JP2002202263A - Method for measuring element concentration and element concentration gradient in film in emission spectrochemical analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the concentration of an element and the concentration gradient of the element in a film for emission spectrochemical analysis, capable of simply measuring the concentration of an element and the concentration gradient of the element in a film obtained by modifying the surface of a carburized layer, or the like. SOLUTION: Tin concentration data and carbon concentration data are calculated from the intensity data of tin or carbon emission spectra generated when spark discharge within a discharge range 205 is applied J times to a test piece 200. A group of meshes 601 are obtained by equally dividing a virtual pixel group 600 corresponding to the discharge range 205 by J. The tin concentration data is allotted to the mesh group; the first one thereof to a mesh S (1, 1) on its upper end in the y-direction, the second one thereof to a mesh neighboring in the x-direction, and so on. The carbon concentration data sets are sequentially allotted ion order of carbon concentration; the first set to a mesh (ns+1, 1) in a row next to the row where the last tin concentration data set is allotted to a mesh S ns, m(ns)}, the second one to a mesh neighboring in the x-direction, and so on. The concentration and concentration gradient of carbon are calculated based on the maximum length in the y- direction of the group of meshes 601 to which the carbon concentration data sets are allotted and on the carbon concentration data allotted to the respective meshes 601 in an array 700 comprising meshes 601 presenting the maximum length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an element concentration and an element concentration gradient of a film in emission spectroscopy.

[0002]

2. Description of the Related Art Conventionally, carburization and carbonitriding of steel have been known as one method of improving the quality (particularly, surface modification) of steel products, and even today, new methods such as gas carburizing and vacuum carburizing (nitriding) are known. Technology is being actively developed.

[0003] Accurate grasp of the carbonized carbon (carbonitriding nitrogen) concentration and the carbonitriding carbon (carbonitriding nitrogen) concentration gradient from the surface to the core of the steel product obtained by the surface modification. However, it is extremely important not only for establishing processing conditions and quality control standards for products obtained by surface modification, but also for elucidating carburizing (nitriding) reactions and diffusion phenomena.

Conventionally, as a method for grasping the carbon concentration and the carbon concentration gradient of a carburized layer, a measuring method using an emission spectrometer and a micrometer is known. In this measurement method, first, the thickness of a measurement sample cut out of a steel product is measured in advance by a micrometer, and the measured measurement sample is analyzed by an emission spectrometer. Thereafter, the analysis surface of the measurement sample is polished by a predetermined amount with a parallel polishing machine, the polished amount is measured by a micrometer, and the polished analysis surface is repeatedly analyzed by an emission spectrometer to repeat the carbonization of the carburized layer. Obtain concentration and carbon concentration gradients. That is, in this measurement method, the depth of the carburized layer is obtained from the difference in thickness of the measurement sample before and after polishing (hereinafter, this measurement method is referred to as “multi-stage method”).

[0005] In addition to this, a method for grasping the carbon concentration and the carbon concentration gradient of the carburized layer, that is, the film thickness of the film of the measurement sample having the film of the carburized layer (carbonitriding) or the plating, the element surface diffusion, etc. Many measurement methods are known, and a typical method is a film thickness measurement method using fluorescent X-rays. This measurement method irradiates the film surface of a measurement sample having a film with X-rays, measures the intensity of fluorescent X-rays generated from the film surface, converts the measured intensity, and sequentially determines the element concentration of the film in the film thickness direction. Is what you want
Further, the element concentration gradient of the film is determined by line analysis using an X-ray microanalyzer (EPMA).

[0006]

However, in the above-mentioned multi-stage method, since the polishing and the measurement of the polished amount are repeated,
In addition to requiring a long time for pretreatment of the measurement sample, there is a problem that polishing is difficult with a measurement sample having a small thickness.

On the other hand, in a film thickness measuring method using fluorescent X-rays, a film such as a carburized (carbonitrided) layer is too thick (about 10 μm).
m or more) and the measurement becomes impossible, and the EPMA line analysis requires a long time.

An object of the present invention is to provide an element concentration and an element concentration gradient of a film obtained by modifying the surface of a carburized layer, etc., the type of a specific element contained in a material, the location of the particles and the particle size. An object of the present invention is to provide a method for measuring the element concentration and the element concentration gradient of a film in emission spectroscopy, which can easily measure the size and the like.

[0009]

According to a first aspect of the present invention, there is provided a method for measuring an element concentration and an element concentration gradient of a coating in emission spectroscopy, comprising the steps of: In the method for measuring the element concentration and the element concentration gradient of a film in emission spectroscopy for calculating the concentration of the first element and the concentration gradient thereof, a second element in which the measurement sample is embedded so that a cut surface of the layer is exposed. A preparing step of preparing a test piece having the member described above, and a predetermined number of times for a predetermined range including a boundary between the layer and the member of the second element and a cut surface of the layer in the prepared test piece. A discharge step of discharging only the first element, a mesh dividing step of dividing the predetermined range by a matrix group of meshes, and the first element or the predetermined number of times generated each time the predetermined range is discharged. A spectrum assigning step of detecting an emission spectrum of a second element and assigning the detected emission spectrum to each mesh of the mesh group; and a step of assigning the emission spectrum of the first element to the plurality of meshes. And a concentration gradient calculating step of calculating a concentration of the first element and a concentration gradient thereof based on a maximum length in a direction perpendicular to the first direction and an emission spectrum assigned to each of the plurality of meshes. .

[0010] According to the method for measuring the element concentration and the element concentration gradient of the film in the emission spectroscopy according to the first aspect, the second sample in which the cut sample of the layer containing the first element is exposed is exposed. Prepare a test piece having a member of the element, discharge a predetermined number of times to a predetermined range including a boundary between the layer and the member of the second element and a cut surface of the layer in the prepared test piece, a predetermined number of times, The range is divided by a matrix-like mesh group,
A predetermined number of emission spectra of the first element or the second element, which are generated every time a predetermined range is discharged, are detected, and the detected emission spectrum is assigned to each mesh of the mesh group. The concentration of the first element and the concentration gradient of the first element are calculated based on the maximum length in the direction perpendicular to the boundary in the plurality of meshes to which the emission spectra of the elements are respectively assigned and the emission spectrum assigned to each of the plurality of meshes. Therefore, the concentration of the first element and the concentration gradient thereof can be easily measured, and the efficiency of the analysis of the concentration of the first element and the concentration gradient thereof can be improved.

[0011] More preferably, in the mesh division step, the predetermined range is divided into a mesh group composed of meshes equal to or less than the predetermined number of times.

[0012] For example, since the predetermined range is divided by a mesh group composed of meshes equal to or less than the number corresponding to the predetermined number of times, when discharging in the predetermined range, even if discharging to the same place, Insufficiency of the emission spectrum assigned to the mesh can be avoided.

[0013] Preferably, in the spectrum assigning step, the second element is moved in a direction parallel to the boundary from a mesh at an end of the matrix element group on the member side with respect to a direction perpendicular to the boundary. And the emission spectrum of the first element is assigned in order of intensity in a direction parallel to the boundary from the mesh in the row next to the row of the mesh to which the emission spectrum of the last second element is assigned. Is good.

For example, an emission spectrum of the second element is allocated in a direction parallel to the boundary from the mesh on the member side end of the second element in a direction perpendicular to the boundary of the matrix group of meshes, and the last second element is allocated. Since the emission spectrum of the first element is assigned in order of intensity in a direction parallel to the boundary from the mesh in the next row of the mesh to which the emission spectrum is assigned, the boundary in a predetermined range can be accurately represented.

[0015] More preferably, based on a ratio of the number of emission spectra of the first element to the number of emission spectra of the second element, the area is set such that the area of the second element on the member side is smaller than the area of the second element. A dividing step of dividing in a direction parallel to the boundary so as to correspond to a ratio of the number of emission spectra of the second element; and in the mesh dividing step, the emission of the first element in the divided range is performed. The range corresponding to the ratio of the number of spectra is divided by a mesh group composed of the same number of meshes as the number of emission spectra of the first element, and in the spectrum assignment step, the boundary of the divided mesh group is The emission spectrum of the first element is preferably assigned in order of intensity from the mesh on the side in a direction parallel to the boundary.

For example, based on the ratio between the number of emission spectra of the first element and the number of emission spectra of the second element,
The range is divided in a direction parallel to the boundary so that the area of the second element on the member side corresponds to the ratio of the number of emission spectra of the second element, and the emission spectrum of the first element in the divided range The range corresponding to the ratio of the numbers is divided into mesh groups composed of the same number of meshes as the number of the emission spectra of the first element, and the meshes on the boundary side of the divided mesh group are moved in a direction parallel to the boundary. Since the emission spectrum of the first element is assigned in order of intensity, it is not necessary to assign the emission spectrum of the second element to the mesh group, and the measurement of the concentration of the first element and its concentration gradient can be performed more easily.

More preferably, when detecting the emission spectrum of the first or second element for the predetermined number of times generated in the discharging step, a first emission spectrum composed of the emission spectrum of the first element is used. It is preferable to have a spectrum arrangement step of creating a second arrangement composed of the arrangement of the first element and the emission spectrum of the second element, and arranging the emission spectrum of the first element in the first arrangement in order of intensity. .

For example, when the emission spectra of the first or second element for a predetermined number of times are detected, the first arrangement composed of the emission spectrum of the first element and the emission spectrum of the second element are used. Since the second arrangement is created and the emission spectra of the first elements in the first arrangement are arranged in the order of the intensity, the assignment of the emission spectra of the first elements in the order of the intensity can be easily performed. .

More preferably, the first prepared first
Preferably, the emission spectrum of the first element is converted into the concentration based on a calibration curve representing the relationship between the emission spectrum of the element and the concentration of the first element.

For example, since the emission spectrum of the first element is converted into the concentration based on a calibration curve which represents the relationship between the emission spectrum of the first element and the concentration of the first element, the first element is converted into the concentration. Can be easily obtained.

More preferably, in the concentration gradient calculating step, based on the average value of the concentration obtained by converting the emission spectrum of the first element assigned to each mesh in the mesh array in a direction parallel to the boundary. The first
It is preferable to calculate the concentration of the element and its concentration gradient.

For example, the concentration of the first element and the concentration gradient of the first element are calculated based on the average value of the concentration obtained by converting the emission spectrum of the first element assigned to each mesh in the mesh arrangement in the direction parallel to the boundary. Therefore, the concentration of the first element and its concentration gradient can be accurately obtained.

[0023] More preferably, said first element is carbon, said layer is a carburized layer, and said second element is tin.

For example, since the first element is carbon and the second element is tin, the emission spectrum of the first element and the emission spectrum of the second element can be clearly distinguished.

[0025] More preferably, said first element is nitrogen, said layer is a carbonitrided layer, and said second element is tin.

For example, since the first element is nitrogen and the second element is tin, the emission spectrum of the first element and the emission spectrum of the second element can be clearly distinguished.

More preferably, the method for measuring the element concentration and the element concentration gradient of the film in the emission spectral analysis is performed by an emission spectral analyzer.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a measuring method according to an embodiment of the present invention will be described in detail with reference to the drawings.

The measuring method according to the embodiment of the present invention is executed by the following emission spectrometer when measuring the carbon concentration and the element concentration gradient of the carburized layer of a steel product.

First, a schematic configuration of an emission spectrometer for executing the measuring method according to the embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of an emission spectrometer for executing a measuring method according to an embodiment of the present invention.

In FIG. 1, an emission spectrometer 100 is shown.
Is composed of a light-emitting unit 101, a light-emitting stand 102 containing a test piece described later, a spectroscopic unit 103, a photometric unit 104, an interface 105, a data processing unit 106, and a data display unit 107.

The light splitting unit 103 includes a light shielding plate 110 having an entrance slit 108 and a plurality of exit slits 109, a concave diffraction grating 111, a plurality of photomultiplier tubes 112, and an oil rotary pump 113.

The light emitting stand 102 is connected to the interface 105 via the light emitting unit 101, and the photomultiplier tube 112 is similarly connected to the interface 105 via the light measuring unit 104.
The interface 105 is connected to the data processing unit 10.
6 to the data display unit 107.

The light emitting unit 101 is disposed at a position where an electrode (not shown) incorporated in the light emitting unit 101 can perform a spark discharge 114 on a test piece included in the light emitting stand 102. It is arranged on the surface of the light splitting unit 103 on an extension of the slit 108 and the concave diffraction grating 111.

In the light shielding plate 110, each exit slit 1
09 is arranged on an extension line rotated by a diffraction angle specific to each of the plurality of elements around the concave diffraction grating 111 from the extension line of the entrance slit 108 and the concave diffraction grating 111, and each photomultiplier tube 112 is also disposed. It is arranged on its extension.

At least the space between the light emitting unit 101 and the light emitting stand 102 is filled with an inert gas (eg, argon gas).

The electrode of the light emitting section 101 is a light emitting stand 102
Spark discharge occurs between the test piece contained in the concave diffraction grating 1 and the emission spectrum containing information of a plurality of elements from the spark-discharged test piece through the entrance slit 108.
11, the concave diffraction grating 111 splits the emitted emission spectrum using a diffraction angle unique to each element,
Each of the split emission spectra is output to each exit slit 109.
, And is incident on each photomultiplier tube 112. At this time, each of the separated emission spectra becomes an emission spectrum containing only information of an element unique to each.

The photomultiplier tube 112 detects the incident light emission spectrum, converts the intensity of the detected light emission spectrum into a current value, and converts the converted current value into the photometric unit 1.
04, the photometric unit 104 converts the transmitted current value into a digital value, and transmits the converted digital value to the data processing unit 106 via the interface 105. Further, the light emitting unit 101 and the light emitting stand 102 transmit the number of spark discharges and the range of the test piece that has undergone the spark discharge to the data processing unit 106 via the interface 105.

The data processing unit 106 executes a carbon concentration gradient calculation process of FIG. 4 described below based on the transmitted digital value, the number of spark discharges, and the range in which the spark discharge has been received, and calculates the carbon concentration and the carbon concentration gradient. calculate.

The data display unit 107 is a CRT or a printer, and displays the concentration gradient obtained by the carbon concentration gradient calculation processing of FIG. 4, the distribution of the emission spectrum of each element, and the like.

Hereinafter, the carbon concentration gradient calculation processing executed by the emission spectrometer 100 of FIG. 1 will be described with reference to the drawings.

FIG. 2 is a diagram showing an example of a schematic configuration of a test piece used in the process of calculating the carbon concentration gradient of a film performed by the emission spectrometer 100 of FIG.

In FIG. 2, the test piece 200 is a ring 2
01, a tin portion 202 (embedded material of the measurement sample 204), and a measurement sample 204 having a carburized layer 203.

The test piece 200 is a disc-shaped test piece having a diameter of 60 mm and a thickness of 20 mm.
The tin portion 202 is embedded in the tin portion 202 such that a cut surface cut in a direction perpendicular to the carburized layer 203 is exposed.
2 is surrounded by a ring 201.

The measurement sample 204 is a sample cut out of the steel product 300 so as to include the carburized layer 203 (FIG. 3).
(A)), having a carburized layer 203 on its surface (FIG. 3)
(B)). The chemical composition of the steel product 300 is shown in Table 1 below.

[0047]

[Table 1]

FIG. 4 is a flowchart of the carbon concentration gradient calculation process executed by the emission spectrometer 100 of FIG.

In FIG. 4, first, spark discharge is applied to a 5 mmφ circular discharge range 205 including the carburized layer 203 and the tin portion 202 on the test piece 200 in which the electrode of the light emitting portion 101 is included in the light emitting stand 102. Is performed J times, and the data processing unit 106 calculates the tin or carbon emission spectrum intensity data based on the digital value obtained for each spark discharge by executing the density data calculation process of FIG. The emission spectrum intensity data of carbon among the emission spectrum intensity data is converted into carbon concentration data based on a calibration curve of FIG. 5 described later. At this time, since the tin purity of the tin portion 202 is 100%, all the emission spectrum intensity data of tin in the obtained emission spectrum intensity data is converted as 100% tin concentration data.

These density data are all stored in the data array I (i) {i = 1, 2,... J} in the order of spark discharge (step S900).

FIG. 5 is a diagram showing a calibration curve used in step S900 of FIG.

The calibration curve 500 shown in FIG. 5 is obtained in advance based on reference test samples (samples 1 to 9) of the carbon content of the chemical composition shown in Table 2 below.

[0053]

[Table 2]

Returning to the processing of FIG. 4, the data processing unit 106 executes the density data classification processing of FIG. 10 to be described later and executes the density data stored in the data array I (i) {i = 1, 2,... J}. The data is represented by a data array Sn (iS) ｛i of tin concentration data.
S = 1, 2,...} And the data array C (i
F) {iF = 1, 2,...} (Step S1)
000).

Let iS _{max be} the number of tin concentration data and iF
_{When max} is the number of carbon concentration data, the data array of tin concentration data is Sn (iS) ｛iS = 1, 2,.
S _max }, and the data array of carbon concentration data is C
(IF) {iF = 1, 2,... IF _max }. At this time, the sum of iS _max and iF _max is J.

Next, the data processing unit 106 executes a carbon concentration data alignment process shown in FIG. 11 to be described later to execute a data array C (iF) ｛iF = 1, 2,... I of carbon concentration data.
F _max } are arranged in order of carbon concentration in order of carbon concentration, and the data array C _max (iFF) {iFF = 1,
2,... IF _max } are created (step S1100).

Next, the data processing unit 106 executes a mesh creation process shown in FIG. 12 to be described later, and a circular virtual pixel group 600 corresponding to the area of the discharge range 205 shown in FIG.
, The virtual pixel group is divided, and a square mesh 601 in FIG. 6 described below is created on a memory (not shown) (step S1200).

FIG. 6 is a diagram showing the mesh created in step S1200 of FIG.

In FIG. 6, the x (row) direction in the figure is a direction parallel to the boundary between the carburized layer 203 and the tin portion 202, and the y (column) direction in the figure is a direction perpendicular to the boundary. Also,
n is the number of rows from the upper end of the virtual pixel group 600 in the y direction (that is, the end on the tin portion 202 side in the direction perpendicular to the boundary in the discharge range 205), and m (n)
Is the mesh 60 from the end in the x direction in the nth row
This is the order of 1. Therefore, each mesh 601 is represented by a mesh S {n, m (n)}.

Returning to the processing of FIG. 4, the data processing unit 106 executes the tin density data assigned row number calculation processing of FIG. 13 described later to calculate the number ns of rows in the virtual pixel group 600 to which tin density data is assigned ( Step S1300),
Further, a tin concentration data allocation process shown in FIG. 14 to be described later is executed, and a data array Sn (iS) ｛iS =
Each tin concentration data of 1, 2,... IS _max } is allocated in the x direction from the mesh S (1, 1) at the upper end in the y direction of the virtual pixel group 600 (step S1400).

Next, the data processing unit 106 executes a carbon concentration data allocation process shown in FIG. 15 to be described later, and a data array Sn (iS) ｛iS = 1, 2,.
_max ｝, the last tin concentration data in mesh S ｛ns, m
(Ns)} and then arranged in carbon concentration order data array C
_max (iFF) {iFF = 1, 2,..., iF _max } is converted to a mesh S (ns + 1, 1) in order of carbon concentration.
Are assigned in the x direction (step S1500).

Next, the data processing unit 106 generates a data array C _max (iFF) ｛iFF = 1, 2,.
_max ｝ of all carbon concentration data in mesh S ｛n, m
After (n)｝, the virtual pixel group 600 is formed by a mesh 601 arranged in the direction opposite to the y direction from the central mesh 601 in the ns + 1st row in the virtual pixel group 600 by executing a carbon concentration gradient graph creation process of FIG. Array 700 in which the length in the y direction of the group of meshes 601 to which the carbon concentration data is assigned is maximized (FIG. 7), and the carbon concentration data of each mesh 601 in the array 700 and the ns row and ns +
The boundary with one line (that is, the tin portion 202 and the carburized layer 203)
Based on the distance from the boundary to the respective meshes 601, a carbon concentration gradient graph showing the relationship between the carbon concentration and the distance from the boundary shown in FIG. 8 is created (step S1600).
This processing ends.

According to the processing of FIG. 4, tin concentration data and carbon concentration data are obtained from emission spectrum intensity data of tin or carbon element generated when J spark discharges are performed on the discharge range 205 of the test piece 200. The calculation is performed (step S900), and the tin concentration data is calculated in the x direction from the mesh S (1, 1) at the upper end in the y direction of the group of meshes 601 obtained by dividing the virtual pixel group 600 corresponding to the discharge range 205 into J equal parts. Assignment (step S140
0), the mesh S (n) in the row next to the row of the mesh S {ns, m (ns)} to which the last tin concentration data is assigned
s + 1, 1), the carbon concentration data is allocated in the x direction in the order of carbon concentration (step S1500), and the maximum length in the y direction of the group of meshes 601 to which the carbon concentration data is allocated and the mesh 601 exhibiting the maximum length The carbon concentration and the carbon concentration gradient are calculated based on the carbon concentration data assigned to each of the meshes 601 of the array 700 constituted by the steps (step S1600), so that the carbon concentration and the carbon concentration gradient of the carburized layer are easily measured. It is possible to improve the efficiency of the analysis of the carbon concentration and the carbon concentration gradient of the carburized layer.

Hereinafter, the processing in each step of the processing in FIG. 4 will be described using a flowchart.

FIG. 9 is a flowchart of the density data calculation processing in step S900 of FIG.

The density data calculation process shown in FIG.
J is calculated by combining J tin concentration data and carbon concentration data based on the emission spectrum obtained when the spark discharge is performed J times with respect to 05.

In FIG. 9, the data processing unit 106 calculates tin or carbon emission spectrum intensity data based on the digital value obtained for each spark discharge (step S901), and sets the counter number i to 1 (step S901). S902).

Further, carbon emission spectrum intensity data among the calculated emission spectrum intensity data is converted into carbon concentration data based on the calibration curve of FIG. 5, or tin emission spectrum intensity is calculated from the calculated emission spectrum intensity data. All data are tin concentration data (all values are 10
0%), and all these density data are stored in the data array I (i) {i = 1, 2,... J} in the order of spark discharge (step S903), and the data array I (i)
{I = 1, 2,... J} are stored in the memory (step S9).
04) Then, it is determined whether or not the counter number i is smaller than the number J of spark discharges (step S905).

If the result of determination in step S905 is that the counter number i is smaller than the number J of spark discharges, 1 is added to the counter number i and the process returns to step S903. Ends this processing.

FIG. 10 is a flowchart of the density data classification processing in step S1000 of FIG.

The concentration data sorting process shown in FIG. 10 separates tin concentration data and carbon concentration data into separate data arrays.

In FIG. 10, first, the counter number iS of tin concentration data and the counter number iF of carbon concentration data are set to 0 (step S1001), the counter number i is set to 1 (step S1002), and the data array I
(I) It is determined whether or not each concentration data of {i = 1, 2,... J} is tin concentration data (step S1003).

If the result of determination in step S1003 is that the concentration data is tin concentration data, 1 is added to the counter number iS of tin concentration data (step S1004), and a data array of tin concentration data Sn (iS) ｛iS = 1,2,
.. (Step S1005).

If the result of determination in step S1003 is that the concentration data is not tin concentration data, 1 is added to the counter number iF of the carbon concentration data (step S1006),
Data array of carbon concentration data C (iF) ｛iF = 1,
,... (Step S1007).

Thereafter, it is determined whether or not the counter number i is smaller than the number J of spark discharges (step S100).
8).

If it is determined in step S1008 that the counter number i is smaller than the number of spark discharges J, 1 is added to the counter number i and the process returns to step S1003. If the counter number i is equal to or greater than the number of spark discharges J, , A data array of tin concentration data Sn (iS) ｛iS = 1, 2,
... and data array C (iF) ｛iF of carbon concentration data
= 1, 2,... Are stored in the memory, and the process is terminated.

FIG. 11 is a flowchart of the carbon concentration data alignment processing in step S1100 of FIG.

In the carbon concentration data alignment process shown in FIG. 11, the data array C (iF) ｛iF = 1, 2,
.. Are arranged in order of carbon concentration.

In FIG. 11, first, the counter number iS of the tin concentration data and the counter number iF of the carbon concentration data after the end of the processing of FIG.
_max and the data number iF _{max of the} carbon concentration (step S
1101).

Next, the counter number iFF is set to 1, and the carbon concentration order data C _max (iFF) is set, and the initial value C _max (1) of the carbon concentration order data is set to the data array C (iF ) ｛IF = 1,2, ... i
F _max炭素 is set to the carbon concentration data C (1) (step S1102).

Next, the counter number iF is set to 1 (step S1103), and the carbon concentration order data C _max (i
FF) and the difference C (iFF) between the carbon concentration data C (iF)
Is calculated (step S1104), and the difference C (iFF) is calculated.
Is greater than 0 (step S110).
5).

As a result of the determination in step S1105, the difference C
If (iFF) is greater than 0, the data C
_max (iFF) is maintained as it is (step S110)
6) If the difference C (iFF) is 0 or less, the carbon concentration data C (iF) is substituted into the carbon concentration order data C _max (iFF) (step S1107).

Next, after adding 1 to the counter number iF (step S1108), it is determined whether or not the counter number iF is equal to or smaller than the carbon concentration data number iF _max (step S1109).

As a result of the determination in step S1109, the count
Data number iF is the data number iF of carbon concentration _maxWhen
Returns to step S1104, and if the counter number iF is
Number of concentration data iF_maxIf greater, the number of counters
One is added to iFF (step S1110), and the carbon concentration is added.
Substituting 0 into data C (iF), the data of carbon concentration data
Array C (iF) ｛iF = 1, 2,... IF_maxReturn to｝
(Step S1111), the counter number iFF becomes carbon
Number of concentration data iF_maxDetermine if
(Step S1112).

[0085] If it is determined in the step S1112, when counter number iFF is less than the number of data iF _max of carbon concentration, the process returns to step S1103, when counter number iFF data number iF _max greater than the carbon concentration, the carbon concentration Order data array C _max (iFF) ｛iFF = 1, 2,...
iF _max } is stored in the memory, and the process ends.

FIG. 12 is a flowchart of the mesh creation processing in step S1200 of FIG.

The mesh creation processing shown in FIG. 12 is to divide the circular virtual pixel group 600 corresponding to the area of the discharge range 205 shown in FIG. 6 and create a square mesh 601 shown in FIG. 6 on the memory. .

In FIG. 12, first, the data processing unit 10
No. 6 sets the number n of rows to 1 (step S1201).

Next, the length L (n) of the array of the mesh 601 in the n-th row and the number m of the mesh 601 in the n-th row
_max (n) is calculated in the following procedure (step S120)
2) Stored in memory.

In general, the radius L, the length L of the line of intersection between the circle having the center coordinates (R, R) and y = c is represented by the following equation (1): L = 2 (c (2R−c)) ^{1 / 2} (1) The height y (n) in the y direction up to the n-th row is represented by the following equation (2), where the length of one side of each square mesh 601 is tmm.

Y (n) = 2R-nt (2) At this time, tmm is a discharge range 205 having a radius of Rmm.
Is calculated based on the area obtained by dividing the area of J by J, and further adjusted so that 2R / t is a natural number. Further, L (n) and y in L and c of the above formula (1), respectively.
By substituting (n), the following equation (3) representing L (n) is obtained.

L (n) = 2 [(2R−nt) ｛2R− (2R−nt)}] ^1/2 (3) Further, m _max (n) is represented by the following equation (4).

M _max (n) = L (n) / t (4) Then, the upper limit number k of rows n represented by the following equation (5) (assumed to be an integer) k = 2R / t (5) ), It is determined whether or not the number n of rows is small (step S1203).

As a result of the determination in step S1203, the number of rows n
Is smaller than the upper limit number k, 1 is added to the row number n (step S1204), and the process returns to step S1202. If the row number n is equal to or larger than the upper limit number k, L (n) and m _max (n)
Is stored in the memory.

After that, the data processing unit 106 divides the virtual pixel group 600 based on L (n) and m _max (n) stored in the memory and converts the square mesh 601 having one side of tmm into J. This process is completed, and the process ends.

FIG. 13 is a flowchart of the tin concentration data allocation row number calculation processing in step S1300 of FIG.

The process of calculating the number of rows of tin concentration data allocated in FIG. 13 is for calculating the number of rows of the virtual pixel group 600 to which tin concentration data is allocated.

In FIG. 13, first, the data processing unit 10
No. 6 sets the number of rows n to 1 (step S1301).

Next, after calculating the integrated value of m _max (n) up to the n-th row (step S1302), it is determined whether or not the calculated integrated value is equal to or larger than the number of tin concentration data iS _max (step S1302). Step S1303).

[0100] accumulated integration value result, calculated in the determination of step S1303 is time less than the data number iS _max of tin concentration, which adds 1 to the line number n (step S1304), the process returns to step S1302, the calculated when the value is more than the number of data iS _max of tin concentration, by substituting the number of lines n in the row number ns of tin concentration data is allocated (step S
1305), this process ends.

FIG. 14 is a flowchart of the tin concentration data allocating process in step S1400 of FIG.

The tin concentration data allocating process shown in FIG. 14 is performed in a data array Sn (iS) ｛iS = 1, 2,
... Each tin concentration data of iS _max } is converted to mesh S {n, m
(N) is assigned to｝.

In FIG. 14, first, the data processing unit 10
6 sets the number n of rows, the order m (n), and the number iS of counters to 1 (step S1401), and sets the tin concentration data Sn (iS) {iS = 1, 2,... IS _max } for each tin concentration. Assign the data to mesh S {n, m (n)}. At this time, in the same n rows, each tin concentration data is assigned in the x direction (step S1402). The data processing unit 106 converts one tin concentration data into a mesh S
After assigning to {n, m (n)}, the order m (n) of the assigned mesh S {n, m (n)} is set to m in the n-th row.
_It is determined whether it is smaller than _max (n) (step S1).
403).

As a result of the determination in step S1403, the order m (n) of the assigned mesh S {n, m (n)} is changed to the n-th
If it is smaller than m _max (n) of the row, 1 is added to the order m (n) of the assigned mesh S {n, m (n)} (step S1404), and then the counter number iS becomes the data number of tin concentration. iS _max smaller determines whether or not a (step S1405).

As a result of the determination in step S1405, the count
Is the number of tin concentration data iS _maxWhen less than
Adds 1 to the counter number iS (step S140
6), the process returns to step S1402, and the counter number iS is
Data number iS_maxIn the case above, this processing is completed
I do.

As a result of the determination in step S1403, the order m (n) of the assigned mesh S {n, m (n)} is changed to the n-th
If the number of rows is equal to or greater than m _max (n), 1 is added to the number of rows n (step S1407), and then it is determined whether or not the number of rows n is equal to or less than the number of rows ns to which tin concentration data is assigned (step S1408). .

As a result of the determination in step S1408, the number of rows n
Is smaller than or equal to the number of rows ns to which tin concentration data is assigned, the order m (n) is set to 1 (step S140).
9), 1 is added to the counter number iS (step S14)
10) Returning to step S1402, if the number of rows n is greater than the number of rows ns to which the tin concentration data is assigned, the process ends.

FIG. 15 is a flowchart of the carbon concentration data allocating process in step S1500 of FIG.

The carbon concentration data allocating process shown in FIG. 15 is based on the data array C (iFF) ｛iFF = 1,
2,... IF _max } are assigned to meshes S {n, m (n)} in order of carbon concentration.

In FIG. 15, first, the data processing unit 10
6 sets the number of rows n to ns + 1 (step S150)
1), the order m (n) is set to 1 (step S150)
2) Then, the counter number iFF is set to 1 (step S1503).

Next, the data array C of the carbon concentration data
(IFF) ｛iFF = 1, 2,... IF _max各 each carbon concentration
Degree data into mesh S {n, m (n)} in order of carbon concentration
assign. At this time, in the same n rows, each carbon concentration data
Data is allocated in the x direction (step S150)
4). The data processing unit 106 stores one piece of carbon concentration data
After assigning to the key S {n, m (n)}
The order m (n) of the mesh S {n, m (n)} is
m_max(N) It is determined whether it is smaller than (step S)
1505).

As a result of the determination in step S1505, the order m (n) of the assigned mesh S {n, m (n)} is changed to the n-th
If it is smaller than m _max (n) of the row, 1 is added to the order m (n) of the assigned mesh S {n, m (n)} (step S1506), and the counter number iFF is equal to the number of data of the carbon concentration. iF _max determines whether or not the following (step S1507).

[0113] If it is determined in the step S1507, the counter number IFF is when the following number of data iF _max carbon concentration, adds 1 to the counter number IFF (step S150
8), the process returns to step S1504, the counter number iFF is when the number of data iF _max greater than the carbon concentration, the process ends.

As a result of the determination in step S1505, the order m (n) of the assigned mesh S {n, m (n)} is changed to the n-th
If the number of rows is equal to or greater than m _max (n), 1 is added to the number of rows n (step S1509), and it is determined whether or not the number of rows n is equal to or less than the upper limit number k (step S1510).

As a result of the determination in step S1510, the number of rows n
Is smaller than or equal to the upper limit number k, m (n) is set to 1 (step S1511), 1 is added to the counter number iFF (step S1512), and the process returns to step S1504, where the row number n is larger than the upper limit number k. In this case, the process ends.

FIG. 16 is a flowchart of the carbon concentration gradient graph creation process in step S1600 of FIG.

[0117] The carbon concentration gradient graph creation processing of FIG.
A carbon concentration gradient graph is created based on the concentration data of each mesh CC (n, nc) in the array 700 and the distance from the boundary to each mesh CC (n, nc).

In FIG. 16, first, the data processing unit 10
6 is the number n of rows and the number ns of rows to which tin concentration data is assigned
Is set to the number obtained by adding 1 to the array 700, and the array 700 is set (step S1601). Then, the order n of the mesh CC (n, nc) constituting the array 700 represented by the following equation (6) is set.
c is calculated (step S1602).

Nc = m _max (n) / 2 (6) Next, the mesh S (n, nc) is changed to the mesh CC (n,
nc), and the mesh CC (n, nc) is arranged in an array 700
(Step S1603), the number of rows n becomes the upper limit k
It is determined whether or not it is smaller (step S1604).

As a result of the determination in step S1604, the number of rows n
Is smaller than the upper limit k, 1 is added to the number of rows n (step S1605), and the process returns to step S1602. If the number of rows n is equal to or larger than the upper limit k, each mesh CC (n, nc) of the array 700 is 8) on the basis of the density data of FIG.
Is created, the created carbon concentration gradient graph is displayed on the data display unit 107, and the process ends.

Further, the carbon concentration gradient graph creation processing in step S1600 of FIG. 4 may use the average value of the carbon concentration data of each mesh S {n, m (n)} in the n-th row.

FIG. 17 is a flowchart of the carbon concentration gradient graph creation processing using the average value of the carbon concentration data in the n-th row in step S1600 in FIG.

The carbon concentration gradient graph creation processing of FIG.
A carbon concentration gradient graph is formed based on the average value C _T (n) of the carbon concentration data substituted for each mesh CC (n, nc) of the array 700 and the distance from the boundary to each mesh CC (n, nc). To create.

In FIG. 17, first, the data processing unit 10
6 is the number n of rows and the number ns of rows to which tin concentration data is assigned
Is set to the number obtained by adding 1 to an array 700, and an array 700 is set. The mesh CC (n,
nc) is calculated, and the mesh S (n, n) is calculated.
c) is set as a mesh CC (n, nc) (step S1).
701) After that, the average value C _T (n) of the carbon concentration data of the n-th row represented by the following equation (7) is calculated (step S17).
02).

[0125]

(Equation 1)

Next, the average value C _T (n) of the carbon concentration data is substituted for the carbon concentration data of the mesh CC (n, nc), and the mesh CC (n, nc) is added to the array 700. Is smaller than the upper limit value k (step S1703).

As a result of the determination in step S1703, the number of rows n
Is smaller than the upper limit k, 1 is added to the number n of rows (step S1704), and the process returns to step S1702. If the number n of rows is equal to or larger than the upper limit k, each mesh C of the array 700 is
The carbon concentration gradient graph of FIG. 8 is created based on the average value C _T (n) of the carbon concentration data of C (n, nc) and the distance from the boundary to each mesh CC (n, nc). The obtained carbon concentration gradient graph is displayed on the data display unit 107, and this processing ends.

The case where the measurement sample 204 is cut out from the steel product 300 shown in Table 1 so as to include a carburized layer has been described above. When the measurement sample 204 is cut out, the composition chemical components shown in Table 3 below are used. If the reference test sample of nitrogen having is used, the nitrogen concentration and the nitrogen concentration gradient in the carbonitrided layer of the measurement sample 204 are changed in the same manner as the carbon concentration and the carbon concentration gradient of the measurement sample 204 including the carburized layer by the processing of FIG. You can ask.

[0129]

[Table 3]

[0130]

Next, embodiments of the present invention will be described specifically.

Example 1 A test sample 200 shown in FIG. 2 was cut out from a steel product 300 shown in Table 1 to prepare a test piece 200 shown in FIG. 2, and a 5 mmφ circular discharge range 205 of the test piece 200 was prepared. Spark discharge was performed 1000 times. Further, the discharge range 205 is defined as a square 1 having a side length of 0.14 mm.
000 meshes 601 and the process of FIG. 4 described above is performed to reduce the carbon concentration gradient of the steel product 300 by 0.5 mm.
The depth was calculated. On the other hand, for comparison, the carbon concentration gradient of the same steel product 300 was calculated to a depth of 0.5 mm by a multi-stage method.

FIG. 18 is a diagram comparing the carbon concentration gradient calculated by the processing of FIG. 4 with the carbon concentration gradient calculated by the multi-stage method.

The solid line in FIG. 18 is the emission spectral analysis value of the carbon concentration gradient calculated by the processing of FIG. 4, and the broken line is the chemical analysis value of the carbon concentration gradient calculated by the multistage method. As shown in FIG. 18, it was recognized that the emission spectral analysis value and the chemical analysis value agreed well, and it was found that the measurement method according to the embodiment of the present invention had the same inspection accuracy as the conventional multistage method. .

Example 2 In the same manner as in Example 1, the nitrogen reference test sample shown in Table 3 was used as shown in FIG.
2 is cut out from the measurement sample 204 shown in FIG.
00 and 5 mmφ in the prepared test piece 200.
Spark discharge is performed for 100
Performed 0 times. Further, the discharge range 205 is divided into 1000 square meshes 601 having a side length of 0.14 mm.
And the above-described processing of FIG. 4 was executed to calculate the nitrogen concentration gradient of the carbon nitride steel to a depth of 0.5 mm. On the other hand, for comparison, the nitrogen concentration gradient of the same carbon nitride steel was calculated to a depth of 0.5 mm by a multi-step method.

FIG. 19 is a diagram for comparing the nitrogen concentration gradient calculated by the processing of FIG. 4 with the nitrogen concentration gradient calculated by the multi-stage method.

The solid line in FIG. 19 is the emission spectral analysis value of the nitrogen concentration gradient calculated by the processing of FIG. 4, and the broken line is the chemical analysis value of the nitrogen concentration gradient calculated by the multistage method. As shown in FIG. 19, it is recognized that the emission spectral analysis value and the chemical analysis value also agree well, and that the measurement method according to the embodiment of the present invention has inspection accuracy equivalent to that of the conventional multistage method. Do you get it.

In the measuring method according to the embodiment of the present invention, the number of spark discharges and the number of meshes 601 are the same. However, there is a possibility that spark discharge is performed at the same location in discharge range 205. is there. Therefore, the number of spark discharges and the number of meshes 601 to be created may be determined by experiments, or the number of meshes 601 to be created in advance may be set to be smaller than the number of spark discharges.

Also, a case has been described in which the measuring method according to the embodiment of the present invention is executed to calculate the carbon concentration and the carbon concentration gradient or the nitrogen concentration and the nitrogen concentration gradient. However, the measuring method according to the embodiment of the present invention is described. The method may be performed to calculate only the film thickness of the carbon layer or the carbon nitride layer. Further, in addition to the steel product 300 and the carbon nitride steel of Table 3 above, the concentration of phosphorus or sulfur in the surface modified layer And the concentration gradient of phosphorus or sulfur, or an element capable of emission spectroscopy analysis of chromium, nickel, copper, etc. in the plating layer, and the concentration of the conductive element and the concentration gradient thereof can be similarly calculated. .

[0139]

As described above in detail, according to the method for measuring the element concentration and the element concentration gradient of the film by the emission spectroscopy according to the first aspect, the cut surface of the layer containing the first element is exposed. Prepare a test piece having a member of the second element in which the measurement sample is embedded in a predetermined range including a cut surface of the layer and a boundary between the layer and the member of the second element in the prepared test piece. Discharges a predetermined number of times, divides a predetermined range into a matrix-like mesh group, and emits a predetermined number of emission spectra of the first element or the second element each time the predetermined range is discharged. Is detected, and the detected emission spectrum is assigned to each mesh of the mesh group. The maximum length in the direction perpendicular to the boundaries of the plurality of meshes to which the emission spectrum of the first element is assigned and each mesh of the plurality of meshes are assigned. Assigned The concentration of the first element and its concentration gradient are calculated based on the emission spectrum obtained, so that the concentration of the first element and its concentration gradient can be easily measured, and the analysis of the element concentration and the element concentration gradient can be performed. Efficiency can be measured.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an emission spectrometer that executes a measurement method according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a schematic configuration of a test piece used in a carbon concentration gradient calculation process of a film performed by the emission spectrometer 100 of FIG.

3A and 3B are diagrams illustrating a schematic configuration of a measurement sample 204 in FIG. 2; FIG. 3A is a diagram illustrating a cutout position of the measurement sample 204 cut out from a steel product 300 so as to include a carburized layer 203; Is the carburized layer 20 in the measurement sample 204
FIG.

FIG. 4 is a flowchart of a carbon concentration gradient calculation process executed by the emission spectrometer 100 of FIG. 1;

FIG. 5 is a diagram showing a calibration curve used in step S900 of FIG. 4;

FIG. 6 is a diagram illustrating a relationship between a circular virtual pixel group 600 corresponding to an area of a discharge range 205 and a mesh 601 created on a memory.

FIG. 7 is a diagram showing an array 700 in which the length in the y direction in the group of the meshes 601 to which the carbon concentration data of FIG.

FIG. 8 is a diagram showing a carbon concentration gradient graph representing the relationship between the carbon concentration and the distance from the boundary created by the processing of FIG. 4;

FIG. 9 is a flowchart of a density data calculation process in step S900 of FIG. 4;

FIG. 10 is a flowchart of density data classification processing in step S1000 of FIG.

FIG. 11 is a flowchart of a carbon concentration data alignment process in step S1100 of FIG.

FIG. 12 is a flowchart of a mesh creation process in step S1200 of FIG.

FIG. 13 is a flowchart of a tin concentration data allocation row number calculation process in step S1300 of FIG. 4;

FIG. 14 is a flowchart of a tin concentration data assignment process in step S1400 of FIG.

FIG. 15 is a flowchart of a carbon concentration data allocation process in step S1500 of FIG.

FIG. 16 is a flowchart of a carbon concentration gradient graph creation process in step S1600 of FIG.

FIG. 17 is a flowchart of a carbon concentration gradient graph creation process using an average value of the carbon concentration data in the n-th row in step S1600 of FIG.

FIG. 18 is a diagram comparing the carbon concentration gradient calculated by the process of FIG. 4 with the carbon concentration gradient calculated by the multi-stage method.

FIG. 19 is a diagram comparing the nitrogen concentration gradient calculated by the processing of FIG. 4 with the nitrogen concentration gradient calculated by the multi-stage method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 emission spectrometer 101 light emitting unit 102 light emitting stand 103 spectral unit 104 photometry unit 105 interface 106 data processing unit 107 data display unit 108 entrance slit 109 exit slit 110 light shielding plate 111 concave diffraction grating 112 photomultiplier tube 113 oil rotary pump 114 Spark discharge 200 test piece 201 ring 202 tin part 203 carburized layer 204 measurement sample 205 discharge range 300 steel product 600 virtual pixel group 601 mesh 700 array

Continued on the front page F term (reference) 2G043 AA01 AA03 BA01 BA07 CA05 CA07 DA01 EA09 GA08 GB21 JA04 LA02 NA01 NA06 NA11 2G055 AA03 AA07 BA16 CA05 CA09 CA10 CA11 CA22 CA29 EA01 EA08 FA02 FA06

Claims (1)

[Claims] 1. A method for measuring an element concentration and an element concentration gradient of a film in emission spectroscopy for calculating a concentration of the first element and a concentration gradient of the first element in a measurement sample having a layer containing the first element on a surface thereof. A step of preparing a test piece having a member of the second element in which the measurement sample is embedded so that a cut surface of the layer is exposed; and a step of preparing the layer and the member of the second element in the prepared test piece. A discharge step of discharging a predetermined number of times to a predetermined range including a boundary of the layer and a cut surface of the layer, a mesh dividing step of dividing the predetermined range by a matrix group of meshes, The first predetermined number of times of the first
A spectrum assignment step of detecting an emission spectrum of the element or the second element and assigning the detected emission spectrum to each mesh of the mesh group, and a plurality of meshes to which the emission spectrum of the first element is assigned, respectively. A concentration gradient calculating step of calculating a concentration of the first element and a concentration gradient thereof based on a maximum length in a direction perpendicular to the boundary and an emission spectrum assigned to each of the plurality of meshes. A method for measuring the element concentration and the element concentration gradient of a film in a characteristic emission spectroscopic analysis.