CN111982930A - Method for testing rapid grading of DIN 50602-inclusion K method - Google Patents

Abstract

The invention discloses a method for testing rapid grading of DIN 50602-inclusion K method, which comprises the following steps: s1, preparing a detection sample; s2, observing and detecting the inclusions in the sample through an optical microscope to obtain the length and width of each chain-shaped inclusion and the diameter of the spherical inclusion; s3, inputting the length and width of each chain inclusion into a chain inclusion grading model of a corresponding type, and inputting all diameters of spherical inclusions into the spherical inclusion grading model; and S4, outputting the grades of various chain inclusions and the grades of spherical inclusions in the detection sample. The atlas does not need to be compared repeatedly, the subjective influence of detection personnel is avoided, the accuracy is improved, the detection speed is accelerated, the staff learning time is shortened, the manpower culture efficiency is improved, and the laboratory is helped to finish the K method detection effectively at a high speed.

Description

A kind of inspection method about DIN 50602-Inclusion K method grade fast grading

technical field

The invention belongs to the technical field of metallographic inspection, and more particularly, the invention relates to an inspection method for rapid grading of DIN 50602-inclusion K method grades.

Background technique

Due to the increasing market demand, there are more and more K-method inspection items for non-metallic inclusions in the steel industry. The K-method inspection uses the German standard DIN 50602 inspection. Compared with the national standard GB/T 10561 commonly used in China, the inspection process is complicated. , each time a result is reported, the entire inspection surface of 6 metallographic samples needs to be tested, and the detection idea is different from the national standard GB/T10561. GB/T 10561 distinguishes chain inclusions (ie SS, OA, The grade of OS three types of inclusions, hereinafter referred to as chain inclusions), spherical inclusions (ie OG spherical oxides, hereinafter referred to as spherical inclusions) are classified by the number of particles, and the K method test is for the four types of inclusions. Both rely on the area boundary to delineate the grade of inclusions. At present, the K-method inspection manpower in most domestic laboratories is still weak; with the improvement of the overall smelting level, the requirements for the purity of steel are getting higher and higher. The method inspection has increased from "K4" to "K0", that is, the inclusion of a small area also needs to be evaluated, which further increases the difficulty of the inspection of the inclusion K method. To sum up, the inspection period of the inclusion K method is longer. , a set of K4 samples will take a skilled inspector 2-3 working days, and K0 will take more. Therefore, the K-method inspection project has become a short board affecting the steel inspection cycle, which restricts the trade of exported steel products to a certain extent. Therefore, it is urgent to try to reduce the difficulty for inspectors to master the K-method inspection and improve the efficiency of the K-method inspection of inclusions. .

Usually, according to the standard, the K method should be compared with the standard atlas when grading the inclusions, but the standard atlas is divided into different levels according to the area of the inclusions, and only the critical value picture is given, which is inevitable in practical work. There are many fields of view that cannot be graded simply by comparing atlases, so the area calculation of inclusions is inevitably involved, especially the area calculation of spherical inclusions, which often consumes a lot of time for inspectors. In addition, grading by inspectors has a greater impact on subjectivity.

SUMMARY OF THE INVENTION

The invention provides an inspection method for rapid grading of DIN 50602-inclusion K method grades, aiming at reducing the difficulty of inclusion K method inspection, improving laboratory K method inspection efficiency and shortening the K method inspection period.

In order to achieve the above purpose, the technical solution adopted by the present invention is: a method for rapid grading of DIN 50602-Inclusion K method grade, the method specifically includes the following steps:

S1. The produced test sample;

S2. Observe and detect the inclusions of the sample through an optical microscope, and obtain the length and width of various chain-shaped inclusions and the diameter of spherical inclusions;

S3. Input the length and width of each chain inclusion into the corresponding type of chain inclusion grading model, and input all diameters of spherical inclusions into the spherical inclusion grading model, each type of chain inclusion corresponds to one Chain inclusion grading model;

S4. Output the levels of various chain inclusions and spherical inclusions in the detected sample.

Further, the chain-shaped inclusions include three types of inclusions: SS, OA, and OS. The construction method of the OA inclusion classification model specifically includes the following steps:

S11. Calculate the area of each OA inclusion, that is, the product of the width and length of the OA inclusion;

S12. Calculate the total area S of all OA inclusions;

S13. Calculate the difference between the sum of areas S and the maximum area defined by each level of OA inclusions, and the level corresponding to the minimum positive difference is the level of OA inclusions in the sample.

Further, the construction method of the OG-like spherical inclusion grading model specifically includes the following steps:

S21. Calculate the area of each OG inclusion, that is, the product of the square of the radius of the spherical inclusion and π;

S22. Calculate the area sum S of all OG inclusions;

S23. Calculate the difference between the sum of the areas S and the maximum area defined by each grade of the OG inclusion, and the grade corresponding to the smallest positive difference is the grade of spherical inclusions in the sample.

Further, after step S4, it also includes:

S5. Calculate the comprehensive total index K of the inclusions in the sample.

Further, the construction method of the comprehensive total index K calculation model is as follows:

S51, count the number of various types of inclusions at each level in the field of view of a single detection sample, multiply it by the corresponding level coefficient and sum up to obtain a first intermediate sum;

S52, calculating the sum of the first intermediate sums of all the detection samples, which is the second intermediate sum s;

S53. Calculate the total area a of all the detected samples, then the comprehensive total index K=(s*1000)/a of sample inclusions.

Further, the preparation method of the detection sample specifically includes the following steps:

S11. Sampling: intercept and cut the sample to be tested according to the standard requirements to obtain a specified number of test samples;

S12, sample preparation, grinding and polishing the surface of the test sample according to the metallographic method to a mirror-smooth state.

The present invention designs an inspection method for quickly calculating the area of inclusions and converting them into the K-method level, which can effectively help metallographic assessors to quickly determine the level of inclusions in any field of view, without the need for repeated comparison of atlases, avoiding the need for The subjective influence of inspectors not only improves the accuracy and speed of inspection, but also shortens the learning time of employees, improves the efficiency of manpower training, and helps the laboratory to complete the K-method inspection quickly and effectively.

Description of drawings

FIG. 1 is a flow chart of an inspection method for rapid grading of DIN 50602-Inclusion K-method grades provided by an embodiment of the present invention.

Detailed ways

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, through the description of the embodiments, to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solutions of the present invention.

1 is a flowchart of an inspection method for rapid grading of DIN 50602-inclusion K method grades provided by an embodiment of the present invention, and the method includes:

S1. Formulate a specified number of test samples;

In the embodiment of the present invention, the preparation method of the detection sample specifically includes the following steps:

S11. Sampling: The sample to be tested is intercepted and cut according to the standard requirements to obtain the sample. According to the DIN50602 standard, generally 6 test samples are taken for each set of K method for testing. If there is a special agreement, the content of the agreement shall prevail;

S12, sample preparation, grind and polish the surface of the test sample according to the metallographic method to a mirror-smooth state; test the inspection surface (longitudinal section) parallel to the processing direction, and the sample is subjected to three metallographic processes of 80#, 240# and 1000#. Sandpaper polishing, 7μm, 2.5μm polishing agent and water polishing ensure that the detection surface of the test sample is mirror-smooth, and there is no dirt under the microscope, so as not to interfere with the inspection accuracy.

S2. Observe and detect the inclusions of the sample through an optical microscope, and obtain the length and width of various chain-shaped inclusions (the maximum width of the inclusions is regarded as the width of the string (strip)-shaped inclusions), and the diameter of spherical inclusions ;

S3. Input the length and width of each chain inclusion into the corresponding type of chain inclusion grading model, and input all diameters of spherical inclusions into the spherical inclusion grading model, each type of chain inclusion corresponds to one Chain inclusion grading model;

In the embodiment of the present invention, various types of chain-shaped inclusions include three types of inclusions: SS, OA, and OS, and the method for constructing a grading model for OA inclusions specifically includes the following steps:

S11. Calculate the area of each OA inclusion, that is, the product of the width and length of the OA inclusion;

S12. Calculate the area sum S of all OA inclusions;

S13. Calculate the difference between the sum of areas S and the maximum area defined by each level in the chain-like inclusions, and the level corresponding to the minimum positive difference is the level of OA inclusions in the sample.

In the embodiment of the present invention, the method for constructing the OS inclusion grading model specifically includes the following steps:

S21. Calculate the area of each OS inclusion, that is, the product of the width and length of the OS inclusion;

S22. Calculate the area sum S of all OS inclusions;

S23. Calculate the difference between the sum of the areas S and the maximum area defined by each level in the chain-like inclusions, and the level corresponding to the smallest positive difference is the OS inclusion level in the sample.

In the embodiment of the present invention, the method for constructing the SS inclusion grading model specifically includes the following steps:

S31. Calculate the area of each SS inclusion, that is, the product of the width and length of the SS inclusion;

S32. Calculate the total area S of all SS inclusions;

S33. Calculate the difference between the sum of the areas S and the maximum area defined by each level in the chain-like inclusions, and the level corresponding to the smallest positive difference is the level of the SS inclusions in the sample.

The construction methods of the SS inclusion grading model and the OS inclusion grading model are the same as those of the OA inclusion grading model.

In the embodiment of the present invention, the construction method of the OG spherical inclusion grading model specifically includes the following steps:

S21. Calculate the area of each OG inclusion, that is, the product of the square of the radius of the spherical inclusion and π;

S22. Calculate the area sum S of all OG inclusions;

S23. Calculate the difference between the sum of the areas S and the maximum area defined by each grade in the OG inclusion, and the grade corresponding to the smallest positive difference is the grade of spherical inclusions in the sample.

S4. Various types of chain inclusion grading models and spherical inclusion grading models output the grades of various types of inclusions in the detected samples.

In this embodiment of the present invention, after step S4, it further includes:

S5. Calculate the comprehensive total index K of the inclusions in the sample. The calculation model of the comprehensive total index K is constructed as follows:

S41, count the number of various types of inclusions at each level in the field of view of a single detection sample, multiply it by the corresponding level coefficient and sum up to obtain a first intermediate sum;

S42, calculating the sum of the first intermediate sums of all the detection samples, which is the second intermediate sum s;

S43. Calculate the total area a of all the tested samples, then the comprehensive total index K=(s*1000)/a.

The present invention designs an inspection method for quickly calculating the area of inclusions and converting them into the K-method level, which can effectively help metallographic assessors to quickly determine the level of inclusions in any field of view, without the need for repeated comparison of atlases, avoiding the need for The subjective influence of inspectors not only improves the accuracy and speed of inspection, but also shortens the learning time of employees, improves the efficiency of manpower training, and helps the laboratory to complete the K-method inspection quickly and effectively.

The present invention has been exemplarily described above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods, as long as various insubstantial improvements made by the method concept and technical solutions of the present invention are adopted, or no improvement is made. It is within the protection scope of the present invention to directly apply the concepts and technical solutions of the present invention to other occasions.

Claims (6)

1. An inspection method for rapid grading of DIN 50602-inclusion K method grade, which is characterized by comprising the following steps:

s1, preparing a detection sample;

s2, observing and detecting the inclusions in the sample through an optical microscope to obtain the length and width of each chain-shaped inclusion and the diameter of the spherical inclusion;

s3, inputting the length and width of each chain inclusion into a chain inclusion grading model of a corresponding type, and inputting all the diameters of the spherical inclusions into the spherical inclusion grading model, wherein each type of chain inclusion corresponds to one chain inclusion grading model;

and S4, outputting the grades of various chain inclusions and the grades of spherical inclusions in the detection sample.

2. The method for testing DIN 50602-inclusion K-process grade rapid grading according to claim 1, wherein the chain-like inclusions comprise inclusions of three types of SS, OA and OS, and the construction method of the OA inclusion grading model comprises the following steps:

s11, calculating the area of each OA inclusion, namely the product of the width and the length of each OA inclusion;

s12, calculating the area sum S of all OA inclusions;

and S13, calculating the difference between the sum of the areas S and the maximum area defined by each level of the OA inclusion, wherein the level corresponding to the minimum positive difference is the level of the OA inclusion in the sample.

3. The method for testing DIN 50602-inclusion K-process grade rapid grading according to claim 1, wherein the construction method of the grading model for OG spheroidal inclusions comprises the following steps:

s21, calculating the area of each OG inclusion, namely the product of the square of the radius of the spherical inclusion and pi;

s22, calculating the area sum S of all OG inclusions;

and S23, calculating the difference between the area sum S and the maximum area defined by each level of OG inclusions, wherein the level corresponding to the minimum positive difference is the level of the spherical inclusions in the sample.

4. The method of claim 1 for testing DIN 50602-inclusion K process grade rapid grading, further comprising after step S4:

and S5, calculating the comprehensive total index K of the inclusions in the sample.

5. The method of claim 4 for testing DIN 50602-inclusion K-process grade rapid grading, wherein the overall index K calculation model is constructed by the following specific steps:

s51, counting the number of various inclusions at each level in a single detection sample view field, and multiplying the number of various inclusions by corresponding level coefficients to obtain a first intermediate sum;

s52, calculating the sum of the first intermediate sums of all the detection samples, namely the second intermediate sum S;

and S53, calculating the total area a of all the detected samples, and then obtaining the total index K of the sample inclusions, which is (S1000)/a.

6. The test method for DIN 50602-inclusion K process grade rapid grading according to claim 1, wherein the preparation method of the test specimen comprises the following steps:

s11, sampling: intercepting and cutting a to-be-tested sample according to standard requirements to obtain a specified number of test samples;

and S12, preparing a sample, and grinding and polishing the surface of the test sample to a mirror surface smooth state according to a metallographic method.

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