Continuous casting slab processing method based on layer-by-layer inclusion scanning inspection

Abstract

The invention provides a continuous casting slab processing method based on layer-by-layer inclusion scanning inspection. The continuous casting slab processing method comprises the steps that a continuous casting slab sulfur printing blank is obtained; cutting the sulfur printing casting blank to obtain a blank with a first size; the blank is rotated by 90 degrees, oxidized surface layers on the two sides of the cross section of the casting blank are cut, and a blank of the second size is obtained; marking end faces of inner and outer arcs on the blank, and cutting the inner and outer arcs to obtain two billets with third sizes; acquiring each layer of sample representing the surface layer of the casting blank from the inner arc steel billet and the outer arc steel billet along the thickness direction, and numbering; grinding the detection surface and the opposite surface of each numbered sample, and then carrying out coarse grinding, fine grinding and polishing; performing scanning inspection on the obtained metallographic specimen, and counting and recording the type, size, quantity, distribution density and form of the inclusions in each layer. According to the method, the problems of single processing period and single inspection position of conventional casting blank layer-by-layer inspection can be solved, rapid layer-by-layer inclusion scanning of the casting blank can be realized, the material utilization rate and the processing efficiency are improved, and efficient casting blank quality monitoring is realized.

Description

Technical Field

[0001] The present invention relates to the field of metallurgical technology, and in particular to a continuous casting slab processing method based on layer-by-layer inclusion scanning inspection. Background Art

[0002] Inclusions generally refer to foreign matter within the material or non-metallic inclusions generated by deoxidation of molten steel or internal chemical reactions, such as oxides and sulfides in steel. These inclusions can affect the material properties of steel, such as strength, toughness, and fatigue life. Numerous inclusions, especially large or sharp ones, can cause stress concentration, leading to crack initiation and propagation. Therefore, inclusion inspection is a core component of material quality control and crucial for ensuring material reliability. Through precise inspection and analysis, defects can be controlled at the source, processes can be optimized, and standard requirements can be met, ultimately ensuring material reliability under complex operating conditions.

[0003] Inclusion inspection is typically accomplished through the following methods: Metallographic microscopy: Observes the morphology, distribution, and quantity of inclusions. Scanning electron microscopy (SEM): Analyzes the microstructure and composition of inclusions. Energy dispersive spectroscopy (EDS): Determines the chemical composition of inclusions. Image analysis software: Quantitatively assesses inclusion size, area percentage, and other factors.

[0004] With the direct supply of materials, such as automotive steel sheets, to customers, more and more are concerned about inclusions in both the product and process stages. This is especially true during product certification, where users are particularly concerned with the level of process control. Understanding source control defects is a crucial step in product certification. Therefore, rapid and accurate analysis of inclusion content in steelmaking slabs is crucial.

[0005] Typically, a layer-by-layer inclusion scanning inspection of a slab involves obtaining a sulfur print during the continuous casting process. A rectangular parallelepiped is then cut from the top to the bottom of the quarter-section of the slab where the print is located. 2mm sections of the upper and lower surfaces are then ground to the desired finish using a grinder. The process then undergoes a rough-grinding, fine-grinding, and polishing step, followed by inclusion scanning. After each inspection, the process is repeated to determine the inclusion content layer by layer. However, this process is complex, results in low material utilization, long inspection times, and significant feedback lag, leading to low inspection efficiency. Summary of the Invention

[0006] In response to the technical problems raised above, a continuous casting slab processing method based on layer-by-layer inclusion scanning inspection is provided.

[0007] The technical means adopted in the present invention are as follows: A continuous casting slab processing method based on layer-by-layer inclusion scanning inspection comprises the following steps: S1. Obtain a sulfur stamped billet for continuous casting and mark the top and bottom surfaces, i.e., the inner and outer arcs of the billet; S2, processing the sulfur-printed casting blank; S21, placing the obtained sulfur-printed billet on a cutting band saw workbench, cutting the billet into a first size, and marking the upper and lower surfaces, i.e., the inner and outer arcs of the billet; S22, rotating the billet in S21 by 90 degrees, and using a band saw to cut the oxidized surface layers produced by flame cutting on both sides of the cross section of the billet to obtain a billet of the second size, and marking the upper and lower surfaces, i.e., the inner and outer arcs of the billet; S23. Mark the end faces of the inner and outer arcs, i.e., the non-cutting faces, on the billet of S22; and use a band saw to cut the inner and outer arcs respectively to obtain two billets of the third size, namely, the inner arc billet and the outer arc billet; S3. Processing of metallographic specimens; S31. Take samples of each layer representing the surface layer of the inner arc steel billet obtained in S23 along the thickness direction, mark the side of each layer of the sample with a steel number, and number each layer of the sample. The upper side of the number is the test surface. S32. Take the outer arc steel billet obtained in S23 and obtain samples of each layer representing the surface layer of the billet along the thickness direction. Mark the side of each layer of sample with a steel number and number each layer. The sample on the positive side of the number is the one to be tested. S33, grinding the test surface and the opposite surface of each numbered sample by a grinding machine; S34, performing coarse grinding, fine grinding, and polishing on the sample ground in S33 to obtain a metallographic sample; S4. Inclusion detection: Scan and inspect the metallographic specimen obtained in S34, scan with a metallographic microscope, and count and record the type, size, quantity, distribution density and morphology of inclusions in each layer.

[0008] Furthermore, in said S1, a suitable pouring time is selected during the continuous casting process, and flame cutting equipment is used to obtain a sulfur-printed billet with a billet width of 900-2000 mm, a thickness of 230 mm, and a thickness of 80-100 mm in the pouring direction.

[0009] Furthermore, in said S21, cutting is performed at ±75 mm at one quarter of the width direction of the sulfur-printed casting billet to obtain billets of 150 mm*80 to 100 mm*230 mm.

[0010] Furthermore, in S22, a band saw is used to cut the 25-35 mm oxidized surface layer produced by flame cutting on both sides of the cross section of the ingot, to obtain a 150 mm*25 mm*230 mm ingot.

[0011] Furthermore, in S23, a band saw is used to cut the inner and outer arcs at 25 mm, respectively, to obtain two steel billets of 150 mm*25 mm*25 mm.

[0012] Furthermore, in said S31, wire cutting is used to obtain samples of each layer representing the surface layer of the ingot at 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, and the samples of each layer are numbered 110, 111, 112, 113, 114, 115, and 116.

[0013] Furthermore, in S32, wire cutting is used to obtain samples of each layer representing the surface layer of the ingot at 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, and the samples of each layer are numbered 210, 211, 212, 213, 214, 215, and 216.

[0014] Furthermore, in S33, the surface roughness of the sample after surface grinding is Ra≤5um.

[0015] Furthermore, in said S34, polishing includes coarse polishing and fine polishing, and the surface roughness of the sample after polishing is Ra≤1.6um.

[0016] Furthermore, in S4, an automatic inclusion analysis system is used to perform scanning inspection.

[0017] Compared with the prior art, the present invention has the following advantages: The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection provided by the present invention can solve the problems of single processing cycle and inspection position in conventional layer-by-layer inspection of cast slabs. The inclusion scanning sample processed according to this method can realize rapid layer-by-layer inclusion scanning of the cast slabs, improve material utilization and processing efficiency, and realize efficient cast slab quality monitoring.

[0018] Based on the above reasons, the present invention can be widely promoted in the fields of continuous casting process of metal materials, inclusion detection technology, intelligent processing control, etc. in the steel metallurgical manufacturing industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 Flowchart of the method of the present invention.

[0021] Figure 2Schematic diagram of the inner arc steel billet and the outer arc steel billet in Example 1 of the present invention.

[0022] Figure 3 Schematic diagram of numbering of samples in each layer in Example 1 of the present invention.

[0023] Figure 4 Schematic diagram of the sulfur-imprinted casting in Example 2 of the present invention.

[0024] Figure 5 Schematic diagram of the metallographic sample obtained in Example 2 of the present invention.

[0025] Figure 6 Schematic diagram of the metallographic examination results in Example 2 of the present invention Figure 1 .

[0026] Figure 7 Schematic diagram of the metallographic examination results in Example 2 of the present invention Figure 2 . DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0031] Example 1 The present invention provides a continuous casting slab processing method based on layer-by-layer inclusion scanning inspection. It is a processing method for steelmaking continuous casting slabs to inspect the slabs layer by layer, which can solve the problems of processing cycle and single inspection position in conventional layer-by-layer inspection of slabs. The inclusion scanning sample processed by this method can realize rapid inclusion scanning of the slabs layer by layer, improve material utilization and processing efficiency, and realize efficient slab quality monitoring.

[0032] The specific implementation steps of the present invention are: 1. Obtain sulfur-printed billets for continuous casting: Select appropriate pouring time during continuous casting and use flame cutting equipment to obtain sulfur-printed billets with a width of approximately 1550 mm, a thickness of approximately 230 mm, and a thickness of 95 mm in the pouring direction (mark the upper and lower surfaces, i.e., the inner and outer arcs of the billet).

[0033] 2. Processing of sulfur-printed castings 2.1. After obtaining the sulfur-printed ingot, move the ingot to the workbench of the cutting band saw and cut it at ±75mm, one quarter of the width of the sulfur-printed ingot, to obtain a 150mm*95mm*230mm ingot (mark the upper and lower surfaces, i.e. the inner and outer arcs of the ingot).

[0034] 2.2. Rotate the billet 90° and use a band saw to cut off the oxidized surface layer produced by flame cutting on both sides of the cross section of the billet by about 25 mm to obtain a billet of 150 mm * 25 mm * 230 mm (mark the upper and lower surfaces, i.e. the inner and outer arcs of the billet).

[0035] 2.3. On the steel billet in 2.2, mark the end faces of the inner and outer arcs (non-cutting faces), and use a band saw to cut the inner and outer arcs at 25mm, respectively, to obtain two billets of 150mm*25mm*25mm, one for the inner arc billet and the other for the outer arc billet. Figure 2 shown.

[0036] 3. Processing of metallographic specimens 3.1. Take the inner arc steel billet obtained in 2.3 and use wire cutting along the thickness direction to obtain samples of each layer representing the surface layer of the billet at 0mm, 2mm, 4mm, 6mm, 8mm, 10mm and 12mm. Mark the steel number on the side of the sample. The sample numbers are 110, 111, 112, 113, 114, 115 and 116. The surface above the number is the test surface. Figure 3 shown.

[0037] 3.2. Take the outer arc steel billet obtained in 2.3 and use wire cutting along the thickness direction to obtain samples of each layer representing the surface layer of the billet at 0mm, 2mm, 4mm, 6mm, 8mm, 10mm and 12mm. Mark the steel number on the side of the sample. The sample numbers are 210, 211, 212, 213, 214, 215 and 216. The surface above the number is the test surface. Figure 3 shown.

[0038] 3.3. The test surface and opposite surface of each numbered sample are ground by a grinder. The surface roughness after grinding is Ra=4um.

[0039] 3.4. For the processed samples, perform rough grinding, fine grinding and polishing (rough polishing and fine polishing) according to the samples tested by metallographic examination. The surface roughness after polishing is Ra=1.3um.

[0040] 4. Inclusion detection Scanning inspection is performed using an automatic inclusion analysis system (existing analysis system), which can scan with a metallographic microscope to count and record the type, size, quantity, distribution density and morphology of inclusions in each layer.

[0041] Example 2 Take continuous casting as an example: 1. During the continuous casting process, select the appropriate pouring time and use flame cutting equipment to obtain the continuous casting billet with furnace number 2265267 and billet number 004. The billet width is about 1600mm, thickness is 230mm, and thickness in the pouring direction is 100mm (mark the upper and lower surfaces, i.e. the inner and outer arcs of the billet. The surface with flame cutting weld spots is the lower surface). Figure 4 shown.

[0042] 2. Processing of sulfur-printed castings 2.1. After obtaining the sulfur-printed ingot, move the ingot to the workbench of the cutting band saw and cut it at +75mm (i.e. 475mm) and -75mm (i.e. 325mm) at 400mm in the width direction of the sulfur-printed ingot to obtain a 150mm*100mm*230mm ingot (mark the upper and lower surfaces, i.e. the inner and outer arcs of the ingot).

[0043] 2.2. Rotate the billet 90° and use a band saw to cut off 35mm of the oxidized surface layer produced by flame cutting on both sides of the cross section of the billet to obtain a billet of 150mm*25mm*230mm (mark the upper and lower surfaces, i.e. the inner and outer arcs of the billet).

[0044] 2.3. On the steel billet in 2.2, mark the end faces of the inner and outer arcs (non-cutting faces), and use a band saw to cut the inner and outer arcs 25 mm apart to obtain two steel billets of 150 mm * 25 mm * 25 mm.

[0045] 3. Processing of metallographic specimens 3.1. Take the inner arc steel billet obtained in 2.3 and use wire cutting along the thickness direction to obtain samples of each layer representing the surface layer of the billet at 0mm, 2mm, 4mm, 6mm, 8mm, 10mm and 12mm. Mark the side of each layer of sample with steel number. The sample numbers of each layer are 110, 111, 112, 113, 114, 115 and 116. The surface above the number is the test surface. Figure 5 shown.

[0046] 3.2. Take the outer arc steel billet obtained in 2.3 and use wire cutting along the thickness direction to obtain samples of each layer representing the surface layer of the billet at 0mm, 2mm, 4mm, 6mm, 8mm, 10mm and 12mm. Mark the side of each layer of sample with steel number. The sample numbers of each layer are 210, 211, 212, 213, 214, 215 and 216. The surface above the number is the test surface. Figure 5 shown.

[0047] 3.2. The test surface and the opposite surface of each numbered sample are ground by a grinder. The surface roughness after grinding is Ra=5um.

[0048] 3.3. For the processed samples, perform rough grinding, fine grinding and polishing (rough polishing and fine polishing) according to the samples tested by metallographic examination. The surface roughness after polishing is Ra=1.4um.

[0049] 4. Inclusion detection The automatic inclusion analysis system is used for scanning inspection, which can realize the scanning of metallographic microscope. The type, size, quantity, distribution density and shape of inclusions in each layer are counted and recorded. The inspection results are as follows: Figure 6 and Figure 7 shown.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A continuous casting slab processing method based on layer-by-layer inclusion scanning inspection, characterized in that: The steps include: S1. Obtain a sulfur stamped billet for continuous casting and mark the top and bottom surfaces, i.e., the inner and outer arcs of the billet; S2, processing the sulfur-printed casting blank; S21, placing the obtained sulfur-printed billet on a cutting band saw workbench, cutting the billet into a first size, and marking the upper and lower surfaces, i.e., the inner and outer arcs of the billet; S22, rotating the billet in S21 by 90 degrees, and using a band saw to cut the oxidized surface layers produced by flame cutting on both sides of the cross section of the billet to obtain a billet of the second size, and marking the upper and lower surfaces, i.e., the inner and outer arcs of the billet; S23. Mark the end faces of the inner and outer arcs, i.e., the non-cutting faces, on the billet of S22; and use a band saw to cut the inner and outer arcs respectively to obtain two billets of the third size, namely, the inner arc billet and the outer arc billet; S3. Processing of metallographic specimens; S31. Take samples of each layer representing the surface layer of the inner arc steel billet obtained in S23 along the thickness direction, mark the side of each layer of the sample with a steel number, and number each layer of the sample. The upper side of the number is the test surface. S32. Take the outer arc steel billet obtained in S23 and obtain samples of each layer representing the surface layer of the billet along the thickness direction. Mark the side of each layer of sample with a steel number and number each layer. The sample on the positive side of the number is the one to be tested. S33, grinding the test surface and the opposite surface of each numbered sample by a grinding machine; S34, performing coarse grinding, fine grinding, and polishing on the sample ground in S33 to obtain a metallographic sample; S4. Inclusion detection: Scan and inspect the metallographic specimen obtained in S34, scan with a metallographic microscope, and count and record the type, size, quantity, distribution density and morphology of inclusions in each layer.

2. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1 is characterized in that: In S1, a suitable pouring time is selected during the continuous casting process, and a flame cutting device is used to obtain a sulfur-printed billet with a width of 900-2000 mm, a thickness of 230 mm, and a thickness of 80-100 mm in the pouring direction.

3. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1 is characterized in that: In the S21, the sulfur-printed casting billet is cut at ±75 mm, one quarter of the width, to obtain billets of 150 mm*80 to 100 mm*230 mm.

4. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In the step S22, a band saw is used to cut off the oxidized surface layer of 25-35 mm produced by flame cutting on both sides of the cross section of the ingot, to obtain an ingot of 150 mm*25 mm*230 mm.

5. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In S23, a band saw is used to cut the inner and outer arcs at 25 mm, respectively, to obtain two steel billets of 150 mm*25 mm*25 mm.

6. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In the S31, wire cutting is used to obtain samples of each layer representing the surface layer of the ingot at 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, and the samples of each layer are numbered 110, 111, 112, 113, 114, 115, and 116.

7. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In the S32, wire cutting is used to obtain samples of each layer representing the surface layer of the ingot at 0 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, and the samples of each layer are numbered 210, 211, 212, 213, 214, 215, and 216.

8. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In the above-mentioned S33, the surface roughness of the sample after surface grinding is Ra≤5um.

9. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In the S34, polishing includes coarse polishing and fine polishing, and the surface roughness of the sample after polishing is Ra≤1.6um.

10. The continuous casting slab processing method based on layer-by-layer inclusion scanning inspection according to claim 1, characterized in that: In S4, an automatic inclusion analysis system is used to perform scanning inspection.

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