorescent X-ray measuring head is configured to pass the metal band from a pass line. An adhesion amount measuring apparatus, which is arranged at a predetermined distance of 10 mm or less from the metal band on the opposite side of the metal band between support rolls arranged to be pushed forward. Distance between the metal strip and the wire is adhesion measuring apparatus according to claim 1, wherein the the same interval as the predetermined interval of the fluorescent X-ray measurement head and the metal strip. A method for measuring a coating amount of a running metal band having a film containing an element having an atomic number smaller than Ca (including Ca) formed on the surface thereof, wherein the metal band is adjacent to the running metal band. As a fluorescent X-ray measurement head for irradiating the surface with X-rays and detecting excited / radiated fluorescent X-rays, an X-ray generator for injecting X-rays into the metal band in the fluorescent X-ray measurement head and the metal An optical system having a semiconductor detector for measuring the intensity of L- and K-series fluorescent X-rays coming out from the band side, and an X-ray incident / exit optical path of the optical system including the inside of the fluorescent X-ray measuring head A fluorescent X-ray measurement head filled with a gas having a small X-ray absorption is placed on the opposite side of the support roll arranged so as to push the metal band forward from the pass line. Arranged at a predetermined distance of 10mm or less from the metal band And measuring the fluorescent X-ray of an element (including Ca) having an atomic number smaller than Ca of the surface treatment film formed on the surface of the metal band, and the metal upstream of the fluorescent X-ray measuring head in the metal band traveling direction Extending from the outer side of one end in the width direction of the metal band to the outer side of the other end at a position where the band is wound around the deflector roll, a wire rod stretched by tension is parallel to the surface of the metal band. A shape sensor is disposed that is spaced apart from the band, detects a contact between the wire and the metal band, and detects a maximum value of strain in the width direction of the metal band, and the shape sensor includes the wire and the metal band. When the contact is detected, the X-ray fluorescence measurement head is retracted to a position where the contact with the metal plate in the direction away from the end of the metal band width direction or away from the plate surface can be avoided. Method. The adhesion amount measuring method according to claim 3, wherein an interval between the wire and the metal band is the same as an interval between the fluorescent X-ray measurement head and the metal band.

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