Scanning electron microscope analysis method for inclusions in rare earth steel

Abstract

The invention discloses a scanning electron microscope analysis method for inclusions in rare earth steel. The scanning electron microscope analysis method comprises the following steps: (1) marking the inclusions under a metallographic microscope by adopting a coordinate method; (2) observing the inclusions in the rare earth steel by a scanning electron microscope; (2.1) analyzing the principle of the rare earth inclusions by a scanning electron microscope; the method comprises the following steps: determining the position of the rare earth inclusion in a back scattering mode, then switching to a secondary electron mode to observe the morphology details, and analyzing the components in combination with an energy spectrum; and (2.2) a scanning electron microscope analysis method, wherein a scanning electron microscope is used to carry out further morphology and component analysis on typical inclusions observed under a metallographic microscope. Typical inclusions in the rare earth steel are marked under a metallographic microscope by adopting a coordinate method, and the target inclusions can be quickly found to carry out corresponding detection analysis by utilizing the working principle of a scanning electron microscope, so that the detection analysis efficiency is greatly improved, and researchers are assisted to quickly and accurately obtain related detection results of the rare earth inclusions.

Description

Technical Field

[0001] The invention belongs to the technical field of metal material detection, and in particular relates to a scanning electron microscope analysis method for inclusions in rare earth steel. Background Art

[0002] In recent years, the application research of rare earth in steel has been rapidly developed. It has been clarified that rare earth elements have the effect of denaturation, deformation and deterioration on non-metallic inclusions in steel. Therefore, the research on inclusions in rare earth steel has become an indispensable detection and analysis project in the development process of rare earth steel. When observing inclusions under a scanning electron microscope, since the scanning electron microscope is an electronic imaging method, it is more difficult to find inclusions on the metallographic polishing surface, and there are high requirements for the operation of the electron microscope, and it often takes a long time to find inclusions. In the process of detecting and analyzing inclusions in rare earth steel, the inventor has invented an analysis method for rapid detection of inclusions in rare earth steel, which can greatly improve the detection and analysis efficiency and assist scientific researchers to quickly and accurately obtain relevant detection results of rare earth inclusions. Summary of the invention

[0003] The purpose of the present invention is to provide a scanning electron microscope analysis method for inclusions in rare earth steel. Typical inclusions in rare earth steel are marked by a coordinate method under a metallographic microscope, and the working principle of the scanning electron microscope is utilized to quickly find the target inclusions and carry out corresponding detection and analysis, thereby greatly improving the detection and analysis efficiency and assisting scientific researchers to quickly and accurately obtain relevant detection results of rare earth inclusions.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a scanning electron microscope analysis method for inclusions in rare earth steel, comprising the following steps:

[0006] (1) Use the coordinate method to mark inclusions under a metallographic microscope

[0007] (2) Scanning electron microscopy observation of inclusions in rare earth steel

[0008] (2.1) Principle of SEM analysis of rare earth inclusions

[0009] There are generally two modes for observing rare earth inclusions under a scanning electron microscope, namely backscattering mode and secondary electron mode. The resolution of secondary electrons is higher, which is helpful for observing the details of inclusions. Although the resolution and signal collection rate of the backscattered electron mode are lower, it is very sensitive to the atomic number of the sample material. Because the atomic number of rare earth elements is higher, they are bright white in the backscattering mode and easy to identify. Therefore, taking advantage of the characteristics of rare earths, the backscattering mode is first used to determine the position of rare earth inclusions, and then switched to the secondary electron mode to observe its morphological details, and combined with the energy spectrum to analyze its composition;

[0010] (2.2) Scanning electron microscopy analysis method

[0011] The use of scanning electron microscopy can further analyze the morphology and composition of typical inclusions observed under a metallographic microscope.

[0012] Furthermore, in the step (1): before the inclusions in the rare earth steel are detected and analyzed by scanning electron microscopy, the inclusions in the rare earth steel sample are usually observed and evaluated using a metallographic microscope. This method marks the positions of the inclusions while observing the inclusions under a metallographic microscope.

[0013] Furthermore, the marking method is that after the target inclusion is found under a microscope, the light source of the microscope is facing the inclusion. At this time, one axis of the stage, the X-axis or the Y-axis, is moved to move the light source to the edge of the sample, and a marking line is drawn with a marker at the position where the light is exposed on the edge, and then the light source is returned to the position of the inclusion along the original path. Then, another axis of the stage, the Y-axis or the X-axis, is moved to move the light source to the edge of the other side of the sample and a marking line is drawn with a marker at the position where the light is exposed on the edge; the sample is removed, and the position of the inclusion is determined by crossing two mutually perpendicular marking positions on the outer surface of the sample, and then the inclusion is circled with a marker, and after marking, it is placed under a microscope for confirmation.

[0014] Furthermore, when marking with a marker, be sure to make the circle slightly larger so as not to cover the inclusions.

[0015] Furthermore, in the step (2.2), the sample with marked inclusions is placed in a scanning electron microscope, and the drawn mark can be quickly found at a low magnification using the secondary electron mode. Then, the backscattering mode is switched to quickly find the rare earth inclusions through the chromatic aberration of the rare earth inclusions. According to the observation needs, the secondary electron mode is switched to zoom in for corresponding morphological observation and energy spectrum analysis.

[0016] Furthermore, the energy spectrum analysis first uses a point scanning method to quickly analyze the components at different positions of the inclusions, and then uses a surface scanning method to analyze the surface distribution of elements in the entire inclusion.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are:

[0018] 1. Non-metallic inclusions in steel are usually detected by metallographic microscope according to GB / T10561-2023. The present invention uses a coordinate method to mark typical inclusions found while detecting non-metallic inclusions in steel by metallographic microscope, so that target inclusions can be found quickly during subsequent observation and analysis by scanning electron microscope, thus avoiding time-consuming search for inclusions under electron microscope. The operation is simple, and the method of marking inclusions is not only applicable to marking inclusions in rare earth steel, but also applicable to common steel grades;

[0019] 2. Use the backscattered color detection principle of the scanning electron microscope to identify rare earth elements with high atomic numbers. In the backscattered color mode, rare earth elements appear bright white and are easy to identify, with good results;

[0020] 3. The combination of the two methods greatly improves the speed of SEM analysis of rare earth inclusions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Figure 1 Schematic diagram of rare earth inclusions marked for coordinate method;

[0023] Figure 2 Mark the location of inclusions for the coordinate method;

[0024] Figure 3 is the marked position under scanning electron microscope;

[0025] Figure 4 The morphology and energy spectrum analysis of inclusions were performed using a scanning electron microscope. DETAILED DESCRIPTION

[0026] A scanning electron microscope analysis method for inclusions in rare earth steel, specifically comprising:

[0027] 1. Use the coordinate method to mark inclusions under a metallographic microscope

[0028] Before the inclusions in rare earth steel are detected and analyzed by scanning electron microscope, a metallographic microscope is usually used to observe and evaluate the inclusions in the rare earth steel sample. One of the key points of the present invention is to mark the position of the inclusions while observing the inclusions under a metallographic microscope. The marking method is that after finding the target inclusions under the microscope, the light source of the microscope is facing the inclusions. At this time, one axis of the stage (X-axis or Y-axis) is moved first, and the light source is moved to the edge of the sample. A marking line is drawn with a marker at the position where the light is exposed on the edge. The light source is then returned to the position of the inclusion along the original path. After that, another axis of the stage (Y-axis or X-axis) is moved to the other side edge of the sample and a marking line is drawn with a marker at the position where the light is exposed on the edge. The sample is removed, and the position of the inclusion is determined by crossing the two mutually perpendicular marking positions on the outer surface of the sample. The inclusion is circled with a marker (note that it should be slightly larger so as not to cover the inclusions). After marking, it is placed under a microscope for confirmation. See the schematic diagram of the marking method. Figure 1 .

[0029] 2. Observation of inclusions in rare earth steel using scanning electron microscope

[0030] 2.1 Principle of SEM analysis of rare earth inclusions

[0031] There are generally two modes for observing rare earth inclusions under a scanning electron microscope, namely backscattering mode and secondary electron mode. The resolution of secondary electrons is higher, which helps to observe the details of inclusions; although the resolution and signal collection rate of the backscattered electron mode are lower, it is very sensitive to the atomic number of the sample material. Because the atomic number of rare earth elements is higher, they are bright white in the backscattering mode and easy to identify. For this reason, the characteristics of rare earths can be used to first use the backscattering mode to determine the location of rare earth inclusions, and then switch to the secondary electron mode to observe its morphological details, and analyze its composition in combination with the energy spectrum.

[0032] 2.2 Scanning electron microscopy analysis method

[0033] The use of scanning electron microscope can further analyze the morphology and composition of typical inclusions observed under the metallographic microscope. Place the sample with marked inclusions in the scanning electron microscope, and use the secondary electron mode at low magnification to quickly find the drawn mark, then switch to the backscattering mode to quickly find the rare earth inclusions through the color difference of the rare earth inclusions. According to the observation needs, you can switch to the secondary electron mode to zoom in for the corresponding morphology observation and energy spectrum analysis. The energy spectrum analysis first uses the point scanning method to quickly analyze the components of the inclusions at different positions, and then uses the surface scanning method to analyze the surface distribution of the elements of the entire inclusion. 2.3 Specific Examples

[0035] 2.3.1 Mark the inclusions in the rare earth steel according to the coordinate method. The actual photos of the marking process are shown in Figure 2 ;

[0036] 2.3.2 Quickly find the marking position under the scanning electron microscope, see Figure 3 ;

[0037] 2.3.3 Using backscattering mode to improve the identification of rare earth inclusions. The comparison of rare earth inclusions observed in backscattering mode and secondary electron mode is shown in Figure 4 (a, b), switch the SEM to backscattering mode to quickly find inclusions within the marked range;

[0038] 2.3.4 According to the needs of observation and analysis, the inclusions can be further analyzed in the secondary electron mode or backscatter mode of the scanning electron microscope;

[0039] 2.3.5 Perform energy spectrum analysis on inclusions by point scanning, see Figure 4 c;

[0040] 2.3.6 Magnified observation of secondary electron morphology of inclusions, see Figure 4 d;

[0041] 2.3.7 Further analysis of the surface distribution of each element in the inclusions is performed, see Figure 4 e.

[0042] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A scanning electron microscope analysis method for inclusions in rare earth steel, characterized in that: The steps include: (1) Use the coordinate method to mark the inclusions under a metallographic microscope; (2) Scanning electron microscopy observation of inclusions in rare earth steel (2.1) Principle of SEM analysis of rare earth inclusions There are generally two modes for observing rare earth inclusions under a scanning electron microscope, namely backscattering mode and secondary electron mode. The resolution of secondary electrons is higher, which is helpful for observing the details of inclusions. Although the resolution and signal collection rate of the backscattered electron mode are lower, it is very sensitive to the atomic number of the sample material. Because the atomic number of rare earth elements is higher, they are bright white in the backscattering mode and easy to identify. Therefore, taking advantage of the characteristics of rare earths, the backscattering mode is first used to determine the position of rare earth inclusions, and then switched to the secondary electron mode to observe its morphological details, and combined with the energy spectrum to analyze its composition; (2.2) Scanning electron microscopy analysis method The use of scanning electron microscopy can further analyze the morphology and composition of typical inclusions observed under a metallographic microscope.

2. The scanning electron microscope analysis method for inclusions in rare earth steel according to claim 1, characterized in that: In the step (1), before the inclusions in the rare earth steel are detected and analyzed by scanning electron microscope, the inclusions in the rare earth steel sample are usually observed and evaluated by metallographic microscope. This method marks the position of the inclusions while observing the inclusions under the metallographic microscope.

3. The scanning electron microscope analysis method for inclusions in rare earth steel according to claim 2, characterized in that: The marking method is that after finding the target inclusion under the microscope, the light source of the microscope is facing the inclusion. At this time, first move one axis of the stage, the X-axis or the Y-axis, move the light source to the edge of the sample, draw a marking line with a marker at the position where the light is exposed on the edge, and then return the light source to the position of the inclusion along the original path. Then move another axis of the stage, the Y-axis or the X-axis, move the light source to the edge of the other side of the sample and draw a marking line with a marker at the position where the light is exposed on the edge; remove the sample, determine the position of the inclusion by crossing the two marking positions perpendicular to each other on the outer surface of the sample, circle the inclusion with a marker, and after marking, place it under the microscope for confirmation.

4. The scanning electron microscope analysis method for inclusions in rare earth steel according to claim 3, characterized in that: When marking with a marker, make sure the circle is slightly larger so as not to cover inclusions.

5. The scanning electron microscope analysis method for inclusions in rare earth steel according to claim 1, characterized in that: In the step (2.2), the sample with marked inclusions is placed in a scanning electron microscope, and the drawn mark can be quickly found at a low magnification using the secondary electron mode. Then, the backscattering mode is switched to quickly find the rare earth inclusions through the chromatic aberration of the rare earth inclusions. According to the observation needs, the secondary electron mode is switched to zoom in for corresponding morphological observation and energy spectrum analysis.

6. The scanning electron microscope analysis method for inclusions in rare earth steel according to claim 5, characterized in that: The energy spectrum analysis first uses a point scanning method to quickly analyze the components at different positions of the inclusions, and then uses a surface scanning method to analyze the surface distribution of elements in the entire inclusion.

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