A mold for continuous casting of high manganese steel and a method for evaluating and maintaining the same

Abstract

The application discloses a crystallizer for high manganese steel continuous casting and an evaluation and maintenance method thereof, and relates to the technical field of metallurgical continuous casting equipment, and comprises a crystallizer body, wherein the crystallizer body comprises a crystallizer upper section, a crystallizer middle section and a crystallizer lower section in sequence along a strand drawing direction; the wide surface taper of the crystallizer upper section is greater than that of the crystallizer lower section; the wide surface of the crystallizer middle section is in a parabolic variable taper, and the wide surface taper of the upper end of the crystallizer middle section is greater than that of the lower end of the crystallizer middle section; and the narrow surface taper of each section of the crystallizer body is 1.2-1.5 times of the corresponding wide surface taper. The segmented composite taper structure is designed according to the nonlinear solidification shrinkage characteristics of 20-30% manganese steel, the shrinkage law of each solidification stage of the steel grade is accurately matched, the air gap in the crystallizer is effectively eliminated, the occurrence rate of surface defects such as corner cracks and longitudinal cracks of the cast strand is significantly reduced, meanwhile, the excessive extrusion of the copper plate by the billet shell is avoided, and the thermal fatigue damage of the copper plate is reduced.

Description

Technical Field

[0001] This invention relates to the field of metallurgical continuous casting equipment technology, and in particular to a crystallizer for continuous casting of high manganese steel and its evaluation and maintenance methods. Background Technology

[0002] High-manganese steel containing 20-30% manganese is widely used in key fields such as mining machinery, metallurgical spare parts, engineering machinery, and containers due to its excellent wear resistance, impact resistance, and low-temperature toughness. However, this type of high-manganese steel exhibits high-temperature physical and metallurgical characteristics that are completely different from ordinary carbon steel during continuous casting, becoming a core technical challenge in continuous casting production: First, it has a large coefficient of linear expansion at high temperatures, and its volume shrinkage rate during solidification is 1.5-2 times that of ordinary carbon steel. The billet shell is prone to forming air gaps with the crystallizer wall, resulting in a sharp drop in heat transfer efficiency and slow and uneven billet shell growth. Second, it has a low thermal conductivity, and the heat dissipation effect at the corners is much worse than that on the wide and narrow surfaces, which easily leads to surface defects such as corner cracks. Third, it has a wide solidification range, low initial solidification shell strength, and a high tendency to adhere to the crystallizer wall, which can easily cause sticking and leakage accidents.

[0003] Existing continuous casting molds are designed based on the solidification shrinkage characteristics of ordinary carbon steel, and mostly adopt a single linear taper structure. This cannot match the nonlinear solidification shrinkage law of high manganese steel, resulting in a loose fit between the billet shell and the copper plate in the upper section of the mold, forming air gaps. In the lower section, excessive shrinkage of the billet shell causes thermal fatigue wear of the copper plate, which not only reduces the quality of the cast billet but also significantly shortens the service life of the mold. At the same time, the current assessment of the service status of high manganese steel continuous casting molds relies heavily on the manual experience of on-site operators, lacking accurate online monitoring indicators and quantitative evaluation systems, making it impossible to achieve early warning of failures. Furthermore, mold maintenance is mostly reactive, meaning that it is only addressed after obvious equipment failure or billet quality exceeding standards, which not only increases maintenance costs but also easily causes continuous casting production interruptions, affecting production efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a crystallizer for continuous casting of high manganese steel and its evaluation and maintenance method.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows: A crystallizer for continuous casting of high manganese steel includes a crystallizer body, which comprises an upper crystallizer section, a middle crystallizer section, and a lower crystallizer section in sequence along the casting direction. The taper of the upper section of the crystallizer is greater than that of the lower section of the crystallizer. The wide surface of the middle section of the crystallizer has a parabolic tapered shape, and the taper of the upper end of the middle section of the crystallizer is greater than that of the lower end of the middle section of the crystallizer. The taper of the narrow face of each section of the crystallizer body is 1.2 to 1.5 times that of the corresponding wide face taper.

[0006] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, the upper section of the crystallizer accounts for 45% of the height of the crystallizer body, the middle section of the crystallizer accounts for 30% of the height of the crystallizer body, and the lower section of the crystallizer accounts for 25% of the height of the crystallizer body.

[0007] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, the wide face taper of the upper section of the crystallizer is 1.0%-1.2%, the wide face taper of the middle section of the crystallizer smoothly decreases from 0.8% to 0.5%, and the wide face taper of the lower section of the crystallizer is 0.4%-0.5%.

[0008] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, a temperature sensor is provided inside the copper plate of the crystallizer body.

[0009] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, wherein: a temperature monitoring point is arranged every 200mm along the billet pulling direction of the crystallizer body, and eight temperature monitoring points are arranged on the wide side of the crystallizer body, and six temperature monitoring points are arranged on the narrow side of the crystallizer body.

[0010] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, the copper plate of the crystallizer body is made of Cr-Zr-Ag high thermal conductivity copper alloy.

[0011] As a preferred embodiment of the crystallizer for continuous casting of high manganese steel according to the present invention, the working surface of the crystallizer body is coated with a Ni-Co-Mo gradient composite coating, and the thickness of the Ni-Co-Mo gradient composite coating is 0.15~0.2mm.

[0012] This invention also provides a method for evaluating a crystallizer used in continuous casting of high-manganese steel, comprising: Temperature data of the copper plate is collected in real time by temperature sensors installed inside the copper plate of the crystallizer body. At the same time, the flow rate of the cooling water in the crystallizer, vibration parameters, billet pulling force and billet surface temperature are also collected. The heat flux density of each section of the crystallizer is calculated based on the monitoring data of the temperature sensor. If the heat flux density of the upper section is lower than 1.2 MW / m², it is determined that an air gap has formed between the billet shell and the copper plate. If the heat flux density of the lower section is higher than 0.8 MW / m², it is determined that the crystallizer is not cooled enough. At the same time, the matching degree between the actual shrinkage of the billet and the design taper is calculated. If the matching degree is lower than 90%, a taper mismatch warning is issued. Based on heat flux density, cooling water flow rate, and billet pulling force data, a multi-source data fusion fault identification model for high manganese steel continuous casting crystallizer is established using artificial intelligence algorithms. The high manganese steel continuous casting crystallizer fault identification model identifies adhesion risk, thermal fatigue risk, and corner crack risk, and classifies the crystallizer fault risk level into 1 to 5 levels. Based on the number of thermal fatigue cycles of the copper plate, the amount of plating wear, and the amount of taper deformation, a multi-factor coupled life prediction model is established to calculate the remaining service life of the crystallizer copper plate in real time.

[0013] The present invention also provides a method for maintaining a crystallizer used in continuous casting of high manganese steel, comprising: When the crystallizer failure risk level is 1-2, monitor the usage status of the special protective slag for high manganese steel every shift, control the amount of protective slag added, and ensure that the slag film thickness inside the crystallizer is 0.2-0.3mm; flush the inside of the crystallizer with high-pressure water every week; and calibrate the monitoring equipment every month. When the crystallizer failure risk level is 3-4, if the taper matching degree is 80%-90%, the taper of the narrow face is adjusted online through the crystallizer narrow face adjustable mechanism, and the adjustment range is 0.05%-0.1%; if the plating wear area is less than 5%, laser cladding technology is used for local repair; if microcracks appear on the copper plate surface, ultrasonic impact strengthening treatment is used to eliminate stress concentration at the crack tip. When the crystallizer failure risk level is 5 or the remaining service life of the crystallizer copper plate is less than 20%, the crystallizer copper plate should be replaced entirely.

[0014] The beneficial effects of this invention are: (1) The segmented composite tapered structure designed for the nonlinear solidification shrinkage characteristics of 20-30% manganese steel in this invention accurately matches the shrinkage law of each solidification stage of the steel, effectively eliminates the air gap in the crystallizer, improves the heat transfer efficiency by 20%-30%, improves the uniformity of billet shell growth by more than 35%, significantly reduces the incidence of surface defects such as corner cracks and longitudinal cracks of the billet, and avoids excessive compression of the copper plate by the billet shell, reducing thermal fatigue damage to the copper plate.

[0015] (2) The distributed online monitoring system built by this invention realizes the real-time collection of crystallizer operation data. The three-level quantitative evaluation system established breaks through the limitations of manual experience evaluation. It can accurately diagnose the working status of the crystallizer, identify fault risks, predict the remaining life, and the accuracy rate of steel leakage accident early warning reaches more than 99%, which provides a guarantee for the smooth operation of continuous casting production.

[0016] (3) The differentiated full life cycle maintenance scheme based on the evaluation results provided by this invention realizes a combination of preventive maintenance and precise repair. Compared with traditional maintenance methods, the service life of the crystallizer copper plate is increased by 40%-50%, the maintenance cost is reduced by 30%, and production interruptions caused by equipment failure are avoided, thereby improving the production efficiency of high manganese steel continuous casting. Through the disassembly, inspection and cause analysis of the retired copper plate, the crystallizer taper design parameters are iteratively upgraded, so that the crystallizer structure is always adapted to the actual working conditions of high manganese steel continuous casting, and the quality of high manganese steel billet and the stability of continuous casting production are continuously improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the segmented composite taper of the crystallizer for continuous casting of high manganese steel provided by the present invention; Figure 2 This is a schematic diagram of the monitoring points in the crystallizer for continuous casting of high manganese steel provided by the present invention; Figure 3 A schematic diagram illustrating the entire process of designing, evaluating, and maintaining a crystallizer for continuous casting of high manganese steel. Detailed Implementation

[0019] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the segmented composite taper of the crystallizer for continuous casting of high-manganese steel provided in this application. The crystallizer for continuous casting of high-manganese steel includes a crystallizer body, see [link to details]. Figure 1 The crystallizer body consists of an upper section, a middle section, and a lower section along the pulling direction.

[0021] The upper section of the crystallizer accounts for 45% of the crystallizer's height, the middle section accounts for 30%, and the lower section accounts for 25%. These three height proportions precisely match the shrinkage patterns of the high-manganese steel billet shell during its initial solidification, rapid growth, and final solidification stages.

[0022] Based on the nonlinear solidification shrinkage characteristics of 20-30% manganese steel, a segmented composite taper design is adopted, as detailed below: The wide taper of the crystallizer is as follows: The upper section adopts a large linear taper of 1.0%-1.2% to match the rapid shrinkage of the molten steel in the initial solidification stage and eliminate the initial air gap; the middle section adopts a parabolic variable taper that smoothly decreases from 0.8% to 0.5% to match the nonlinear shrinkage of the billet shell in the rapid growth stage and ensure that the billet shell and the copper plate are in close contact throughout the process; the lower section adopts a small linear taper of 0.4%-0.5% to match the slow shrinkage of the billet shell at the end of solidification and avoid the billet shell from excessively squeezing the copper plate and causing thermal fatigue.

[0023] Narrow face taper of crystallizer: The taper of each section of the narrow face is 1.2-1.5 times that of the corresponding wide face taper, which compensates for the slow heat dissipation and lag in shrinkage of the corner of high manganese steel, completely eliminates the air gap at the corner, and reduces the risk of corner cracks.

[0024] Preferably, the crystallizer copper plate is made of Cr-Zr-Ag high thermal conductivity copper alloy, which improves the thermal conductivity and thermal fatigue resistance of the copper plate. At the same time, the working surface is coated with a 0.15-0.2mm thick Ni-Co-Mo gradient composite coating to improve the copper plate's wear resistance and slag corrosion resistance, making it suitable for the harsh working conditions of high manganese steel continuous casting.

[0025] In addition, distributed fiber Bragg grating temperature sensors are embedded inside the copper plate of the crystallizer, with one monitoring point every 200mm along the drawing direction, eight monitoring points on the wide side and six monitoring points on the narrow side, to collect copper plate temperature data in real time. See details... Figure 2 .

[0026] This application also provides a method for evaluating a crystallizer used in continuous casting of high-manganese steel, the method specifically including the following steps: Step S101: The temperature data of the copper plate is collected in real time by temperature sensors installed inside the copper plate of the crystallizer body. At the same time, key operating data such as the flow rate of cooling water in the crystallizer, vibration parameters, billet pulling force and surface temperature of the billet are also collected.

[0027] Step S102: Level 1 Basic Assessment (Real-time Status Monitoring): Calculate the heat flux density of each section of the crystallizer using temperature sensor data. If the heat flux density of the upper section is lower than 1.2 MW / m², it is determined that an air gap has formed between the billet shell and the copper plate. If the heat flux density of the lower section is higher than 0.8 MW / m², it is determined that the crystallizer is not cooling sufficiently. At the same time, calculate the matching degree between the actual shrinkage of the billet and the design taper. When the matching degree is lower than 90%, the system automatically issues a taper mismatch warning.

[0028] Step S103: Secondary comprehensive assessment (fault risk diagnosis): Based on heat flux density, cooling water flow rate, and billet pulling force data, a multi-source data fusion fault identification model for high manganese steel continuous casting crystallizer is established through artificial intelligence algorithms. The high manganese steel continuous casting crystallizer fault identification model identifies adhesion risk, thermal fatigue risk, and corner crack risk, and classifies the crystallizer fault risk level into 1 to 5 levels.

[0029] Specifically, an AI algorithm is used to construct a fault identification model. The input layer of the model consists of fault feature parameters such as the cyclic change amplitude of the copper plate heat flux density and the stability coefficient of the cooling water flow rate. The output layer is the risk probability values (0 - 1) of three types of faults, corresponding to the bonding risk probability P1, the thermal fatigue risk probability P2, and the corner crack risk probability P3 respectively. The comprehensive fault risk value P is calculated, and the calculation formula is P = 0.4P1 + 0.35P2 + 0.25P3. The value range of the comprehensive fault risk value P is 0 - 1.

[0030] According to the comprehensive fault risk value P, the mold fault risk is quantified into levels 1 - 5. The grading criteria are as follows: level 1 (P ≤ 0.2), level 2 (0.2 < P ≤ 0.4), level 3 (0.4 < P ≤ 0.6), level 4 (0.6 < P ≤ 0.8), level 5 (P > 0.8). Among them, levels 1 - 2 are judged as the normal working state of the mold without warning; level 3 and above trigger hierarchical warnings. The warning rules are as follows: level 3 (mild risk) triggers a yellow light and sound warning, and pushes the fault type and preliminary disposal suggestions to the on - site operation terminal; level 4 (moderate risk) triggers an orange light and sound warning, locks the adjustment authority of the relevant process parameters of the mold, and forcibly reminds the operator to stop the machine for inspection; level 5 (severe risk) triggers a red light and sound warning,联动 the continuous casting machine control system to issue a speed reduction / stop instruction, and at the same time synchronize the fault information to the workshop central control system.

[0031] Step S104: Three - level life assessment (remaining life prediction): Based on the number of copper plate thermal fatigue cycles, the coating wear amount, and the taper deformation amount, a multi - factor coupled life prediction model is established to calculate the remaining service life of the copper plate of the mold in real - time.

[0032] Specifically, first, the core indicators are quantified: the number of thermal fatigue cycles is counted as 1 effective thermal cycle per single - furnace steel casting in continuous casting; the coating wear amount is the weighted value calculated from off - line laser thickness measurement and on - line billet drawing length; the taper deformation amount takes the maximum relative deviation rate between the actual taper of each section of the wide / narrow face and the designed taper. Subsequently, based on the total designed life of the copper plate, the single - factor life attenuation coefficients of the three indicators are calibrated, and the weights are assigned according to thermal fatigue (0.5), coating wear (0.25), and taper deformation (0.25). The comprehensive life attenuation coefficient is calculated, and combined with the number of used furnaces, the real - time remaining life and its proportion are obtained. The remaining life proportion > 30% is the normal state; 20% < proportion ≤ 30% triggers a blue reminder warning to plan the preparation of materials in advance; proportion ≤ 20% triggers a red forced replacement warning, reminding to stop the machine to change the plate after the casting is completed, providing a basis for the production plan. The off - line detection data and on - line monitoring data of maintenance and replacement are continuously supplemented to the database, and the model parameters are iteratively optimized regularly to adapt to the changes in production conditions and ensure the accuracy of life calculation.

[0033] In addition, this application also provides a maintenance method for a mold used in high - manganese steel continuous casting. This method specifically includes the following steps: Step S201: Routine preventive maintenance (assessment level 1-2, normal condition): Monitor the usage status of the special protective slag for high manganese steel every shift, control the amount of protective slag added, and ensure that the slag film thickness inside the crystallizer is 0.2-0.3mm to achieve good lubrication and heat insulation; flush the inside of the crystallizer with high-pressure water every week to clean the residual protective slag and steel slag, and check the integrity of the coating surface at the same time; calibrate the monitoring equipment such as temperature sensors and cooling water flow meters every month to ensure the accuracy of monitoring data.

[0034] Step S202: Targeted Repair and Maintenance (Assessment Level 3-4, Minor Fault Status): When the crystallizer fault risk level is 3-4, if the taper matching degree is 80%-90%, the taper of the narrow face is adjusted online through the crystallizer narrow face adjustable mechanism, and the adjustment range is 0.05%-0.1%; if the plating wear area is less than 5%, laser cladding technology is used for local repair, and the cladding material is consistent with the original Ni-Co-Mo gradient composite material, so that the performance of the repaired plating layer remains consistent with the original plating layer; if microcracks appear on the copper plate surface, ultrasonic impact strengthening treatment is used to eliminate stress concentration at the crack tip and prevent further crack propagation.

[0035] Step S203: Overhaul and Decommissioning Maintenance (Assessment Level 5, Severe Failure State / Remaining Life Less Than 20%): When the crystallizer failure risk level is 5 or the remaining life of the crystallizer copper plate is less than 20%, the crystallizer copper plate is replaced entirely. The crystallizer copper plate is replaced entirely, and the decommissioned copper plate is disassembled and inspected to analyze the causes of plating wear, copper plate thermal fatigue, and taper deformation. Based on the inspection results, the taper design parameters for the next batch of crystallizers are optimized to achieve iterative design upgrades. Simultaneously, the crystallizer's vibration mechanism and cooling system are comprehensively overhauled, and aging seals and cooling pipes are replaced to ensure the overall performance of the crystallizer meets standards.

[0036] The above technical solution will be further explained below through specific embodiments.

[0037] Example 1: This example focuses on the continuous casting production of high-manganese steel billets containing 25% manganese in a steel enterprise. The cross-sectional dimensions are 150mm × 1200mm. The design, evaluation, and maintenance methods for high-manganese steel continuous casting provided in this application are adopted. The specific implementation steps are as follows: 1. Crystallizer structural design and implementation (1) Crystallizer segmentation: The total height is 1800mm, and it is divided into upper section (0-800mm), middle section (800-1400mm), and lower section (1400-1800mm) along the throwing direction. (2) Determination of taper parameters: The upper part of the wide face adopts a linear taper of 1.1%, the middle part adopts a parabolic variable taper of 0.8%→0.5%, and the lower part adopts a linear taper of 0.45%; the taper of each section of the narrow face is 1.2 times that of the wide face, that is, 1.32% for the upper section, 0.96%→0.6% for the middle section, and 0.54% for the lower section; (3) Copper plate matching: Cu-Cr-Zr-Ag high thermal conductivity copper alloy copper plate is used, with a thermal conductivity ≥380W / (m·K), and the working surface is plated with a Ni-Co-Mo gradient composite coating of 0.18mm thickness.

[0038] 2. Implementation of Crystallizer Usage Process Evaluation (1) Monitoring system setup: Fiber optic temperature sensors are embedded in the copper plate of the crystallizer, with 8 monitoring points on the wide side and 6 monitoring points on the narrow side, to simultaneously collect data on cooling water flow rate, billet pulling force, and billet surface temperature. (2) Level 3 assessment: During the continuous casting production process, the first-level basic assessment calculated that the heat flux density of the upper section was 1.35MW / m², the middle section was 1.0MW / m², and the lower section was 0.7MW / m², all of which were within the normal range. The actual shrinkage of the billet matched the design taper by 96%. The second-level comprehensive assessment did not identify any fault risks, and the risk level was 2. The third-level life assessment calculated that the remaining service life of the copper plate was 65% of the total life, and no replacement was required.

[0039] 3. Crystallizer Maintenance Implementation Based on the assessment results (Level 2, normal condition), routine preventive maintenance is performed: monitor the condition of the protective slag every shift and control the slag film thickness to 0.25mm; flush the crystallizer cavity with high-pressure water weekly and check for wear on the coating; calibrate the monitoring equipment monthly to ensure accurate data.

[0040] In this embodiment, the crystallizer designed using the method of the present invention is used for continuous casting of high manganese steel. The incidence of corner cracks in the billet is reduced from 12% to 1.5%, there are no steel leakage accidents due to adhesion, and the crystallizer operates stably.

[0041] Example 2: This example focuses on the continuous casting production of high-manganese steel slabs containing 25% manganese in a steel enterprise. The cross-sectional dimensions are 200mm × 1200mm. The technical solution provided in this application is adopted, and the specific implementation steps are as follows: 1. Crystallizer structural design and implementation (1) Crystallizer segmentation: total height 1800mm, upper section (0-800mm), middle section (800-1400mm), lower section (1400-1800mm); (2) Determination of taper parameters: 1.2% linear taper in the upper part of the wide face, 0.8%→0.5% parabolic variable taper in the middle part, and 0.5% linear taper in the lower part; the taper of each section of the narrow face is 1.5 times that of the wide face, that is, 1.8% in the upper part, 1.2%→0.75% in the middle part, and 0.75% in the lower part; (3) Copper plate matching: Cu-Cr-Zr-Ag copper alloy plate, with a 0.2mm thick Ni-Co-Mo gradient composite coating on the working surface.

[0042] 2. Implementation of Crystallizer Usage Process Evaluation (1) Monitoring system setup: Fiber optic temperature sensors are set up as required to collect various operational data synchronously; (2) Level 3 assessment: Level 1 basic assessment found that the heat flux density in the lower section of the narrow face dropped to 0.5MW / m², which was determined to be a local blockage of the cooling pipe, and the billet shrinkage and taper matching degree was 85%; Level 2 comprehensive assessment identified it as a cooling failure, with a risk level of 3, and issued an early warning; Level 3 life assessment calculated that the remaining service life of the copper plate was 58% of the total life.

[0043] 3. Crystallizer Maintenance Implementation Based on the assessment results (Level 3, minor fault), perform targeted repair and maintenance: (1) Suspend continuous casting production, clean local scale in cooling pipes, restore cooling water flow rate to design value, and restore heat flux density in the lower section of the narrow face to 0.72MW / m²; (2) The taper of the lower section of the narrow face is finely adjusted online by the narrow face adjustable mechanism, with an adjustment range of 0.08%, and the matching degree between the billet shrinkage and the taper is improved to 94%; (3) Upon inspection of the copper plate plating, a slight wear of 1.5% was found on the lower section of the narrow face. Laser cladding technology was used for local repair, and the cladding material was consistent with the original plating.

[0044] After the repair was completed, continuous casting production was restarted, the crystallizer assessment level was restored to level 2, the billet quality met the standards, and no faults occurred, achieving a balance between precise repair and production continuity.

[0045] Therefore, the technical solution of this application is designed with a segmented composite tapered structure for the nonlinear solidification shrinkage characteristics of 20-30% manganese steel. It accurately matches the shrinkage law of each solidification stage of the steel, effectively eliminates the air gap in the crystallizer, improves the heat transfer efficiency by 20%-30%, improves the uniformity of billet shell growth by more than 35%, significantly reduces the incidence of surface defects such as corner cracks and longitudinal cracks in the billet, and avoids excessive compression of the copper plate by the billet shell, thus reducing thermal fatigue damage to the copper plate.

[0046] In addition to the above embodiments, the present invention may have other implementation methods; all technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A crystallizer for continuous casting of high manganese steel, characterized in that: It includes a crystallizer body, which, along the pulling direction, sequentially includes an upper crystallizer section, a middle crystallizer section, and a lower crystallizer section; The taper of the upper section of the crystallizer is greater than that of the lower section of the crystallizer. The wide surface of the middle section of the crystallizer has a parabolic tapered shape, and the taper of the upper end of the middle section of the crystallizer is greater than that of the lower end of the middle section of the crystallizer. The taper of the narrow face of each section of the crystallizer body is 1.2 to 1.5 times that of the corresponding wide face taper.

2. The crystallizer for continuous casting of high manganese steel according to claim 1, characterized in that: The upper section of the crystallizer accounts for 45% of the height of the crystallizer body, the middle section of the crystallizer accounts for 30% of the height of the crystallizer body, and the lower section of the crystallizer accounts for 25% of the height of the crystallizer body.

3. The crystallizer for continuous casting of high manganese steel according to claim 1, characterized in that: The taper of the upper section of the crystallizer is 1.0%-1.2%, the taper of the middle section of the crystallizer smoothly decreases from 0.8% to 0.5%, and the taper of the lower section of the crystallizer is 0.4%-0.5%.

4. The crystallizer for continuous casting of high-manganese steel according to claim 1, characterized in that: A temperature sensor is installed inside the copper plate of the crystallizer body.

5. The crystallizer for continuous casting of high-manganese steel according to claim 4, characterized in that: The crystallizer body has a temperature monitoring point every 200mm along the drawing direction, and the wide side of the crystallizer body has eight temperature monitoring points, while the narrow side of the crystallizer body has six temperature monitoring points.

6. The crystallizer for continuous casting of high manganese steel according to claim 1, characterized in that: The copper plate of the crystallizer body is made of Cr-Zr-Ag high thermal conductivity copper alloy.

7. The crystallizer for continuous casting of high manganese steel according to claim 1, characterized in that: The working surface of the crystallizer body is coated with a Ni-Co-Mo gradient composite coating, and the thickness of the Ni-Co-Mo gradient composite coating is 0.15~0.2mm.

8. A method for evaluating a crystallizer used in continuous casting of high-manganese steel, characterized in that: include: Temperature data of the copper plate is collected in real time by temperature sensors installed inside the copper plate of the crystallizer body. At the same time, the flow rate of the cooling water in the crystallizer, vibration parameters, billet pulling force and billet surface temperature are also collected. The heat flux density of each section of the crystallizer is calculated based on the monitoring data of the temperature sensor. If the heat flux density of the upper section is lower than 1.2 MW / m², it is determined that an air gap has formed between the billet shell and the copper plate. If the heat flux density of the lower section is higher than 0.8 MW / m², it is determined that the crystallizer is not cooled enough. At the same time, the matching degree between the actual shrinkage of the billet and the design taper is calculated. If the matching degree is lower than 90%, a taper mismatch warning is issued. Based on heat flux density, cooling water flow rate, and billet pulling force data, a multi-source data fusion fault identification model for high manganese steel continuous casting crystallizer is established using artificial intelligence algorithms. The high manganese steel continuous casting crystallizer fault identification model identifies adhesion risk, thermal fatigue risk, and corner crack risk, and classifies the crystallizer fault risk level into 1 to 5 levels. Based on the number of thermal fatigue cycles of the copper plate, the amount of plating wear, and the amount of taper deformation, a multi-factor coupled life prediction model is established to calculate the remaining service life of the crystallizer copper plate in real time.

9. A method for maintaining a crystallizer used in continuous casting of high-manganese steel, characterized in that: include: When the crystallizer failure risk level is 1-2, monitor the usage status of the special protective slag for high manganese steel every shift, control the amount of protective slag added, and ensure that the slag film thickness inside the crystallizer is 0.2-0.3mm; flush the inside of the crystallizer with high-pressure water every week; and calibrate the monitoring equipment every month. When the crystallizer failure risk level is 3-4, if the taper matching degree is 80%-90%, the taper of the narrow face is adjusted online through the crystallizer narrow face adjustable mechanism, and the adjustment range is 0.05%-0.1%; if the plating wear area is less than 5%, laser cladding technology is used for local repair; if microcracks appear on the copper plate surface, ultrasonic impact strengthening treatment is used to eliminate stress concentration at the crack tip. When the crystallizer failure risk level is 5 or the remaining service life of the crystallizer copper plate is less than 20%, the crystallizer copper plate should be replaced entirely.

Images