Method for detecting non-metallic inclusions in steel and application

Abstract

The invention relates to the technical field of detection of non-metallic inclusions in steel, and particularly discloses a method for detecting non-metallic inclusions in steel and application, the method comprises the following steps: intercepting a steel sample from a hydrogenation reactor, and grinding the surface of the steel sample into a coarse grinding area and a fine grinding area; putting the polished steel sample between two electrodes of a current detection device to form a current path; applying current to the steel sample by using a current detection device, detecting the electromagnetic field change of the steel sample, and observing the steel sample by using a microscope; and analyzing the change of the electromagnetic field and an observation result to determine the position, the size, the form, the number, the distribution and the type of the non-metallic inclusions. The method comprises the following steps: performing quantitative analysis on non-metallic inclusions by using a current detection method to know the total amount and distribution condition of the inclusions; then observing the form, size and distribution of the non-metallic inclusions by using a microscope, and understanding the characteristics of the inclusions; by combining the detection results of the two methods, the specific conditions of the non-metallic inclusions are comprehensively known, and the detection accuracy is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-metallic inclusion detection in steel, and particularly relates to a non-metallic inclusion detection method in steel and application. BACKGROUND

[0002] Non-metallic inclusions are endogenous and exogenous inclusions, oxides formed by deoxidization of metal, sulfides and nitrides precipitated due to reduced solubility of sulfur and nitrogen in the process of steel solidification, collectively referred to as endogenous inclusions, and refractory materials and slag introduced in the smelting process of metal, collectively referred to as exogenous inclusions. It is generally believed that the quantity, size, composition and distribution of non-metallic inclusions are one of the important factors affecting the performance of steel. The existence of non-metallic inclusions breaks the continuity of the metal matrix, so that the stress between the matrix cannot be transmitted through the inclusions, and stress is easily generated at the interface between the brittle and undeformed inclusions and the matrix, thereby causing cracks. The size of the non-metallic inclusion particles has a greater impact on the strength, and in general, the strength of the steel increases with the decrease of the size of the non-metallic inclusions. Therefore, it is necessary to further study the distribution of non-metallic inclusions in order to investigate the stability and reliability of various processing techniques.

[0003] For example, the publication number CN111860176A discloses a non-metallic inclusion full-field quantitative statistical distribution characterization method, which comprises the following steps: step S1: establishing an image database composed of non-metallic inclusions, scratches and external interference images; step S2, establishing a target detection model based on non-metallic inclusion feature spectrum; step S3, automatically collecting full-field non-metallic inclusion feature data of the treated metal material surface; step S4, accurately segmenting and extracting the non-metallic inclusions to the pixel level; and step S5, in-situ quantitative statistical distribution characterization of large-scale full-field non-metallic inclusions. The non-metallic inclusion full-field quantitative statistical distribution characterization method provided by the present application can improve the recognition accuracy and avoid errors caused by manual recognition through the establishment of a target detection model for full-field recognition and positioning of non-metallic inclusions in metal materials, and has a high level of automation.

[0004] The non-metallic inclusion full-field detection of hydrogenation reactor steel usually adopts a metallographic microscope method. The metallographic microscope method is to observe the morphology, size and distribution of non-metallic inclusions through an optical microscope. This method can clearly observe the specific conditions of non-metallic inclusions, but has weak quantitative analysis ability for inclusions. A single detection method cannot fully understand the specific conditions of non-metallic inclusions. Therefore, the present application provides a non-metallic inclusion full-field detection method for hydrogenation reactor steel to meet the needs.

[0005] Based on this technical background, the present application studies a non-metallic inclusion detection method in steel and application. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides a steel non-metallic inclusion detection method and application, which first uses current detection method to quantitatively analyze the non-metallic inclusions, understands the total amount and distribution of the inclusions, then uses a metallographic microscope to observe the morphology, size and distribution of the non-metallic inclusions, further understands the characteristics of the inclusions, and comprehensively understands the specific conditions of the non-metallic inclusions by combining the detection results of the two methods, thereby improving the accuracy of detection.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a steel non-metallic inclusion detection method, comprising:

[0008] A steel sample is intercepted from a hydrogenation reactor and the surface thereof is polished into a rough polishing area and a fine polishing area;

[0009] The polished steel sample is placed between two electrodes of a current detection device to form a current path;

[0010] The current detection device is used to apply current to the steel sample, the electromagnetic field change of the steel sample is detected, and the steel sample is observed by using a microscope;

[0011] The electromagnetic field change and the observation results are analyzed to determine the position, size, morphology, quantity, distribution and type of the non-metallic inclusions.

[0012] The second aspect of the present application provides an application of the above-mentioned method in the detection of non-metallic inclusions in hydrogenation reactor steel.

[0013] The technical effects of the present application include:

[0014] (1) The steel non-metallic inclusion detection method provided by the present application first uses current detection method to quantitatively analyze the non-metallic inclusions, understands the total amount and distribution of the inclusions, then uses a microscope to observe the morphology, size and distribution of the non-metallic inclusions, further understands the characteristics of the inclusions, and comprehensively understands the specific conditions of the non-metallic inclusions by combining the detection results of the two methods, thereby improving the accuracy of detection.

[0015] (2) The steel non-metallic inclusion detection method provided by the present application uses current detection method which has high sensitivity and can detect tiny non-metallic inclusions, and can quantitatively analyze the non-metallic inclusions to understand the content and distribution of the inclusions, thereby providing basis for subsequent quality control and optimization; the current detection method is suitable for the detection of various non-metallic inclusions, including different types of materials such as metals, non-metals and ceramics.

[0016] (3) The steel non-metallic inclusion detection method provided by the application has high efficiency, sensitivity, wide applicability, quantitative analysis, real-time online, automatic control and easy integration, and helps to improve product quality, reduce production cost and improve production efficiency

[0017] Other features and advantages of the present application will be described in detail in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the several views, and in which:

[0019] Figure 1 The flowchart of the steel non-metallic inclusion detection method provided by the application.

[0020] Figure 2 The flowchart of one specific embodiment of the steel non-metallic inclusion detection method provided by the application. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present application will be described in more detail below. Although the preferred embodiments of the present application are described below, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0022] In the present application, the orientation words such as "up, down" used without the opposite description generally refer to the up and down of the device in the normal use state, and "inner, outer" refer to relative to the outline of the device. In addition, the terms "first, second, third" are only for descriptive purposes, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first, second, third" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0023] The present application provides a steel non-metallic inclusion detection method, as shown in Figure 1 , comprising:

[0024] The steel sample is taken from the hydrogenation reactor and the surface is polished into a rough polishing area and a fine polishing area;

[0025] The polished steel sample is placed between the two electrodes of the current detection device to form a current path;

[0026] The current detection device is used to apply current to the steel sample, detect the electromagnetic field change of the steel sample, and observe the steel sample by using a microscope;

[0027] The electromagnetic field change and the observation result are analyzed to determine the position, size, shape, quantity, distribution and type of the non-metallic inclusions.

[0028] In the present application, the non-metallic inclusions are first quantitatively analyzed by using the current detection method to understand the total amount and distribution of the inclusions; then, the shape, size and distribution of the non-metallic inclusions are observed by using a microscope to further understand the characteristics of the inclusions; combined with the detection results of the two methods, the specific situation of the non-metallic inclusions can be comprehensively understood, and the accuracy of the detection is improved.

[0029] According to the present application, the steel sample is cut or trimmed after being intercepted from the hydrogenation reactor;

[0030] The thickness of the steel sample is 10-20mm, the width is 100-400mm, and the length is 100-400mm;

[0031] The interception position of the steel sample meets the requirements of the corresponding technical conditions;

[0032] The corresponding technical condition requirements include:

[0033] For a forged blank, the sample is taken from the head, middle or tail of the center to the edge of the forged blank;

[0034] For rolled and cold-drawn steel, the sample is taken along the longitudinal direction through the center line;

[0035] For quenching cracking, forging cracks, hot rolling, stamping and failure fatigue fracture positions, the sample is taken at the cracking and fracture positions.

[0036] According to the present application, the areas of the coarse grinding area and the fine grinding area are equal;

[0037] The coarse grinding area is polished by using 180-240 mesh sandpaper, and the fine grinding area is polished by using 320-600 mesh sandpaper;

[0038] After the fine grinding area is polished, the polishing treatment is carried out under a field of view of not less than 100 times.

[0039] In the present application, the area of the surface of the sample that is finely ground needs to be polished to make the surface of the sample under a field of view of 100 times free of scratches, peeling, water marks, stains, and smooth and bright like a mirror.

[0040] According to the present application, the electrode is a metal electrode, and is fixed with the steel sample by using a clamp or a clip;

[0041] The current is 10-1000mA;

[0042] The current is applied to the steel sample from small to large;

[0043] The microscope is a metallographic microscope.

[0044] In the present application, the current applied to the steel sample for hydrogenation reactor can be between 10 and 1000 mA, in order to ensure reliable current passing through the sample and obtain accurate detection results, a lower current value is used for detection first, and then the circuit strength is gradually increased.

[0045] Preferably, detecting the change of the electromagnetic field of the steel sample comprises:

[0046] An alternating electromagnetic field is generated by the current detection device acting on the steel sample, and the change of the electromagnetic field of the steel sample is detected by the detection instrument.

[0047] According to the present application, the change of the electromagnetic field is the change of the current intensity or the change of the magnetic field intensity.

[0048] In the present application, the sample after polishing and polishing is placed on the current detection device, the current detection device is composed of two electrodes, one electrode is placed at one end of the sample, and the other electrode is placed at the other end of the sample, forming a current path, the electrode is a metal electrode, in order to ensure good contact between the electrode and the sample, a clamp or a clip is used to fix the electrode and the sample.

[0049] The equipment used for current detection preparation can accurately output current, and the current detection device is near the sample, generating an alternating electromagnetic field, when the alternating electromagnetic field interacts with the inclusions in the sample, a detected signal will be generated, which can be the change of current or the change of magnetic field.

[0050] According to the present application, the electromagnetic field change and the observation result are analyzed to determine the position, size, shape, number, distribution and type of non-metallic inclusions.

[0051] The data analysis of the change of the electromagnetic field determines whether the non-metallic inclusions exist, and the position, size, shape and type of the non-metallic inclusions;

[0052] The size, shape, number, distribution and type of the non-metallic inclusions are determined by the observation result.

[0053] Preferably, the change of the shape of the non-metallic inclusions is caused by the resistance heating effect and / or electrochemical reaction when the current is applied to the steel sample.

[0054] According to the present application, the change of the shape of the non-metallic inclusions caused by the electrochemical reaction is that the electrolyte solution in the steel sample under the action of the current generates chemical reaction, generates gas, dissolved substances or forms deposits, resulting in dissolution, precipitation or precipitation of the non-metallic inclusions, so as to change its shape;

[0055] The resistance heating effect causes the change in the morphology of the non-metallic inclusions, and the steel sample generates heat under the action of the current, so that the temperature of the steel sample is increased, and the non-metallic inclusions are melted, diffused or recrystallized at high temperature, so that the morphology thereof is changed.

[0056] In the present application, when the current is in the range of 10-500 mA, the non-metallic impurities detected by the current detection have a higher accurate value, and the non-metallic impurities in the sample in the range of 500-1000 mA are affected by the current to produce deformation, at this time, the position, size and morphology of the inclusions can be more intuitively detected by the microscope observation method.

[0057] In the present application, the current detection method has high sensitivity, can detect small non-metallic inclusions, and can also quantitatively analyze the non-metallic inclusions to understand the content and distribution of the inclusions, and provide a basis for subsequent quality control and optimization; the current detection method is suitable for the detection of various non-metallic inclusions, including different types of materials such as metals, non-metals and ceramics.

[0058] In the present application, the current detection is to convert the detected signal into the value of current intensity or magnetic field intensity by a detection instrument, and to perform data analysis, according to the change of the signal, whether the inclusions exist, the position, size and morphology of the inclusions can be determined;

[0059] The non-metallic inclusion detection using the current detection method has the following effects and benefits:

[0060] High efficiency and sensitivity: the current detection method has high sensitivity and can detect small non-metallic inclusions;

[0061] Wide applicability: the current detection method is suitable for the detection of various non-metallic inclusions, including different types of materials such as metals, non-metals and ceramics;

[0062] Quantitative analysis: the current detection method can quantitatively analyze the non-metallic inclusions to understand the content and distribution of the inclusions, and provide a basis for subsequent quality control and optimization;

[0063] Real-time online: the current detection method can realize online detection and real-time monitoring of the non-metallic inclusions in the production process, which is helpful for timely discovery and problem solving;

[0064] Easy to integrate: the current detection method can be easily integrated into existing production lines and equipment without the need for large-scale modification, saving cost and time;

[0065] The use of current detection for non-metallic inclusion detection is highly efficient, sensitive, widely applicable, allows for quantitative analysis, real-time online operation, automatic control, and easy integration, which helps improve product quality, reduce production costs, and increase production efficiency.

[0066] In this invention, by analyzing images or signals of electromagnetic field changes, the location, size, and shape of inclusions can be determined. Non-metallic inclusions in steel used in hydrogenation reactors can be indirectly detected by measuring changes in the electromagnetic field. Since inclusions have different effects on the electromagnetic field, the type and properties of inclusions can be determined based on the characteristics of electromagnetic field changes.

[0067] Among them, the shape, size, quantity, distribution and type of inclusions can be directly observed and identified under a metallographic microscope.

[0068] Combining current detection with metallographic microscopy can achieve high efficiency in the full field of view detection of non-metallic inclusions, and the combination can improve the accuracy and comprehensiveness of the detection.

[0069] Current detection method mainly detects non-metallic inclusions through impedance method and electrochemical method. This method can perform quantitative analysis of non-metallic inclusions, has high sensitivity, and is suitable for detecting various non-metallic inclusions. However, this method cannot directly observe the morphology and distribution of inclusions. For inclusions with complex morphology, the detection effect will be affected.

[0070] Metallurgical microscopy, on the other hand, uses an optical microscope to observe the morphology, size, and distribution of non-metallic inclusions. This method can clearly observe the specific details of non-metallic inclusions, but its ability to perform quantitative analysis of inclusions is relatively weak.

[0071] Combining these two methods can achieve highly effective detection of non-metallic inclusions.

[0072] The present invention also provides an application of the above-described method in the detection of non-metallic inclusions in steel used in hydrogenation reactors.

[0073] The present invention will now be described in more detail through specific embodiments.

[0074] Example 1

[0075] like Figure 2 As shown, this embodiment provides a method for detecting non-metallic inclusions in steel, including the following steps:

[0076] Step 1, Sample preparation: Prepare steel samples for the hydrogenation reactor in advance, and ensure that the sample surface is clean and free of dirt and impurities. The sample can be cut or trimmed to obtain sample slices with a thickness of 10-20 mm, a width of 100-400 mm, and a length of 100-400 mm.

[0077] In this embodiment, the sample is a rolled and cold-drawn steel material, which is preferably sampled along the longitudinal direction through the center line;

[0078] Step two, surface polishing: the prepared sample surface is evenly divided into two parts, the coarse grinding area and the fine grinding area. The coarse grinding area is polished with 200 mesh sandpaper, and the fine grinding area is polished with 400 mesh sandpaper.

[0079] In this embodiment, the area of the sample surface that is finely ground needs to be polished to make the sample surface smooth and bright under a 100x field of view, without scratches, peeling, water marks, stains, or unevenness.

[0080] Step three, current detection preparation: the polished sample is placed in a current detection device, which consists of two electrodes. One electrode is placed at one end of the sample, and the other electrode is placed at the other end of the sample, forming a current path. The electrodes are metal electrodes, and clips are used to fix the electrodes and the sample to ensure good contact between the electrodes and the sample.

[0081] Step four, applying current: the current applied to the hydrogenation reactor steel sample can be between 10 and 1000 milliamperes. To ensure reliable current flow through the sample and obtain accurate detection results, a lower current value is used for detection first, and then the current intensity is gradually increased.

[0082] Step five, current detection: a specific current is applied to the sample through the current detection device, and then the electromagnetic field change is observed. The sensor or detector detects the electromagnetic field change around the sample. The presence of inclusions will affect the electromagnetic field, causing changes in the electromagnetic field.

[0083] Step six, microscope observation: the sample is observed using a metallographic microscope. The metallographic microscope can magnify the microstructure of the sample and detect larger inclusions. When observing, the focus and light source need to be adjusted to obtain clear observation results.

[0084] Step seven, extracting inclusion information: by analyzing the images or signals of the electromagnetic field change, the position, size and morphology of the inclusions can be determined. The non-metallic inclusions in the hydrogenation reactor steel are indirectly detected by measuring the change of the electromagnetic field. Since the inclusions have different effects on the electromagnetic field, the type and properties of the inclusions can be determined according to the characteristics of the electromagnetic field change.

[0085] In this embodiment, the current detection method is used to quantitatively analyze the non-metallic inclusions first to understand the total amount and distribution of the inclusions. Then, the morphology, size and distribution of the non-metallic inclusions are observed using a metallographic microscope to further understand the characteristics of the inclusions.

[0086] The detection results of the two methods can comprehensively understand the specific conditions of the non-metallic inclusions, and improve the detection accuracy.

[0087] In the embodiment, the computer image processing technology and artificial intelligence algorithm are also used to process and analyze the images observed by the metallographic microscope, so as to realize the automatic detection, identification and counting of the non-metallic inclusions, further improve the detection efficiency and accuracy, and help to optimize the material quality and performance.

[0088] The non-metallic inclusion detection method in the embodiment first uses the current detection method to quantitatively analyze the non-metallic inclusions, understands the total amount and distribution of the inclusions, then uses the microscope to observe the shape, size and distribution of the non-metallic inclusions, further understands the characteristics of the inclusions, and combines the detection results of the two methods to comprehensively understand the specific conditions of the non-metallic inclusions and improve the detection accuracy.

[0089] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for detecting non-metallic inclusions in steel, characterized in that, include: A steel sample was taken from the hydrogenation reactor and its surface was ground into a coarse grinding zone and a fine grinding zone. The polished steel sample is placed between the two electrodes of the current detection device to form a current path. A current is applied to the steel sample using a current detection device to detect changes in the electromagnetic field of the steel sample, and the steel sample is observed using a microscope. The location, size, shape, quantity, distribution, and type of the non-metallic inclusions are determined by analyzing the changes in the electromagnetic field and the results of the observations.

2. The method according to claim 1, characterized in that, After steel samples are taken from the hydrogenation reactor, they are further cut or trimmed. The steel sample has a thickness of 10-20 mm, a width of 100-400 mm, and a length of 100-400 mm. The cut portion of the steel sample meets the relevant technical requirements; The corresponding technical requirements include: For forging blanks, samples are taken from the head, middle, or tail of the blank from its center to the edge. For rolled and cold-drawn steel, samples are taken longitudinally along the centerline; For quenching cracks, forging cracks, hot rolling, stamping, and fatigue fracture sites, samples are taken at the cracks and fracture sites.

3. The method according to claim 1, characterized in that, The areas of the coarse grinding zone and the fine grinding zone are equal; The coarse grinding zone is polished with 180-240 grit sandpaper, and the fine grinding zone is polished with 320-600 grit sandpaper. After the fine grinding area is finished, it is polished under a field of view of not less than 100x.

4. The method according to claim 1, characterized in that, The electrode is a metal electrode and is fixed to the steel sample with clips or clamps; The current is 10 to 1000 mA; The current is applied to the steel sample from low to high; The microscope in question is a metallurgical microscope.

5. The method according to claim 4, characterized in that, The detection of electromagnetic field changes in the steel sample includes: An alternating electromagnetic field is generated using the current detection device and applied to the steel sample. The change in the electromagnetic field of the steel sample is detected by a detection instrument.

6. The method according to claim 5, characterized in that, The change in the electromagnetic field is a change in current intensity or a change in magnetic field intensity.

7. The method according to claim 6, characterized in that, The analysis of the electromagnetic field changes and observation results determines the location, size, shape, quantity, distribution, and type of the non-metallic inclusions, including: Data analysis of the electromagnetic field changes is performed to determine whether the non-metallic inclusions exist, and the location, size, shape, and type of the non-metallic inclusions. The size, shape, quantity, distribution, and type of the non-metallic inclusions are determined based on the observation results.

8. The method according to claim 1, characterized in that, The change in the morphology of the non-metallic inclusions is caused by the resistance heating effect and / or electrochemical reaction when an electric current is applied to the steel sample.

9. The method according to claim 8, characterized in that, The electrochemical reaction causes the morphological change of the non-metallic inclusions by the chemical reaction of the electrolyte solution inside the steel sample under the action of current, generating gas, dissolving substances or forming deposits, which leads to the dissolution, precipitation or sedimentation of the non-metallic inclusions, thereby changing their morphology. The change in morphology of the non-metallic inclusions caused by the resistance heating effect is that the steel sample generates heat under the action of current, which raises the temperature of the steel sample. The non-metallic inclusions melt, diffuse, or recrystallize at high temperature, thereby changing their morphology.

10. The application of the method according to any one of claims 1-9 in the detection of non-metallic inclusions in steel for hydrogenation reactors.

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