KR100776078B1 - Method and system for quantitatively evaluating a graphite structure of a gray cast iron by an image analysis apparatus, and a computer-readable recording medium - Google Patents

Abstract

It is to provide a method capable of quantitatively determining the characteristics of the structure with the number of graphite of the graphite structure in the gray cast iron and the specific degree of constituent graphite. Specifically, only the non-spherical graphite having an average diameter of 5 µm or more is extracted for the image of the graphite structure subjected to the pretreatment to calculate the number thereof (step S5 in FIG. 3). Moreover, only the graphite whose length is less than 150 micrometers is extracted from 50 micrometers or more, and the length and area of each graphite are measured (step S6). From these data, in order to represent the graphite group, a graphite having a maximum length (maximum diameter) of 100 µm is assumed, and the area thereof is obtained, and the area is excluded from 100 µm of the length (step S7). The value of this non-hydrophobicity is displayed with graphite number (step S8).

Description

METHODS AND SYSTEM FOR QUANTITATIVELY EVALUATING A GRAPHITE STRUCTURE OF A GRAY CAST IRON BY AN IMAGE ANALYSIS APPARATUS, AND A COMPUTER -READABLE RECORDING MEDIUM}

This invention image-analyzes the form of flake graphite, eutectic graphite, or the mixed structure of both which are shown to gray cast iron structure, and has the numerical value inherent to the graphite structure, such as shape (long and short size of graphite), distribution, and roughness of graphite, and a numerical value. The present invention relates to a method that enables quantitatively and easily and accurately determination, or to a medium and a determination system in which a program for executing the method is recorded.

Examples of this kind of technology include, for example, Japanese Unexamined Patent Application Publication No. 2002-162348, and "Nakae Hideo, et al.," Determination of Graphite Forms by Waveform Analysis of Flat Graphite Cast Iron Using a Laser Displacement Meter. " , Foundry, Japan Foundry, Vol. 74, 2002, 10, P644-649. In this conventional technique, the surface roughness of the cast iron is irradiated to the fractured surface of the cast iron, and the shape, distribution, and the like of graphite contained in the cast iron structure are determined based on the roughness.

In the prior art as described above, although the most practical use is currently expected among several known graphite form determination methods, the final determination only needs to be read directly from the obtained graph, and the determination result is subject to individual differences. In addition to being easy to occur due to variations, there is a problem that it is difficult to image the determined graphite form, leaving room for improvement.

1 is an explanatory diagram showing a schematic configuration of an entire judgment system as a preferred embodiment of the present invention.

FIG. 2 is a functional block diagram of the main part of FIG.

3 is a flowchart similarly showing a procedure in the determination method as a preferred embodiment of the present invention.

4 is a flowchart showing an image analysis procedure in measuring graphite spheroidization ratio.

FIG. 5 is an explanatory diagram showing an example of an analysis result in the graphite spheroidization ratio measurement of FIG. 4. FIG.

6A is an explanatory diagram of a maximum diameter method that is a method of determining graphite size.

6B is an explanatory diagram of an average diameter method that is a method of determining graphite size.

7 is a graph showing the number of detections for each shape and size of graphite.

FIG. 8 is an explanatory view in which the graphite structure on the left side of the drawing is divided into graphite having a maximum diameter of less than 10 μm and graphite of 10 μm or more.

9 is a graph showing the relationship between the roughness of graphite structure and the number of detected graphite.

10 is a graph showing the relationship between the minimum graphite setting condition and the number of detected graphite.

11 is an explanatory diagram showing the relationship between the structure of gray cast iron and the number of graphite.

It is explanatory drawing which shows the example of the difference of graphite non-aqueousness based on graphite-like structure.

FIG. 13 is an explanatory diagram in which graphite of each size is dividedly displayed in the structure of the graphite water 90. FIG.

14 is an explanatory diagram of a plurality of connected graphites starting to increase from around 150 µm.

15 is an explanatory diagram showing a result of measuring the length and area of individual graphite with respect to the structure of the graphite water 90.

FIG. 16 is a graph showing the relationship between graphite length (maximum diameter) and graphite area for the structure of FIG.

Fig. 17 is an explanatory diagram showing a non-hydrophobic display form of hypothetical representative graphite having a length of 100 μm.

FIG. 18 is an explanatory diagram three-dimensionally illustrating the distribution of graphite number in the cross section of the brake disc rotor in order to improve the casting method of the cast iron brake disc rotor. FIG.

Fig. 19 is an explanatory diagram three-dimensionally showing the distribution of graphite water in the cross section of the brake disc rotor for the optimization of the molten metal treatment.

20 is a flowchart showing a second embodiment of the present invention.

Fig. 21 is an explanatory diagram comparing graphite structures before and after removing and erasing graphite that is in contact with the analysis frame outer frame.

Fig. 22 is an explanatory diagram comparing graphite structures before and after removing and erasing graphite which is in contact with the outer frame of the analysis screen.

Fig. 23 is an explanatory diagram of graphite structure in the case of proportionally adding and adding the number of graphite to be erased due to being in contact with an external frame of the analysis screen.

FIG. 24 is a functional block diagram showing a modification of FIG.

This invention is made | formed in view of such a subject, and especially the existing image analysis apparatus, for example, the graphite spheroidization ratio measuring apparatus etc. are utilized effectively, and the graphite structure in gray cast iron is quantitatively and easily and accurately judged quantitatively. We want to provide the technology that makes it possible.

The various graphite structures found in gray cast iron are determined by the shape, size, length, shortness, thickness, and thickness of the graphite pieces constituting the graphite pieces, the density of the distribution and the presence or absence of directionality, but the type of graphite pieces and the number of graphite pieces that constitute the graphite pieces. There is a close relationship between the two and knowing the number of graphite pieces, the form of the graphite structure can also be inferred.

Gray cast iron is generally an iron alloy containing 3 to 4% carbon and 2 to 3% silicon, but exemplifies a tissue form in which graphite of various shapes and sizes is dispersed in an iron matrix. The carbon in the cast iron is separated into compound carbon, which forms graphite carbon and cementite, depending on solidification, and a slight carbon that is solid melted in the iron base. Graphite that can be viewed by inspecting the polished cast iron sample is graphite carbon therein, and cementite can be visually recognized in the ferrite which can be seen by corroding the abrasive sample. When a small amount of solid molten carbon that cannot be directly recognized is considered separately, the position in which the remaining graphite carbon and the compound carbon are determined determines the form of the graphite structure of the cast iron.

In the case of gray cast iron having a thickness of about 10 to 30 mm, the proportion of the compound carbon is usually in the range of about 0.4 to 0.9%, and the amount of the compound carbon does not change much even if the total carbon amount is increased. That is, since the remaining portion obtained by subtracting the compound carbon amount from the total carbon amount becomes graphite carbon, the graphite carbon increases as much as the total carbon amount increases, and as a result, the graphite area ratio in the iron base increases.

What shape and distribution this graphite carbon takes upon solidification depends mainly on the melt treatment and the casting conditions in addition to the mixing, dissolving and pouring conditions. For example, even if the chemical composition is the same, the graphite structure also changes significantly. . However, in general, graphite grows in a thick portion where the solidification rate is slow, and becomes a pole. In the thin thickness portion or in the molten metal portion, the solidification rate is fast, and graphite cannot grow, so that it tends to be minimized.

On the other hand, since the amount of carbon that becomes graphite is constant, the larger the amount of graphite per graphite, the larger the amount of graphite, and the lower the number of graphite.

From this, the present invention has been devised under the prediction that there is a close relationship between the form of graphite tissue and the number of graphites constituting it.

Invention of Claim 1 is a method of quantitatively determining the graphite structure in gray cast iron with an image analysis apparatus, image analysis of the enlarged image of the graphite structure of gray cast iron, and the non-spherical graphite of the specific size contained in the graphite structure. Extracting and calculating the number together with the area of each graphite; calculating a non-aqueous degree representing the thickness of the non-spherical graphite based on the calculated number and area of the graphite; and calculating the number of graphite. And outputting both values with the non-hydrophobicity as a result of determination in relation to each other.

The image to be subjected to image analysis is, as described in claim 2, for example, by capturing a speculum screen of graphite tissue with an imaging device (CCD) such as a video camera or a digital camera. It may have been done or read by a scanner or the like.

The calculation of the number of graphites to be extracted in the calculation of the number of graphites is carried out with the diameter of a circle equal to the area of the graphite or the maximum length of the graphite, as described in claim 3, preferably as described in claim 4 As the minimum size of graphite to be extracted in the calculation of the number, the area corresponds to the area of a circle having a diameter of 5 m or the maximum length is 10 m. More preferably, as described in claim 5, it is assumed that the area corresponds to the area of a circle having a diameter of 5 µm as the size of the minimum graphite to be extracted in the calculation of the number of graphites.

In this case, in excluding and erasing graphite in contact with the analysis screen frame as a pretreatment of the image before extracting non-spherical graphite of a specific size as described in claim 6, the number of graphites to be excluded and erased is determined. And counting each number by extracting the graphite other than the graphite to be excluded and eliminated by dividing the specific size into a plurality of size divisions including the specific size in one size division, and counting the number of the graphite to be excluded and eliminated. It is preferable from the aspect of improving the accuracy of analysis that the ratio is added to each graphite number in proportion to the ratio of the graphite number for each size division to be added to each graphite number.

The total area of the graphite extracted as described in claim 7 is divided by the total number of graphite and is referred to as non-aqueous. More preferably, as described in claim 8, the maximum length of the graphite groups extracted in the calculation of the number of graphite. The maximum length and area of each graphite contained in the range of 50 micrometers or more and less than 150 micrometers are computed, and based on these data, the area of graphite equivalent to a maximum length of 100 micrometers is computed, and the area divided by 100 It is set as the non-hydrophobicity of typical graphite of a graphite structure with a value.

The invention according to claim 9 is specified as a computer-readable recording medium such as a CD-ROM or a flexible disk on which a program for executing each step according to any one of claims 1 to 8 is recorded.

In addition, the invention described in claim 10 specifies the method as a system for quantitatively determining the graphite structure in gray cast iron by image analysis. As shown in FIG. 2, the image analysis means 1 and this image analysis means. It is assumed that the image input means 2 which inputs the enlarged image of the graphite structure of gray cast iron and the display means 3 which display an analysis result with respect to (1) are provided. In addition, the image analysis means 1 performs an image analysis of an enlarged image of the graphite structure of gray cast iron, extracts non-spherical graphite of a specific size contained in the graphite structure, and calculates the number together with the area of each graphite. And a non-hydrophobicity calculating means 5 for calculating the non-aqueous degree indicating the thickness of the non-spherical graphite on the basis of the number / area calculating means 4 and the calculated number and area of the graphite. It is characterized in that both values are visually displayed on the display means 3, with the number and the non-number of degrees as the determination result in relation to each other.

In this case, as described in claim 11, it is preferable that the size of the minimum graphite to be extracted in the calculation of the number of graphite in the same manner as described in claim 5 corresponds to the area of a circle having a diameter of 5 m.

In addition, as described in claim 12, in the same manner as described in claim 6, the image analysis means removes and erases the graphite in contact with the analysis screen frame as a preprocessing of the image before extracting the non-spherical graphite of a specific size. Counting the number of graphites to be excluded and eliminated, and then extracting the graphite other than the graphite to be excluded and eliminated by dividing the specific size into a plurality of size divisions that include the specific size in one size division. Means for correcting the number of non-spherical graphites of a specific size extracted by counting and adding the number of graphites to be excluded and erased in proportion to the ratio of the number of graphites for each size division to each graphite number. It is preferable to provide (13) (see FIG. 24).

More preferably, as described in claim 13, in the same manner as described in claim 8, the maximum length of each graphite included in the range of the maximum length of 50 µm or more and less than 150 µm in the graphite group extracted in the calculation of the graphite number; The area is calculated, and based on these data, the area of graphite corresponding to the maximum length of 100 m is calculated, and the area is divided by 100, and it is assumed that it is the specific hydrograph of the representative graphite of the graphite structure.

Therefore, in the present invention, the graphite structure can be quantitatively determined numerically with the number of graphite and the non-water related thereto.

According to the present invention, since the graphite structure can be quantitatively determined numerically and easily and accurately with the number of graphite and its associated non-hydrophobicity, fluctuations due to individual differences do not occur in the determination result, and the reliability of the determination result is high. In addition to this, there is an effect that it is easy to image the shape of the actual graphite structure.

1 to 3 show a preferred embodiment of the present invention.

FIG. 1 shows a schematic configuration of a determination system according to the present invention, and FIG. 2 shows its functional block circuit diagram, respectively, in addition to the image analysis device 20, which is the image analysis means 1 having the personal computer 6 as a main element. It is comprised with the optical metal microscope 7 and the CCD camera (video camera) 8 etc. as image input means (imaging means) 2, and the image taken with the CCD camera 8 turns the input port 9 into an image. It is blown into the image analysis apparatus 20 via the. In addition, the personal computer 6 has a built-in storage device such as a hard disk in addition to the CPU, ROM, and RAM, and predetermined image analysis software is installed in advance, and the display means (in addition to the keyboard or mouse not shown) as the input means ( CRT display 10 as 3) and printer 11 as output means, or an external storage device 12 such as MO or the like are provided.

The graphite structure of the gray cast iron to be determined is magnified 100 times by the metal microscope 7, and the speculum screen is picked up by the CCD camera 8 and taken into the image analysis device 20. In the 100-times microscope image taken in this way, for example, the range of 640 x 480 pixels (pixels) is the object of image analysis, and the scale of 640 µm is set for the width 640 pixels of the analyzed image frame. , 1 pixel = 1 μm.

As shown in step S1 of Fig. 3, when an image is input to the image analysis device 20, the image is first binarized in contrast, and the iron matrix of the tissue is displayed in white, and the graphite is displayed in black, respectively (step S2). At the same time, this is erased in order to exclude the graphite intersecting (crossing) or in contact with the analysis screen outer frame (step S3). In addition, in step S4, only the non-spherical graphite whose graphite area ratio is less than 54% is extracted, and the number is computed.

As a method of determining the graphite size to be extracted in this way, there are generally two systems as shown in Figs. 6A and 6B. One is a method of making a graphite size (maximum diameter method) having a diameter of a circle inscribed at its longest part irrespective of the area of graphite as shown in FIG. 6A, and the other is graphite as shown in FIG. 6B. Irrespective of the length of, it is a system (average diameter method) having a diameter of a circle equal to the area of the graphite and having a graphite size.

In this embodiment, the size of the graphite to be extracted is determined to be 5 µm or more in average diameter, and as described above, only graphite having an area of less than 54% aspheric graphite and having an average diameter of 5 µm or more is extracted. Calculate and display the number. However, 10 micrometers or more may be extracted as a maximum diameter (maximum length) instead of an average diameter system, and both formulas may be used together and 10 micrometers or more as a maximum diameter and 5 micrometers or more by an average diameter may be extracted. An example of the graphite form thus extracted is shown on the left side of Fig. 13, and the detected graphite number is set to 90, for example.

As is apparent from Fig. 13, the whole image of the graphite form has a maximum length of 50 μm or more and a thickness of less than 150 μm as shown in the lower left of the drawing (as described below, in the present embodiment, this is non-uniform). Under the assumption that it is greatly dependent on the diameter, the graphite having a maximum length of 50 µm or more and less than 150 µm is extracted, and the maximum diameter (maximum length) and the area of each graphite are measured (step S5 in FIG. 3). . Fig. 15 shows the maximum length and area of each graphite measured in this way, and Fig. 16 shows the graph of the distribution of such graphite. And the thing corresponding to the median of the length of each graphite is calculated | required from the relational formula of FIG. 16, and the area of the graphite corresponding to the median is calculated | required.

In FIG. 16, since the median value of each graphite of 50 µm to 150 µm is 100 µm, the area in the case of 100 µm serving as the median is 1006 µm ² . The meaning of this numerical value assumes graphite having a maximum length (maximum diameter) of 100 µm temporarily to be representative of the graphite group from each data of the graphite group of 50 µm or more and less than 150 µm, and the area is 1006 µm ² . As shown in Fig. 17, dividing the area 1006 탆 ² by 100 탆 in length yields a numerical value of 10.06, which is referred to as non-aqueous (step S6 in Fig. 3). The value of this non-hydrophobicity must be equivalent to the width dimension of the same spherical shape when a spherical sphere having a length of 100 µm is assumed in the same area, and can be a numerical value connected to a specific non-hydrophobic image.

Then, the width 10.06 of the virtual graphite is rounded to 10.1, and added after the value of the form of "graphite water (non-water)", that is, the detected graphite number 90 obtained first, and having the notation "90 (10.1)". (Step S7 in Fig. 3). Thereby, not only the graphite form but the display including the non-hydrophobicity of the constituent graphite is attained. In addition, the above series of arithmetic processing is executed by the function of the image analysis device 20 as shown in FIG.

Then, using the existing graphite spheroidization ratio measuring apparatus, it is verified whether the evaluation and determination method of the graphite structure of gray cast iron, including the non-hydrophobicity evaluation, which is carried out with a numerical value of two or three digits as described above, is appropriate or valid. see.

Fig. 4 shows the processing procedure in the case of using the graphite spheroidization ratio measuring device which has been widely used in the past, and as is apparent from the figure, in the graphite spheroidization ratio measurement, all graphite in the image pickup screen regardless of spherical or non-spherical shape The determination of the magnitude of graphite by the designated size and the measurement of the number thereof are performed. Here, quantitative determination of flake graphite or eutectic graphite structure was attempted using this counting function effectively.

As for the 100-times microscope image taken in the video camera (image pickup element, such as CCD) 8 of FIG. 1, the range of 640x480 pixel (pixel) in it becomes an object of image analysis, for example. Incidentally, the one having a relationship of 1 pixel = 1 mu m is as described above. Specifications of the analysis results are as shown in Fig. 5, for example, and the number of detected graphite is divided and displayed for each of spherical and non-spherical (flakes) according to JIS standards.

As described above, there are two methods of determining the size of graphite to be extracted in this way, the maximum diameter method and the average diameter method. The graphite spheroidization ratio is determined according to the maximum diameter method in JIS. However, since both methods are meaningful in their own way, the methods of both the maximum diameter method and the average diameter method are used in combination here.

First, as a sample, three types of things were prepared in addition to the small graphite structure with a comparatively large graphite length, and the intermediate graphite structure of both the dense process graphite structure, and both. 7 shows measurement results for the shape and size of graphite of the intermediate graphite structure as an example.

In Fig. 7, the size of graphite is divided into several steps to extract the graphite. For example, the size of graphite is divided into seven steps of each size of 1 µm, 2 µm, 3 µm, 5 µm, 10 µm, 15 µm, and 20 µm. And measured for both the maximum diameter and the average diameter, respectively. At the same time, the number of detected graphites is displayed for both the size section and the cumulative total, and also the spherical and non-spherical graphite of the graphite.

As is apparent from Fig. 7, in the comparatively large range, the graphite number at the maximum diameter mostly decreases in the average diameter. On the contrary, in the small size range, the graphite number in the average diameter mostly decreases the graphite number in the maximum diameter. This is, of course, contrary to the difference in definition of graphite size described above. On the other hand, when the size of the minimum graphite is set to 1 µm or more of extremes, since there is no part different from the case where all the graphite in the screen is measured, regardless of the shape, the total number of detected graphite is the maximum diameter. About 433 and about 436 in average diameter, both show the same number.

Although the measurement results for the two remaining samples, namely, the small graphite structure and the process graphite structure, are not shown, the total number of detected graphite when the minimum graphite size is 1 μm or more is about 221 as the maximum diameter and the average diameter in the small graphite structure. Therefore, about 223 and process graphite structure, there exists a tendency equivalent to the thing of the said intermediate | middle structure except having shown about 1172 by the largest diameter and about 1176 by the average diameter.

On the other hand, it is a characteristic that both samples can be seen in common, and the minimum graphite size is in the range of 5 to 10 µm as a boundary, and most of them are determined as spherical graphite, whereas the In the following ranges, it was found that the determination of spherical graphite tended to increase.

Therefore, the difference in graphite morphology was observed by dividing the sample into a maximum diameter of 10 μm or more and less than 10 μm, and an average diameter of 5 μm or more and less than 5 μm. Although Fig. 8 shows the results of the division display at the maximum diameter in the inside, 134 graphites in total are detected in the range of less than the maximum diameter of 10 µm, but most of the spherical and non-spherical shapes are almost impossible to visually identify as spherical and granular or small. It should also be referred to as a block, although it may look like graphite inside, but it may actually be slug or melted. Importantly, the impression or image when the graphite structure is viewed by the naked eye is formed by the graphite structure having a maximum diameter of 10 µm or more, and the graphite group of less than 10 µm does not play any role in image formation at the naked eye. It is only recognized as noise. In addition, although not shown, this observation result is the same also about the image divided and displayed by 5 micrometers or more and less than 5 micrometers by the average diameter method.

An object of the present invention is to make a difference between the graphite structures and to clarify the difference. From this purpose, point or granular graphite having a maximum diameter of less than 10 µm and an average diameter of less than 5 µm is nothing other than mere noise unless it contributes at least to image formation of the entire structure. Therefore, in subsequent observations, only non-spherical graphite with a maximum diameter of 10 µm or more and an average diameter of 5 µm or more shall be the measurement target.

In this way, the conditions for measuring the graphite number of the graphite structure are throttled, and therefore, these conditions were applied to the actual graphite structure, and then experimented.

First, samples of various graphite structures were prepared, and 10 samples from No. 1 to No. 10 were selected side by side in the order in which 5 observers approve, from very grand graphite structures to dense process graphite structures. And the setting of the minimum graphite size was made into 4 steps of 5 micrometers or more, 10 micrometers or more, 15 micrometers or more, and 20 micrometers or more, and the number of non-spherical graphite determined by JIS was measured.

The result is shown in Fig. 9, in which the relationship between the graphite structure and the number of detected graphites is repeated in the order of the dense structure of the structure from the pole piece to the short-form process graphite, and the data at the maximum diameter (dashed line) and the data at the average diameter (solid line) It is displaying. From this result, it is understood that the most linear relationship with the dense order of the graphite structure is the number of graphites when the minimum graphite size is set to 5 µm or more in the average diameter and 10 µm or more in the maximum diameter. Of these, it is confirmed that it is most effective to adopt either of them as a standard, and the number of graphites when the average diameter is 5 µm or more and the maximum diameter is 10 µm or more, respectively, for many samples. It was measured. The result is shown in FIG.

As is apparent from Fig. 10, in a relatively large graphite structure having a graphite number of about 300, both show the same value, but in a structure close to relatively small process graphite having a graphite number exceeding 300, the average diameter is 5; It turns out that more graphite is detected by one side of more than a micrometer. The reason for this is that, as described above, the maximum diameter is the length of graphite and the average diameter is the area of graphite, respectively, as a measure of size. Even if the size does not reach the designated maximum length and is separated from the measurement target (detection target or extraction target), it can be estimated that the area may exceed the designated average diameter.

In the differentiation of the graphite structure, the finer the graphite becomes, the more difficult it becomes to detect the difference in the structure. However, it is highly desirable that the graphite order can be detected sensitively even if the graphite structure is compact. Therefore, in the case where the form of the graphite structure is to be determined with the number of constituent graphites, it has been concluded that the setting of the minimum graphite size is appropriate not to have the maximum diameter but to have the average diameter.

From the above examination results, by measuring the number of non-spherical (flakes) graphite of 5 µm or more in the average diameter, as described above, the graphite structure of gray cast iron is easy and reliable, including the non-aqueous evaluation performed with a numerical value of two or three digits. It was found that it can be evaluated and judged without individual differences.

As another specific example, FIG. 11 shows the relationship between the micrograph and the detected number of flaky graphites of ten tissue samples Nos. 1 to 10 previously used. It will be appreciated that the graphite number is in constant correlation. In Fig. 11, the preceding numerals 1 to 10 are replaced with the numerals K-1 to K-10, and at the same time, the number of detected non-spherical graphite is indicated in parentheses.

Here, even if the number of detected graphite temporarily is the same, the thickness and fineness of the individual graphite which form the graphite structure may differ, and such influence is not yet fully considered. In the case where the degree of thickness (thickness) of the graphite is temporarily referred to as non-water, here, an example in which remarkable difference is recognized in the graphite non-water is shown in FIG.

Although the number of detected graphite in each graphite structure shown in the said figure is all 90, it is clear also from the difference of graphite area ratio that there exists a difference in the specificity of graphite, respectively. If there is a difference only in this, it is natural that difference other than the mechanical property of gray cast iron itself arises, and even this non-aqueous degree is considered, it cannot be said that it is incomplete as a determination method of graphite structure.

In this case, the simplest method is also effective for each graphite number being the same but comparing the respective total graphite areas or comparing the total graphite areas by the number of graphites, i.e., the average area per graphite. However, considering that the ratio of graphite size is immovable even if the number of graphite is the same, it is not necessarily appropriate only by comparison of the graphite area.

Therefore, the graphite composed of three sizes of graphite having a maximum length of 10 μm or more and less than 50 μm, 50 μm or more and less than 150 μm, and 150 μm or more in relation to the structure of the non-water content 10.1 on the left side among the four types of graphite structures shown in FIG. 12. Figure 13 shows the distribution of. In addition, the figure on the left side of FIG. 13 is the same as the figure on the left side of FIG. As apparent from Figs. 12 and 13, it is recognized that the non-aqueous image of graphite in this graphite structure is mainly determined by the group of graphites having a maximum length of 50 µm or more and less than 150 µm. Similar attempts have been made to other types of graphite structures with different graphite numbers, but graphite having a maximum length of 50 µm or more and less than 150 µm dominates the non-aqueous image of graphite throughout the entire structure. It was confirmed. Therefore, when the object can be throttled and compared with the non-hydrophobicity in the graphite group of the size of 50 micrometers or more and less than 150 micrometers in size, the image of the graphite non-water content of the whole graphite structure can be expressed.

Here, as is apparent from Fig. 14, in the group of graphites having a maximum length of 150 µm or more, a plurality of graphites are connected and recognized as if they are one graphite, so that the maximum length is also excluded to exclude such graphite from being included in the number. It is preferable to exclude graphite of 150 micrometers or more.

Fig. 15 shows the maximum diameters (maximum lengths) and the areas of the individual graphites, and the graphs of these graphite groups. . If the area in the case of 100 micrometers used as the median of the length of graphite is calculated | required from such a figure, it will be 1006 micrometer <^2> .

The meaning of this number is, from the respective data of the graphite group of less than 50 ㎛ 150 ㎛, the maximum length of say, representative of the graphite group temporarily (maximum diameter) intended for the 100 ㎛ graphite, and ask the area 1006 ㎛ ² As shown in Fig. 17, when the area 1006 m ² is divided by 100 m in length, a numerical value of 10.06 is obtained. This value must correspond to the width dimension of the same rectangle when a rectangle having a length of 100 µm is assumed in the same area, and can be a numerical value connected to a specific non-hydrophobic image.

When the width dimension 10.06 of the virtual graphite is rounded up to 10.1, and the notation of 90 (10.1) is added after the value of the detected number of detected graphite 90, the expression including not only the graphite form but also the non-hydrophobicity of the constituent graphite. This becomes possible.

As mentioned above, it was able to confirm that the specific hydrophobicity evaluation of the graphite which has a 2-digit or 3-digit numerical value is performed.

Here, in fabricating a cast iron brake disc rotor, in order to improve the casting method, the distribution of graphite water in the cross section of the brake disc rotor in three dimensions is shown in FIG. Fig. 19 shows three-dimensional distributions of the graphite number in the cross section of the brake disc rotor, respectively. When numerical value display of such a graphite structure is carried out, when the value of the non-water degree mentioned above is written together, it becomes more effective.

20 to 24 show a second embodiment of the present invention.

As is apparent from the flowchart in Fig. 20, regardless of whether the graphite to be extracted is spherical or non-spherical, the graphite crossing the analysis screen outer frame or in contact with the outer frame in the image analysis is excluded as the measurement object during the pretreatment step. And erasing are as described above (see step S3 in FIG. 3 and step S3 in FIG. 20). This is because the graphite hanging on the frame outside the analysis screen must be excluded and erased because it is impossible to determine what shape and size is other than the part displayed on the screen. to be.

In this case, even if the number of graphite particles to be measured is slightly smaller than the actual number of graphite in the measurement of the graphite spheroidization ratio, the graphite spheroidization ratio can be obtained by measuring the graphite remaining in the outer frame of the screen because the purpose is to measure the spheroidization ratio of the graphite. We do not have any problem that much practically.

On the other hand, in the present invention in which the method of quantitative evaluation of the flake graphite structure in gray cast iron is obtained from the difference in the number of constituent graphite particles, it is never preferable in terms of analysis accuracy that the number of critical graphite particles differs from the actual one.

FIG. 21 compares the states before and after the traversal of the analysis screen outer frame (measurement frame) or the graphite in contact with the outer frame, and before and after elimination and erasing. When the graphite is excluded and erased, a blank portion is noticeable in the portion near the outer frame of the screen. Since only the graphite remaining in the outer frame becomes the measurement target, the analysis result thus obtained becomes a partially different structure even if it approximates the actual graphite structure.

Moreover, graphite of gray cast iron is characterized by having a much higher proportion of graphite which is much thinner and longer than graphite of spherical graphite cast iron. Thus, the longer the flake graphite, the easier it is to contact the outer frame of the screen, and the longer the graphite, the smaller the number of constituent graphite particles. As a result, the graphite structure containing the long graphite is in contact with the outer frame. The proportion of graphite to be increased.

This specific and remarkable example is shown in Fig. 22, and as is apparent from the drawing, at least half of the actual graphite is excluded and erased, and as is clear from the drawing on the right, the graphite texture to be measured completely shows the appearance of the original graphite texture. The less you leave, the more organized you become. In addition, this example is an extreme long graphite structure, which is not seen as a normal FC-250 graphite structure, but as a general so-called A type graphite structure, for example, a screen outside frame of 640 × 480 μm. It is unavoidable that 5 to 20% of graphite is excluded and erased due to contact with the outer frame.

Since the graphite form has almost the same exclusion and scavenging ratios in the approximate structure, the graphite structure is not so much a problem in terms of practical comparison, but in order to faithfully reflect the graphite form as it is, It is preferable that the evaluation which blows the graphite which should be excluded and removed also takes place.

Here, even if the total shape and size of the individual graphite to be excluded and erased due to being in contact with the analysis frame external frame as described above cannot be measured, the number can be measured. In addition, even from the probability, it is thought that the configuration of the shape and size of the graphite to be excluded and erased due to being in contact with the frame outside the analysis screen is not significantly different from the composition ratio of most graphites left in the frame.

Therefore, while counting the number of graphites to be excluded and erased due to being in contact with the outer frame, the graphite remaining in the outer frame is counted by dividing into a plurality of size divisions, and the graphite composition ratio for each size division is obtained. When the number of graphites to be excluded and erased is added in proportion to the graphite composition ratio and added to increase the number of graphites in each size division, the original number considering the number of graphites to be excluded and erased due to contact with the outer frame is considered. It is possible to reproduce a composition ratio very close to that of the entire graphite of the graphite structure.

In addition to FIG. 20, FIG. 23 shows an example of the specific procedure, and the processes of steps S1 to S3 in FIG. 20 are the same as those shown in FIG. Excluding and erasing the graphite crossing the analysis screen outer frame or contacting the outer frame from the image of the graphite binary structure (total graphite) binarized in step S3, the analysis screen outer frame is crossed with the outer frame or the outer frame thereof. The number of graphites to be excluded and erased for the reason of contact is counted (step S3-1). In step S4, as in the case of Fig. 3, non-spherical graphite having a graphite area ratio of less than 54% and an average diameter of 5 µm or more is extracted separately from graphite of less than 5 µm, and the number of graphites is counted or calculated. .

In the example of Fig. 23, the number of graphites to be excluded and erased because of crossing the outer frame of the analysis screen or in contact with the outer frame is 32, and the number of graphites of less than 5 μm in the outside frame of the screen is 26, and also 5 μm. The case where the above graphite number is 148 is shown.

Then, in addition to step S4-1 of FIG. 20, as shown in FIG. 23, the graphite number to be excluded and erased has a ratio of 26 graphite particles of less than 5 μm and 148 graphite particles of 5 μm or more left in the screen outer frame. Allocate 32. That is, the number of 32 graphites to be excluded and eliminated is proportionally distributed at a ratio of 26: 148 and divided by 5:27. When the number is added to 148 pieces of graphite having a size of 5 μm or more in the outside frame of the screen in order to raise 27 pieces, the number of graphite having a size of 5 μm or more is corrected to 175. As a result, a hypothetical number of graphites having an average diameter of 5 µm or more to be extracted, which is 148 which are not completely considered because the number of graphites to be excluded and erased due to crossing the outer frame of the analysis screen or in contact with the outer frame is not considered. Proportional allocation of the graphite texture index and the number of graphites to be excluded and erased due to crossing the outer frame of the analysis screen or contacting the outer frame gives a real graphite texture index closer to the actual value than the corrected value of 175. You lose.

Thereafter, similarly to the case of Fig. 3, the non-hydrophobicity is calculated in steps S5 and S6, and in step S7, the non-hydrophobicity is written together with the actual graphite structure index obtained earlier, for example, as shown in "175 (10.1)". I shall do it. The above series of arithmetic processing is executed by the function of the image analysis device as shown in FIG. That is, FIG. 24 differs from that shown in FIG. 2 in that a proportional addition means 13 for graphite number excluding frame contact is provided.

As described above, according to the present embodiment, in extracting and counting the number of non-spherical graphite having a specific size, the number of graphites to be excluded and erased due to the fact that the outer frame of the analysis screen is transversely or in contact with the outer frame is counted. Since the proportion of the graphite to be extracted is corrected by proportional distribution, the image analysis accuracy of the graphite structure is further improved, and the reliability of the analysis result is also high.

Claims (13)

It is a method of quantitatively determining the graphite structure in gray cast iron by an image analysis device, Image analysis of an enlarged image of the graphite structure of gray cast iron, extracting non-spherical graphite of a specific size contained in the graphite structure, and calculating the number together with the area of each graphite; Calculating a non-aqueous degree representing the thickness of the non-spherical graphite based on the calculated number and area of the graphite; A method of quantitatively determining a graphite structure in gray cast iron by an image analysis device, comprising the step of combining the calculated number of graphite and the non-water degree and outputting two values as a determination result. 2. The method according to claim 1, wherein the image to be subjected to the image analysis is obtained by capturing a speculum screen of graphite structure with an image pickup device. The graphite structure in gray cast iron is quantitatively determined by the image analysis device. The graphite in gray cast iron according to claim 1 or 2, wherein the size of the graphite to be extracted in the calculation of the number of graphites is performed with the diameter of a circle equal to the area of the graphite or the maximum length of the graphite. A method of quantitatively determining a tissue by an image analysis device. The size of the minimum graphite to be extracted in calculating the number of graphites is that the area corresponds to the area of a circle having a diameter of 5 µm or the maximum length is 10 µm. A method of quantitatively determining a graphite structure in gray cast iron by an image analysis device. The graphite structure in gray cast iron according to claim 4, wherein the size of the minimum graphite to be extracted in the calculation of the number of graphites corresponds to the area of a circle having a diameter of 5 m. Method of Determination Quantitatively. The method according to claim 1 or 2, wherein the number of graphites to be excluded and erased in excluding and erasing graphite in contact with the analysis screen frame as a pretreatment of the image before extracting non-spherical graphite of a specific size. Counting, Subsequently, the graphite other than the graphite to be excluded and eliminated is extracted by dividing the specific size into a plurality of size divisions that include the specific size in one size division, and counting each number. Gray cast iron, characterized in that the correction is added to the number of non-spherical graphite of a specific size extracted by proportionally allocating the number of graphite to be excluded and erased in proportion to the ratio of the number of graphite for each size division. The method of quantitatively determining the graphite structure in an image analysis apparatus. 3. The process of claim 1 or 2, wherein the step of calculating the non-hydrophobicity includes a step of dividing the total area of the extracted graphite by the total number of graphite, wherein the graphite structure in gray cast iron is quantitatively determined by the image analysis device. How to. The process of calculating the non-water content is a process of calculating the non-water content of the representative graphite of the graphite structure, and in calculating the number of graphites, in the range of the length of 50 µm or more and less than 150 µm, A process of calculating the maximum length and area of each graphite included, a step of calculating the area of graphite corresponding to a maximum length of 100 μm based on such data, and a step of dividing the area by 100; A method of quantitatively determining a graphite structure in gray cast iron by an image analysis device. A computer-readable recording medium having recorded thereon a program for executing each step according to claim 1. It is a system for quantitatively determining graphite structure in gray cast iron by image analysis, An image analysis means, an image input means for inputting an enlarged image of the graphite structure of gray cast iron to the image analysis means, and a display means for displaying the analysis result, The image analysis means, Graphite number / area calculation means for image-analyzing an enlarged image of the graphite structure of gray cast iron, extracting non-spherical graphite of a specific size contained in the graphite structure, and calculating the number together with the area of each graphite; Non-hydrophobicity calculation means for calculating the non-hydrophobicity which shows the thickness degree of non-spherical graphite based on the number and area of the graphite which were computed, A system for quantitatively determining the graphite structure in gray cast iron by image analysis, characterized in that two values are displayed on the display means as a result of determination by combining the calculated number of graphite and the non-hydrophobicity with each other. The graphite structure in gray cast iron is quantitatively determined by image analysis according to claim 10, wherein the size of the minimum graphite to be extracted in calculating the number of graphites corresponds to the area of a circle having a diameter of 5 m. System to determine. The image analysis means according to claim 10 or 11, In excluding and eliminating graphite in contact with an analytical display frame as a pretreatment of the image prior to extracting non-spherical graphite of a particular size, the number of graphites to be excluded and erased is counted, Subsequently, the graphite other than the graphite to be excluded and eliminated is extracted by dividing the specific size into a plurality of size divisions included in one size division to count each number, The proportion of the graphite to be excluded and erased is proportionally distributed according to the ratio of the number of graphite for each size division, and added to each graphite number, And a means for correcting the extracted number of non-spherical graphite having a specific size, wherein the graphite structure in gray cast iron is quantitatively determined by image analysis. 12. The maximum length and area of each graphite contained in the range of the maximum length 50 micrometers or more and less than 150 micrometers among the graphite groups extracted in calculation of graphite number are computed, The maximum length 100 based on such data. A system for quantitatively determining the graphite structure in gray cast iron by image analysis, which calculates the area of graphite corresponding to μm, divides the area by 100, and refers to the non-hydrophobicity of representative graphite of the graphite structure. .