Experimental device and method for evaluating stability of refractory material after erosion resistance

Abstract

The invention relates to the field of stability evaluation experiment devices, and discloses a stability evaluation experiment device and method for a refractory material after erosion resistance, and the evaluation experiment method comprises the following steps: preparing N cylinders with the diameter of 50mm + / -0.5 mm and the height of 50mm + / -0.5 mm on a refractory brick manufactured by the same production process, the parallelism of a sample is not more than 0.2 mm, the perpendicularity of the sample is not more than 0.5 mm, and the thickness of the sample is not more than 0.2 mm; respectively measuring the surface area, the apparent porosity and the volume density of the sample, and selecting the sample with the volume density deviation smaller than 0.02 g / cm < 3 > as a standard sample to be detected; and testing the normal-temperature compressive strength of one sample in a room-temperature environment to obtain the original compressive strength P0. According to the technical scheme, the performance of the refractory material is evaluated through a thermal shock stability attenuation experiment method and a reducing gas erosion attenuation resisting method, and the technical effect that the strength change rule of the product under the conditions of rapid temperature change, reducing gas erosion and compression is comprehensively reflected is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of stability evaluation experimental apparatus, specifically to an experimental apparatus and method for evaluating the stability of refractory materials after erosion resistance. Background Technology

[0002] Refractory materials are used in complex, high-temperature environments for extended periods, and these environments play a crucial role in their erosion and damage. Simulating the working conditions of refractory materials and effectively evaluating the changes in their performance after environmental erosion is of great significance for assessing their long-term use.

[0003] Dry quenching coke ovens are widely used in China, and the development and research of dry quenching technology has become a hot topic in the industry. Among these, the performance of the dry quenching column (corbel bricks) is crucial for extending the lifespan of the oven. Structurally, the dry quenching column (corbel bricks) bears the weight of the upper refractory material of the furnace and is constantly under the influence of moving hot coke and flowing cooling gases. Damage to these parts is mainly due to thermal stress and structural stress caused by temperature changes, resulting in material cracks, spalling, and cracking or breakage of the brick joints, primarily due to thermal shock damage. The inner lining bricks of dry quenching coke ovens undergo more than 20,000 temperature changes annually, so it is essential to pay attention to the thermal shock performance of the material, especially the pattern and timing of crack appearance, not just the number of cracks. Therefore, simple thermal shock resistance testing methods cannot simulate actual working conditions, nor can they accurately predict the material's trajectory.

[0004] Hydrogen-based reduction ironmaking has become an important aspect of technological innovation in the steel industry. Hydrogen metallurgy generally refers to the direct reduction of iron ore and pellets into high-quality DRI (distilled iron) using a gas-based vertical shaft furnace under conditions where the hydrogen content in the reducing gas fed into the furnace is higher than 55% (H2 / CO greater than 1.5). Therefore, studying the performance changes of refractory materials after being eroded by CO / H2 is of great significance.

[0005] Existing test methods for the thermal shock resistance of refractory materials include: GB / T30873-2014 water quenching method - straight brick specimen, GB / T30873-2014 water quenching method - small specimen, and GB / T30873-2014 natural air cooling method. The above test methods cannot evaluate the changes in strength of the specimen under rapid temperature changes and the law of strength decay. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an experimental apparatus and method for evaluating the post-erosion stability of refractory materials, solving the problems that existing methods cannot effectively reflect the actual operating conditions of refractory materials in the dry quenching furnace column and cannot reflect the actual quality changes of refractory materials under pressure and temperature rapid cooling and heating conditions.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an experimental apparatus for evaluating the post-erosion stability of refractory materials, characterized in that it is used to test experimental samples, the experimental apparatus comprising: The thermal shock attenuation device is used to simulate the thermal shock process of refractory materials under high-temperature cycling environment, and to evaluate the thermal shock stability of the material by performing temperature rise and fall and thermal cycling. The CO corrosion resistance device is used to simulate the corrosion phenomenon of refractory materials when they come into contact with CO atmosphere at high temperature, and to evaluate the material's resistance to CO corrosion. The H2 corrosion resistance device is used to simulate the corrosion phenomenon of refractory materials when they come into contact with H2 atmosphere under high temperature and high pressure environment, and to evaluate the material's resistance to H2 corrosion. A dryer is used to dry the samples after thermal shock cycling to remove surface moisture and ensure the accuracy of subsequent strength testing. A hydraulic press is used to test the compressive strength of a specimen after each thermal shock cycle, measure the change in the compressive strength of the specimen, and evaluate the strength decay of the material during thermal shock. Computers are used to monitor and record experimental data in real time, including temperature changes, thermal shock counts, crack propagation of specimens, and compressive strength data, to perform data analysis and processing, and to output experimental results. The CO corrosion resistance device delivers nitrogen and CO gas to the interior of a heating furnace. The heating furnace is connected to a reflux flask, which in turn is connected to a bubble bottle, which is then connected to an antifreeze bottle. This ensures stable and uniform gas flow and prevents condensation or freezing during cooling, thus guaranteeing the smooth progress of the experiment. By precisely controlling the gas flow, temperature, and pressure, the device simulates the oxidation and reduction reactions of refractory materials under actual working conditions, thereby more accurately evaluating the material's CO corrosion resistance and thermal shock stability.

[0008] Furthermore, the thermal shock attenuation device simulates the thermal shock process of materials under actual working conditions by controlling temperature rise and fall and the thermal cycling process, testing the strength changes and crack propagation at different thermal cycles, and thus evaluating the thermal shock stability of the material. In each thermal shock cycle stage, the refractory material sample undergoes a strictly controlled heating and cooling process, with heating temperatures reaching 1300℃ and cooling achieved through a combination of water cooling and air drying, ensuring the stability of the material in high-temperature environments and the controllability of the performance degradation process. The CO corrosion resistance device precisely controls the flow rate and ratio of nitrogen and CO gases, delivering these two gases into the heating furnace to simulate the corrosion reaction of refractory materials exposed to a CO atmosphere at high temperatures, testing the material's resistance to CO corrosion. The heating furnace is connected to a reflux flask, a bubble flask, and an antifreeze flask. The reflux flask and bubble flask work together to ensure stable and uniform gas flow, the bubble flask can control the flow rate through bubbles and gas flow rate, and the antifreeze flask ensures that the equipment will not freeze due to gas cooling in low-temperature environments. This system simulates the oxidation and reduction reactions that materials may encounter in a high-temperature CO atmosphere by precisely adjusting gas flow, temperature, and pressure. This allows for a more comprehensive assessment of the material's resistance to CO corrosion and can be combined with the thermal shock attenuation process to evaluate the overall performance degradation of the material under complex atmospheres. A dryer dries the samples after each thermal shock cycle, removing surface or internal moisture to prevent interference with strength testing and ensure the accuracy and consistency of test data. A hydraulic press is used to perform room-temperature compressive strength tests on refractory samples after each thermal shock cycle, measuring changes in compressive strength to assess the strength degradation during thermal shock cycling and provide quantitative data for the material's long-term performance. A computer system monitors the experimental process in real time, collecting data such as temperature, number of thermal shocks, and compressive strength, and recording crack propagation. Data analysis algorithms process the results, outputting a final experimental report. This computer system not only generates experimental data charts but also reveals the performance degradation patterns of materials under different thermal shock cycles and CO corrosion conditions through data analysis. Through this complete experimental procedure, the device can efficiently and accurately simulate and test the thermal shock stability and CO corrosion resistance of refractory materials in actual high-temperature and complex environments, thereby providing important experimental data support for the research and development and application of refractory materials.

[0009] A method for testing the thermal shock stability attenuation of refractory materials includes the following steps: N cylinders with a diameter of 50 mm ± 0.5 mm and a height of 50 mm ± 0.5 mm were prepared from refractory bricks produced using the same manufacturing process. The parallelism of the samples should not exceed 0.2 mm, and the perpendicularity of the samples should not exceed 0.5 mm. The surface area, apparent porosity, and bulk density of the samples were measured, and the bulk density deviation was selected to be less than 0.02 g / cm³. 3The samples within the range are used as standard samples to be tested; the room temperature pressure resistance strength of one of the samples is tested at room temperature to obtain the original pressure resistance strength P0; the remaining samples are subjected to thermal cycling, CO corrosion, and H2 corrosion respectively. Environmental erosion resistance test of the specimen: The thermal cycling test was conducted as follows: The sample was placed in a furnace and heated to 1000℃ at a rate of 5℃ / min, then heated to 1300℃ at a rate of 5℃ / min. After holding at 1300℃ for 5 minutes, the sample was water-cooled for 3 minutes and air-cooled for 15 minutes. After the sample completed the first thermal cycle of heating with the furnace, it was placed directly into a 1300℃ electric furnace again and cycled according to the experimental method of holding at 1300℃ for 10 minutes, water-cooled for 3 minutes, and air-cooled for 15 minutes. The corrosion and damage of CO to the sample is as follows: The sample is heated to 500 degrees under nitrogen protection, CO gas is introduced, and the CO concentration reaches more than 95%. The sample is kept at this temperature for 5 hours, which is recorded as P5, and for 10 hours, it is recorded as P10, and so on. The holding time can be selected according to the requirements of the test. When the number of cycles or the holding time reaches 5 times / hour, stop the test, select the sample with severe cracks, dry it, and test the room temperature compressive strength P5 of the sample; then, test samples P10, P15, P20, P25...P200 respectively. The number of tests or the holding time can be selected according to the test requirements. The formula for calculating the performance degradation rate is: ; in: V i This indicates the rate of performance degradation of the sample after immersion in the environment. P0 refers to the original compressive strength of the sample. i This represents the product's compressive strength measured at room temperature after the i-th environmental immersion.

[0010] Preferably, the experimental sample group is placed in a high-temperature electric furnace, and the high temperature is controlled at 1300°C or a temperature that meets the working conditions. The cyclic sample to be subjected to thermal shock is placed in the thermal shock furnace and heated; the heating temperature is controlled to be the service temperature of the refractory material under actual working conditions; the heating time is controlled to be 10 minutes. The heated sample group was cooled by circulating water; the temperature of the cooling water was maintained at <18℃, and the cooling time was 3 minutes. The water-cooled sample was air-dried for 15 minutes. The heating and cooling processes are alternately performed to achieve the required number of thermal shocks, thereby completing the thermal shock attenuation experiment. The experimental sample group was placed in a CO atmosphere electric furnace, the high temperature was controlled at 500℃ or the temperature that met the working conditions; the CO concentration was ≥95%, and the temperature was continuously controlled until the required holding time was required. By analyzing the performance stability trends of V5, V10, V15, V20, V25, and V30 refractory materials after environmental erosion, the strength changes of the samples under long-term service can be reasonably assessed.

[0011] Furthermore, several cylindrical samples with a diameter of 50mm ± 0.5mm and a height of 50mm ± 0.5mm were prepared under the same production process, ensuring that the parallelism of the samples did not exceed 0.2mm and the perpendicularity did not exceed 0.5mm. The surface area, apparent porosity, and bulk density of the samples were measured respectively, and samples with a bulk density deviation of less than 0.02g / cm³ were selected. 3 The sample is used as the standard sample to be tested; then, the room temperature pressure resistance of one of the samples is tested at room temperature to obtain the original pressure resistance P0; the remaining samples are subjected to environmental corrosion tests such as thermal cycling, CO corrosion and H2 corrosion in sequence. In the thermal cycling test, the sample was placed in a reheat furnace and heated to 1000℃ at a rate of 5℃ / min, then continued to be heated to 1300℃ at a rate of 5℃ / min. After holding at 1300℃ for 5 minutes, it was water-cooled for 3 minutes and air-cooled for 15 minutes. After completing one thermal cycle, the sample was placed in an electric furnace at 1300℃ and held for 10 minutes, then the process of water cooling for 3 minutes and air cooling for 15 minutes was repeated. In the CO corrosion test, the sample was heated to 500℃ under nitrogen protection and CO gas was introduced to ensure that the CO concentration reached above 95%. This condition was maintained for holding tests for different times (e.g., 5 hours, 10 hours, etc.), and the corresponding compressive strength data such as P5, P10, and P15 were recorded according to the experimental requirements. After all samples completed the thermal cycling and CO corrosion tests, their room temperature compressive strength was tested periodically, and the performance degradation rate V was calculated. i : ; Where: V i This indicates the rate of performance degradation of the sample after immersion in the environment. P0 refers to the original compressive strength of the sample. iThe compressive strength of the product measured at room temperature after the i-th environmental immersion is used to evaluate the material's resistance to environmental erosion and thermal shock stability. The experiment may further include an H2 erosion test, similar to CO erosion, where nitrogen protection is used for heating and H2 gas is introduced, with different holding times set. The decay rate is then calculated, and the results of thermal shock and environmental erosion are combined to reasonably infer the long-term strength changes of the material in actual use. Preferably, in the experiment, the sample can be heated in a high-temperature electric furnace at a temperature of 1300℃ or the actual operating temperature, with a heating time of 10 minutes. Afterward, it is cooled by circulating water, with the cooling water temperature maintained below 18℃ for 3 minutes. Then, the water-cooled sample is air-dried for 15 minutes. This heating and cooling process is repeated until the required number of thermal shocks is completed, thus completing the thermal shock decay experiment. Simultaneously, the sample is placed in a CO atmosphere electric furnace, ensuring a CO concentration of over 95%, and held at 500℃ or a suitable operating temperature until the specified holding time is reached. Through multiple environmental erosion tests and room temperature compressive strength tests, the performance stability trend of refractory materials during long-term service was obtained, providing a scientific basis for reasonably assessing the service life and reliability of the materials.

[0012] Preferably, after completing the thermal shock and CO erosion tests, the sample is further subjected to an erosion test under an H2 atmosphere. The test method is as follows: the sample is placed in a heating furnace, H2 gas is introduced, the temperature is raised to 1000℃~1500℃, the pressure of H2 in the furnace is maintained at 0.01~0.8MPa, and the holding time is 5 hours, 10 hours, 15 hours, etc., depending on the experimental requirements. The room temperature compressive strength P5, P10, and P15 after each holding are recorded, and the attenuation rate V is calculated. i .

[0013] Preferably, the initial heating step of the thermal cycling damage is as follows: the sample is placed in a reheat furnace and heated to 1000°C at a heating rate of 10°C / min, then heated to 1300°C at a heating rate of 5°C / min, held at this temperature for 5 minutes, and then water-cooled and air-cooled; the CO erosion damage step of the sample is as follows: the sample is heated to 500°C at a heating rate of 5°C / min, then CO gas is introduced to make its content reach more than 90%, and held at this condition.

[0014] Preferably, experimental data is transmitted to a computer system in real time. The computer system automatically analyzes and outputs a trend graph of material performance degradation, and provides strength change curves under different thermal cycles and CO erosion cycles to help evaluate the service life and reliability of the material in practical applications.

[0015] Preferably, the water cooling system used in the experiment is equipped with a temperature sensor to monitor the temperature of the cooling water in real time, ensuring the temperature control accuracy during the cooling process, so as to avoid the instability of the sample performance caused by the fluctuation of the cooling temperature.

[0016] Preferably, during environmental erosion testing, the cooling process after each heating of the sample is completed by multiple cooling media, including cooling water, air, and special cooling gas, to ensure that the thermal shock and erosion process of the material under actual working conditions is simulated, so as to achieve a more accurate evaluation.

[0017] Furthermore, after completing the thermal shock and CO erosion tests, the samples were further subjected to an erosion test under an H2 atmosphere. The test method involved placing the sample in a heating furnace and introducing H2 gas, heating it to 1000℃~1500℃, maintaining the H2 pressure inside the furnace at 0.01~0.8MPa, and selecting different holding times according to experimental requirements, such as 5 hours, 10 hours, 15 hours, etc. The room temperature compressive strength P5, P10, P15, etc., after each holding time were recorded, and the attenuation rate V was calculated. i This test comprehensively evaluates the durability and strength changes of refractory materials under various atmospheric conditions. Experimental data is transmitted to a computer system in real time, which automatically analyzes and generates trend graphs of material performance degradation, providing strength change curves under different thermal cycles and CO erosion cycles. This helps assess the material's service life, reliability, and resistance to environmental erosion in practical applications. The water-cooling system used in the experiment is equipped with a temperature sensor to monitor the temperature of the cooling water in real time, ensuring that temperature fluctuations are controlled within a precise range during the cooling process. This avoids the impact of unstable temperature control on the sample performance, ensuring the reliability and accuracy of the test results. During the environmental erosion test, the cooling process after each heating is completed through multiple cooling media, including cooling water, air, and special cooling gas, simulating the thermal shock and erosion processes experienced by the material under actual working conditions. This allows for a more accurate evaluation, ensuring that the test conditions are as close as possible to the complex environment of the material's actual application, further improving the accuracy and reference value of the evaluation results.

[0018] This invention provides an experimental apparatus and method for evaluating the post-erosion stability of refractory materials. It has the following beneficial effects: 1. This invention provides a technical solution for evaluating the performance of refractory materials through a thermal shock stability decay test method, achieving a comprehensive representation of the quality change patterns of the product under rapid temperature and pressure conditions. Compared to existing methods that only use single temperature or pressure conditions for testing, this invention overcomes the deficiency of existing methods in comprehensively reflecting the performance change trends of materials under complex working conditions.

[0019] 2. This invention employs a strength attenuation rate analysis method to provide a data-driven assessment of material thermal shock damage, achieving the technical effect of accurately determining the damage mode of materials during thermal shock cycling through quantitative analysis. Compared to existing methods that rely on qualitative observation or experience-based judgment, this invention overcomes the deficiency of existing methods in accurately quantifying and assessing material thermal shock damage.

[0020] 3. This invention, through a thermal shock stability attenuation test method combined with a technical solution of strength attenuation rate and linear relationship analysis, achieves the technical effect of effectively judging the trend of material strength attenuation, damage situation, and service life. Compared with existing technologies that fail to discover the material's pressure resistance attenuation law and abrupt change point, this invention solves the shortcomings of existing methods in accurately predicting material service life and optimizing application scenarios. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is an overall frame diagram of the device of the present invention; Figure 3 This is a schematic diagram of the anti-CO device of the present invention. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see the appendix Figure 1 - Appendix Figure 3 This invention provides an experimental apparatus and method for evaluating the stability of refractory materials after erosion resistance.

[0024] The thermal shock stability decay test method of this refractory material can effectively determine the decay rate of the sample strength, the linear relationship of decay, and the final damage situation of the product. It can also detect the pressure decay pattern of the product at different stages of thermal shock, identify the point of sudden drop in pressure decay, and thus determine the application location of the product to avoid unintended use.

[0025] The experimental specimens are cylindrical in structure, made of refractory material according to a set size. As a preferred embodiment, 7-10 cylinders with a diameter of 50mm ± 0.5mm and a height of 50mm ± 0.5mm are used. The parallelism of the specimens does not exceed 0.2mm, and the perpendicularity does not exceed 0.5mm. This size facilitates processing and is well-suited for use in an electro-hydraulic pressure testing machine. The electro-hydraulic pressure testing machine is used to determine the room-temperature compressive strength of the experimental specimens. A thermal shock furnace is used to heat the experimental specimens. A circulating water tank is used to cool the heated experimental specimens. The thermal shock test is completed by repeatedly passing the experimental specimens through the thermal shock furnace heating process and the water cooling process. After the thermal shock test, the experimental specimens are placed in the electro-hydraulic pressure testing machine to test their room-temperature compressive strength.

[0026] Preferably, the room temperature pressure resistance includes: the original pressure resistance P0 of the sample; the room temperature pressure resistance P5 of the product after the 5th thermal shock cycle; the room temperature pressure resistance P10 of the product after the 10th thermal shock cycle; the room temperature pressure resistance P15 of the product after the 15th thermal shock cycle; the room temperature pressure resistance P20 of the product after the 20th thermal shock cycle; the room temperature pressure resistance P25 of the product after the 25th thermal shock cycle; and the room temperature pressure resistance P30 of the product after the 30th thermal shock cycle.

[0027] The strength testing method is as follows: the room temperature compressive strength of one of the original samples is measured as the original strength P0.

[0028] The P5 room temperature compressive strength is the room temperature compressive strength of the sample after the sample has been subjected to five cycles of testing, including holding at 1300℃ for 10 min, water cooling for 3 min, and air cooling for 15 min, and then dried.

[0029] The P10 room temperature compressive strength is the room temperature compressive strength of the sample after the sample has been subjected to 10 cycles of testing, including holding at 1300℃ for 10 minutes, water cooling for 3 minutes, and air cooling for 15 minutes, and then dried.

[0030] And so on, we obtain P15, P20, P25, P30, P35, P40, P45, and P50.

[0031] The formula for calculating the performance degradation rate is: ; in: V i This indicates the rate of performance degradation of the sample after immersion in the environment. P0 refers to the original compressive strength of the sample. i This represents the product's compressive strength measured at room temperature after the i-th environmental immersion.

[0032] The decay rate of the thermal shock stability of the sample after the i-th thermal shock cycle is equal to the percentage of the room temperature compressive strength of the product after the i-th thermal shock cycle to the original compressive strength of the sample. This percentage is used to determine the strength decay rate of the sample and predict the damage mode and direction of the material.

[0033] This application also provides a method for evaluating the performance stability of refractory materials after CO erosion, including the following steps: S1: Prepare 10 cylinders with a diameter of 50mm ± 0.5mm and a height of 50mm ± 0.5mm using the same process for sample bricks. The parallelism of the samples should not exceed 0.2mm, and the perpendicularity of the samples should not exceed 0.5mm. Measure the surface area, apparent porosity, and bulk density of each sample, selecting those with a bulk density deviation of less than 0.02g / cm³. 3 The samples within the specified range are used as standard samples to be tested; S2: Detect the room temperature compressive strength of one of the original samples as the original strength P0; S3: The sample is heated to 500℃ in the furnace, and CO gas is introduced to achieve a concentration of ≥95%; S4: Keep the sample at the above conditions for 5 hours; S6: Shut down the furnace, remove the sample to be tested, and test its compressive strength P5; S7: The remaining samples are subjected to S3-S4 operations again, and the cumulative heat preservation time reaches 10 hours. Then, S6 operation is performed, and the cycle is repeated. S8: When the number of cycles reaches i, select the severely cracked sample, dry it, and test the room temperature compressive strength P of the sample. i .

[0034] S9: Calculate the percentage of the room temperature compressive strength of the product after i hours of CO erosion to the original compressive strength of the sample using the strength decay rate formula. Use this percentage to determine the strength decay rate of the sample and predict the damage mode and direction of the material.

[0035] To better understand the above technical solution, the specific implementation methods will be explained in detail below using products made of two different materials: Example 1: S1: Prepare 7-10 cylinders with a diameter of 50.2 mm and a height of 50 mm from the same brick. The parallelism of the samples should be 0.1 mm, and the perpendicularity of the samples should be 0.3 mm. Measure the surface area, apparent porosity, and bulk density of each sample, selecting those with a bulk density deviation of less than 0.02 g / cm³. 3 The samples within the specified range are used as standard samples to be tested; S2: Detect the room temperature compressive strength of one of the original samples as the original strength of 180 MPa; S3: The sample is heated in the furnace at a heating rate of 10℃ / min from 0 to 1000℃ and a heating rate of 5℃ / min from 1000℃ to 1300℃, and held at 1300℃ for 5 minutes. S4: Cool the sample with water, keeping the temperature of the cooling water in the circulating water tank at 20℃ for 3 minutes.

[0036] S5: Air cooling 15min; S6: After the sample completes the first thermal cycle of heating with the furnace, it is placed directly into the 1300℃ electric furnace during subsequent heating. The test is carried out by holding at 1300℃ for 10 minutes, water cooling for 3 minutes, and air cooling for 15 minutes. S7: The heating and cooling processes are alternately performed 5, 10, 15, 20, 25, 30, 35, and 40 times respectively; S8: When the number of cycles reaches 5, a severely cracked sample is selected, dried, and its room temperature compressive strength P5 = 114 MPa is tested; when the number of cycles reaches 10, a severely cracked sample is selected, dried, and its room temperature compressive strength P10 = 96 MPa is tested; when the number of cycles reaches 15, a severely cracked sample is selected, dried, and its room temperature compressive strength P15 = 95 MPa is tested; when the number of cycles reaches 20, a severely cracked sample is selected, dried, and its room temperature compressive strength P20 = 86 MPa is tested; when the number of cycles reaches 25, a severely cracked sample is selected, dried, and its room temperature compressive strength P25 = 77 MPa is tested; when the number of cycles reaches 30, a severely cracked sample is selected, dried, and its room temperature compressive strength P30 = 48 MPa is tested; when the number of cycles reaches 35, a severely cracked sample is selected, dried, and its room temperature compressive strength P35 = 21 MPa is tested. S9: Calculate the percentage of the room temperature compressive strength of the product after the i-th thermal shock cycle to the original compressive strength of the sample using the strength decay rate formula. V5=37%, V10=47%, V15=47%, V20=52%, V25=57%, V30=84%, V35=98%.

[0037] Example 2: S1: Prepare 7-10 cylinders with a diameter of 50.1 mm and a height of 50.1 mm from the same brick. The parallelism of the samples should be 0.1 mm, and the perpendicularity of the samples should be 0.3 mm. Measure the surface area, apparent porosity, and bulk density of each sample. Select samples with a bulk density deviation of less than 0.02 g / cm³. 3 The samples within the specified range are used as standard samples to be tested; S2: The room temperature compressive strength of one of the original samples is tested as the original strength, which is 98.4 MPa; S3: The sample is heated to 500℃ in the furnace, and CO gas is introduced to achieve a concentration of ≥95%; S4: Keep the sample at the above conditions for 5 hours; S6: Shut down the furnace, remove the sample to be tested, and test its compressive strength P5; S7: The remaining samples are subjected to S3-S4 operations again, and the cumulative holding time reaches 10 hours. Then, S6 operation is performed, and the process is repeated to carry out heating and holding times of 3H, 5H, 10H, 20H, 50H, 100H, 100H, 150H, and 200H in sequence. S8: When the CO corrosion resistance time reaches 3 hours, severely cracked samples are selected, dried, and their room temperature compressive strength P3 = 98.4 MPa is tested; when the CO corrosion resistance time reaches 5 hours, severely cracked samples are selected, dried, and their room temperature compressive strength P5 = 98.6 MPa is tested; when the CO corrosion resistance time reaches 10 hours, severely cracked samples are selected, dried, and their room temperature compressive strength P10 = 98.4 MPa is tested; when the CO corrosion resistance time reaches 20 hours, severely cracked samples are selected, dried, and their room temperature compressive strength P20 = 95.6 MPa is tested; when the CO corrosion resistance time reaches 1 ...20 = 95.6 MPa is tested. After 50 hours of CO corrosion resistance, severely cracked samples were dried and their room temperature compressive strength P50 was tested to be 95.1 MPa; after 100 hours of CO corrosion resistance, severely cracked samples were dried and their room temperature compressive strength P100 was tested to be 92.3 MPa; after 150 hours of CO corrosion resistance, severely cracked samples were dried and their room temperature compressive strength P150 was tested to be 79.4 MPa; after 200 cycles of CO corrosion resistance, severely cracked samples were dried and their room temperature compressive strength P200 was tested to be 67.1 MPa. S9: Calculate the percentage of the room temperature compressive strength of the product after the i-th thermal shock cycle to the original compressive strength of the sample using the strength decay rate formula. V3=0.00%, V5=0.00%, V10=0.00%, V20=2.80%, V50=3.31%, V100=6.16%, V150=19.27%, V200=31.85%.

[0038] Examples 1 and 2 illustrate that as the number of environmental erosion cycles of refractory materials increases, their compressive strength gradually decreases and their attenuation rate gradually increases. However, the attenuation rate varies depending on the material. For example, the material in Example 1 initially has high strength, but when the number of thermal shock cycles reaches 25-30, the attenuation rate reaches a sudden inflection point, and the strength attenuation shows a significant upward trend, resulting in fundamental damage. The strength attenuation is sudden and not linear, making the material prone to sudden breakage. The material in Example 2 has relatively ordinary initial strength, but the strength attenuation shows a regular relationship. After 100 hours of CO erosion resistance, no abrupt change occurs, indicating relatively stable long-term service life. This evaluation method can predict the damage mode and usage of materials. The results are highly regular and consistent with the damage mode of refractory materials used in the column section of dry quenching coke ovens, demonstrating the effectiveness of the method provided in this application.

Claims

1. An experimental apparatus for evaluating the stability of refractory materials after erosion, characterized in that, The experimental apparatus is used for testing experimental samples and includes: The thermal shock attenuation device is used to simulate the thermal shock process of refractory materials under high-temperature cycling environment, and to evaluate the thermal shock stability of the material by performing temperature rise and fall and thermal cycling. The CO corrosion resistance device is used to simulate the corrosion phenomenon of refractory materials when they come into contact with CO atmosphere at high temperature, and to evaluate the material's resistance to CO corrosion. A dryer is used to dry the samples after thermal shock cycling to remove surface moisture and ensure the accuracy of subsequent strength testing. A hydraulic press is used to test the compressive strength of a specimen after each thermal shock cycle, measure the change in the compressive strength of the specimen, and evaluate the strength decay of the material during thermal shock. Computers are used to monitor and record experimental data in real time, including temperature changes, thermal shock counts, crack propagation of specimens, and compressive strength data, to perform data analysis and processing, and to output experimental results. The CO corrosion resistance device delivers CO gas into a heating furnace, which is connected to a reflux flask, which in turn connects to a bubble bottle, which in turn connects to an antifreeze bottle. This ensures stable and uniform gas flow and prevents condensation or freezing during cooling, thus guaranteeing the smooth progress of the experiment. By precisely controlling the gas flow, temperature, and pressure, the device simulates the reduction reaction of refractory materials under actual working conditions, thereby more accurately evaluating the CO corrosion resistance of the materials.

2. A method for testing the thermal shock stability attenuation of refractory materials, wherein the experimental apparatus for evaluating the post-erosion stability of refractory materials according to claim 1 is characterized in that, Includes the following steps: N cylinders with a diameter of 50 mm ± 0.5 mm and a height of 50 mm ± 0.5 mm were prepared from refractory bricks produced using the same manufacturing process. The parallelism of the samples should not exceed 0.2 mm, and the perpendicularity of the samples should not exceed 0.5 mm. The surface area, apparent porosity, and bulk density of the samples were measured, and the bulk density deviation was selected to be less than 0.02 g / cm³. 3 The samples within the range are used as standard samples to be tested; the room temperature pressure resistance strength of one of the samples is tested at room temperature to obtain the original pressure resistance strength P0; the remaining samples are subjected to thermal cycling, CO corrosion, and H2 corrosion respectively. Environmental erosion resistance test of the specimen: The thermal cycling test was conducted as follows: The sample was placed in a furnace and heated to 1000℃ at a rate of 5℃ / min, then heated to 1300℃ at a rate of 5℃ / min. After holding at 1300℃ for 5 minutes, the sample was water-cooled for 3 minutes and air-cooled for 15 minutes. After the sample completed the first thermal cycle of heating with the furnace, it was placed directly into a 1300℃ electric furnace again and cycled according to the experimental method of holding at 1300℃ for 10 minutes, water-cooled for 3 minutes, and air-cooled for 15 minutes. The corrosion and damage of CO to the sample is as follows: The sample is heated to 500 degrees under nitrogen protection, CO gas is introduced, and the CO concentration reaches more than 95%. The sample is kept at this temperature for 5 hours, which is recorded as P5, and for 10 hours, it is recorded as P10, and so on. The holding time can be selected according to the requirements of the test. When the number of cycles or the holding time reaches 5 times / hour, stop the test, select the sample with severe cracks, dry it, and test the room temperature compressive strength P5 of the sample; then, test samples P10, P15, P20, P25...P200 respectively. The number of tests or the holding time can be selected according to the test requirements. The formula for calculating the performance degradation rate is: ； in: V i This indicates the rate of performance degradation of the sample after immersion in the environment. P0 refers to the original compressive strength of the sample. i This represents the product's compressive strength measured at room temperature after the i-th environmental immersion.

3. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, The experimental sample group was placed in a high-temperature electric furnace, and the high temperature was controlled at 1300℃ or a condition temperature that met the working conditions. The cyclic sample to be subjected to thermal shock is placed in the thermal shock furnace and heated; the heating temperature is controlled to be the service temperature of the refractory material under actual working conditions; the heating time is controlled to be 10 minutes. The heated sample group was cooled by circulating water; the temperature of the cooling water was maintained at <18℃, and the cooling time was 3 minutes. The water-cooled sample was air-dried for 15 minutes. The heating and cooling processes are alternately performed to achieve the required number of thermal shocks, thereby completing the thermal shock attenuation experiment. The experimental sample group was placed in a CO atmosphere electric furnace, the high temperature was controlled at 500℃ or the temperature that met the working conditions; the CO concentration was ≥95%, and the temperature was continuously controlled until the required holding time was required. By analyzing the performance stability trends of V5, V10, V15, V20, V25, and V30 refractory materials after environmental erosion, the strength changes of the samples under long-term service can be reasonably assessed.

4. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, After completing thermal shock and CO erosion tests, the samples were further subjected to erosion tests under an H2 atmosphere. The test method was as follows: the sample was placed in a vacuum furnace, H2 gas was introduced, and the temperature was raised to 1000–1500°C. The pressure of H2 inside the furnace was maintained at 0.01–0.8 MPa, and the holding time was 5 hours, 10 hours, and 15 hours. Appropriate furnace pressure and holding time were selected according to experimental requirements. The room temperature compressive strength P5, P10, and P15 of the sample after each holding were recorded, and the decay rate V was calculated. i .

5. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, The initial heating step of the thermal cycling damage is as follows: the sample is placed in a reheat furnace and heated to 1000°C at a heating rate of 10°C / min, then heated to 1300°C at a heating rate of 5°C / min, held at this temperature for 5 minutes, and then water-cooled and air-cooled. The CO erosion damage step of the sample is as follows: the sample is heated to 500°C at a heating rate of 5°C / min, then CO gas is introduced to make its content reach more than 90%, and held at this condition.

6. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, The experimental data is transmitted to the computer system in real time. The computer system automatically analyzes and outputs a trend graph of material performance degradation, and provides strength change curves under different thermal cycles and CO erosion cycles to help evaluate the service life and reliability of the material in practical applications.

7. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, The water cooling system used in the experiment is equipped with a temperature sensor to monitor the temperature of the cooling water in real time, ensuring the accuracy of temperature control during the cooling process and avoiding instability in sample performance due to fluctuations in cooling temperature.

8. The method for testing the thermal shock stability attenuation of refractory materials according to claim 2, characterized in that, During environmental erosion testing, the cooling process after each heating of the sample is completed by multiple cooling media, including cooling water, air, and special cooling gas, to ensure that the thermal shock and erosion process of the material under actual working conditions is simulated.

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