JPH0643889B2 - How to measure the amount of plating of metal materials - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an adhesion amount of a metal material, and is particularly suitable for use in measuring an adhesion amount of a plating film of various plating metal plates such as iron and aluminum. The present invention relates to an improvement in the method of measuring the amount of adhered metal deposits.

[Prior art]

Various plated steel sheets with excellent corrosion resistance, workability, paintability, weldability, etc. have been developed and are widely used for automobile bodies, household electric appliances, building materials, food canning products, etc. During production of these plated steel sheets, in order to stabilize the quality, it is essential to analyze the amount of the plated coating and control the process. As a method of analyzing the amount of adhesion of the coating film, there is a chemical analysis method in which only the coating film layer is electrolyzed or dissolved and removed by an appropriate acid, and the amount of adhesion of the coating film is obtained from the removed amount. Since it is very difficult to electrolyze only the coating layer without melting the (base metal), it takes a great deal of skill and time, and it is a destructive analysis that takes a sample from the product and cannot be put online. However, there is a problem that the measurement results are reflected in the process control very slowly. In order to solve such a problem, in recent years, a plated steel sheet is irradiated with X-rays having a wide wavelength distribution in order to excite various elements, and fluorescent X-rays of the elements present in the plated film are generated. The fluorescent X-ray analysis method of measuring the intensity of the generated fluorescent X-rays and analyzing the amount of the plating film adhered from the calibration curve obtained in advance has been put into practical use, and the online device will be marketed. It is becoming popular.

[Problems to be Solved by the Invention]

However, the fluorescent X-ray analysis method is expensive because a spectroscopic single crystal, a detector, a counting circuit, and the like must be installed for each type of metal element to be plated, and it is expensive in the usual method. When analyzing alloyed steel sheets containing the same metal, fluorescent X-rays from the base metal and fluorescent X-rays from the coating
There was a problem that analysis was impossible because it could not be distinguished from the line. In order to solve such a problem, the applicant has already proposed in Japanese Patent Application No. 59-209097 a method for measuring the amount and composition of the plating film of a plating steel plate containing an alloy containing the same metal as the base metal. . This method is suitable for alloy plated steel sheets with characteristic X
Of the X-ray and white X-ray, the composition of the alloy coating is measured from the diffraction angle of the X-ray diffracted by the alloy coating, and the fluorescent X-ray intensity from the metal different from the base metal in the alloy coating by the white X-ray is measured by the alloy. The amount of adhesion of the alloy coating is obtained by correcting the composition of the coating. However, in this measurement method, it is necessary to simultaneously measure the composition and the amount of deposition of the plating film of the alloy plating steel plate containing the same metal as the base metal, and the X-ray diffraction method and the fluorescent X-ray analysis method are used in combination. In this respect, there is a problem that the apparatus becomes expensive, and accordingly, it is not necessary to analyze the composition of the plating film and it is uneconomical to measure only the adhesion amount.

[Object of the Invention]

The present invention has been made in order to solve the above-mentioned conventional problems, various kinds of plating metal materials, for example, alloy plating steel plate containing the same metal as the base metal, conventionally, it is difficult to measure the plating adhesion amount. It is also an object of the present invention to provide a method for measuring the amount of sticking of a metal material, which enables economical and easy online measurement of the amount of sticking coating of a hard metal material.

[Means for solving problems]

The present invention relates to a method for measuring the amount of sticking of a metal material, as shown in FIG. 1, in which a fluorescent X-ray of the metal material (characteristic X (Also referred to as a line) is irradiated with a characteristic X-ray of a predetermined wavelength different from the wavelength of
Among the X-rays emitted from the metal material or its plating layer at an angular position where the diffracted X-rays do not appear, X-rays having the same wavelength as the irradiated characteristic X-rays are selected, and the selected X-rays The strength is detected as the back ground strength, and the metal deposition quantity of the metal material is calculated from the detected back ground strength using a calibration curve previously obtained based on the relationship between the back contact strength and the back ground strength. Thus, the above-mentioned object is achieved.

[Action]

When the sample is irradiated with X-rays when measuring the amount of adhered deposits, diffraction lines, background, and fluorescent X-rays due to the crystal structure of the sample (also called characteristic X-rays of the sample)
Is measured. Conventionally, the back ground is caused by scattering of incident X-rays by the sample, etc., and it has been said that it interferes with analysis, such as requiring correction when performing precise analysis. However, as a result of various investigations by the inventors, it was found that it provides very effective information for measuring the adhesion amount of the plating film. In particular, in the analysis of the amount of deposition of an alloy plating film having various problems as described above, particularly in the analysis of the amount of deposition of an alloy plating film containing the same metal as the base metal, the measured background strength is very high. It was found to be useful information. On the basis of such points, the present invention has further been made to find a method capable of measuring the background intensity as described above with higher accuracy. In particular, the influence of the above-mentioned diffraction lines and fluorescent X-rays (also referred to as characteristic X-rays of the sample) emitted from the sample together with the background is not affected, or the influence thereof is reduced, and According to the present invention, the intensity of the background having such characteristics can be measured with higher accuracy. FIG. 1 is a flow chart showing the gist of the present invention. In the method for measuring the amount of sticking of a metal material according to the present invention, as shown in step 104 in FIG. 1, first, a fluorescent X-ray of the metal material (characteristics of the metal material The characteristic X-ray having a predetermined wavelength different from the wavelength (also referred to as X-ray) is emitted. By irradiating the plated metal material with a characteristic X-ray having a predetermined wavelength different from the wavelength of the fluorescent X-ray of the metal material, due to the difference in the wavelength, the background of the irradiated characteristic X-ray is changed. The intensity can be detected while reducing the influence of the fluorescent X-ray of the metal material. For example, in Examples described later, the wavelength of the fluorescent X-rays generated from the plated steel plate 14 is in accordance with the elemental components contained in the plated steel plate 14. On the other hand, the X-ray tube 16
The wavelength of the characteristic X-rays irradiated from the above to the plated steel plate 14 becomes a wavelength peculiar to the Cr target when the X-ray tube 16 is made to be the Cr target. Therefore, in this embodiment, the wavelengths of these fluorescent X-rays and the wavelengths of the characteristic X-rays emitted from the X-ray tube 16 are different. Then, in step 106, among the X-rays emitted from the metal material or the plating layer thereof, the X-rays having the same wavelength as the irradiated characteristic X-rays are selected at the angular position where the diffracted X-rays do not appear. The intensity of the diffracted X-ray is according to the crystal structure of the target sample, specifically, the crystal spacing. Therefore, for a metal material having an alloy plating, the diffracted X-ray intensity fluctuates due to the fluctuation of the alloy element component ratio of the plating, and such fluctuation causes the plating adhesion. It adversely affects the quantity measurement. Therefore, in the present invention,
By setting the angular position where the diffracted X-ray does not appear, the influence of such diffracted X-ray is reduced. Further, the intensity of fluorescent X-rays from the metal material, which is generated when the metal material is irradiated with X-rays, is also affected by the component ratio when the target plating film is an alloy. The variation in the composition ratio of the alloy forming the plating film is a size that cannot be ignored from the viewpoint of measuring the plating adhesion amount. For example, in the case of a plating film of a Zn-Fe alloy on a base metal of Fe, if the ratio of Zn in the alloy increases, the fluorescent X-ray intensity due to Zn increases, and the fluorescent X-ray intensity is reduced. Therefore, the amount of sticking to be detected becomes a large value. For this reason, in the present invention, the background intensity is measured by performing the selection according to the wavelength while reducing the influence of such fluorescent X-rays. For example, in the embodiment described later, the wave height selector 26 selects only the X-rays having the wavelength of the incident characteristic X-rays, while reducing the influence of the fluorescent X-rays from the plated steel plate 14. Further, such selection is performed at an angular position where the diffracted X-ray does not appear. Then, in step 108, the intensity of the selected X-ray is detected as the background intensity. Further, in step 110, using the calibration curve obtained from the back ground strength detected in this way, based on the relationship between the amount of sticking deposit and the back ground strength, which is previously obtained, the metal material The sticking amount is determined. Therefore, in the present invention, as described above, by measuring the background intensity while reducing the influence of diffracted X-rays and the influence of fluorescent X-rays, it is possible to more effectively determine the amount of in-coat adhesion. . Hereinafter, the relationship between the amount of deposit and the back ground strength will be described. That is, the back ground intensity measured at the same angular position (2θ) using the same X-ray tube varies depending on the types of the base metal and the plating film metal, and, for example, the back ground strength only by the base metal is When the back ground intensity is weaker than that of the coating metal alone, as the thickness of the coating film (adhesion amount) increases within the penetration depth of the incident X-ray, for example, the X of the Cr target shown in FIG.
The measured back ground strength increases as in the measurement results of galvannealed steel plates using a wire tube. This figure shows the relationship between the back ground strength and the adhesion amount of the alloy plating film (Zn-Fe alloy) when the angular position (2θ) is set to 94 °. From the figure, the measured plated alloy layer of the galvannealed steel sheet contains 8 to 14% Fe (Z
It can be seen that a good calibration curve is obtained despite the fact that n varies from 92 to 86%). From this,
Alloy plating containing the same metal as the base metal (Fe) (Zn-
It can be seen that even with Fe), and even if the composition of the alloy plating film changes within the practical range, the plating adhesion amount can be accurately analyzed. On the other hand, in the opposite case, the back ground strength decreases as shown in the result of measuring the tinned steel plate using the X-ray tube of Cr target shown in FIG. 3, for example. This figure shows the relationship between the back ground strength and the adhesion amount of the tin (Sn) plating film when the angular position (2θ) is 90 °. It can be seen from FIG. 3 that a very good calibration curve can be obtained, and by using this calibration curve, the amount of adhesion of tin plating on the steel sheet can be accurately analyzed. Therefore, if a standard sample is prepared in advance for each type of plating metal plate and a calibration curve is created from the relationship between the adhesion amount of plating metal and the background ground strength, the background ground strength can be measured. The amount of adhered metal material to be measured is obtained. The background intensity measured in this case is not the background intensity at the diffraction angle (2θ) of the diffracted X-ray estimated for the background correction as shown in FIG. Any measurement may be performed as long as the background intensity is measured at a diffraction angle (2θ) that does not appear. The present invention has been made based on the above knowledge, and a characteristic X-ray is applied to a metal material to be measured, and an angular position (2θ) at which no diffraction line appears based on an X-ray diffraction method.
Then, the background strength generated from the metal material is detected, and a calibration curve obtained in advance based on the relationship between the adhesion amount and the background strength is used to detect the plating of the metal material from the detected background strength. The amount of adhesion is determined. Therefore, unlike the fluorescent X-ray analysis method, it is not necessary to install a spectroscopic system (single crystal for spectroscopic analysis, detector, counting circuit, etc.) for each element of the plated metal. It is possible to measure the amount of adhered metal coating. Further, it becomes possible to nondestructively and economically measure the adhesion amount of the alloy coating film containing the same metal as the base metal, which has been very difficult to measure conventionally. Here, when the method of the present invention is considered to be on-line, the plated metal plate is, for example, 100 to several hundred m / m in the production line.
Since the flow is performed at a high speed of min, the plated metal plate flutters to a greater or lesser extent and is susceptible to the influence in the concentration method, so it is effective to use the parallel beam method.

EXAMPLE Hereinafter, an example of an apparatus for measuring the amount of sticking of metal, which adopts the method for measuring the amount of sticking of metal according to the present invention, will be described in detail. In this embodiment, as shown in FIG.
The present invention is applied to an online plating amount measuring device for measuring the thickness (coating amount) of the plating film of the plating steel plate 14 which is plated by the roll 12 and conveyed in the direction of the arrow A by the roll 12. . The plating amount measuring device for plating is arranged at an appropriate position of the horizontal transporting part (or vertical transporting part) of the plating steel plate 14,
An X-ray tube 16 for generating a characteristic X-ray of an appropriate wavelength capable of removing fluorescent X-rays from the plated steel plate 14 due to a difference in wavelength, such as a Cr target, as will be described later in detail, and the X-ray tube. The divergent solar slit 18 that makes the X-rays emitted from 16 a parallel beam, the light receiving solar slit 20 that makes the background generated from the plated steel plate 14 a parallel beam, and the intensity of the background that has passed through the light receiving solar slit 20. And a goniometer 24 for installing the light receiving solar slit 20 and the back ground detector 22 at arbitrary angular positions, and a wave height selector 26 for extracting X-rays having an appropriate wave height (wavelength). A counting circuit 28 for measuring the intensity of the X-rays extracted by the wave height selector 26, and a computer for calculating the adhesion amount of the plating film. Includes a motor 30, and a display 32 for displaying the operation results of the computer 30 in the field lines and the like,
A signal is output to the process computer 34 that controls the plating conditions of the plating tank 10. The operation of the embodiment will be described below. The steel plate 14 that has been plated by the plating layer 10 is conveyed by the roll 12 in the direction of arrow A. At that time, X-ray tube 16
The X-rays emitted from the laser beam are made into a parallel beam through the divergent solar slit 18 and are directed toward the plated steel plate 14 at an incident angle ψ. Then, a back ground, a diffraction line, and a fluorescent X-ray are generated from the plated steel plate 14. The wavelength of the fluorescent X-ray generated from the plated steel plate 14 is Fe,
This is in accordance with the elemental components contained in Zn, Sn, etc. On the other hand, the wavelength of the characteristic X-ray emitted from the X-ray tube 16 is the Cr target when the Cr target is used as described above.
This is a wavelength unique to the target. Therefore, the wavelength of the fluorescent X-ray generated from the plated steel plate 14 and the wavelength of the characteristic X-ray emitted from the X-ray tube 16 are different. The back ground intensity of the generated X-rays is adjusted at an appropriate angular position (2θ) where the diffraction line from the plating film of the plating steel plate 14 and the base steel plate does not appear, and the light receiving solar slit 20
It is detected by the background detector 22 via the. The background intensity detected by the background detector 22 is adjusted to an appropriate wave height (wavelength) by the wave height selector 26.
X-rays are taken out, and the background intensity is measured by the counting circuit 28. The measured value of the background intensity measured by the counter circuit 28 is input to the computer 30 and the amount of adhered coating film is calculated based on a calibration curve previously obtained for each type of plating. The result is the field line display 32.
Is displayed on the screen and is also input to the process computer 34, and the plating conditions of the plating layer 10 and the like are controlled by the analysis values. If the light receiving solar slit 20 and the background detector 22 are installed on the goniometer 24,
Since the background ground strength can be measured at any angle position (2θ), various plated steel sheets can be measured, which is very effective, but the type of plated steel sheet is fixed and the same measurement is performed. If the position (2θ) can be selected, they may be fixed. Further, the wave height selector 26 extracts the wavelength of the incident characteristic X-rays, for example, and the plating film excited by the white X-rays generated from the X-ray tube 16 at the same time as the characteristic X-rays. It is important to remove the fluorescent X-rays of the elements contained in the base steel sheet. In this way, fluorescent X-rays from the plated steel plate 14 can be removed because of the elements contained in the plated film and the base steel plate with respect to the wavelength of the characteristic X-rays emitted from the X-ray tube 16. This is because the wavelength of the fluorescent X-ray is different. Further, the opening angle between the divergent solar slit 18 and the light-receiving solar slit 20 is determined by the method of measuring the alloying degree of galvannealed steel sheet which the applicant of the present invention has already filed (Japanese Patent Laid-Open No. 59-913).
As shown in 43), 1 to 4 ° is optimal. By doing so, the range that is not affected by the displacement due to the flapping of the steel plate 14 to be measured and the like is wide, so that it is easy to go online. Moreover, in the method of measuring the alloying degree,
The X-ray diffraction intensity and the back ground intensity of the target crystal lattice plane are also measured at the same time to obtain the alloying degree after the back ground intensity correction. However, if the method of the present invention is used together, not only the alloying degree but also the plating It can be seen that the thickness (adhesion amount) of the coating can be measured at the same time, and it provides a very effective method which is a further developed method for measuring the alloying degree of the galvannealed steel sheet of the prior application. In addition, in the above-mentioned example, as the plated metal material, various plated metal plates were illustrated, but the metal material is not limited thereto.
Includes all metal plates or materials such as iron and aluminum.

【The invention's effect】

As described above, according to the present invention, a spectroscopic system (single crystal for spectroscopic analysis,
It is not necessary to install a detector, a counting circuit, etc., and an inexpensive and simple device can be used to measure the adhesion amount of all kinds of plated metal coatings. Further, it becomes possible to nondestructively and economically measure the adhesion amount of the alloy film containing the same metal as the base metal, which has been very difficult to measure conventionally. Furthermore, since it can be measured online and the analysis results can be immediately fed back to the line, it has an excellent effect that it contributes to stable operation and quality improvement in the production line of all kinds of plated metal. .

[Brief description of drawings]

FIG. 1 is a flow chart showing the gist of the present invention, and FIG. 2 is an example of the relationship between the amount of alloy (Zn-Fe) plating adhered on a galvannealed steel plate and the back ground strength for explaining the principle of the present invention. FIG. 3 is a diagram showing an example of the relationship between the amount of tin deposit on the steel plate and the back ground intensity, and FIG. 4 is a diagram showing the relationship between the diffraction angle (2θ) and the X-ray intensity. FIG. 5 is a block diagram including a partial layout diagram showing a configuration of an embodiment of a deposit adhesion amount measuring device adopting the method for measuring deposit adhesion amount of a metal material according to the present invention. It is a figure. 10 ... Plating tank, 14 ... Plating steel plate, 16 ... X-ray tube, 18 ... Divergence solar slit, 20 ... Photosensitive solar slit, 22 ... Back ground detector, 26 ... Wave height selector, 28 ... Counting circuit, 30 ... Computer , Ψ ... X-ray incident angle, 2θ ... Back ground measurement angle.

Front page continuation (72) Inventor Masaharu Masaharu 1 Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Works (56) References JP, B1) JP-B 46-42137 (JP, B1) JP-B 50-2020 (JP, Y1)

Claims (1)

[Claims] 1. A metal material to which plating is applied is irradiated with a characteristic X-ray having a predetermined wavelength different from the wavelength of the fluorescent X-ray of the metal material, and the metal is plated at an angular position where no diffracted X-ray appears. Of the X-rays emitted from the material or its plating layer, X-rays having the same wavelength as the irradiated characteristic X-rays are selected, and the intensity of the selected X-rays is detected as the background intensity, Using a calibration curve previously obtained based on the relationship between the amount of adhesion and the background ground strength, the amount of adhered adhesion of the metal material is obtained from the detected background ground strength Method.