A method and system for measuring and calculating the surface tension of molten metal

Abstract

The present invention relates to the field of metal processing and manufacturing technology, and discloses a method for measuring and calculating the surface tension of a metal melt. The method calculates the length 2a, height h, and bottom length 2l of a metal ball by identifying the coordinates of the endpoints of a melted metal ball. First, the coordinates of the endpoints of the metal ball are obtained through image recognition technology; then, the relevant geometric parameters of the ball are calculated. Next, using these geometric parameters, the surface tension of the metal melt is calculated according to a known physical model. Compared with traditional surface tension measurement methods, the present invention does not require complex ellipse fitting or the solution of contact angles, thereby simplifying the calculation process. In addition, the method of the present invention has high recognition accuracy, strong anti-interference ability, short calculation steps, and takes up less memory space after programming implementation. This method not only improves measurement efficiency, but also reduces the requirements for hardware equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal processing and manufacturing, and in particular relates to a method and system for measuring and calculating the surface tension of a metal melt. Background Art

[0002] In metal processing and manufacturing fields such as welding, casting, and additive manufacturing, surface tension is a very important parameter among material properties. Understanding the surface tension of molten metal materials is of great significance for engineering processing and production. Therefore, accurately measuring the surface tension of molten metal is very necessary. The traditional sessile drop method for measuring surface tension first obtains the contact angle and the minor axis length of the ellipse through the ellipse fitting method, and then calculates the surface tension according to the Young-Laplace formula and the Bashforth-Adams equation. However, this surface tension calculation method is sensitive to the values of the contact angle and the minor axis length of the ellipse, and even slight disturbances can cause large errors. When the sessile drop method is actually used to test the surface tension of molten metal, due to the presence of disturbance factors, the small balls formed are not regular ellipses, which causes errors in the measured value of the minor axis length of the ellipse, resulting in drastic fluctuations in the surface tension measurement value. Therefore, reducing data fluctuations is the key to improving the accuracy of surface tension measurement.

[0003] Through the above analysis, the problems and defects of the existing technology are as follows:

[0004] Surface tension calculation methods are sensitive to the contact angle and the semi-minor axis length of the ellipse; even slight disturbances can result in significant errors. When measuring the surface tension of molten metal using the sessile drop method, the disturbance causes the resulting sphere to be irregularly elliptical. This introduces errors in the measured semi-minor axis length and contact angle, leading to dramatic fluctuations in the surface tension measurements. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a method for measuring and calculating the surface tension of a metal melt.

[0006] The present invention is achieved in that a method for measuring and calculating the surface tension of a metal melt comprises:

[0007] Step 1: Take a sample from the metal plate to be tested and use a mechanical method to process the sample into a small cylinder with a diameter of 3 mm and a height of 5 mm. Then use 400-1200 grit sandpaper to polish it to remove the oxide layer on the surface of the cylinder;

[0008] Step 2: Using the traditional sessile drop method, the small cylinder after removing the oxide layer in step 2 is placed on a 20*20 mm alumina substrate. The cylinder is placed in a heating furnace, purged with argon, and heated to a specified temperature. The temperature is maintained for 10-30 minutes, and an image acquisition system is used to obtain image information of the sample shape during the heating and holding process.

[0009] Step 3: Use image processing software to identify the coordinates of each endpoint of the ball in the image obtained in step 2, and then calculate the length 2a, height h, and bottom length 2l of the ball based on the coordinates of each endpoint;

[0010] Step 4: Consider the ball as a regular ellipse with a horizontal cut. Calculate the length b of the ellipse's minor axis based on the values of 2a, h, and 2l. The calculation formula is shown in formula (1):

[0011]

[0012] In the formula, b is the length of the short semi-axis of the ball, h is the height of the ball, l is half the length of the bottom of the ball, and a is the length of the long semi-axis of the ball. The schematic diagram of the four is as follows: Figure 3 shown.

[0013] Step 5, calculate the shape factor β of the ellipse. The shape factor calculation formula used in the present invention is shown in formula (2):

[0014]

[0015] Where β is the shape factor defined in the traditional sessile drop method;

[0016] Step 6: Calculate the surface tension σ of the metal melt according to the surface tension calculation formula (3) in the traditional sessile drop method.

[0017]

[0018] Where σ is the surface tension, ρm and ρg are the density of the metal melt and the density of argon in the container, respectively, and g is the acceleration due to gravity.

[0019] Furthermore, the metal plate in step 1 is made of steel, aluminum alloy or titanium alloy.

[0020] Furthermore, the specified temperature in step 2 must be higher than the melting point of the material itself and lower than the upper temperature limit allowed by the heating furnace equipment.

[0021] Furthermore, the image information collected in step 2 is an 8 / 16 / 24 / 32-bit bmp format bitmap, and each temperature point corresponds to at least 5 images.

[0022] Furthermore, the endpoint coordinates to be identified in step 3 include the horizontal coordinate x1 of the leftmost endpoint of the ball, the horizontal coordinate x2 of the rightmost endpoint of the ball, the vertical coordinate y3 of the topmost endpoint of the ball, the horizontal and vertical coordinates x4 and y4 of the bottom left endpoint of the ball, and the horizontal and vertical coordinates x5 and y5 of the bottom right endpoint of the ball.

[0023] Furthermore, the calculation formulas for the length 2a, height h and bottom length 2l of the ball in step 3 are shown in formulas (4) to (6):

[0024] 2a=x2-x1(4)

[0025]

[0026] 2l=x5-x4(6).

[0027] Another object of the present invention is to provide a metal melt surface tension measurement and calculation system comprising:

[0028] The sampling module is used to take samples from the metal sheet to be tested, and use mechanical methods to process the samples into small cylinders with a diameter of 3 mm and a height of 5 mm, and then use 400-1200 grit sandpaper to polish them to remove the oxide layer on the surface of the cylinder;

[0029] The heating module is used to place the small cylinder after removing the oxide layer on a 20*20mm alumina substrate using the traditional sessile drop method. The cylinder is then placed in a heating furnace, purged with argon gas, and heated to a specified temperature for 10-30 minutes. The image acquisition system is used to obtain image information of the sample shape during the heating and holding process.

[0030] The calculation module is used to use image processing software to identify the coordinates of each endpoint of the ball in the obtained image, and then calculate the length 2a, height h and bottom length 2l of the ball based on the coordinates of each endpoint; the shape of the ball is regarded as a regular ellipse with a horizontal cut, and the length of the minor axis b of the ellipse is calculated based on the values of 2a, h and 2l. The calculation formula is shown in formula (1);

[0031]

[0032] Calculate the shape factor β of the ellipse. The shape factor calculation formula used is shown in formula (2):

[0033]

[0034] The surface tension σ of the metal melt is calculated according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively;

[0035]

[0036] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the calculation steps of the metal melt surface tension measurement method.

[0037] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the steps of the metal melt surface tension measurement and calculation method.

[0038] Another object of the present invention is to provide an information data processing terminal, which is used to implement the metal melt surface tension measurement and calculation system.

[0039] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0040] First, the present invention aims to provide a new method for measuring and calculating the surface tension of molten metals, reduce data fluctuations, improve the measurement accuracy of the surface tension of metal materials, and provide strong data support for simulation models.

[0041] 1. Traditional ellipse fitting method requires identification Figure 3 The elliptical gas-liquid interface of the entire ball is then fitted into an ellipse for solution. The method provided by the present invention only needs to measure the length, height and bottom length of the ball, and the recognition accuracy is higher.

[0042] 2. The traditional ellipse fitting method requires calculating the contact angle before solving the surface tension. However, the improved method of the present invention does not need to solve the contact angle, and the calculation steps are shorter.

[0043] 3. The traditional ellipse fitting method is highly sensitive to the data b, resulting in large fluctuations in the surface tension σ calculation results. However, in the method provided by the present invention, b is expressed in terms of h, l, and a, and σ is less sensitive to h, l, and a. Therefore, the method provided by the present invention has small fluctuations in the calculation results, strong anti-interference ability, and high calculation accuracy.

[0044] 4. The method provided by the present invention does not require fitting of elliptic curves, and requires less computing resources after programming.

[0045] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0046] Compared with the traditional ellipse fitting method, the method provided by the present invention only needs to identify a few endpoint coordinates and does not need to fit the entire gas-liquid interface curve. After programming, data storage occupies less memory and has lower requirements for user computer configuration, which is conducive to increasing the number of potential users.

[0047] Third, this invention addresses technical issues with existing methods for measuring the surface tension of molten metals in industrial applications by proposing an improved measurement method. In traditional sessile drop measurement, non-ideal sample shape can lead to errors in the measurement results. This invention improves measurement accuracy and reliability through sample pretreatment and precise calculation of shape parameters.

[0048] In industrial applications, the method of this invention demonstrates significant technological advancement. It uses precise image processing techniques to obtain information about the sample's shape at high temperatures. By calculating the ellipse's shape factor and the surface tension formula, it yields more accurate surface tension values. These improvements significantly reduce the standard deviation of the measurement results, improving data stability and anti-interference capabilities.

[0049] Specifically, the method of the present invention measured the surface tension of EH36 steel at 1650°C, yielding a result of 1776.14 mN / m with a standard deviation of 108.59. This compares to 1785.34 mN / m with a standard deviation of 155.86 using the traditional ellipse fitting method. This comparison shows that the method of the present invention reduces the standard deviation by nearly one-third while maintaining similar measured values, demonstrating reduced data fluctuation and greater resistance to interference.

[0050] In summary, the metal melt surface tension measurement and calculation method provided by the present invention overcomes the shortcomings of traditional methods in industrial applications through precise shape parameter calculation, significantly improves the accuracy and reliability of measurement, and provides more reliable data support for the research and application of metal materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for measuring and calculating the surface tension of a metal melt provided by an embodiment of the present invention.

[0052] Figure 2 This is a structural block diagram of a metal melt surface tension measurement and calculation system provided by an embodiment of the present invention.

[0053] Figure 3 It is a schematic diagram of the shape of the metal melt ball in the sessile drop method provided in an embodiment of the present invention.

[0054] Figure 4 This is a diagram of the shape of the small balls during the sessile drop method for testing the surface tension of EH36 steel provided in an embodiment of the present invention.

[0055] Figure 5 Schematic diagram of surface tension measurement results of EH36 steel at 1650℃. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0057] Analysis of the technological progress of this invention in industrial applications.

[0058] 1. Improvement of measurement accuracy

[0059] The geometric parameters of the ball (such as length, bottom length and height) are automatically extracted through image processing technology, and combined with the calculation formula of the shape factor β, the accuracy of the traditional formula is optimized and human operation errors are reduced.

[0060] 2. Improved experimental efficiency

[0061] The image acquisition system is used to achieve automated measurement and real-time data processing, which optimizes the calculation steps, shortens the experimental time and improves operational efficiency.

[0062] 4. Scalability and industrial value

[0063] The technical solution provides a modular design (sampling module, heating module, calculation module), which is easy to integrate into industrial production lines to achieve continuous and large-scale measurement.

[0064] Its automation and precision characteristics make it widely used in fields such as material science research and industrial casting process optimization.

[0065] This invention improves the accuracy and efficiency of surface tension measurement of molten metals. Its technical solution has high reliability and wide material applicability, and can be widely used in the following fields:

[0066] 1. Metal processing and casting: Optimize casting and welding processes to improve product quality.

[0067] 2. New material research and development: Support the design of high-performance alloy formulas and improve the efficiency of new material development.

[0068] 3. Scientific research: Provide accurate data support for material rheology and metal physics research.

[0069] The present invention has achieved technological progress in terms of measurement accuracy and efficiency, and has good market competitiveness and industrialization potential.

[0070] Example 1: Application in high temperature casting process

[0071] In high-temperature casting, the surface tension of the melt directly affects the metal's fluidity, filling properties, and the surface quality of the final casting. However, traditional processes lack the means to accurately measure the melt's surface tension, resulting in a reliance on empirical experience to control process parameters, leading to defects such as porosity and inclusions.

[0072] This paper uses a sessile drop method-based surface tension measurement system to measure the surface tension of aluminum alloy melts at different temperatures. A small alloy sample is extracted from the casting line, and the system measures the surface tension to analyze its sensitivity to casting temperature and melting time.

[0073] By accurately measuring surface tension and combining it with simulation, the system optimized the casting temperature range for aluminum alloys, reducing surface defects in castings, improving production yields, and lowering production costs. Using this system has reduced product scrap rates by approximately 15%.

[0074] Example 2: Application in aviation titanium alloy welding

[0075] Aviation manufacturing has extremely high quality requirements for titanium alloy welded parts. The weld formation is significantly affected by the surface tension of the melt. Currently, titanium alloy welding has problems such as cracks and pores.

[0076] During the welding process design phase, the surface tension measurement system of the present invention is used to analyze the variation of the surface tension of the titanium alloy melt at different temperatures.

[0077] By accurately understanding the surface tension characteristics of titanium alloy melt and combining simulation methods, the welding process parameters (such as welding speed and inclination angle) were optimized, and problems such as cracks and pores were solved.

[0078] The two embodiments demonstrate the wide application of the present invention in metal processing. Through precise surface tension measurement, it helps to optimize the process and has significant technical value and economic benefits in high-end manufacturing fields such as casting and welding.

[0079] like Figure 1 As shown, a method for measuring and calculating the surface tension of a metal melt provided by an embodiment of the present invention includes the following steps:

[0080] S101: Take a sample from the metal plate to be tested and use mechanical methods to process the sample into a small cylinder with a diameter of 3 mm and a height of 5 mm. Then use 400-1200 grit sandpaper to polish it to remove the oxide layer on the surface of the cylinder;

[0081] In S102, the traditional sessile drop method was used to place the small cylinder after removing the oxide layer in S102 on a 20*20 mm alumina substrate. The cylinder was placed in a heating furnace, purged with argon gas, and heated to a specified temperature. The temperature was kept at this temperature for 10-30 minutes, and an image acquisition system was used to obtain image information of the sample shape during the heating and holding process.

[0082] S103, using image processing software to identify the coordinates of each endpoint of the ball in the image obtained in S102, and then calculating the length 2a, height h and bottom length 2l of the ball based on the coordinates of each endpoint;

[0083] S104: Consider the ball as a regular ellipse with a horizontal cut. Calculate the length b of the ellipse's minor axis based on the values of 2a, h, and 2l. The calculation formula is shown in formula (1):

[0084]

[0085] S105, calculating the shape factor β of the ellipse. The shape factor calculation formula used in the present invention is shown in formula (2):

[0086]

[0087] S106, calculating the surface tension σ of the metal melt according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of the argon gas in the container, respectively;

[0088]

[0089] The present invention provides a method for measuring and calculating the surface tension of molten metals. Its basic principle is to accurately determine the surface tension of a molten metal by observing and analyzing the morphology of a metal sample heated to a liquid state, combined with a calculation formula. Compared to the traditional sessile drop method, this method improves the accuracy and reliability of measurement by improving shape measurement and calculation methods, providing a more scientific approach for studying the physical properties of molten metals.

[0090] First, prepare a sample from the metal sheet to be tested and machine a cylindrical sample with a diameter of 3mm and a height of 5mm. To ensure the accuracy of the sample's morphology during measurement, polish the sample with 400-1200 grit sandpaper to remove the surface oxide layer. This treatment creates a brighter surface, avoids errors caused by the oxide layer, and ensures that the sample surface will present more accurate morphological characteristics during subsequent high-temperature melting.

[0091] Next, the processed cylindrical sample is placed on a 20x20mm alumina substrate and placed in a heating furnace. An argon atmosphere protects the furnace to prevent oxidation, and the furnace temperature is gradually raised to the specified temperature. During the 20-30 minute holding period, the sample gradually melts and forms a liquid sphere on the alumina substrate. To obtain morphological information of the liquid sphere at different temperatures, an image acquisition system captures real-time images of the sample during the heating and holding processes, providing a foundation for subsequent data processing and analysis.

[0092] After image acquisition, the images are input into image processing software to identify the endpoint coordinates of the liquid sphere. These endpoint coordinates are used to measure the sphere's length 2a, height h, and bottom length 2l. Accurately capturing these critical dimensional parameters provides the necessary data for subsequent calculations. This step relies on image processing technology to ensure data accuracy and eliminate manual measurement errors through automated processing.

[0093] To accurately analyze the geometric shape of the liquid sphere, the present invention considers the sphere as an ellipse with a horizontally cutout portion. By calculating the length 2a, height h, and base length 2l, the length of the ellipse's semi-minor axis, b, is derived. The semi-minor axis is a key characteristic of the ellipse, and its value is directly related to the sphere's geometric proportions and its surface properties during heating. This elliptical shape assumption provides a reasonable shape approximation, helping to simplify the analysis process and improve measurement accuracy.

[0094] Next, the sphere shape characteristics are further quantified by calculating the elliptical shape factor. The shape factor is a dimensionless parameter that characterizes the roundness of the liquid metal sphere; the smaller the shape factor, the rounder the sphere. This invention uses a specific shape factor calculation formula to calculate the shape factor β based on the data obtained from the coordinates of each endpoint, providing reliable data support for further calculations of surface tension.

[0095] After obtaining the shape factor, the surface tension σ of the metal melt is calculated using the improved sessile drop method surface tension calculation formula, combined with the shape factor β, sample density ρm and argon density ρg.

[0096] In summary, the present method addresses the accuracy issues associated with traditional sessile drop method surface tension measurements of molten metals by incorporating precise shape measurement and correction mechanisms into the sessile drop method. By accurately calculating the shape factor, more reliable surface tension data is ultimately obtained, providing robust data support for the research and development and performance analysis of metal materials in practical applications.

[0097] In the embodiment of the present invention, the metal plate in S101 is made of steel, aluminum alloy or titanium alloy.

[0098] The embodiment of the present invention provides that the specified temperature in S102 must be higher than the melting point of the material itself and lower than the upper temperature limit allowed by the heating furnace equipment.

[0099] The embodiment of the present invention provides that the image information collected in S102 is a bitmap in 8 / 16 / 24 / 32-bit bmp format, and each temperature point corresponds to at least 5 images.

[0100] The embodiment of the present invention provides that the endpoint coordinates to be identified in S103 include the horizontal coordinate x1 of the leftmost endpoint of the ball, the horizontal coordinate x2 of the rightmost endpoint of the ball, the vertical coordinate y3 of the topmost endpoint of the ball, the horizontal and vertical coordinates x4 and y4 of the bottom left endpoint of the ball, and the horizontal and vertical coordinates x5 and y5 of the bottom right endpoint of the ball.

[0101] The embodiment of the present invention provides calculation formulas for the length 2a, height h and bottom length 2l of the ball in S103 as shown in formulas (4) to (6);

[0102] 2a=x2-x1(4)

[0103]

[0104] 2l=x5-x4(6).

[0105] like Figure 2 As shown, an embodiment of the present invention provides a metal melt surface tension measurement and calculation system comprising:

[0106] The sampling module is used to take samples from the metal sheet to be tested, and use mechanical methods to process the samples into small cylinders with a diameter of 3 mm and a height of 5 mm, and then use 400-1200 grit sandpaper to polish them to remove the oxide layer on the surface of the cylinder;

[0107] The heating module is used to place the small cylinder after removing the oxide layer on a 20*20mm alumina substrate using the traditional sessile drop method. The cylinder is then placed in a heating furnace, purged with argon gas, and heated to a specified temperature for 10-30 minutes. The image acquisition system is used to obtain image information of the sample shape during the heating and holding process.

[0108] The calculation module is used to use image processing software to identify the coordinates of each endpoint of the ball in the obtained image, and then calculate the length 2a, height h and bottom length 2l of the ball according to the coordinates of each endpoint; the shape of the ball is regarded as a regular ellipse with a horizontal cut, and the length of the minor axis b of the ellipse is calculated according to the values of 2a, h and 2l. The calculation formula is shown in formula (1):

[0109]

[0110] Calculate the shape factor β of the ellipse. The shape factor calculation formula used is shown in formula (2):

[0111]

[0112] The surface tension σ of the metal melt is calculated according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively;

[0113]

[0114] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the calculation steps of the metal melt surface tension measurement method.

[0115] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the steps of the metal melt surface tension measurement and calculation method.

[0116] Another object of the present invention is to provide an information data processing terminal, which is used to implement the metal melt surface tension measurement and calculation system.

[0117] The present invention is specifically implemented:

[0118] The present invention provides a novel method for measuring and calculating the surface tension of a metal melt, which is performed according to the following steps:

[0119] Step 1: Take a sample from the metal plate to be tested and use mechanical methods to process the sample into a small cylinder with a diameter of 3mm and a height of 5mm. Then use 400-1200 grit sandpaper to polish it to remove the oxide layer on the surface of the cylinder.

[0120] Step 2: Using the traditional sessile drop method, the small cylinder after removing the oxide layer in step 2 is placed on a 20*20 mm alumina substrate. The cylinder is placed in a heating furnace, purged with argon gas, and heated to a specified temperature. The temperature is maintained for 10-30 minutes, and an image acquisition system is used to obtain image information of the sample shape during the heating and holding process.

[0121] Step 3: Use image processing software to identify the image obtained in step 2 as shown in the attached image. Figure 3 The coordinates of each endpoint of the ball are then calculated based on the coordinates of each endpoint to obtain the length 2a, height h and bottom length 2l of the ball;

[0122] Step 4: Calculate the length b of the ellipse's minor axis based on the ball's length 2a, height h, and bottom length 2l. The calculation formula is shown in formula (1):

[0123]

[0124] Step 5: Calculate the shape factor β of the ellipse. The shape factor calculation formula used in the present invention is shown in formula (2):

[0125]

[0126] Step 6: Calculate the surface tension σ of the metal melt according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively;

[0127]

[0128] The metal material to be tested is steel, aluminum alloy or titanium alloy. The lowest heating temperature in the heating furnace is higher than the melting point of the metal material, and the highest heating temperature is lower than the upper limit of the tolerable temperature of the heating furnace. The image information collected during the sample heating and insulation process is an 8 / 16 / 24 / 32-bit bmp format image, and there are at least 5 images corresponding to each temperature point. The endpoint coordinates to be identified in the image include the horizontal coordinate x1 of the leftmost endpoint of the ball, the horizontal coordinate x2 of the rightmost endpoint of the ball, the vertical coordinate y3 of the top endpoint of the ball, the horizontal and vertical coordinates x4 and y4 of the left end of the bottom of the ball, and the horizontal and vertical coordinates x5 and y5 of the right end of the bottom of the ball. The calculation formulas for the length 2a, height h and bottom length 2l of the ball are shown in formulas (4)-(6):

[0129] 2a=x2-x1(4)

[0130]

[0131] 2l=x5-x4(6)

[0132] The surface tension of EH36 steel at 1650°C was measured using the following measurement steps.

[0133] Step 1: Use wire cutting to machine a cylinder with a diameter of 3mm and a height of 20mm from a 200*50*20mm EH36 steel plate. Then cut this cylinder into four small EH36 steel cylinders with a diameter of 3mm and a height of 5mm along the cross section. Then, select the one with the smoothest surface from the four small EH36 steel cylinders with a diameter of 3mm and a height of 5mm. Use 400-grit sandpaper to gently polish it to remove the oxide layer on the surface of the EH36 steel cylinder.

[0134] Step 2: Using the sessile drop method, a small EH36 steel cylinder with the oxide layer removed was placed on a 20*20mm alumina substrate. The cylinder was then placed in a heating furnace, purged with argon, and heated to 1650°C at a rate of 2°C per minute. The temperature was then kept at this temperature for 15 minutes. An image acquisition system was then used to capture 8-bit bmp images of the EH36 steel cylinder during the heating and holding process after it was melted into a small ball. One image was captured every 6 seconds. Figure 4 This is one of the pictures collected during this process;

[0135] Step 3: Use image processing software ImageJ to identify the image obtained in step 2 as shown in the attached image. Figure 3 The leftmost end of the ball is x1, the rightmost end is x2, the top end is y3, the leftmost end of the ball is x4 and y4, the rightmost end of the ball is x5 and y5, and then the length 2a, height h and bottom length 2l of the ball are calculated according to formulas (4)-(6);

[0136] 2a=x2-x1(4)

[0137]

[0138] 2l=x5-x4(6)

[0139] Step 4: Consider the ball as a regular ellipse with a horizontal cut. Calculate the length b of the ellipse's minor axis based on the values of 2a, h, and 2l. The calculation formula is shown in formula (1):

[0140]

[0141] Step 5: Calculate the shape factor β of the ellipse. The shape factor calculation formula used in the present invention is shown in formula (2):

[0142]

[0143] Step 6: Calculate the surface tension σ of the metal melt according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively;

[0144]

[0145] Accurately measuring the surface tension of metal materials under high-temperature conditions is crucial for materials science and engineering applications. EH36 steel is a high-strength, low-alloy steel commonly used in shipbuilding. Its surface tension characteristics at high temperatures directly impact the quality of welding and casting processes. Traditional ellipse fitting methods are commonly used to measure the surface tension of high-temperature melts, but this method has limitations in terms of data fluctuation and interference resistance.

[0146] This paper proposes an improved measurement method, the effectiveness of which was verified by analyzing the surface tension of EH36 steel at 1650°C. According to the data in Table 1, the average surface tension measured using the inventive method is 1776.14 mN / m, with a standard deviation of 108.59 mN / m. In contrast, the traditional ellipse fitting method yields an average of 1785.34 mN / m, with a standard deviation of 155.86 mN / m. While the average values of the two methods are similar, the standard deviation of the inventive method is significantly lower, by nearly one-third, indicating less data fluctuation and greater resistance to interference.

[0147] Figure 5 The measurement results of the two methods are further presented. It can be seen that the measurement values using the method of the present invention have less fluctuation and less data dispersion, verifying its stability and reliability in measuring surface tension under high-temperature conditions. This improvement is of great significance for improving the accuracy of high-temperature melt surface tension measurements.

[0148] The measurement method provided by this invention demonstrates higher accuracy and stability in measuring the surface tension of EH36 steel under high-temperature conditions. Compared with the traditional ellipse fitting method, it significantly reduces standard deviation, minimizes data fluctuation, and enhances interference resistance. This provides a more reliable technical approach for measuring the surface tension of high-temperature metal materials and has broad application prospects.

[0149] Table 1 Surface tension measurement results of EH36 steel at 1650°C (unit: mN / m)

[0150] Measurement 1 Measurement 2 Measurement 3 Measurement 4 Measurement value 5 average value Standard deviation Ellipse fitting 1679.73 1776.65 1738.65 2053.98 1677.67 1785.34 155.86 The present invention 1710.89 1851.50 1851.50 1851.50 1615.29 1776.14 108.59

[0151] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. Those skilled in the art will appreciate that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, or can be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0152] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for measuring and calculating the surface tension of a metal melt, characterized in that: The following steps are involved: Step 1: Take a sample from the metal plate to be tested and use a mechanical method to process the sample into a small cylinder with a diameter of 3 mm and a height of 5 mm. Then use 400-1200 grit sandpaper to polish it to remove the oxide layer on the surface of the cylinder; Step 2: Using the traditional sessile drop method, the small cylinder after removing the oxide layer in step 2 is placed on a 20*20 mm alumina substrate. The cylinder is placed in a heating furnace, purged with argon, and heated to a specified temperature. The temperature is maintained for 10-30 minutes, and an image acquisition system is used to obtain image information of the sample shape during the heating and holding process. Step 3: Use image processing software to identify the coordinates of each endpoint of the ball in the image obtained in step 2, and then calculate the length 2a, height h, and bottom length 2l of the ball based on the coordinates of each endpoint; Step 4: Consider the ball as a regular ellipse with a horizontal cut. Calculate the length b of the ellipse's minor axis based on the values of 2a, h, and 2l. The calculation formula is shown in formula (1): Step 5, calculate the shape factor β of the ellipse. The shape factor calculation formula used in the present invention is shown in formula (2): Step 6, calculate the surface tension σ of the metal melt according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively; 2. The method for measuring and calculating the surface tension of a molten metal according to claim 1, wherein: The metal plate in step 1 is made of steel, aluminum alloy or titanium alloy.

3. The method for measuring and calculating the surface tension of a molten metal according to claim 1, wherein: The specified temperature in step 2 must be higher than the melting point of the material itself and lower than the upper temperature limit allowed by the heating furnace equipment.

4. The method for measuring and calculating the surface tension of a molten metal according to claim 1, wherein: The image information collected in step 2 is an 8 / 16 / 24 / 32-bit bmp format bitmap, and each temperature point corresponds to at least 5 images.

5. The method for measuring and calculating the surface tension of a molten metal according to claim 1, wherein: The endpoint coordinates to be identified in step 3 include the horizontal coordinate x1 of the leftmost endpoint of the ball, the horizontal coordinate x2 of the rightmost endpoint of the ball, the vertical coordinate y3 of the topmost endpoint of the ball, the horizontal and vertical coordinates x4 and y4 of the bottom left endpoint of the ball, and the horizontal and vertical coordinates x5 and y5 of the bottom right endpoint of the ball.

6. The method for measuring and calculating the surface tension of a molten metal according to claim 1, wherein: The calculation formulas for the length 2a, height h and bottom length 2l of the ball in step 3 are shown in formulas (4) to (6): 2a=x2-x1(4) 2l=x5-x4(6).

7. A metal melt surface tension measurement and calculation system for implementing the metal melt surface tension measurement method according to any one of claims 1 to 6, characterized in that: The metal melt surface tension measurement and calculation system includes: The sampling module is used to take samples from the metal sheet to be tested, and use mechanical methods to process the samples into small cylinders with a diameter of 3 mm and a height of 5 mm, and then use 400-1200 grit sandpaper to polish them to remove the oxide layer on the surface of the cylinder; The heating module is used to place the small cylinder after removing the oxide layer on a 20*20mm alumina substrate using the traditional sessile drop method. The cylinder is then placed in a heating furnace, purged with argon gas, and heated to a specified temperature for 10-30 minutes. The image acquisition system is used to obtain image information of the sample shape during the heating and holding process. The calculation module is used to use image processing software to identify the coordinates of each endpoint of the ball in the obtained image, and then calculate the length 2a, height h and bottom length 2l of the ball according to the coordinates of each endpoint; the shape of the ball is regarded as a regular ellipse with a horizontal cut, and the length of the minor axis b of the ellipse is calculated according to the values of 2a, h and 2l. The calculation formula is shown in formula (1): Calculate the shape factor β of the ellipse. The shape factor calculation formula used is shown in formula (2): The surface tension σ of the metal melt is calculated according to the surface tension calculation formula (3) in the traditional sessile drop method, where ρm and ρg are the density of the metal melt and the density of argon gas in the container, respectively; 8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the metal melt surface tension measurement and calculation method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the method for measuring and calculating the surface tension of a metal melt according to any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the metal melt surface tension measurement and calculation system as described in claim 7.

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