Method and system for measuring and calculating surface tension of metal melt

Abstract

The invention relates to the technical field of metal processing and manufacturing, and discloses a metal melt surface tension measuring and calculating method. According to the method, the length 2a, the height h and the bottom length 2l of the metal ball are calculated by recognizing the coordinates of the end points of the molten metal ball. Firstly, end point coordinates of a metal ball are obtained through an image recognition technology; then, relevant geometric parameters of the small balls are calculated; and then, calculating the surface tension of the metal melt according to a known physical model by utilizing the geometric parameters. Compared with a traditional surface tension measuring method, the method has the advantages that complex ellipse fitting is not needed, the contact angle does not need to be solved, and therefore the calculation process is simplified. In addition, the method provided by the invention has the advantages of higher identification precision, strong anti-interference capability and shorter calculation steps, and occupies less memory space after programming is realized. The method not only improves the measurement efficiency, but also reduces the requirement on hardware equipment.

Description

Technical Field

[0001] The 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 the fields of metal processing and manufacturing such as welding, casting, and additive manufacturing, surface tension is a very important parameter in material properties. Understanding the surface tension of molten metal materials is of great significance for engineering processing and production. Therefore, it is necessary to accurately measure the surface tension of molten metal. The traditional sessile drop method for measuring surface tension is to first obtain the contact angle and the minor semi-axis length of the ellipse through the ellipse fitting method, and then calculate 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 semi-axis length of the ellipse, and a slight disturbance will cause a large error. When the sessile drop method is actually used to test the surface tension of the molten metal, due to the presence of disturbance factors, the small ball formed is not a regular ellipse, which causes an error in the measured value of the minor semi-axis length of the ellipse, resulting in a sharp fluctuation in the measured value of the surface tension. 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 prior art are as follows:

[0004] The surface tension calculation method is sensitive to the contact angle and the length of the minor semi-axis of the ellipse. A slight disturbance will cause a large error. When the sessile drop method is used to test the surface tension of a molten metal, due to the presence of disturbance factors, the small ball formed is not a regular ellipse, which causes errors in the measured values ​​of the minor semi-axis length of the ellipse and the contact angle, resulting in drastic fluctuations in the measured values ​​of the surface tension. 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, and 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, placing the small cylinder after the oxide layer is removed in step 2 on a 20*20 mm alumina substrate, sending it into a heating furnace, passing argon gas, heating it to a specified temperature, and keeping it warm for 10-30 minutes, and using an image acquisition system to obtain image information of the sample shape during the heating and insulation process;

[0009] Step 3, using image processing software to identify the coordinates of each endpoint of the ball in the image obtained in step 2, and then calculating the length 2a, height h and bottom length 2l of the ball according to the coordinates of each endpoint;

[0010] Step 4: Consider the ball shape as a regular ellipse with a horizontal cut, and calculate the length b of the minor semi-axis of the ellipse according to 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, calculating 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 gravitational acceleration.

[0019] Furthermore, the metal plate in step 1 is steel material or 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 a bitmap in 8 / 16 / 24 / 32-bit bmp format, 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 and 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, send it into a heating furnace, pass argon gas, heat it to a specified temperature, keep it warm for 10-30 minutes, and use an image acquisition system to obtain image information of the sample shape during the heating and insulation 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 according to the coordinates of each endpoint; the shape of the ball is regarded as a regular ellipse that is cut horizontally, and the length b of the minor semi-axis of the ellipse is calculated according to the values ​​of 2a, h and 2l. The calculation formula is shown in formula (1);

[0031]

[0032] The shape factor β of the ellipse is calculated using the shape factor calculation formula 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 executes 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, wherein when the computer program is executed by a processor, the processor executes 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 metal, 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 needs to calculate the contact angle first before solving the surface tension, while 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, and the calculation result of the surface tension σ fluctuates greatly. In the method provided by the present invention, b is expressed by h, l, and a, and σ is less sensitive to h, l, and a. Therefore, the calculation result of the method provided by the present invention fluctuates little, has strong anti-interference ability, and has high calculation accuracy.

[0044] 4. The method provided by the present invention does not need to fit the elliptic curve, 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 on user computer configuration, which is conducive to increasing the number of potential users.

[0047] Third, the present invention proposes an improved measurement method to solve the technical problems existing in the existing metal melt surface tension measurement method in industrial applications. In the measurement process of the traditional sessile drop method, the non-ideal shape of the sample leads to errors in the measurement results. The present invention improves the accuracy and reliability of the measurement by pre-processing the sample and accurately calculating the shape parameters.

[0048] In industrial applications, the method of the present invention has shown significant technological progress. The present invention uses precise image processing technology to obtain the shape information of the sample at high temperature, and obtains a more accurate surface tension value by calculating the shape factor of the ellipse and the surface tension formula. These improvements significantly reduce the standard deviation of the measurement results and improve the stability and anti-interference ability of the data.

[0049] Specifically, when measuring the surface tension of EH36 steel at 1650°C, the method of the present invention obtained a result of 1776.14 mN / m with a standard deviation of 108.59, while the measurement result of the traditional ellipse fitting method was 1785.34 mN / m with a standard deviation of 155.86. By comparison, it can be seen that the method of the present invention reduces the standard deviation by nearly one third while keeping the measured values ​​close, indicating that the data fluctuation is smaller and the anti-interference ability is stronger.

[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 accurate 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 It is a flow chart of a method for measuring and calculating the surface tension of a metal melt provided in an embodiment of the present invention.

[0052] Figure 2 It is a structural block diagram of a metal melt surface tension measurement and calculation system provided in 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 ball 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 solution 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 used to limit the present invention.

[0057] Analysis of the technological progress of the 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 realize automated measurement and real-time data processing, which optimizes the calculation steps, shortens the experimental time and improves the operation efficiency.

[0062] 4. Scalability and industrialization value

[0063] The technical solution provides a modular design (sampling module, heating module, computing 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] The present invention improves the accuracy and efficiency of metal melt surface tension measurement. The 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, efficiency, etc., 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 fluidity, filling performance and surface quality of the final casting. However, in traditional processes, there is a lack of means to accurately measure the surface tension of the melt, resulting in process parameter control relying on experience, resulting in defects such as pores and inclusions.

[0072] The present invention measures the surface tension values ​​of aluminum alloy melt at different temperatures through a metal melt surface tension measurement system based on the sessile drop method. In the casting production line, a small piece of alloy sample is first extracted, and the surface tension is measured by the system to analyze its sensitivity to casting temperature and melting time.

[0073] By accurately measuring the surface tension value and combining simulation methods, the casting temperature range of aluminum alloy is optimized, the surface defects of castings are reduced, the production yield is improved, and the production cost is reduced. After using this system, the product scrap rate is reduced by about 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] In the welding process design stage, the surface tension measurement system of the present invention is used to analyze the variation law 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 it with 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 accurate 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 comprises the following steps:

[0080] S101, 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, and then use 400-1200 grit sandpaper to polish it to remove the oxide layer on the surface of the cylinder;

[0081] S102, using the traditional sessile drop method, the small cylinder after the oxide layer is removed in S102 is placed on a 20*20mm alumina substrate, sent into a heating furnace, argon gas is passed, the temperature is raised to the specified temperature, and the temperature is kept for 10-30 minutes, and the image acquisition system is used to obtain the image information of the sample shape during the heating and holding process;

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

[0083] S104, the ball shape is regarded as a regular ellipse with a horizontal cut, and the length b of the minor semi-axis of the ellipse is calculated according to 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 argon gas in the container, respectively;

[0088]

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

[0090] First, prepare to take samples from the metal sheet to be tested, and machine a cylindrical sample with a diameter of 3mm and a height of 5mm. In order to ensure the accuracy of the sample morphology during the measurement process, use 400-1200 mesh sandpaper to polish the sample to remove the surface oxide layer. After this treatment, the sample surface is brighter, which can avoid the error caused by the oxide layer, and ensure that the sample surface can present more accurate morphological characteristics when it is melted at high temperature later.

[0091] Next, the processed cylindrical sample is placed on a 20x20mm alumina substrate and sent into a heating furnace. The heating furnace is protected by an argon environment to prevent the sample from oxidizing, and the furnace temperature is gradually raised to the specified temperature. During the 20-30 minute insulation process, the sample gradually melts and forms a liquid ball on the alumina substrate. In order to obtain the morphological information of the liquid ball at different temperatures, the image acquisition system captures the sample images during the heating and insulation process in real time, providing a basis for subsequent data processing and analysis.

[0092] After the image acquisition is completed, the image is input into the image processing software to identify the endpoint coordinate data of the liquid ball. These endpoint coordinates are used to measure the length 2a, height h and bottom length 2l of the ball. By accurately capturing these key dimensional parameters, the necessary data support is provided for subsequent calculations. This step relies on image processing technology to ensure the accuracy of the data and avoid manual measurement errors through automated processing.

[0093] In order to accurately analyze the geometric shape of the liquid ball, the present invention regards the shape of the ball as an ellipse with a part cut off horizontally, and obtains the length b of the minor axis of the ellipse by calculating the length 2a, height h and bottom length 2l. The minor semi-axis is one of the key features of the ellipse shape, and its value is directly related to the geometric proportions of the ball and its surface characteristics during the heating process. The ellipse shape assumption provides a reasonable shape approximation, which helps to simplify the analysis process and improve measurement accuracy during calculation.

[0094] Next, the shape characteristics of the spheres are further quantified by calculating the elliptical shape factor. The shape factor is a dimensionless parameter that characterizes the roundness of the liquid metal spheres. The smaller the shape factor, the rounder the sphere. The present invention adopts a specific shape factor calculation formula to calculate the shape factor β based on the data obtained from the coordinates of each endpoint, thereby providing a reliable data support for further calculation of the 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 method of the present invention solves the accuracy problem existing in the traditional sessile drop method for measuring the surface tension of metal melts by introducing an accurate shape measurement and correction mechanism into the sessile drop method. By accurately calculating the shape factor, more reliable surface tension data is finally obtained, which can provide strong 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 a steel material, an aluminum alloy, or a 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 endpoint coordinates to be identified in S103 provided by the embodiment of the present invention 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 calculation formulas for the length 2a, height h and bottom length 2l of the ball in S103 provided in the embodiment of the present invention are 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 and 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, send it into a heating furnace, pass argon gas, heat it to a specified temperature, keep it warm for 10-30 minutes, and use an image acquisition system to obtain image information of the sample shape during the heating and insulation 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 that is cut horizontally, and the minor semi-axis length 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] The shape factor β of the ellipse is calculated using the shape factor calculation formula 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 executes 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, wherein when the computer program is executed by a processor, the processor executes 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 a mechanical method to process the sample into a small cylinder with a diameter of 3mm and a height of 5mm, and 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 the oxide layer is removed in step 2 is placed on a 20*20 mm alumina substrate, sent into a heating furnace, argon gas is passed, the temperature is raised to the specified temperature, and the temperature is kept for 10-30 minutes, and an image acquisition system is used to obtain image information of the sample shape during the heating and insulation 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 end point of the ball are shown, and then the length 2a, height h and bottom length 2l of the ball are calculated based on the coordinates of each end point;

[0122] Step 4: Calculate the length b of the minor axis of the ellipse according to the values ​​of the ball 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] Among them, the metal material to be tested is steel or 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 heating furnace's tolerance temperature. 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 equations (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. The following are the measurement steps.

[0133] Step 1: Use wire cutting to process a cylinder with a diameter of 3mm and a height of 20mm from a 200*50*20mm EH36 steel plate, and then cut the 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, and gently polish it with 400-grit sandpaper to remove the oxide layer on the surface of the small EH36 steel cylinder;

[0134] Step 2: Using the sessile drop method, the EH36 steel small cylinder after the oxide layer is removed is placed on a 20*20mm alumina substrate, sent into a heating furnace, and heated to 1650℃ at a rate of 2℃ per minute with argon gas. The temperature is kept at this temperature for 15 minutes, and an image acquisition system is used to collect 8-bit bmp images of the EH36 steel small cylinder melted into a small ball during the heating and insulation process. One image is collected 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, y4, the rightmost end of the ball is x5, 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 shape as a regular ellipse with a horizontal cut, and calculate the length b of the minor axis of the ellipse according to 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 affect the quality of welding and casting processes. The traditional ellipse fitting method is often used to measure the surface tension of high-temperature melts, but this method has certain limitations in terms of data fluctuation and anti-interference ability.

[0146] The present invention proposes an improved measurement method, and verifies its effectiveness by analyzing the surface tension of EH36 steel at 1650°C. According to the data in Table 1, the average value of the surface tension measured by the method of the present invention is 1776.14 mN / m, and the standard deviation is 108.59 mN / m; while the average value of the measurement result of the traditional ellipse fitting method is 1785.34 mN / m, and the standard deviation is 155.86 mN / m. Although the average values ​​of the two methods are similar, the standard deviation of the method of the present invention is significantly reduced, reduced by nearly 1 / 3, indicating that the data fluctuation is smaller and the anti-interference ability is stronger.

[0147] Figure 5 The measurement results of the two methods are further shown. It can be seen that the measurement value fluctuation of the method of the present invention is smaller and the data dispersion is lower, which verifies 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 measurement.

[0148] The measurement method provided by the present invention shows higher accuracy and stability in measuring the surface tension of EH36 steel under high temperature conditions. Compared with the traditional ellipse fitting method, the standard deviation is significantly reduced, the data fluctuation is reduced, and the anti-interference ability is enhanced. This provides a more reliable technical means 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℃ (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 part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, 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. Such code is provided on the carrier medium. The device and its 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, etc., 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, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0152] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope 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, and 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, placing the small cylinder after the oxide layer is removed in step 2 on a 20*20 mm alumina substrate, sending it into a heating furnace, passing argon gas, heating it to a specified temperature, and keeping it warm for 10-30 minutes, and using an image acquisition system to obtain image information of the sample shape during the heating and insulation process; Step 3, using image processing software to identify the coordinates of each endpoint of the ball in the image obtained in step 2, and then calculating the length 2a, height h and bottom length 2l of the ball according to the coordinates of each endpoint; Step 4: Consider the ball shape as a regular ellipse with a horizontal cut, and calculate the length b of the minor semi-axis of the ellipse according to 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, 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 argon gas in the container, respectively; 2. The method for measuring and calculating the surface tension of a molten metal according to claim 1, characterized in that: The metal plate in step 1 is steel material, aluminum alloy or titanium alloy.

3. The method for measuring and calculating the surface tension of a molten metal according to claim 1, characterized in that: 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, characterized in that: The image information collected in step 2 is a bitmap in 8 / 16 / 24 / 32 bit bmp format, 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, characterized in that: 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, characterized in that: 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 comprises: 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 and 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, send it into a heating furnace, pass argon gas, heat it to a specified temperature, keep it warm for 10-30 minutes, and use an image acquisition system to obtain image information of the sample shape during the heating and insulation 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 that is cut horizontally, and the minor semi-axis length b of the ellipse is calculated according to the values ​​of 2a, h and 2l. The calculation formula is shown in formula (1): The shape factor β of the ellipse is calculated using the shape factor calculation formula 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, wherein 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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