Phase analysis method of steelmaking composite deoxidizer

Abstract

The invention discloses a phase analysis method of a steelmaking composite deoxidizer, and belongs to the technical field of steelmaking processes. The method comprises the specific steps of sample preparation and scanning electron microscope observation and analysis. By means of the method, the composition, morphology, size and distribution of various phases of the composite deoxidizer can be effectively analyzed, and the method has very important significance on control over the quality of the steelmaking deoxidizer, control over the deoxidation process, control over steelmaking inclusions and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of steelmaking process, and in particular relates to a phase analysis method of a steelmaking composite deoxidizer. Background Art

[0002] Composite deoxidizers are alloys composed of two or more deoxidizing elements, commonly used examples include calcium-silicon alloys, calcium-silicon-barium alloys, silicon-manganese alloys, and ferrosilicon alloys. In recent years, with the continuous improvement of steel performance requirements, the cleanliness requirements for steel have also become increasingly stringent, leading to an increasing emphasis on analyzing the composition and phase composition of steelmaking deoxidizers. However, chemical analysis methods only measure the total content of each element in the deoxidizer alloy and cannot determine whether each element exists as a single element, forms an alloy phase, or forms an oxide. While X-ray diffractometers can perform phase analysis, their results are not intuitive and cannot characterize the morphology, distribution, size, and other information of the various phases in the deoxidizer. The method of the present invention performs metallographic sample preparation on a composite deoxidizer sample, utilizes the element surface scanning function of a scanning electron microscope energy dispersive spectrometer, and can accurately determine the composition of various phases in the deoxidizer by superimposing the positions of the elements, and simultaneously obtains information such as their corresponding morphology, distribution, and size. In particular, the method can quickly and accurately analyze the composition and morphology of harmful oxides that are of greatest concern in the deoxidizer, which is of great significance to the quality control of the deoxidizer, the control of the steelmaking process, and the improvement of the quality of steel materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a phase analysis method for a steelmaking composite deoxidizer, which can effectively analyze the various phase compositions, morphologies, sizes and distributions of the composite deoxidizer, and is of great significance for the quality control of the steelmaking deoxidizer, the control of the deoxidation process and the control of steelmaking inclusions.

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

[0005] The present invention provides a phase analysis method for a steelmaking composite deoxidizer, comprising:

[0006] 1) Sample preparation

[0007] 1.1) Sample selection

[0008] Deoxidizer alloy samples are usually in block or small granular form. For block samples, two relatively parallel surfaces are ground with a belt grinder to facilitate subsequent sample preparation and observation. For granular samples with small particle size, appropriate particles are selected for sample inlay preparation.

[0009] 1.2) Sample preparation

[0010] Grind the selected block sample on a grinding wheel machine or a belt sander to produce two relatively parallel upper and lower surfaces;

[0011] For small particle samples, sample inlay preparation is required;

[0012] The block samples with parallel surfaces after grinding and the embedded small particle samples are subjected to metallographic sample preparation, and multiple metallographic sandpapers are selected for grinding in sequence, and then polished to obtain the prepared samples;

[0013] 2) Scanning electron microscopy observation and analysis

[0014] 2.1) Place the sample on the SEM sample stage;

[0015] 2.2) Observe the morphology of the sample using a scanning electron microscope, magnifying it from low to high magnification, and select the appropriate observation magnification, and preliminarily determine the elements of each phase in the deoxidizer by energy spectrum;

[0016] 2.3) Select representative characteristic areas by observation, and then select these elements based on the elements preliminarily determined by the energy spectrum in the surface scan function interface for elemental surface scan analysis;

[0017] 2.4) Phase analysis of the deoxidizer was performed using the position overlap method.

[0018] Furthermore, a sample block with a size of 10-20 mm was selected and two relatively parallel surfaces were ground using a belt sander to facilitate subsequent sample preparation and observation.

[0019] Furthermore, for samples with small particles of 1-5 mm, 3-5 mm particles are selected for sample inlay preparation.

[0020] Furthermore, the inlay preparation uses an inlay machine to make samples. After the stage of the inlay machine is raised, a layer of double-sided tape needs to be attached to the stage to fix the small particle sample before placing the small particle sample. Then the stage is lowered and the inlay powder is poured in for inlaying.

[0021] Furthermore, 240#, 320#, 500#, and 800# metallographic sandpapers are selected in sequence for grinding.

[0022] Furthermore, the parallel surface of the block sample is polished to keep the bottom of the sample parallel to the upper surface, so that the focal plane of the sample is consistent when observing the image, making the image easy to focus clearly.

[0023] Furthermore, when placing the mounted sample, the sample observation surface needs to be connected to the bottom sample stage with conductive tape.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The method of the present invention can effectively analyze the various phase compositions, morphologies, sizes and distributions of the composite deoxidizer, and is of great significance for the quality control of the steelmaking deoxidizer, the control of the deoxidation process and the control of steelmaking inclusions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings.

[0027] Figure 1 It is a composite deoxidizer with two particle sizes;

[0028] Figure 2 These are two prepared metallographic samples of composite deoxidizers;

[0029] Figure 3 Energy spectrum analysis of each phase composition under scanning electron microscope;

[0030] Figure 4 It is the surface distribution analysis of each element of the scanning electron microscope energy spectrum;

[0031] Figure 5 Analyze the process for the position overlap method;

[0032] Figure 6 This is the phase analysis result of silicon calcium barium deoxidizer;

[0033] Figure 7 This is the phase analysis result of ferrosilicon deoxidizer. DETAILED DESCRIPTION

[0034] Example

[0035] The phase analysis method of the deoxidizer is described using silicon-calcium-barium alloy and silicon-ferroalloy as examples.

[0036] Phase analysis of silicon calcium barium alloy deoxidizer:

[0037] According to the method of the present invention, a blocky silicon calcium barium deoxidizer was selected for sample preparation. The composition of each phase was observed under a scanning electron microscope, as shown in Figure Group 3. It was mainly composed of the following phases with different colors and morphologies: black blocky morphology, mainly Si element, see spectrum 58 in Figure Group 3; light gray long strip morphology, mainly Si and Fe elements, see spectrum 56 in Figure Group 3; medium gray blocky morphology, mainly Si and Ca elements, see spectrum 55 in Figure Group 3; white granular morphology, mainly Si, Ba, Al, Ca elements, see spectrum 59 in Figure Group 3.

[0038] On this basis, we further zoomed in and selected a representative typical area to conduct energy spectrum scanning analysis on the elements Si, Ca, Ba, Al, C, O, etc. that were preliminarily judged to be contained in the above energy spectrum (Figure Group 4).

[0039] Each phase was analyzed according to the position overlap method. The analysis process is shown in Figure 5 , the same color in the figure represents a phase, and the final analysis results are shown in Figure 6 This method can be used to clearly determine the composition, morphology, size and distribution of each phase in the silicon calcium barium deoxidizer.

[0040] Phase analysis of ferrosilicon alloy deoxidizer: The analysis method is the same as above. The phase of ferrosilicon alloy is relatively simple. The results are shown in Figure 7.

[0041] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A phase analysis method for a steelmaking composite deoxidizer, characterized by comprising: 1) Sample preparation 1.1) Sample selection Deoxidizer alloy samples are usually in block or small granular form. For block samples, two relatively parallel surfaces are ground with a belt grinder to facilitate subsequent sample preparation and observation. For granular samples with small particle size, appropriate particles are selected for sample inlay preparation. 1.2) Sample preparation Grind the selected block sample on a grinding wheel machine or a belt sander to produce two relatively parallel upper and lower surfaces; For small particle samples, sample inlay preparation is required; The block samples with parallel surfaces after grinding and the embedded small particle samples are subjected to metallographic sample preparation, and multiple metallographic sandpapers are selected for grinding in sequence, and then polished to obtain the prepared samples; 2) Scanning electron microscopy observation and analysis 2.1) Place the sample on the SEM sample stage; 2.2) Observe the morphology of the sample using a scanning electron microscope, magnifying it from low to high magnification, and select the appropriate observation magnification, and preliminarily determine the elements of each phase in the deoxidizer by energy spectrum; 2.3) Select representative characteristic areas by observation, and then select these elements based on the elements preliminarily determined by the energy spectrum in the surface scan function interface for elemental surface scan analysis; 2.4) Phase analysis of the deoxidizer was performed using the position overlap method.

2. The phase analysis method of the steelmaking composite deoxidizer according to claim 1 is characterized in that: a sample block with a size of 10-20 mm is selected and two relatively parallel surfaces are ground with a sanding machine to facilitate subsequent sample preparation and observation.

3. The phase analysis method of the steelmaking composite deoxidizer according to claim 1, wherein: For samples with small particles of 1-5 mm, 3-5 mm particles are selected for sample inlay preparation.

4. The phase analysis method of the steelmaking composite deoxidizer according to claim 1, wherein: The inlay preparation uses a mounting machine to make samples. After the mounting machine's stage is raised, a layer of double-sided tape needs to be attached to the stage to fix the small particle sample before placing it. Then the stage is lowered and the mounting powder is poured in for inlaying.

5. The phase analysis method of the steelmaking composite deoxidizer according to claim 1, wherein: Use 240#, 320#, 500# and 800# metallographic sandpaper for grinding in turn.

6. The phase analysis method of the steelmaking composite deoxidizer according to claim 1, wherein: The purpose of grinding parallel surfaces of block samples is to keep the bottom of the sample parallel to the upper surface, so that the focal plane of the sample is consistent when observing the image, making the image easy to focus clearly.

7. The phase analysis method of the steelmaking composite deoxidizer according to claim 1, wherein: When placing the mounted sample, use conductive tape to connect the sample observation surface to the bottom sample stage.

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