KR20110028017A - Method for measuring the weight and component of coating layer - Google Patents

Abstract

PURPOSE: A method for measuring the plating amount and component content of a plating layer is provided to calculate the plating amount and component content of a plating layer formed on a steel plate using a non-destructive method. CONSTITUTION: A method for measuring the plating amount and component content of a plating layer comprises following steps. One or more relational expressions are prepared between regression analysis relational expression 1 and regression analysis relational expression 2. The regression analysis relational expression 1 relates to fluorescence X-rays intensity emitted from a steel plate, fluorescence X-rays intensity emitted from each component of a planting layer, and the planting amount. The regression analysis relational expression 2 relates to fluorescence X-rays intensity emitted from the steel plate, fluorescence X-rays intensity emitted from each component of the planting layer, and the content of each component. X rays are irradiated on the steel plate formed with the planting layer. The intensity of the fluorescence X-ray emitted from the steel plate and the intensity of the fluorescence X-ray emitted from each component of the plating layer are measured using an X-ray detector(2).

Description

Method for measuring plating amount and component content of plating layer

The present invention relates to a method for measuring the plating amount and the component content, and more particularly, to a method capable of quickly and accurately measuring the plating amount and the component content of a plated layer by using a relational expression derived by X-ray and regression analysis.

In general, plating products are used in a wide range of fields such as home appliances, automobiles and building materials. The plated product depends on its use and corrosion resistance depending on the amount of plating and the component content. Therefore, accurate measurement and control of their plating amount and ingredient content is an important factor in the quality control of products.

Conventionally, the wet method was used as a method of measuring the plating amount of a plating layer. The wet method is to take the selected position of the plated steel sheet as a sample and measure the weight, and then melt the plated layer using an acid solution that can only dissolve the plated layer in the sample of the plated steel sheet and weighed again to measure the weight The plating amount was measured by the value which the sample weight after melt | dissolving a plating layer from the sample weight was taken out. The method can obtain a relatively accurate value, but it has a disadvantage in that it takes a lot of manpower and time according to the measurement.

Therefore, the fluorescent X-ray method is used a lot as a method of measuring the thickness or plating amount of a plating layer. Fluorescence X-ray method can be used to measure the amount of plating and the content of the plating layer quickly and accurately without destroying the sample, which is widely used in the industrial field, offline and online measurement.

The intensity of the fluorescent X-rays emitted from the material constituting the plating layer increases as the plating amount of the plating layer increases. The plating amount of the plating layer can be measured using this. Also, even when the plating layer is composed of two or more alloys, the content (component ratio) of each component can be known as long as the fluorescent X-rays of the components constituting the plating layer can be measured.

However, when a component having a low atomic number is included in the alloy component, the fluorescent X-rays emitted from the component are absorbed in the air and do not reach the X-ray detector. Therefore, it is difficult to measure the plating amount and component content of a plating layer by the conventional method.

In addition, in order to easily reach the X-ray detector by the fluorescent X-ray emitted from the plating layer, there is a method of making the path into a vacuum state or filling with a light gas such as He, but for this purpose, additional devices such as a vacuum device and a helium supply device Was required and could not be applied online.

The present invention provides a method capable of quickly and accurately measuring the plating amount and the component content of a plating layer by substituting the intensity value of the fluorescent X-rays emitted by the X-rays into the relational expression derived by regression analysis in advance by using X-rays. I would like to.

In one embodiment, the present invention relates to a method for measuring the plating amount and the component content of a plating layer, wherein X-rays are irradiated onto a standard sample steel sheet having a plating layer, and each component of the fluorescent X-ray intensity and the plating layer emitted from the steel sheet of the standard sample. At least one of a regression relation 1 between the fluorescence X-ray intensity emitted from and the amount of plating and a regression relation 2 between the fluorescence X-ray intensity emitted from the steel sheet and the fluorescence X-ray intensity emitted from each component of the plating layer and the content of each component Preparing the above relations; Irradiating X-rays on the steel plate on which the plating layer to be measured is formed from the X-ray source; Measuring the intensity of the fluorescent X-rays emitted from the steel sheet and the intensity of the fluorescent X-rays emitted from each component of the plating layer by using an X-ray detector, and measuring the intensity of the measured fluorescent X-rays by at least one of It provides a measuring method comprising the step of calculating at least one or more of the plating amount and the component content of the plating layer by substituting a relational expression.

It is preferable that the said plating layer consists of a binary alloy.

It is preferable that said relationship 1 is the following relationship (1).

Relation (1): plating amount (g / m 2) = a + b (I _Fe ) + c (I _A ) + d (I _Fe ) ² + e (I _A ) ²

(However, a, b, c, d, e: constant, I _Fe : fluorescence X-ray intensity (cps) of the steel sheet and I _A : fluorescence X-ray intensity (cps) of the components contained in the plating layer)

The I _A is preferably the fluorescent X-ray intensity of the component having the highest atomic number among the components included in the plating layer.

It is preferable that said relationship 2 is the following relationship (2).

Relation (2): Component content (% by weight) to be measured = f + g (I _Fe ) + h (I _A ) + i (I _Fe ) ² + j (I _A ) ²

(However, f, g, h, i, j: constant, I _Fe : fluorescence X-ray intensity (cps) of the steel sheet and I _A : fluorescence X-ray intensity (cps) of the component to be measured among the components included in the plating layer)

The component to be measured is a component having the highest atomic number, and I _A is preferably the fluorescent X-ray intensity of the component having the highest atomic number among the components included in the plating layer.

Using the measuring method of the present invention, it is possible to calculate the plating amount and the component content of the plating layer plated on the steel sheet quickly and precisely by a non-destructive method. In addition, when used for on-line measurement, it is possible to check the plating amount and the component content in real time during the manufacturing process, it can also be adjusted automatically can be useful in the production site of alloy plated steel sheet.

In order to calculate the plating amount or component content of the plating layer, a plurality of samples have already been prepared and the plating amount or component content of the plating layer is measured by a wet method, and the relational expression is derived using the intensity value of the fluorescent X-ray. Under the same conditions as above, the plating amount or component content of the plating layer may be measured by substituting the intensity value of the fluorescent X-rays emitted from the unknown sample into the relational expression.

The measuring method of this invention is demonstrated.

A number of standard samples (plated steel sheets) of various thicknesses and components are prepared. Here, the thickness and the component range of the standard sample preferably include the thickness and the component range to be measured.

In the prepared standard sample, the plating layer is dissolved in a solution that can dissolve the plating layer, and then the plating amount and the component content of the plating layer are first measured by using a wet analysis method. In this case, a method that can be mainly used as a wet analysis method is Indutively Coupled Plasma (ICP).

As shown in FIG. 1, X-rays are irradiated onto the standard sample using the X-ray supply source 1. As shown in FIG. At this time, the X-ray source 1 generates X-rays in an X-ray tube having tungsten or rhodium as the cathode.

Fluorescent X-rays are secondary X-rays emitted from a sample irradiated with X-rays. When X-rays are irradiated from the X-ray source as described above, fluorescent X-rays are emitted from the steel sheet and the plating layer. The intensity of the emitted fluorescent X-rays is measured using the X-ray detector 2. At this time, the intensity of the fluorescent X-rays emitted by Fe of the steel sheet and the intensity of the fluorescent X-rays emitted by the heavy component having a high atomic number among the components included in the plating layer are measured.

In the case of a component having a low atomic number, the fluorescent X-rays emitted by the component are often absorbed in the air and cannot be detected. In particular, in the case of atomic number 14 or less, the emitted fluorescent X-rays are absorbed in the air.

The method of measuring the component content is preferably applied when the plating layer is a binary alloy system. The content of the higher atomic number is derived first, and the other components correspond to the balance.

Using the amount of plating and the fluorescent X-rays measured in the above can be derived using a regression analysis method. The following relational expression (1) is a relational expression derived by the said regression analysis method. The following constants a, b, c, d and e can be obtained using commercial programs.

Relation (1): plating amount (g / m 2) = a + b (I _Fe ) + c (I _A ) + d (I _Fe ) ² + e (I _A ) ²

(However, a, b, c, d, e: constant, I _Fe : fluorescence X-ray intensity of steel sheet and I _A : fluorescence X-ray intensity of component contained in plating layer)

(The unit of each constant is a: g / m 2, b, c: (cps) * g / m 2, d, e: (cps) ² * g / m ^2. )

Using the component content and the fluorescence X-rays measured in the above can be derived using a regression analysis method. The following relation (2) is a relation derived by the regression analysis. The following constants f, g, h, i and j can be obtained using a commercial program.

Relation (2): Component content (% by weight) to be measured = f + g (I _Fe ) + h (I _A ) + i (I _Fe ) ² + j (I _A ) ²

(However, f, g, h, i, j: constant, I _Fe : fluorescence X-ray intensity of the steel sheet and I _A : fluorescence X-ray intensity of the component to be measured among the components included in the plating layer)

(The unit of each constant is f: weight%, g, h: (cps) * weight%, i, j: (cps) ² * weight%.)

The amount of plating can be calculated by measuring the intensity of fluorescent X-rays emitted after irradiating X-rays under the same conditions as the standard sample with respect to the unknown sample to be measured and substituting it into the above-mentioned equation (1). In addition, the component content can be calculated by substituting the relation (2). Here, the same condition as the standard sample means that the X-ray intensity, the detector condition, and the measurement time are the same when measuring an unknown sample.

Hereinafter, the present invention will be described through examples.

(Example)

Samples 1 to 14 including the Zn-based plating layer were measured by the inductively coupled plasma method (wet) and the amounts of Zn and the contents of Zn were measured and described in Table 1 below. In order to determine the accuracy of the measuring method according to the present invention, after irradiating X-rays to the samples 1 to 14 and measuring the intensity of the fluorescent X-rays emitted by Zn and Fe of the steel sheet, a relational expression derived by regression analysis ( Substituting in 1) and (2), the plating amount and the content of Zn were calculated and described in addition to Table 2 below.

Relation (1): Plating amount (g / m 2) = 72.3165 -0.4939 (I _Fe ) + 0.1168 (I _A ) + 0.0008 (I _Fe ) ² -0.002 (I _A ) ²

The unit of each constant is a: g / m 2, b, c: (cps) * g / m 2, d, e: (cps) ² * g / m ^2. )

Relation (2): Component content to be measured (% by weight) = -187.45 + 1.3555 (I _Fe ) + 0.4272 (I _A ) + 0.0017 (I _Fe ) ² + 0.0004 (I _A ) ²

3 is a graph showing the relationship between the plating amount calculated by the present invention and the plating amount measured by the inductively coupled plasma method, and FIG. 4 shows the Zn content calculated by the present invention and the Zn content measured by the inductively coupled plasma method. A graph showing the relationship.

sample Zn XRF
Strength (cps) Fe XRF
Strength (cps) Plating amount
(Wet, g / ㎡) Plating amount
(Invention, g / ㎡) Zn content
(Wet, Weight%) Zn content
(Invention, weight%) One 112.2 246.0 14.47 15.07 93.79 93.76 2 95.7 259.4 12.18 12.29 91.53 90.14 3 84.7 267.4 10.85 11.01 89.89 86.17 4 73.9 279.1 9.73 9.66 88.46 83.72 5 77.6 273.7 10.19 10.15 87.28 83.42 6 71.4 271.6 9.73 9.52 84.91 81.05 7 65.9 273.0 9.22 9.02 83.46 79.88 8 57.2 279.2 8.31 8.26 80.67 74.17 9 52.2 282.6 7.85 7.76 78.51 69.69 10 253.9 130.8 38.53 38.25 94.36 94.31 11 251.6 130.2 38.78 38.56 93.57 93.71 12 220.2 152.7 32.92 34.00 91.51 89.72 13 214.2 156.1 31.95 32.43 90.81 90.07 14 227.2 144.4 35.21 34.91 90.95 91.03

As can be seen in Table 1, Figure 3 and Figure 4, the value of the plating amount and the content of Zn measured by the conventional inductively coupled plasma method and the amount of plating and Zn calculated by the measuring method according to the present invention is You can see a close match. Figure 2 shows a graph measuring the fluorescence X-ray intensity of Sample 1.

1 is a conceptual diagram of a generation principle of fluorescent X-rays.

2 is a graph showing the intensity of the measured fluorescent X-rays of Sample 1. FIG.

3 is a graph showing the relationship between the inductively coupled plasma method and the amount of plating measured by the measuring method according to the present invention for Samples 1 to 14;

4 is a graph showing the relationship between the inductively coupled plasma method and the Zn content measured by the measuring method according to the present invention with respect to Samples 1 to 14.

<Description of Drawing>

1: X-ray source

2: X-ray detector

Claims (6)

In the method of measuring the plating amount and the component content of the plating layer, Irradiating X-rays on the standard sample steel sheet having a plating layer, and the regression relationship between the fluorescent X-ray intensity emitted from the steel sheet of the standard sample, the fluorescence X-ray intensity emitted from each component of the plating layer and the plating amount Preparing at least one relationship of fluorescence X-ray intensity, regression relationship 2 between fluorescence X-ray intensity emitted from each component of the plating layer and content of each component; Irradiating X-rays on the steel plate on which the plating layer to be measured is formed from the X-ray source; Measuring the intensity of the fluorescent X-rays emitted from the steel sheet and the intensity of the fluorescent X-rays emitted from each component of the plating layer using an X-ray detector; and And calculating at least one or more of the plating amount and the component content of the plating layer by substituting the measured intensity of the fluorescent X-rays into at least one relational expression among the relational expressions 1 and 2. The method of claim 1, wherein the plating layer is made of a binary alloy. The method of claim 1, wherein the relational expression 1 is the relational expression (1) below. Relation (1): plating amount (g / m 2) = a + b (I _Fe ) + c (I _A ) + d (I _Fe ) ² + e (I _A ) ² (However, a, b, c, d, e: constant, I _Fe : fluorescence X-ray intensity (cps) of the steel sheet and I _A : fluorescence X-ray intensity (cps) of the components contained in the plating layer) The method of claim 3, wherein I _A is a fluorescent X-ray intensity of a component having the highest atomic number among the components included in the plating layer. The method of claim 1, wherein the relational expression 2 is the relational expression (2) below. Relation (2): Component content (% by weight) to be measured = f + g (I _Fe ) + h (I _A ) + i (I _Fe ) ² + j (I _A ) ² (However, f, g, h, i, j: constant, I _Fe : fluorescence X-ray intensity (cps) of the steel sheet and I _A : fluorescence X-ray intensity (cps) of the component to be measured among the components included in the plating layer) The method according to claim 5, wherein the component to be measured is a component having the highest atomic number, and the I _A is a fluorescent X-ray intensity of the component having the highest atomic number among the components included in the plating layer.

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