JPH0375549A - Method and apparatus for measuring amount of plated material of plated steel plate and composition of plated film - Google Patents

Abstract

PURPOSE:To make it possible to measure the amount of plating and the composition of plating highly accurately by correcting the shifted amount of a wavelength due to Compton scattering obtained by the incident angle and the received angle of monochromatic X rays. CONSTITUTION:At first, monochromatic X rays are projected on a scattering plate by using the same optical system as in the measurement of a plated steel plate. The wavelength of the monochromatic X rays is measured from a theoretical expression by using the wavelength of Compton scattering lines. An optical system is adjusted so as to obtain an intended wavelength. Then, the theoretical computing expression for fluoresence X-ray intensity or the intensity ratio of the element for intended analysis obtained by using said optical system is determined beforehand. Then, a standard sample is used, and a converting coefficient for converting the actually measured values into the theoretically computed value is obtained beforehand. The fluorescence X-ray intensity or the intensity ratio obtained from the plated steel plate whose plated amount and composition of the plated film are unknown is measured. The values are converted into the theoretical intensity or the intensity ratio by using the converting coefficient. The plated amount and the composition of the plated film of the plated steel plate to be measured are determined from the plated amount and the composition of the film which are the parameters in the theoretical computing expression that are most close to the converted theoretical intensity or intensity ratio.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for measuring the amount of plating and the composition of the plating film on a plated steel sheet, in which the amount of plating and the composition of the plating film on a plated steel sheet are measured online. Monochromatic X of the wavelength required for equipment, especially simple and highly accurate
The present invention relates to a method and apparatus for accurately measuring the coating amount and coating composition of a plated steel plate by obtaining lines.

[Conventional technology]

Fluorescent X-ray analysis is used to measure the coating amount and coating composition of this type of plated steel sheet. This fluorescent X-ray analysis method involves irradiating a plated steel sheet with X-rays, then measuring the intensity of the fluorescent X-rays, which is a function of the plating thickness and coating composition, and comparing this measured value with a calibration curve. Zn-plated steel sheet or Zn-Ni
For plated steel plates that do not contain a base metal, it is possible to measure the amount of plating and the composition of the plated film online.

However, in recent years, Zn-Fe alloy plated steel sheets have attracted attention for their excellent properties such as corrosion resistance and workability. It is difficult to distinguish the fluorescent X-rays from the fluorescent X-rays caused by Fe, which makes it difficult not only to correlate the fluorescent X-ray intensity with the amount of plating deposited and the composition of the plating film, but also to analyze it online. .

Therefore, the following two analysis methods have been proposed as methods for improving the above-mentioned problems.

One of them had multiple wavelengths on a Zn-Fe alloy plated steel plate. After irradiating so-called white X-rays, the first measurement angle is such that the fluorescent X-rays from the base metal of the plated steel plate are virtually undetectable from the point of view of the X-ray penetration depth, and the fluorescent X-rays from the base metal are detected. This is an online analysis method that measures the fluorescent X-ray intensity of each series by placing a detector at each of the second measurement angles that can be measured, and determines the amount of plating and the composition of the plating film based on the constant values on both sides. Showa 58-22
Publication No. 3047).

The other method is to use absorption by the coating on a Zn-Fe alloy plated steel sheet to determine the coating amount from the diffraction
This is a method of determining the plating film composition from the diffraction X-ray intensity of one or more phases selected from the alloy phase and the η phase.
0-169553).

[Problem to be solved by the invention]

However, as mentioned above, of the two analysis methods, the former fluorescent X-ray analysis method using two measurement angles uses white X-rays as the incident X-rays, so the following problems have been pointed out. ing.

■-1 High-energy XtIs in white X-rays has a tendency to penetrate deep due to low attenuation in the coating of plated steel sheets, and for this reason, fluorescent X-rays from the underlying metal cannot be detected. The measurement angle of No. 1 needs to be very small, within 5 degrees.

As a result, fluctuations in the measurement distance due to vertical movement of the surface of the plated steel plate, that is, fluctuations, and fluctuations in the fluorescent X-ray intensity due to fluctuations in the measurement angle are large, resulting in a problem that measurement accuracy is reduced.

■-2 In addition, the amount of plating deposited and the composition of the plating film are calculated by comparing the measured strength obtained by actually irradiating the plated steel plate with X-rays and the theoretical strength obtained by applying it in advance to a well-known theoretical strength calculation formula. However, when calculating the theoretical intensity, there is a problem in that the measurement accuracy decreases because it is affected by spectral fluctuations of incident X-rays due to changes in the X-ray tube over time.

■-3 In addition, when calculating the analytical value by comparing the above-mentioned measured intensity with the theoretical intensity calculated from the well-known theoretical intensity calculation formula, the calculation time is longer because wavelength integration is required when calculating the theoretical intensity. It is undeniable that the measurement time will increase.

■-4 Furthermore, in order to avoid the problem pointed out in ■-3 above, there is a method using a calibration curve, but this method requires 20 to 30 types of standard samples to create a model that takes into account matrix effects. This necessitates a very complicated analysis method.

On the other hand, in the latter analysis method using diffraction X-rays, ■-1
The diffraction X-ray intensity of α-Fe in the base metal depends not only on the amount of plating deposited, but also on the different textures and plating film composition caused by the steel type and thickness of the steel sheet, the manufacturing conditions of the plated steel sheet, etc., and therefore the measurement accuracy is affected. There is a problem in terms of

■-2 On the other hand, the diffraction X-ray intensity of the alloy phase differs depending on the plating conditions, and the structure and composition of the alloy differ between hot-dip plated materials and electroplated materials, so sufficient measurement accuracy cannot be obtained in this case as well. .

The present invention has been developed in view of the above-mentioned circumstances, and it is possible to measure the amount of coating and the composition of the coating on-line by reducing the influence of vibration in the coating of a plated steel plate, and to improve the accuracy of analysis and shorten the analysis time. It is an object of the present invention to provide a method for measuring the amount of plating deposit and the composition of the plating film on a plated steel sheet, which allows the amount of plating deposit and the composition of the plating film to be measured reliably using a small number of standard samples.

In addition, the purpose of the measuring device, which is another invention, is to
The object of the present invention is to accurately measure the amount of plating coating and the composition of the plating film online using a simple configuration.

[Means and effects for solving the problem] Therefore, in order to solve the above problem, the invention corresponding to claim 1 uses the same optical system as when measuring a plated steel plate and uses monochromatic X-rays instead of the plated steel plate. A scattering plate with high Compton scattering, such as a polymeric material (eg, acrylic) or glass, is irradiated with light, and the wavelength of the Compton scattered radiation obtained from the scattering plate is measured. At this time, by correcting the amount of wavelength shift due to Compton scattering determined from the incident angle and acceptance angle of the monochromatic X-ray using a theoretical formula, the wavelength of the monochromatic X-ray used during measurement is indirectly measured, and this measured value is determined as the desired value. Adjust the optical system to calibrate to the wavelength of This is obtained when monochromatic X-rays are incident on the plated steel plate at a predetermined angle of incidence using this adjusted optical system. In addition to the theoretical calculation formula for the series fluorescent X-ray intensity or intensity ratio of the target element for analysis at two types of predetermined measurement angles, the above theoretical calculation formula can be calculated using a standard sample whose plating coating amount and plating film composition are known. The fluorescent X-ray intensity or intensity ratio is actually measured under the same conditions as those used to determine the value, and a conversion coefficient for converting the actual value into a theoretically calculated value is determined in advance based on the measured value and the theoretical calculation formula.

After determining the theoretical calculation formula and conversion coefficient as described above, use monochromatic Xi calibrated to have the desired wavelength on a plated steel sheet whose coating amount and composition are unknown, and Irradiate the plated steel plate using the same measurement conditions as those used to obtain the theoretical calculation formula, measure the fluorescent X-ray intensity or intensity ratio obtained from the plated steel plate, and then convert this fluorescent XR intensity or intensity ratio. Convert to theoretical intensity or intensity ratio using coefficients. Then, the plated steel plate to be measured is determined using the plating coating amount and the plating film composition, which are parameters in the theoretical calculation formula, to bring the theoretical strength or strength ratio obtained from the theoretical calculation formula closest to the converted theoretical strength or strength ratio. The amount of plating deposited and the composition of the plating film are as follows.

Next, the invention corresponding to claim 2 uses the same optical system as when measuring a plated steel plate, and uses a material with high Compton scattering such as a polymer material (such as acrylic) or glass instead of the plated steel plate to emit monochromatic X-rays. A scattering plate is irradiated, and the wavelength of Compton scattered radiation obtained from the scattering plate is measured. At this time, the amount of wavelength shift due to Compton scattering determined from the incident angle and acceptance angle of the monochromatic X-ray is corrected as follows:
By using a calibration curve determined in advance, the wavelength of monochromatic X-rays used during measurement is indirectly measured, and the optical system is adjusted so that this measured value is calibrated to the desired wavelength. This is obtained when monochromatic X-rays are incident on the plated steel plate at a predetermined angle of incidence using the optical system adjusted as described above. 2
Series of fluorescence X of the target element for analysis at a given measurement angle
In addition to the theoretical calculation formula for the linear intensity or intensity ratio, the fluorescent Conversion coefficients for converting actual measured values into theoretically calculated values are determined in advance.

After obtaining the theoretical calculation formula and conversion coefficient as described above, use monochromatic , irradiate the plated steel plate using the same measurement conditions as those used to obtain the theoretical calculation formula, measure the fluorescent X-ray intensity or intensity ratio obtained from the plated steel plate, and then measure the fluorescent X-ray intensity or intensity ratio. Convert to theoretical intensity or intensity ratio using a conversion coefficient. Then, the plated steel plate to be measured is determined using the plating coating amount and the plating film composition, which are parameters in the theoretical calculation formula, to bring the theoretical strength or strength ratio obtained from the theoretical calculation formula closest to the converted theoretical strength or strength ratio. The amount of plating deposited and the composition of the plating film are as follows.

Next, the invention corresponding to claim 3 uses the same optical system as when measuring a plated steel plate, and uses a material with high Compton scattering such as a polymer material (such as acrylic) or glass instead of the plated steel plate to emit monochromatic X-rays. A scattering plate is irradiated, and the wavelength of Compton scattered radiation obtained from the scattering plate is measured. At this time, by correcting the amount of wavelength shift due to Compton scattering determined from the incident angle and acceptance angle of the monochromatic X-ray using a theoretical formula, the wavelength of the monochromatic X-ray used during measurement is indirectly measured, and this measured value is determined as the desired value. Adjust the optical system to calibrate to the wavelength of

On the other hand, the 2
Series of fluorescence X of the target element for analysis at a given measurement angle
A calibration curve of linear intensity or intensity ratio is determined using the plating deposit amount and plating film composition as parameters, and then, the calibration curve is calibrated to the desired wavelength for a plated steel sheet whose plating deposit amount and plating film composition are unknown. Using monochromatic X-rays,
Then, the fluorescent X-ray intensity or intensity ratio obtained from the plated steel sheet to be measured is measured by irradiation using the same measurement conditions as those used to obtain the calibration curve. Furthermore, the plating coating amount and plating film composition of the plated steel sheet to be measured are defined as the plating coating amount and plating film composition, which are the parameters in the calibration curve, which are closest to the fluorescent X-ray intensity or intensity ratio obtained from the calibration curve. be.

Next, the invention corresponding to claim 4 uses the same optical system as when measuring the plated steel plate, and instead of the plated steel plate, the monochromatic A large scattering plate is irradiated with radiation, and the wavelength of the Compton scattered radiation obtained from the scattering plate is measured. At this time, by correcting the amount of wavelength shift due to Compton scattering using a calibration curve determined in advance, the wavelength of the monochromatic X-ray used during measurement is indirectly measured.
The optical system is adjusted so that this measured value is calibrated to the desired wavelength.

On the other hand, when monochromatic X-rays are incident on a plated steel plate at a predetermined angle of incidence using the optical system adjusted here,
Calibration curves of fluorescent X-ray intensities or intensity ratios of the target element for analysis at two types of predetermined measurement angles are determined using the amount of plating or the composition of the plating film as parameters, and then the amount of plating and the plating film composition are determined. Fluorescence obtained from a plated steel plate whose composition is unknown by irradiating it with monochromatic X-rays calibrated to the desired wavelength and using the same measurement conditions as those used to obtain the calibration curve. Measure the X-ray intensity or intensity ratio. Furthermore, the plating coating amount and plating film composition of the plated steel sheet to be measured are defined as the plating coating amount and plating film composition, which are the parameters in the calibration curve, which are closest to the fluorescent X-ray intensity or intensity ratio obtained from the calibration curve. be.

Next, the invention corresponding to claim 5 includes an X-ray generator that generates X-rays, a monochromator that monochromates the X-rays generated from the X-ray generator, and A slit system that makes the beam incident on the plated steel plate at a predetermined incident angle and receives the light at a predetermined acceptance angle, and two systems that measure the intensity of series fluorescent X-rays of the analysis target element generated from the plated steel plate at different angles. a traverse mechanism for appropriately moving a detector and these measurement systems between a scattering plate that generates strong Compton scattered radiation and the plated steel plate; and a traverse mechanism for moving the measurement system onto the scattering plate by the traverse mechanism. At the time of setting, a wavelength converting means for determining the wavelength of the monochromatic X-rays incident on the scattering plate using a theoretical formula from the wavelength of the scattered rays scattered from the scattering plate due to the incidence of the monochromatic X-rays; A wavelength adjustment means for adjusting the optical system constituting the measurement system so that the determined wavelength becomes a desired wavelength, and a theoretical calculation of the theoretical intensity or intensity ratio that should be obtained by the measurement system adjusted by the wavelength adjustment means. means for storing a formula; means for converting a fluorescent X-ray intensity or intensity ratio actually measured using the measurement system whose optical system is adjusted by the wavelength adjustment means into a theoretical intensity or intensity ratio; The present invention is equipped with means for determining the amount of plating deposited and the composition of the plating film that minimizes the difference between the theoretical strength or strength ratio obtained by the theoretical calculation formula.

Therefore, by taking the above measures, we can irradiate monochromatic X-rays onto a scattering plate with large Compton scattering, measure the wavelength of the Compton scattered rays, and measure the wavelength of the Compton scattered rays using the same optical system used when measuring plated steel sheets. By correcting the amount of wavelength shift due to Compton scattering determined from the scattering angle based on a theoretical formula, the wavelength of monochromatic X-rays irradiated to the plated steel plate used during measurement is indirectly measured, and the optical system is adjusted according to the measured value. Adjust and calibrate to the desired wavelength. After that, the X-rays generated from the X-ray generator are passed through a slit, and a monochromator is used to obtain monochromatic X-rays of the calibrated wavelength, and the monochromatic X-rays are incident on the plated steel plate at a predetermined angle of incidence. The fluorescent X-ray intensity of the analysis target element generated from the steel plate is detected using two detectors at different predetermined acceptance angles.

Then, the fluorescent X-ray intensity or intensity ratio measured by these two detectors is converted into a theoretical intensity or intensity ratio, and the theoretical intensity or intensity ratio is calculated using a theoretical calculation formula using the plating amount and the plating film composition as variable parameters. The amount of plating deposited and the plating film composition of the plated steel sheet to be measured are obtained from the parameters whose calculated values are closest to the converted values.

Furthermore, the invention corresponding to claim 6 provides a wavelength conversion means for determining the wavelength of the monochromatic X-rays incident on the scattering plate according to claim 5 using a calibration curve determined in advance, instead of determining the wavelength of the monochromatic X-rays incident on the scattering plate based on a theoretical formula. The configuration and operation are the same as in claim 5 except for other points.

Furthermore, the invention corresponding to claim 7 includes an X-ray generator, a monochromator, a slit system, two detectors, and a wavelength conversion means using the theoretical formula, as well as a theory that should be obtained in a measurement system for plated steel plates. The apparatus is equipped with means for storing a calibration curve of intensity or intensity ratio, and means for determining the plating coating amount and plating film composition that minimize the difference between the actually measured fluorescent X-ray intensities or intensity ratios.

In this apparatus, the amount of plating deposited and the plating film composition of the plated steel sheet to be measured are measured by using a calibration curve instead of the theoretical calculation formula and by using almost the same signal processing means as described above.

Furthermore, the invention corresponding to claim 8 is the same as claim 7 in that it includes means for storing a calibration curve of theoretical strength or intensity ratio that should be obtained by the measurement system for plated steel sheets, and in particular, claim 7.
The difference is that a wavelength conversion means is provided that uses a pre-determined calibration curve instead of a theoretical formula.
The configuration and operation are the same as in claim 7 except for other points.

〔Example〕

Hereinafter, prior to a detailed explanation of the present invention, it is assumed that the present invention is constructed with a measurement system that satisfies the following conditions in order to be suitable for on-line measurement.

(b) Incident X-rays are collected using a commercially available X-ray tube to generate sufficient fluorescent X-rays.
Obtain line strength.

(b) Measurement angles such as the X-ray incident angle and fluorescent X-ray acceptance angle must be achievable online, that is, 5° or more.

Further, the intensity of fluorescent X-rays generated from the plated steel plate is measured using a radiation detector, preferably using a semiconductor detector.

Hereinafter, an example of a method for measuring the coating amount and the coating film composition (F%) of a Zn--Fe alloy plated steel sheet will be described.

First, when a monochromator is irradiated with X-rays generated from an X-ray tube, it is necessary to obtain monochromatic X-rays of the desired wavelength from the monochromator, so a scattering plate with a large Compton scattering is used to set up the same optical system as used for measurement. The position of each element of the optical system is adjusted and set using the optical system. This specific method uses a traverse mechanism to move and set a measurement head containing an optical system used for measuring the plated steel plate from above the plated steel plate to a predetermined position on the scattering plate. This scattering plate uses a material with high Compton scattering, such as a polymer material (eg, acrylic) or glass.

After setting up the optical system in this manner, the monochromator is irradiated with X-rays generated from the X-ray tube of the measurement head, and at this time, the monochromatic X-rays obtained from the monochromator are irradiated onto the scattering plate. Then, the wavelength λCCλ] of the Compton scattered radiation obtained from this scattering plate is measured. Thereafter, the wavelength λ [input] of the incident X-rays on the scattering plate is determined by the following theoretical formula using the incident angle φ of the monochromatic X-rays on the scattering plate and the scattered acceptance angle ψ of the scattered rays.

λ−λc −0,0488sln21(φ10ψ)/2+
[λ Co... (1) After determining the amount of deviation (wavelength shift amount) between this wavelength λ and the desired wavelength, the optical system in the measurement head is adjusted so that this λ becomes the desired wavelength. Adjust the angles and positions of the system components, such as the X-ray tube, monochromator, and slit system.Here, once λ has reached the desired wavelength, use the traverse mechanism again to adjust the measurement head. from the scattering plate to a predetermined position on the plated steel plate,
Enter the original all specifications of plated steel sheets. Note that, for convenience of explanation, an optical system for only one measurement angle has been described, but in reality, the optical system is adjusted so that a desired wavelength can be obtained for two measurement angles.

After adjusting the optical system so that the monochromator generates monochromatic X-rays of the desired wavelength as described above,
X-rays are irradiated from the X-ray tube to the monochromator. and,
As shown in FIGS. 1 and 2, the desired wavelength λ1. After obtaining X-rays of λ2, an incident angle of φ1. The light is incident at φ2, and the intensity of the Feka line and the intensity of Znkα generated from the plated steel plate 11 at this time are measured at a receiving angle of ψ1°ψ2.

Therefore, the Feka line intensity and Znka line intensity measured under the conditions of this measurement angle (φ1.ψ1) are respectively I↓e+I
Za, and the Feka line intensity and Znka line intensity measured under the measurement angle (φ2.ψ2) are x, , xL, and X, -1 shi, /I) 7 is performed (step S2). Furthermore, this X.

Convert to the theoretical value Y, , Y2 using X2. Here, X
,, When converting X2 into a theoretical value Y,, Y2, this theoretical value is the fluorescent , is calculated using a theoretical calculation formula using the coating amount of the plated steel sheet and the coating film composition as parameters, and based on these values, the values corresponding to the above-mentioned X, , and X2 are determined.

Actual measured values differ from these theoretical intensities due to the sensitivity characteristics of the detector, the influence of the slit system, etc.

Therefore, in the method of the present invention, the measured values X, ., X2 are converted into theoretical values Y, ., Y2 using the following theoretical calculation formula (step S2).

Y, ma, X, +b.

Y2mll, x2+b2 In addition, in the above formula, al + a2 r bl r
b2 is a conversion coefficient, which is determined by actually measuring the fluorescent X-ray intensity or intensity ratio under the same conditions as those used to obtain the theoretical calculation formula using a standard sample whose plating coating amount and plating film composition are known in advance. This measured value is obtained by converting it into a theoretical intensity or intensity ratio using the above-mentioned theoretical calculation formula. In other words, the above formula holds between Y, , Yl, which is the value calculated using the theoretical formula using the plating deposition amount and plating film composition of the standard sample, and X,, X, which is calculated from the actually measured fluorescent X-ray intensity. The conversion coefficient a is determined by regression analysis or the like.

``2 r bl + b2 is determined in advance.

In this way, we used a theoretical calculation formula and calibrated the difference with the actual measurement system using a standard sample, so we used a small number of standard samples to calculate the amount of plating, the composition of the plating film, and the fluorescent X-ray intensity. Alternatively, a relational expression of intensity ratio can be obtained.

Next, once the theoretical values Y, , Y2 have been obtained in step S2, using the parameter Pk (k-1) in which the plating adhesion amount and Fe% are varied, the above formula is calculated from the existing fluorescent X-ray intensity calculation formula. Y,,Yl corresponding to Y,,Y2
(Steps S3 and S4). After that, the process moves to step S5, where (Ys − Yl ) 2 + (Yl Y
l) Perform the operation 2 and further set the parameter P
Perform similar calculations by changing k (step S6.S4.S
5) Determine the value of the parameter when the calculated value is the smallest among these calculated values. Step S7). By using this determined parameter value as the plating adhesion amount and Fe%, the plating adhesion amount of the plated steel sheet 11 is determined. and a plating film composition.

Next, analysis results obtained using the above measurement method will be specifically explained. Now, the measurement conditions for Xl are, for example, the wavelength of the incident X-ray λI -1,26 input, the measurement angle (φ1.
ψ, ) - (15@, 45'), and the measurement conditions for X2 are, for example, the wavelength of the incident
2. ψ2)−(75″, 60″). Note that for Xl, an X-ray tube with a tungsten target is used, and for X2
If an X-ray tube with a molybdenum target is used, the wavelength λ1. λ2 is the WLβ line, respectively.

The wavelength is near the M o kα line, and the above-mentioned condition (a) is met.
can be satisfied.

On the other hand, of the two measurement angles, the lower measurement angle (φ1.ψ
1) uses the wavelength λ1-1.26, which has a large attenuation to the plating film and a small penetration depth (15'
, 45@), and the measurement angle can be set to fully satisfy the above-mentioned condition (b). As a result, the plated steel plate 1
The influence of measurement distance fluctuation and measurement angle fluctuation due to the first flap can be reduced.

Note that the accuracy improves as there is a difference between Xl and X2 in the characteristics with respect to the amount of plating and Fe%, so λ2 is equal to λ1.
The wavelength was set to have a smaller attenuation to the plating film compared to , the measurement angle (φ2.ψ2) was also set to a larger angle compared to (φ1.ψ1), and the maximum depth at which fluorescent X-rays could be detected, that is, the analysis depth was increased. Furthermore, in order to reduce the variation in measurement distance, the beam diameter of the incident It is desirable to detect fluorescent X-rays. Therefore, this can be realized by using a pinhole collimator with a diameter of 2.0 to 5.0+ m on the incident side and opening the window of the detector on the light receiving side.

Furthermore, as another method of the invention, instead of wavelength calibration using a theoretical formula, for example, as shown in FIG. Wavelength calibration may be performed based on a defined calibration curve. In addition, when it is possible to use a large number of standard samples, the standard samples can be used in place of the above theoretical calculation formula to calculate the relationship between the plating amount, the plating film composition, and the fluorescent X-ray intensity or intensity ratio, that is, the calibration curve. Plated steel plate 1 to be measured using
The amount of plating deposited and the composition of the plating film of No. 1 may be determined.

Next, an embodiment of the apparatus of the present invention will be described with reference to FIGS. 3 and 4. Figure 3 is a diagram showing the adjustment of the same optical system used during measurement so that the wavelength of monochromatic X-rays becomes the desired wavelength, and Figure 4 is a diagram showing how a plated steel plate is measured. . Note that, for convenience of explanation, FIG. 3 shows adjustment of one measurement angle.

In FIG. 3, reference numeral 12 denotes a measuring head, and this head 12 moves the measuring head 12 from above the plated steel plate ll onto the scattering plate 13 which is the calibration position, or from above the scattering plate 13 to the plated steel plate 11 which is the measurement position. The traverse mechanism 14 moves the X-rays upward, and the X-rays generated from the X-ray tube 21 are incident on the monochromator 23 through the collimator 22 to produce monochromatic X-rays.
After obtaining the line, this monochromatic X-ray is passed through the pinhole collimator 24.
wavelength converting means 15 for determining the wavelength of the monochromatic X-rays before scattering by detecting the wavelength of the scattered rays obtained from the scattering plate 13 through the plate slit 25 and the detector 26; An optical system, that is, an X-ray tube 21. converts the wavelength obtained by the wavelength conversion means 15 into a desired wavelength. Collimator 22. A wavelength adjustment mechanism 16 is provided that performs wavelength calibration by adjusting the position and angle of the monochromator 23 and the like.

Although only one optical system is shown in the measurement head 12,
Actually, two optical systems are arranged as shown in FIG. 4, and after wavelength calibration, they are moved onto a plated steel plate 11 by a traverse mechanism 14 as shown in FIG.

That is, this measurement head 12 includes two X-ray tubes 21.31 that generate X-rays in a predetermined direction, and this X-ray tube 21.31.
Monochromators 23 and 33 monochromatize the white X-rays incident from 31 via collimators 22 and 32, and make the monochromated X-rays incident on the plated steel plate 11 at a desired angle of incidence; It is composed of a collimator 24.34 that makes the radiation incident on the plated steel plate 11, and a detector 26.36 that measures the fluorescent X-ray intensity obtained from the plated steel plate 11 via a flat plate slit 25.35 whose width is variable. . Note that the collimator 24 is preferably a pinhole collimator in order to reduce the influence of measurement distance fluctuations. Also,
These X-ray tubes 21, 31, monochromators 23, 33,
Collimator 22゜32.24.34, slit 25,3
5. The positions of the detectors 26, 36, etc. can be adjusted using drive control signals from the drive control section 17.

18 is a signal processing means, which includes two detectors 26
．． Theoretical value conversion means 1 for converting the fluorescent X-ray intensity or intensity ratio measured in 36 into a theoretical intensity or intensity ratio, that is, a theoretical value
8a1 Theoretical value calculation means 18b1 Theoretical value conversion means 18 which calculates and stores a theoretical value using an existing fluorescent X-ray intensity calculation formula using the plating adhesion amount and Fe% as variable parameters.
It is constituted by parameter value determining means 18c, etc., which determines the parameter at which the theoretical value obtained in step a is equal to the theoretical value obtained by the theoretical value calculating means 18b, and this parameter value is used as the plating deposit amount and the plating film composition. According to
This method is used to obtain the amount of plating and the composition of the plating film on a plated steel sheet.

Next, the operation of the apparatus configured as above will be explained.

First, when performing wavelength calibration, the entire measuring head 12 is set on the scattering plate 13 shown in FIG. 3, which is the calibration position, by the traverse mechanism 14, and then the scattering plate 1 is
3, and the Compton scattered radiation obtained from the scattering plate 13 at this time is detected by the detectors 26 and 36. Then, from this Combton scattered radiation, the wavelength converting means 15 applies the above-mentioned theoretical formula, and the monochromators 23 and 33 convert the X
After determining the wavelength of the line, the optical system is adjusted by the wavelength adjustment mechanism 16 so that this wavelength becomes a desired wavelength. After this wavelength calibration is completed, the measurement head 12 is moved to the measurement position using the traverse mechanism 14.

Therefore, during measurement, two X-ray tubes 21 and 31
When white X-rays are generated, the white X-rays pass through a collimator 22.32, are made monochromatic by a monochromator 23.33, and then strike the plated steel plate 11 at incident angles φ and -10, respectively.
It is irradiated at an angle of ˜30˚φ2=45″˜90″. Note that a tungsten target is used as the X-ray tube 21, and X-rays with a wavelength near the WL β line, which has a large attenuation with respect to the plating film, are taken out from the monochromator 23 and used as incident X-rays on the plated steel plate 11. Wire tube 31
On the side, a molybdenum target is used, which extracts from the monochromator 33 X-rays with a wavelength near the M o kα ray, which is much less attenuated by the plating film than the WLβ ray, and combines it with the incident X-rays on the plated steel plate 11. do.

After irradiating the monochromatic X-rays as described above,
The ka-ray intensities of Zn and Fe generated from the plated steel plate 11 are determined by the acceptance angle ψ1-30" ~ 60° and ψ2-45° ~
The rain detector 26.36 detects the rain at an angle of 90''.Then, the rain detector 26.36 detects the rain using the theoretical value conversion means 18a.
Based on the fluorescent X-ray intensity etc. obtained in step 36, the
After determining 2, it is converted into a theoretical value and sent to the parameter value determining means 118C. On the other hand, the theoretical value calculation means 18
In b, the plating adhesion amount and Fe% are sequentially set as variable parameters, and theoretical values are determined using the existing fluorescent X-ray intensity calculation formula and sent to the parameter value determining means 18c. Therefore, this parameter value determining means 18c uses the theoretical value sent from the theoretical value converting means 18a and the theoretical value calculating means 1.
A predetermined calculation is performed using the theoretical values obtained by changing the parameters in step 8b, the parameter values are determined when both theoretical values are equal, and from this parameter values, the amount of plating deposited on the plated steel sheet 11 and the composition of the plating film are determined. This is what you get.

By the way, Figure 5 shows the relationship between the wavelength of Compton scattered rays according to the theoretical formula and the wavelength of incident X-rays before scattering for a certain scattering angle, along with actual measured values. It can be seen that the value is shown. Also, the 6th
The figure and FIG. 7 are diagrams showing analysis results obtained using the apparatus of FIG. 4. Note that FIGS. 6 and 7 show the wavelength calibration means in FIG. 3, that is, the monochromators 23 and 3.
3, scattering plate 13, wavelength conversion means 15, wavelength adjustment mechanism 16
etc., the wavelength λl-1.26, λ2-
0.71λ, and each DJ constant angle is (φ1.
ψ, ) − (15°, 45°) (<62, ψ2) −
(75', 60'), of which FIG. 6 shows the amount of plating deposited and FIG. 7 shows the composition of the plating film.

Therefore, as is clear from these figures, highly accurate measurements can be made in a short measurement time of 10 seconds, even though this is an actual line in which measurement distance fluctuations, measurement angle fluctuations, temperature and humidity fluctuations, etc. are added. In addition, this analysis value was obtained from the intensity ratio of Fe and Zn fluorescent X-rays rather than the fluorescent X-ray intensity of Fe or Zn, but by taking this intensity ratio, it is possible to reduce the effects of temperature/humidity fluctuations and changes over time. .

In the apparatus of the above embodiment, the Compton shift was corrected using a theoretical formula as wavelength calibration, but instead of using this theoretical formula, the wavelength of the Compton scattered ray and the incident X-ray before scattering were calculated in advance, for example, as shown in FIG. Wavelength calibration may be performed based on a calibration curve that defines the relationship between wavelength and wavelength. Further, in the apparatus of the above embodiment, theoretical calculation formulas were used to determine the amount of plating deposited and the composition of the plating film, but a calibration curve may be used instead.

In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

〔Effect of the invention〕

As explained above, according to the present invention, various effects can be achieved as described below.

First, in the inventions of claims 1 to 4, since the wavelength calibration is performed using the wavelength calibration means, the wavelength of the monochromatic X-ray can be set with high accuracy in online measurement, and accurate measurement can be performed. In addition, since the monochromatic treatment extracts X-rays with wavelengths that are largely absorbed by the plating film and irradiates them onto the plated steel sheet, it is possible to measure the fluorescence The influence of fluctuations and measurement angle fluctuations is small, and the influence of spectral fluctuations of incident X-rays is small.
Furthermore, since wavelength integration is not required, measurement accuracy can be improved and measurement time can be shortened. Further, several types of standard samples are required for measurement in order to obtain conversion parameters from actual measured values to theoretical values, and the standard sample can be suitable for online measurement.

Next, in the inventions of claims 5 to 8, the wavelength of monochromatic X-rays can be easily and accurately calibrated, and the coating amount and coating composition of a plated steel sheet can be calibrated online with high accuracy using a very simple configuration. can be measured, making a significant contribution to improving the quality of plated products.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship between Xfi and a plated steel plate when using the method of the present invention, Fig. 2 is a diagram illustrating the analysis operation according to the method of the present invention, and Fig. 3 is a diagram showing wavelength calibration using the apparatus of the present invention. Figure 4 is a diagram showing the configuration of the device of the present invention during measurement, and Figure 5 is a theory of the wavelength of Compton scattered radiation and the wavelength of monochromated incident X-rays at a certain scattering angle. Figures 6 and 7 are diagrams showing the analysis results obtained using the device of the present invention, and Figure 8 is a diagram showing the calibration to determine the wavelength of monochromatic incident X-rays from the wavelength of Compton scattered rays. It is a curve diagram. 11... Plated steel plate, 12... Measuring head, 21° 31-X II tube (X-ray generator) 23.33-.
・Monochromator, 26.36...Detector, 14...
・Traverse mechanism, 15...Wavelength conversion means, 16...
- Wavelength adjustment mechanism, 17... Drive control section, 18... Signal processing means, 18a... Theoretical value conversion means, 18b...
- Theoretical value calculation means, 18c...Parameter value determination means.

Claims (9)

[Claims] (1) A method for measuring the coating amount and coating composition of a plated steel sheet to be measured, which comprises the following steps (a) to (e). (a) Using the same optical system as when measuring the plated steel plate, a scattering plate made of a material with large Compton scattering is irradiated with monochromatic X-rays,
At this time, the wavelength of the monochromatic X-ray is indirectly measured based on a theoretical formula from the wavelength of the Compton scattered rays scattered from the scattering plate, and wavelength calibration is performed in which the optical system is adjusted so that the measured wavelength becomes a desired wavelength. (b) Analysis of the target element for analysis at two types of predetermined measurement angles obtained when monochromatic X-rays are incident on a plated steel plate at a predetermined angle of incidence using the optical system adjusted in this wavelength calibration step. K of
A step of predetermining a theoretical calculation formula for the fluorescent X-ray intensity or intensity ratio of the series, (c) using a standard sample with a known plating coating amount and plating film composition, under the same conditions as those used to obtain the theoretical calculation formula. ,
a step of actually measuring the fluorescent X-ray intensity or intensity ratio, and calculating in advance a conversion coefficient for converting the measured value into a theoretical calculation value from the actual measurement value and the theoretical calculation formula; (d) determining the theoretical calculation formula; A step of measuring the fluorescent X-ray intensity or intensity ratio obtained from a plated steel sheet with unknown plating amount and plating film composition under the same conditions as in the above, and converting it into a theoretical intensity or intensity ratio using the conversion coefficient, (e) The plating adhesion amount and film composition, which are parameters in the theoretical calculation formula, that bring the theoretical strength or intensity ratio obtained from the theoretical calculation formula closest to the converted theoretical strength or strength ratio, are used for the measured plating. A process to determine the amount of plating on a steel plate and the composition of the plating film. (2) A method for measuring the coating amount and coating composition of a plated steel sheet to be measured, which comprises the following steps (a) to (e). (a) Using the same optical system used to measure the plated steel plate, irradiate the scattering plate made of a material with large Compton scattering, based on the calibration curve determined in advance from the wavelength of the Compton scattered radiation scattered from the scattering plate. (b) using the optical system adjusted in this wavelength calibration step; The K of the target element for analysis at two types of predetermined measurement angles obtained when monochromatic X-rays are incident on a plated steel plate at a predetermined angle of incidence.
A step of predetermining a theoretical calculation formula for the fluorescent X-ray intensity or intensity ratio of the series, (c) using a standard sample with a known plating coating amount and plating film composition, under the same conditions as those used to obtain the theoretical calculation formula. ,
a step of actually measuring the fluorescent X-ray intensity or intensity ratio, and calculating in advance a conversion coefficient for converting the measured value into a theoretical calculation value from the actual measurement value and the theoretical calculation formula; (d) determining the theoretical calculation formula; A step of measuring the fluorescent X-ray intensity or intensity ratio obtained from a plated steel sheet with unknown plating amount and plating film composition under the same conditions as in the above, and converting it into a theoretical intensity or intensity ratio using the conversion coefficient, (e) The theoretical intensity or intensity ratio obtained from the theoretical calculation formula,
A step of setting the coating amount and coating composition, which are parameters in the theoretical calculation formula, that are closest to the converted theoretical strength or strength ratio, as the coating coating amount and coating coating composition of the plated steel sheet to be measured. (3) A method for measuring the coating amount and coating composition of a plated steel sheet to be measured, which comprises the following steps (a) to (d). (a) Using the same optical system as when measuring the plated steel plate, a scattering plate made of a material with large Compton scattering is irradiated with monochromatic X-rays,
At this time, the wavelength of the monochromatic X-ray is indirectly measured based on a theoretical formula from the wavelength of the Compton scattered rays scattered from the scattering plate, and wavelength calibration is performed in which the optical system is adjusted so that the measured wavelength becomes a desired wavelength. (b) Analysis of the target element for analysis at two types of predetermined measurement angles obtained when monochromatic X-rays are incident on a plated steel plate at a predetermined angle of incidence using the optical system adjusted in this wavelength calibration step. K of
(c) Calculating the plating amount and plating film composition under the same conditions as those used to obtain the calibration curve. (d) measuring the fluorescent X-ray intensity or intensity ratio obtained from the calibration curve; (d) measuring the fluorescent X-ray intensity or intensity ratio obtained from the calibration curve; A step of determining the coating amount and coating composition of the plated steel sheet to be measured as the parameters in the calibration curve that most closely approximate the ratio. (4) A method for measuring the coating amount and coating composition of a plated steel sheet to be measured, which comprises the following steps (a) to (d). (a) Using the same optical system used to measure the plated steel plate, irradiate the scattering plate made of a material with large Compton scattering, based on the calibration curve determined in advance from the wavelength of the Compton scattered radiation scattered from the scattering plate. (b) using the optical system adjusted in this wavelength calibration step; The K of the target element for analysis at two types of predetermined measurement angles obtained when monochromatic X-rays are incident on a plated steel plate at a predetermined angle of incidence.
(c) Calculating the plating amount and plating film composition under the same conditions as those used to obtain the calibration curve. (d) measuring the fluorescent X-ray intensity or intensity ratio obtained from the plated steel sheet of unknown composition; (d) converting the fluorescent X-ray intensity or intensity ratio obtained from the calibration curve to the measured fluorescent Alternatively, a step of setting the coating amount and coating composition of the plated steel sheet to be the parameters in the calibration curve that most closely approximate the intensity ratio. (5) An X-ray generator that generates X-rays, a monochromator that monochromates the X-rays generated from the X-ray generator, and a predetermined incidence of the monochromatic X-rays on the plated steel plate. A slit system that makes light incident at an angle and receives light at a predetermined acceptance angle, and 2 that measures the K-series fluorescent X-ray intensity of the analysis target element generated from the plated steel plate at different angles.
a traverse mechanism for appropriately moving these measurement systems between a scattering plate that generates strong Compton scattered rays and the plated steel plate; a wavelength conversion means for determining the wavelength of the monochromatic X-rays incident on the scattering plate using a theoretical formula from the wavelength of the scattered rays scattered from the scattering plate due to the incidence of the monochromatic X-rays; A wavelength adjustment means for adjusting an optical system constituting the measurement system so that the wavelength determined by the means becomes a desired wavelength, and a theory of the theoretical intensity or intensity ratio that should be obtained by the measurement system adjusted by the wavelength adjustment means. means for storing a calculation formula; means for converting a fluorescent X-ray intensity or intensity ratio actually measured using the measurement system whose optical system is adjusted by the wavelength adjustment means into a theoretical intensity or intensity ratio; and this conversion. Plating coating amount and plating coating of a plated steel sheet, comprising means for determining the plating coating amount and plating coating composition that minimize the difference between the theoretical strength or strength ratio obtained by a theoretical calculation formula. Composition measuring device. (6) An X-ray generator that generates X-rays, a monochromator that monochromates the X-rays generated from the X-ray generator, and a predetermined incidence of the monochromatic X-rays on the plated steel plate. A slit system that makes light incident at an angle and receives light at a predetermined acceptance angle, and 2 that measures the K-series fluorescent X-ray intensity of the analysis target element generated from the plated steel plate at different angles.
a traverse mechanism for appropriately moving these measurement systems between a scattering plate that generates strong Compton scattered rays and the plated steel plate; wavelength conversion means for determining the wavelength of the monochromatic X-rays incident on the scattering plate using a calibration curve determined in advance from the wavelength of the scattered rays scattered from the scattering plate due to the incidence of the monochromatic X-rays; a wavelength adjustment means for adjusting the optical system constituting the measurement system so that the wavelength determined by the wavelength conversion means becomes a desired wavelength; and a theoretical intensity that should be obtained by the measurement system adjusted by the wavelength adjustment means. or converting the actually measured fluorescent X-ray intensity or intensity ratio into a theoretical intensity or intensity ratio using means for storing a theoretical calculation formula for the intensity ratio and the measurement system whose optical system is adjusted by the wavelength adjustment means. and means for determining the coating amount and coating composition that minimize the difference between the converted theoretical strength or strength ratio and the theoretical strength or strength ratio obtained by the theoretical calculation formula. Measuring device for plating deposition amount and plating film composition. (7) An X-ray generator that generates X-rays, a monochromator that monochromates the X-rays generated from the X-ray generator, and a predetermined incidence of the monochromatic X-rays on the plated steel plate. A slit system that projects light at an angle and receives light at a predetermined receiving angle, and 2 that measures the K-series fluorescent X-ray intensity of the analysis target element generated from the plated steel plate at different angles.
a traverse mechanism for appropriately moving these measurement systems between a scattering plate that generates strong Compton scattered rays and the plated steel plate; a wavelength conversion means for determining the wavelength of the monochromatic X-rays incident on the scattering plate using a theoretical formula from the wavelength of the scattered rays scattered from the scattering plate due to the incidence of the monochromatic X-rays; A wavelength adjustment means for adjusting the optical system constituting the measurement system so that the wavelength determined by the means becomes a desired wavelength, and a calibration of the theoretical intensity or intensity ratio that should be obtained by the measurement system adjusted by the wavelength adjustment means. the difference between the fluorescence X-ray intensity or intensity ratio actually measured using the measurement system in which the optical system is adjusted by the wavelength adjustment means and the fluorescence X-ray intensity or intensity ratio obtained from a calibration curve; A measuring device for measuring the amount of plating and the composition of the plating film on a plated steel sheet, comprising means for determining the amount of plating and the composition of the plating film that minimize the amount of plating and the composition of the plating film. (8) An X-ray generator that generates X-rays, a monochromator that monochromates the X-rays generated from the X-ray generator, and a predetermined incidence of the monochromatic X-rays on the plated steel plate. A slit system that projects light at an angle and receives light at a predetermined receiving angle, and 2 that measures the K-series fluorescent X-ray intensity of the analysis target element generated from the plated steel plate at different angles.
a traverse mechanism for appropriately moving these measurement systems between a scattering plate that generates strong Compton scattered rays and the plated steel plate; wavelength conversion means for determining the wavelength of the monochromatic X-rays incident on the scattering plate using a calibration curve determined in advance from the wavelength of the scattered rays scattered from the scattering plate due to the incidence of the monochromatic X-rays; a wavelength adjustment means for adjusting the optical system constituting the measurement system so that the wavelength determined by the wavelength conversion means becomes a desired wavelength; and a theoretical intensity that should be obtained by the measurement system adjusted by the wavelength adjustment means. or a means for storing a calibration curve of intensity ratios, and a fluorescent X-ray intensity actually measured using the measurement system whose optical system is adjusted by the wavelength adjustment means, or a fluorescent X-ray intensity obtained from the intensity ratio and the calibration curve. Alternatively, a device for measuring the coating amount and coating composition of a plated steel sheet, comprising means for determining the coating coating amount and the coating coating composition that minimize the difference in strength ratio. (9) The slit system has a pinhole collimator on the incident side,
9. The apparatus for measuring the coating amount and coating composition of a plated steel sheet according to any one of claims 5 to 8, comprising a flat plate slit with a variable width on the light receiving side.