Method for testing melting performance of casting powder

Abstract

The invention provides a method for testing the melting performance of casting powder. The method comprises the steps that a casting powder sample is obtained from to-be-tested casting powder; the casting powder sample is put into a melting point measuring instrument, and the melting point measuring instrument is controlled to conduct heating treatment on the casting powder sample according to the first heating speed; controlling the melting point measuring instrument to determine the softening temperature, the hemispherical point temperature and the flowing temperature of the casting powder sample under the condition that the temperature in the melting point measuring instrument is greater than or equal to a first temperature threshold value; according to a first temperature difference value A between the softening temperature and the hemispherical point temperature and a second temperature difference value B between the flowing temperature and the hemispherical point temperature, the melting performance of the casting powder is determined; wherein the melting performance is at least characterized by the melting speed uniformity degree of the casting powder. According to the method, the accuracy of casting powder melting performance evaluation can be improved, the casting powder melting performance evaluation process is optimized, the overall production efficiency can be improved, and casting powder with more excellent melting performance can be selected conveniently.

Description

Technical Field

[0001] This application relates to the field of iron and steel metallurgy technology, and in particular to a test method for the melting performance of protective slag. Background Technology

[0002] Protective slag is an important auxiliary material in continuous casting production. It plays an important role in preventing secondary oxidation of molten steel, insulating and reducing heat loss of molten steel, absorbing and dissolving non-metallic inclusions, acting as a lubricant between the mold wall and the billet shell, and improving and controlling heat transfer between the billet and the mold.

[0003] To achieve high-quality and efficient hot charging in continuous casting production, it is essential to correctly select and use protective slag with qualified melting performance. An important indicator for evaluating the melting performance of protective slag is its melting rate. If the melting rate changes drastically, it means that the material uniformity of the protective slag is poor, which can easily lead to an excessively thick or thin liquid slag layer, thus negatively affecting the quality of castings and even production efficiency.

[0004] However, in the actual assessment of the melting rate of protective slag, related technologies often rely on methods such as manual observation of the physical morphology of the protective slag, which has drawbacks such as cumbersome assessment process and low assessment accuracy. Summary of the Invention

[0005] This application provides a test method for the melting performance of protective slag, in order to solve the problem that in the relevant technology, when actually evaluating the melting rate of protective slag, the method of manually observing the physical morphology of protective slag is often used, which has the problems of cumbersome evaluation process and low evaluation accuracy.

[0006] This application provides a method for testing the melting performance of protective slag, comprising the following steps:

[0007] Obtain protective slag samples from the protective slag to be tested;

[0008] The protective slag sample was placed in the melting point measuring instrument, and the instrument was heated according to the first heating rate.

[0009] When the temperature inside the melting point measuring instrument is greater than or equal to the first temperature threshold, the melting point measuring instrument is controlled to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample.

[0010] The melting performance of the protective slag is determined based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature; wherein the melting performance is at least characterized by the uniformity of the melting rate of the protective slag.

[0011] According to embodiments of this application, the melting properties of the protective slag are determined based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature, including:

[0012] If the first temperature difference A and the second temperature difference B satisfy the conditions: |AB|≤20℃, 15≤A≤45℃, and 15≤B≤45℃, then the melting performance of the protective slag is determined to have reached the preset qualified parameters.

[0013] According to an embodiment of this application, a protective slag sample is placed in a melting point measuring instrument, and the melting point measuring instrument is used to heat the protective slag sample according to a first heating rate, including:

[0014] When the temperature inside the melting point measuring instrument is greater than or equal to the second temperature threshold, the protective slag sample is placed into the melting point measuring instrument; wherein the second temperature threshold is less than the first temperature threshold.

[0015] According to an embodiment of this application, before placing the protective slag sample into the melting point measuring instrument when the temperature inside the instrument is greater than or equal to a second temperature threshold, the method further includes:

[0016] The melting point measuring instrument is heated according to a second heating rate, wherein the second heating rate is greater than the first heating rate.

[0017] According to an embodiment of this application, the first temperature threshold is 800°C and the second temperature threshold is 600°C.

[0018] According to an embodiment of this application, the first heating rate is 10°C / min, and the second heating rate is 15°C / min.

[0019] According to an embodiment of this application, obtaining a protective slag sample from the protective slag to be tested includes:

[0020] The protective slag to be tested was sampled and ground to obtain sample powder;

[0021] A cylindrical sample is prepared based on the sample powder; wherein the diameter of the cylindrical sample is equal to the height of the cylindrical sample.

[0022] The cylindrical sample was dried to obtain a protective slag sample.

[0023] According to the embodiments of this application, the particle size of the sample powder is less than or equal to 0.074 mm.

[0024] According to an embodiment of this application, the diameter of the cylindrical sample is 3 mm and the height of the cylindrical sample is 3 mm.

[0025] The cylindrical sample was dried to obtain a protective slag sample, including:

[0026] According to an embodiment of this application, a cylindrical sample is placed in a constant temperature furnace at a temperature of 60℃-80℃ for drying treatment to obtain a protective slag sample, wherein the drying time of the drying treatment is 8min-15min.

[0027] This application obtains a protective slag sample from a protective slag to be tested; places the protective slag sample into a melting point measuring instrument, and controls the melting point measuring instrument to heat the protective slag sample according to a first heating rate; subsequently, when the temperature inside the melting point measuring instrument is greater than or equal to a first temperature threshold, controls the melting point measuring instrument to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample; thereby determining the melting performance of the protective slag based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature; wherein the melting performance is characterized at least by the uniformity of the melting rate of the protective slag, the application has the following technical effects:

[0028] Since the softening temperature, hemispherical point temperature, and flow temperature of the protective slag can reflect the melting temperature of the protective slag at different melting stages, this application can reflect the temperature change stability during the melting process of the protective slag by using the first temperature difference A between the softening temperature and the hemispherical point temperature measured under a fixed heating rate, and the second temperature difference B between the flow temperature and the hemispherical point temperature. This allows for the determination of the overall melting rate uniformity of the protective slag, enabling accurate and rapid detection and confirmation of the material uniformity of the protective slag. It also helps predict whether the thickness of the liquid slag layer during the production process can meet the process standards, thus determining the melting performance of the protective slag. This improves the accuracy of the protective slag melting performance evaluation, optimizes the protective slag melting performance evaluation process, helps improve overall production efficiency, facilitates the selection of protective slag with better melting performance, and ultimately improves the cleanliness and quality of castings. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This is a flowchart of the test method for the melting performance of the protective slag provided in this application;

[0031] Figure 2 This is a schematic diagram comparing the softening temperature, hemispherical point temperature, and flow temperature values ​​of Embodiment 1, Comparative Example 1, and Comparative Example 2 provided in this application.

[0032] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0033] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] To achieve high-quality and efficient hot charging in continuous casting production, it is essential to correctly select and use protective slag with qualified melting performance. An important indicator for evaluating the melting performance of protective slag is its melting rate. If the melting rate changes drastically, it means that the material uniformity of the protective slag is poor, which can easily lead to an excessively thick or thin liquid slag layer, thus negatively affecting the quality of castings and even production efficiency.

[0037] However, in the actual assessment of the melting rate of protective slag, related technologies often rely on methods such as manual observation of the physical morphology of the protective slag, which has drawbacks such as cumbersome assessment process and low assessment accuracy.

[0038] In view of the above problems, this application provides a method for testing the melting performance of protective slag, which can accurately and quickly detect and confirm the material uniformity of protective slag, help predict whether the thickness of the liquid slag layer in the production process can meet the process standards, improve the accuracy of protective slag melting performance evaluation, optimize the protective slag melting performance evaluation process, help improve overall production efficiency, facilitate the selection of protective slag with better melting performance, and thus improve the cleanliness and quality of castings.

[0039] This application provides a method for testing the melting performance of protective slag. Please refer to [link / reference needed]. Figure 1 It includes the following steps:

[0040] S100: Obtain a protective slag sample from the protective slag to be tested;

[0041] S200: Place the protective slag sample into the melting point measuring instrument, and control the melting point measuring instrument to heat the protective slag sample according to the first heating rate;

[0042] S300: When the temperature inside the melting point measuring instrument is greater than or equal to the first temperature threshold, control the melting point measuring instrument to determine the softening temperature, hemispherical point temperature and flow temperature of the protective slag sample.

[0043] S400: The melting performance of the protective slag is determined based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature; wherein the melting performance is at least characterized by the uniformity of the melting rate of the protective slag.

[0044] The initial height at which the protective slag sample begins to melt can be recorded as 100%. Specifically, the height of the protective slag when the temperature inside the melting point measuring instrument reaches the first temperature threshold can be determined as the initial height at which melting begins. Based on this, during the melting process, the temperature corresponding to when the height of the protective slag reaches 75% of the initial height can be recorded as the softening temperature, the temperature corresponding to when the height of the protective slag reaches 50% of the initial height can be recorded as the hemispherical point temperature, and the temperature corresponding to when the height of the protective slag reaches 25% of the initial height can be recorded as the flow temperature.

[0045] Since the softening temperature, hemispherical point temperature, and flow temperature of the protective slag reflect the melting temperature at different melting stages, and the heating rate is maintained at the initial heating rate after the protective slag sample is placed in the melting point measuring instrument, this means that the temperature rise rate is the same at each stage, controlling the uniformity of external conditions during the melting process. Based on this, the changes in melting temperature at different stages during the melting process can directly reflect the uniformity of the melting rate of the protective slag. For example, if the temperature difference between different temperature stages is too large, it indicates that the uniformity of the melting rate of the protective slag may be poor. If melting occurs too quickly or too slowly in one or more stages of the melting process, it means that the material uniformity of the protective slag is poor.

[0046] Therefore, this application can reflect the temperature change stability during the melting process of the protective slag by using the first temperature difference A between the softening temperature and the hemispherical point temperature measured under a fixed heating rate, and the second temperature difference B between the flow temperature and the hemispherical point temperature. This allows for the determination of the overall melting rate uniformity of the protective slag, enabling accurate and rapid detection and confirmation of the material uniformity of the protective slag. Furthermore, it helps predict whether the thickness of the liquid slag layer during production meets process standards, improving the accuracy of the protective slag melting performance evaluation, optimizing the evaluation process, and contributing to improved overall production efficiency. It also facilitates the selection of protective slags with superior melting performance, thereby improving casting cleanliness and casting quality.

[0047] In this embodiment, the uniformity of melting rate refers to the uniformity of the melting rate from the start of melting to complete melting of the protective slag. For example, if the melting rate is stable and the variation is small during the melting process, the uniformity of the melting rate of the protective slag can be considered good. Conversely, if the variation in melting rate is large during the melting process, the uniformity of the melting rate of the protective slag can be considered poor. A good uniformity of the melting rate of the protective slag can be considered to indicate good material uniformity and satisfactory melting performance.

[0048] The specific steps for S100 are as follows:

[0049] A protective slag sample is obtained from the protective slag to be tested. Specifically, 5g to 10g of slag sample can be taken from the original protective slag and then ground, prepared and dried in sequence to obtain the protective slag sample.

[0050] In some embodiments, obtaining a protective flux sample from the protective flux to be tested includes:

[0051] The protective slag to be tested was sampled and ground to obtain sample powder;

[0052] A cylindrical sample is prepared based on the sample powder; wherein the diameter of the cylindrical sample is equal to the height of the cylindrical sample.

[0053] The cylindrical sample was dried to obtain a protective slag sample.

[0054] In practice, 5g to 10g of slag sample can be taken from the original protective slag and ground in an agate mortar to obtain sample powder. This sample powder can then be formed into cylindrical samples, the diameter of which can be equal to the height. Finally, the cylindrical samples are dried to obtain the protective slag sample. This process ensures the protective slag sample conforms to certain morphological standards, reducing errors caused by irregular shapes. Furthermore, removing moisture from the sample further reduces the risk of errors.

[0055] In some embodiments, the particle size of the sample powder is less than or equal to 0.074 mm.

[0056] In practical applications, the particle size of the sample powder can be controlled to be less than or equal to 0.074 mm. For example, it can be specified that the particle size of the sample powder obtained after grinding should all pass through 0.074 mm (100 mesh). This controls the uniformity of the powder and helps improve the accuracy of the protective slag melting performance test.

[0057] In some embodiments, the diameter of the cylindrical sample is 3 mm and the height of the cylindrical sample is 3 mm.

[0058] A cylindrical sample with a diameter of 3 mm and a height of 3 mm can be prepared from the sample powder, thereby standardizing the sample specifications for each test and improving the consistency between the test results and the test procedure.

[0059] In some embodiments, the cylindrical sample is dried to obtain a protective slag sample, including:

[0060] The cylindrical sample was placed in a constant temperature furnace at 60℃-80℃ for drying to obtain a protective slag sample. The drying time was 8min-15min.

[0061] In practical applications, when drying cylindrical samples, the samples can be placed in a constant temperature furnace at 60℃-80℃ for 8-15 minutes to fully remove moisture and obtain a protective slag sample. This further avoids the influence of moisture on the melting performance test results and improves the accuracy of the test results.

[0062] The S200 steps are as follows: Place the protective slag sample into the melting point measuring instrument, and control the melting point measuring instrument to heat the protective slag sample according to the first heating rate.

[0063] After obtaining the protective slag sample, the sample can be placed in a melting point measuring instrument, and the instrument can be heated according to the first heating rate to conduct melting tests on the protective slag sample under a fixed heating rate.

[0064] The specific steps for S300 are as follows:

[0065] When the temperature inside the melting point measuring instrument is greater than or equal to the first temperature threshold, the melting point measuring instrument is controlled to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample.

[0066] When the temperature inside the melting point measuring instrument is greater than or equal to the first temperature threshold, the instrument can be controlled to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample. The first temperature threshold can be set based on the melting point of the protective slag. For example, when the temperature inside the melting point measuring instrument reaches the first temperature threshold, the image capture function of the instrument can be activated to calibrate the original height of the sample (calibrated to 100%). The computer then begins image comparison and analysis, continuously measuring the temperature at 75%, 50%, and 25% of the sample height. The measurement can end when the sample melts to 25%.

[0067] In some embodiments, placing the protective slag sample into a melting point measuring instrument and controlling the melting point measuring instrument to heat the protective slag sample according to a first heating rate includes:

[0068] When the temperature inside the melting point measuring instrument is greater than or equal to the second temperature threshold, the protective slag sample is placed into the melting point measuring instrument; wherein the second temperature threshold is less than the first temperature threshold.

[0069] In practical applications, the protective slag sample can be placed into the melting point measuring instrument and the high-temperature camera can be turned on when the temperature inside the melting point measuring instrument reaches the second temperature threshold. At this time, the melting point measuring instrument has been fully preheated, which reduces the impact of the instrument's heating process on the sample's melting performance test results before the sample's melting point is reached, thus improving the stability and accuracy of the melting performance test.

[0070] In some embodiments, before placing the protective slag sample into the melting point measuring instrument when the temperature inside the melting point measuring instrument is greater than or equal to a second temperature threshold, the method further includes:

[0071] The melting point measuring instrument is heated according to a second heating rate, wherein the second heating rate is greater than the first heating rate.

[0072] In practical applications, the melting point measuring instrument can be preheated at a rate faster than the initial heating rate, thereby optimizing the performance testing process, shortening the preheating stage, avoiding ineffective temperature control time, and thus improving performance testing efficiency.

[0073] In some embodiments, the first temperature threshold is 800°C and the second temperature threshold is 600°C.

[0074] In practical applications, the first temperature threshold can be 800℃ and the second temperature threshold can be 600℃. The difference between the first temperature threshold of 800℃ and the second temperature threshold of 600℃ can achieve a smooth transition of temperature change after the protective slag is put in, avoiding the influence of external conditions on the melting performance test.

[0075] In some embodiments, the first heating rate is 10°C / min, and the second heating rate is 15°C / min.

[0076] In practical applications, the first heating rate can be 10℃ / min, and the second heating rate can be 15℃ / min. By defining the temperature thresholds and heating rate values, clear control standards can be provided for effective melting performance testing. The difference between the first temperature threshold of 800℃ and the second temperature threshold of 600℃ ensures a smooth transition in temperature change after the protective slag is added, avoiding the influence of external conditions on the melting performance test. The heating rate settings of 10℃ / min and 15℃ / min allow for improved testing efficiency without compromising the accuracy and stability of the protective slag melting performance test.

[0077] The S400 steps are as follows: Determine the melting performance of the protective slag based on the first temperature difference A between the softening temperature and the hemispherical point temperature, and the second temperature difference B between the flow temperature and the hemispherical point temperature; wherein, the melting performance is at least characterized by the uniformity of the melting rate of the protective slag.

[0078] Since the softening temperature, hemispherical point temperature, and flow temperature of the protective slag can reflect the melting temperature of the protective slag at different melting stages, this application can reflect the temperature change stability during the melting process of the protective slag by using the first temperature difference A between the softening temperature and the hemispherical point temperature measured under a fixed heating rate, and the second temperature difference B between the flow temperature and the hemispherical point temperature. This allows for the determination of the overall melting rate uniformity of the protective slag, thereby enabling accurate and rapid detection and confirmation of the material uniformity of the protective slag. Furthermore, it helps predict whether the thickness of the liquid slag layer in the production process can meet the process standards, thus determining the melting performance of the protective slag.

[0079] For example, multiple tests can be conducted based on the temperature difference between the softening temperature and the hemispherical point temperature, as well as the temperature difference between the flow temperature and the hemispherical point temperature, to determine the specific range of relevant temperature differences when the protective slag has good melting characteristics, no bubbling or low-melting-point material aggregation, no segregation, and the liquid slag layer thickness meets the requirement of 10-15 mm. This will help to form judgment rules for evaluating the melting performance of protective slag and improve the accuracy and efficiency of the evaluation.

[0080] In some embodiments, determining the melting properties of the protective flux based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature, includes:

[0081] If the first temperature difference A and the second temperature difference B satisfy the conditions: |AB|≤20℃, 15≤A≤45℃, and 15≤B≤45℃, then the melting performance of the protective slag is determined to have reached the preset qualified parameters.

[0082] In practical applications, the temperature difference between the softening temperature and the hemispherical point temperature can be defined as A, and the temperature difference between the flow temperature and the hemispherical point temperature can be defined as B. Multiple tests can be conducted to calibrate and determine the corresponding ranges of A, B, and |AB| when the protective slag exhibits good melting characteristics, without bubbling or aggregation of low-melting-point substances, without segregation, and the liquid slag layer thickness is 10-15 mm. This allows for the formation of quantitative judgment rules for evaluating the melting performance of protective slag, improving the accuracy and efficiency of the evaluation. The melting rate of the protective slag can be calculated using a melting point measuring instrument.

[0083] In one example, under the conditions that |AB|≤20℃, 15≤A≤45℃, and 15≤B≤45℃, the melting performance of the protective slag can be determined to meet the preset qualified parameters. This indicates that the melting rate uniformity of the protective slag is good, and its melting performance is qualified. Furthermore, because the heating rate is constant, under the above conditions, the temperature difference between the softening temperature and the hemispherical point temperature of the protective slag, as well as the temperature difference between the flow temperature and the hemispherical point temperature, remains within a certain range. This can, to some extent, reflect that the melting rate of the protective slag is moderate, i.e., there is no phenomenon of melting too fast or too slow. This can serve as a quantitative judgment rule for evaluating the melting performance of the protective slag, further improving the accuracy and efficiency of the evaluation.

[0084] The range settings of 15≤A≤45℃ and 15≤B≤45℃ reflect the stability of the melting process between the softening temperature and the hemispherical point temperature, as well as the stability of the melting process between the flow temperature and the hemispherical point temperature. The range setting of |AB|≤20℃ further clarifies the temperature difference between the softening, hemispherical, and flow temperatures, indicating that the temperature changes during the overall melting process remain within a reasonable range. This confirms that the melting process is neither too fast nor too slow, the melting speed is moderate, the uniformity of the melting speed of the protective slag is good, the melting performance is qualified, the melting speed is moderate, there is no bubbling or low-melting-point material aggregation, no segregation, and the liquid slag layer thickness meets the process standard range of 10-15mm.

[0085] In one example, under the condition that the initial heating rate is 10℃ / min, the melting performance of the protective slag can be determined to meet the preset qualified parameters when |AB|≤20℃, 15≤A≤45℃, 15≤B≤45℃, the time difference between the softening temperature determination time and the hemispherical point temperature determination time is 90s-270s, and the time difference between the hemispherical point temperature determination time and the flow temperature determination time is 90s-270s. This indicates that the melting speed of the protective slag is uniform and moderate, and the melting performance is qualified. This can serve as a quantitative judgment rule for evaluating the melting performance of protective slag, further improving the accuracy and efficiency of the evaluation. Specifically, the softening temperature determination time is the time when the protective slag height reaches 75% of the initial height, the hemispherical point temperature determination time is the time when the protective slag height reaches 50% of the initial height, and the flow temperature determination time is the time when the protective slag height reaches 25% of the initial height.

[0086] The settings of a time difference of 90s-270s between the softening temperature determination time and the hemispherical point temperature determination time, and between the hemispherical point temperature determination time and the flow temperature determination time, help to further accurately determine whether the melting rate of the protective slag is appropriate in each stage, and whether there is a phenomenon of melting too fast or too slow in one or more stages, on the premise of judging the uniformity of the melting rate of the protective slag (for example, if the time difference between the softening temperature determination time and the hemispherical point temperature determination time is less than 90s, it can be determined that the protective slag has melted too fast in this melting stage), thereby further improving the accuracy of melting performance testing.

[0087] To achieve high-quality and efficient hot charging in continuous casting production, it is essential to correctly select and use protective slag with qualified melting performance. An important indicator for evaluating the melting performance of protective slag is its melting rate. If the melting rate changes drastically, it means that the material uniformity of the protective slag is poor, which can easily lead to an excessively thick or thin liquid slag layer, thus negatively affecting the quality of castings and even production efficiency.

[0088] However, in the actual assessment of the melting rate of protective slag, related technologies often rely on methods such as manual observation of the physical morphology of the protective slag, which has drawbacks such as cumbersome assessment process and low assessment accuracy.

[0089] This application obtains a protective slag sample from a protective slag to be tested; places the protective slag sample into a melting point measuring instrument, and controls the melting point measuring instrument to heat the protective slag sample according to a first heating rate; subsequently, when the temperature inside the melting point measuring instrument is greater than or equal to a first temperature threshold, controls the melting point measuring instrument to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample; thereby determining the melting performance of the protective slag based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature; wherein the melting performance is characterized at least by the uniformity of the melting rate of the protective slag, and is capable of... By measuring the relationship between the softening temperature, hemispherical point temperature, and flow temperature of the protective slag under a fixed heating rate, the stability of temperature changes during the slag melting process can be reflected, thereby determining the overall uniformity of the slag melting rate. This allows for accurate and rapid detection and confirmation of the material uniformity of the protective slag, assisting in predicting whether the thickness of the liquid slag layer during production meets process standards, and determining the slag's melting performance. This improves the accuracy of the slag melting performance evaluation, optimizes the evaluation process, helps improve overall production efficiency, facilitates the selection of slags with superior melting performance, and ultimately improves casting cleanliness and casting quality.

[0090] Example

[0091] The following embodiments describe the disclosure of this application in more detail. These embodiments are for illustrative purposes only, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0092] Example 1:

[0093] Select 5g to 10g of the protective residue to be tested and grind it in an agate mortar to obtain sample powder. The particle size of the powder after grinding should all pass through 0.074mm (100 mesh).

[0094] Prepare cylindrical samples from the sample powder, each 3 mm in diameter and 3 mm in height. Place the cylindrical samples in a constant temperature furnace at 50°C for 10 minutes to remove moisture.

[0095] Start the melting point measuring instrument and begin heating from room temperature. Initially, use a heating rate of 50°C per minute. Once the temperature inside the melting point measuring instrument exceeds 600°C, insert the cylindrical sample into the instrument for measurement, setting the heating rate to 15°C per minute.

[0096] When the ambient temperature is greater than or equal to 800℃, turn on the high-temperature camera of the melting point measuring instrument, start the image capture system to capture the sample, calibrate the sample, calibrate the original height of the sample to 100%, the computer starts image comparison and analysis, continuously and uninterruptedly measure, analyze and record the softening temperature, hemispherical point temperature and flow temperature.

[0097] The softening temperature, hemispherical point temperature, and flow temperature were measured to be 1020℃, 1050℃, and 1092℃, respectively.

[0098] The sample measurements showed that |AB| = 12℃, A = 30℃, and B = 42℃. Further testing revealed that the protective slag material had good uniformity, no partial melting, and a suitable melting rate. The corresponding measurement showed that the slag layer of the protective slag continuous casting liquid was 12mm, which meets the process requirements.

[0099] Comparative Example 1:

[0100] Select 5g to 10g of the protective residue to be tested and grind it in an agate mortar to obtain sample powder. The particle size of the powder after grinding should all pass through 0.074mm (100 mesh).

[0101] Prepare cylindrical samples from the sample powder, each 3 mm in diameter and 3 mm in height. Place the cylindrical samples in a constant temperature furnace at 50°C for 10 minutes to remove moisture.

[0102] Start the melting point measuring instrument and begin heating from room temperature. Initially, use a heating rate of 50°C per minute. Once the temperature inside the melting point measuring instrument exceeds 600°C, insert the cylindrical sample into the instrument for measurement, setting the heating rate to 15°C per minute.

[0103] When the ambient temperature is greater than or equal to 800℃, turn on the high-temperature camera of the melting point measuring instrument, start the image capture system to capture the sample, calibrate the sample, calibrate the original height of the sample to 100%, the computer starts image comparison and analysis, continuously and uninterruptedly measure, analyze and record the softening temperature, hemispherical point temperature and flow temperature.

[0104] The softening temperature, hemispherical point temperature, and flow temperature were measured to be 1080℃, 1086℃, and 1112℃, respectively.

[0105] The sample measurements showed that |AB| = 20℃, A = 6℃, and B = 26℃. Further testing revealed poor uniformity of the protective slag, partial melting, and excessively fast melting rate. The slag layer in the continuous casting liquid reached 17mm, which did not meet the process requirements.

[0106] Comparative Example 2:

[0107] Select 5g to 10g of the protective residue to be tested and grind it in an agate mortar to obtain sample powder. The particle size of the powder after grinding should all pass through 0.074mm (100 mesh).

[0108] Prepare cylindrical samples from the sample powder, each 3 mm in diameter and 3 mm in height. Place the cylindrical samples in a constant temperature furnace at 50°C for 10 minutes to remove moisture.

[0109] Start the melting point measuring instrument and begin heating from room temperature. Initially, use a heating rate of 50°C per minute. Once the temperature inside the melting point measuring instrument exceeds 600°C, insert the cylindrical sample into the instrument for measurement, setting the heating rate to 15°C per minute.

[0110] When the ambient temperature is greater than or equal to 800℃, turn on the high-temperature camera of the melting point measuring instrument, start the image capture system to capture the sample, calibrate the sample, calibrate the original height of the sample to 100%, the computer starts image comparison and analysis, continuously and uninterruptedly measure, analyze and record the softening temperature, hemispherical point temperature and flow temperature.

[0111] The softening temperature, hemispherical point temperature, and flow temperature were measured to be 1090℃, 1150℃, and 1190℃, respectively.

[0112] The sample measurements showed that |AB| = 20℃, A = 60℃, and B = 40℃. Further testing revealed poor uniformity of the protective slag, partial melting, and excessively fast melting rate. The slag layer in the continuous casting liquid reached 7mm, which did not meet the process requirements.

[0113] like Figure 2 The diagram shows a comparison of softening temperature, hemispherical point temperature, and flow temperature values ​​for Example 1, Comparative Example 1, and Comparative Example 2. Based on the examples and comparative examples, it can be seen that when |AB|≤20℃, 15≤A≤45℃, and 15≤B≤45℃, the melting rate of the protective slag is relatively uniform, the melting performance is qualified, the melting rate is moderate, there is no bubbling or low-melting-point material aggregation, no partial melting, and the liquid slag layer thickness meets the process standard range of 10-15mm.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for testing the melting performance of protective slag, characterized in that, The method includes: Obtain protective slag samples from the protective slag to be tested; The protective slag sample is placed in a melting point measuring instrument, and the melting point measuring instrument is used to heat the protective slag sample according to a first heating rate. When the temperature inside the melting point measuring instrument is greater than or equal to a first temperature threshold, the melting point measuring instrument is controlled to determine the softening temperature, hemispherical point temperature, and flow temperature of the protective slag sample. The melting performance of the protective slag is determined based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature; wherein the melting performance is at least characterized by the uniformity of the melting rate of the protective slag.

2. The method for testing the melting performance of protective slag according to claim 1, characterized in that, The melting properties of the protective slag are determined based on a first temperature difference A between the softening temperature and the hemispherical point temperature, and a second temperature difference B between the flow temperature and the hemispherical point temperature, including: If the first temperature difference A and the second temperature difference B satisfy the conditions: |AB|≤20℃, 15≤A≤45℃, and 15≤B≤45℃, then the melting performance of the protective slag is determined to have reached the preset qualified parameters.

3. The method for testing the melting performance of protective slag according to claim 1, characterized in that, The protective slag sample is placed in a melting point measuring instrument, and the instrument is used to heat the sample according to a first heating rate, including: When the temperature inside the melting point measuring instrument is greater than or equal to the second temperature threshold, the protective slag sample is placed in the melting point measuring instrument; wherein the second temperature threshold is less than the first temperature threshold.

4. The test method for the melting performance of the protective slag according to claim 3, characterized in that, Before placing the protective slag sample into the melting point measuring instrument when the temperature inside the instrument is greater than or equal to the second temperature threshold, the method further includes: The melting point measuring instrument is heated according to a second heating rate, wherein the second heating rate is greater than the first heating rate.

5. The method for testing the melting performance of the protective slag according to claim 4, characterized in that, The first temperature threshold is 800℃, and the second temperature threshold is 600℃.

6. The method for testing the melting performance of the protective slag according to claim 4, characterized in that, The first heating rate is 10℃ / min, and the second heating rate is 15℃ / min.

7. The method for testing the melting performance of protective slag according to claim 1, characterized in that, Obtaining a protective slag sample from the protective slag to be tested includes: The protective slag to be tested was sampled and ground to obtain sample powder; A cylindrical sample is prepared from the sample powder; wherein the diameter of the cylindrical sample is equal to the height of the cylindrical sample. The cylindrical sample was dried to obtain the protective slag sample.

8. The method for testing the melting performance of the protective slag according to claim 7, characterized in that, The particle size of the sample powder is less than or equal to 0.074 mm.

9. The method for testing the melting performance of the protective slag according to claim 7, characterized in that, The cylindrical sample has a diameter of 3 mm and a height of 3 mm.

10. The method for testing the melting performance of the protective slag according to claim 7, characterized in that, The process of drying the cylindrical sample to obtain the protective slag sample includes: The cylindrical sample is placed in a constant temperature furnace at a temperature of 60℃-80℃ for drying treatment to obtain the protective slag sample, wherein the drying time of the drying treatment is 8min-15min.

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