Apparatus for calculating temperature difference in billet heat treatment process and method of use

Abstract

The application relates to a device for calculating the temperature difference in the steel billet heat treatment process, which comprises a curve plate, a horizontal slide mark and a vertical slide mark; the front surface of the curve plate is engraved with a beta curve and a C curve, the horizontal coordinate is Bi, the left vertical coordinate is beta, and the right vertical coordinate is C; the back surface of the curve plate is engraved with a curve and a cosbeta curve, the bottom horizontal coordinate is beta 2 The top horizontal coordinate is beta, the left vertical coordinate is the function value of an exponential function and a trigonometric function cosbeta; the horizontal slide mark is perpendicular to the horizontal coordinate and penetrates through the front and back surfaces of the curve plate and slides along the horizontal coordinate direction; the vertical slide mark is perpendicular to the vertical coordinate and penetrates through the front and back surfaces of the curve plate and slides along the vertical coordinate direction; the horizontal slide mark is not connected with the vertical slide mark and is independently arranged. The device mainly comprises the front and back surfaces of the curve plate, four coordinate curves are engraved on the two surfaces, the vertical coordinate value of each curve is obtained by using only one independent variable, the chart searching is simple, fast, convenient, the chart searching result is high in precision, and the internal maximum temperature difference in the steel billet heat treatment process can be quickly and accurately calculated.

Description

Technical Field

[0001] This invention belongs to the field of heat transfer calculation, and specifically relates to a device and method for calculating the temperature difference during the heat treatment process of steel billets. Background Technology

[0002] The heat treatment of steel billets in a heating furnace is a crucial process in the hot rolling of steel. The heating rate of the billets significantly impacts production indicators such as the quality, yield, and energy consumption of hot-rolled steel. The maximum internal temperature difference of the billet during heat treatment is a key factor determining the heating rate. The maximum temperature difference between the surface and center of the billet is the maximum temperature difference; therefore, calculating the surface and center temperatures of the billet is of great importance.

[0003] Heat-treated steel billets are generally square or rectangular billets, or thin steel strips (plates). When heated in a furnace by flue gas, the changes in surface and core temperatures of the billets over time can be calculated using formulas related to unsteady-state heat conduction of flat plates in heat transfer theory. However, these formulas are complex and cumbersome to calculate, making them inconvenient for engineering applications. Therefore, they are not widely used in actual steel billet heat treatment.

[0004] According to heat transfer theory, the surface temperature versus the center temperature of a steel billet can be calculated using a set of graphs called the Heisler graphs. There are two Heisler graphs in total. Figure 1 and Figure 2 These are the two figures. The Hessler diagram is the closest existing technology to this invention. A brief introduction to the principle of temperature calculation using the Hessler diagram is given below.

[0005] Taking the calculation of the heat treatment temperature of thin steel plate as an example, this problem can be described as follows: The thin steel plate has a uniform initial temperature θ0, and is suddenly heated by high-temperature flue gas in a heating furnace with a heating intensity of Bi. The temperature calculation problem is: at any moment Fo after heating, what is the surface temperature θ of the thin steel plate? s and center temperature θ m How much of each?

[0006] According to heat transfer theory, the above problem can be solved using the following equations.

[0007] The temperature equation for the billet heating process is:

[0008]

[0009] In the formula, θ0 is the initial temperature of the billet, and Fo is the heat treatment time of the billet, both of which are known quantities; C and β are calculation parameters, which can be obtained by calculating them with the known heating intensity Bi of the billet; η is the position inside the billet, η = 1 at the surface of the billet and η = 0 at the center of the billet. Therefore, the surface temperature θ of the billet is...s and center temperature θ m The formula for calculation is:

[0010] Surface temperature:

[0011] Core temperature:

[0012] However, the relationship between β and Bi is a transcendental equation, and β cannot be solved by simple calculation. The relationship between C and Bi is a complex functional relationship, and the calculation is very cumbersome. Moreover, equations (A) and (B) also contain exponential and trigonometric functions, making the calculations relatively complicated. Therefore, to facilitate temperature calculation, heat transfer uses a set of curves (i.e., Heisler diagrams) as a simplified solution method, which is briefly described below.

[0013] Through mathematical analysis, the center temperature θ m The ratio θ to the initial temperature m / θ0 depends only on Bi and Fo, therefore θ can be plotted on a coordinate graph with Bi and Fo as independent variables. m The relationship between / θ0 and them, such as Figure 1 As shown.

[0014] Figure 1 In the diagram, the horizontal axis is Fo, and the value corresponding to each curve is λ / (hδ) = 1 / Bi. Therefore, from Fo and Bi, through... Figure 1 θ can be found m / θ0, thus the center temperature θ of the steel plate can be obtained. m .

[0015] Mathematical analysis shows that the ratio of the temperature at any point on the steel plate to the temperature at the center point, θ / θ m It only depends on Bi and η, therefore θ / θ can be plotted on a coordinate graph with Bi and η as independent variables. m Their relationship, such as Figure 2 As shown.

[0016] Figure 2 In the diagram, the horizontal axis is λ / (hδ) = 1 / Bi, and the value x / δ corresponding to each curve is η. For the steel plate surface, η = 1. Therefore, the curves with Bi and η = 1, through... Figure 2 θ can be found s / θ m Then multiply by Figure 1 The θ found m The surface temperature θ of the steel plate can then be calculated. s .

[0017] Using the Heisler chart to calculate the temperature of steel plates has the following disadvantages: 1. Figure 1 There are more than 40 curves, and Figure 1In some areas, curves are densely packed, making it very inconvenient to find the desired curve. 2. Figure 1 Two independent variables are needed to obtain the result, and the process of looking up the graph is cumbersome. 3. Figure 1 and Figure 2 Some parts of the curve have a very steep slope, and the independent variable varies greatly between adjacent curves; these factors can lead to significant errors in graph lookup. 4. Figure 1 Near Fo=1, the curves are very dense, making it impossible to distinguish them with the naked eye, thus rendering the chart lookup method unusable. 5. The mathematical principles involved in chart lookup calculations are quite complex; the calculation of the steel plate surface temperature must be based on the calculation of the core temperature and cannot be calculated independently. Summary of the Invention

[0018] To address the aforementioned problems and overcome the cumbersome calculation process for the surface and core temperatures of steel plates in existing technologies, this invention proposes a method for rapidly calculating the surface and core temperatures of steel plates using a graph plate with engraved coordinate curves.

[0019] To achieve the above objectives, the technical solution of the present invention is as follows:

[0020] A device for calculating the temperature difference during the heat treatment of steel billets includes a curve plate, a horizontal slider, and a vertical slider. The front of the curve plate is engraved with a β curve and a C curve, with the horizontal axis representing Bi, the left vertical axis representing β, and the right vertical axis representing C. The β curve is used to find the β value corresponding to the horizontal axis Bi based on the left vertical axis β, and the C curve is used to find the C value corresponding to the horizontal axis Bi based on the right vertical axis C. The back of the curve plate is engraved with... The curve and the cosβ curve, with the bottom x-axis being β. 2 Fo, with β as the top x-axis and the exponential function as the left y-axis. And the function value of the trigonometric function cosβ, The function of the curve is to find the relationship between the vertical coordinate and the horizontal coordinate β based on the function value on the left. 2 The corresponding Fo value The function value; the function of the cosβ curve is to find the cosβ function value corresponding to the β value on the x-axis based on the y-axis of the function value on the left; the horizontal slider is perpendicular to the x-axis, runs through the entire front and back of the curve board, and slides along the direction of the x-axis; the vertical slider is perpendicular to the y-axis, runs through the entire front and back of the curve board, and slides along the direction of the y-axis; there is no connection between the horizontal slider and the vertical slider, and they are set independently of each other.

[0021] Preferably, the horizontal axis Bi ranges from 0.1 to 100, and the scale is logarithmic; the left vertical axis β ranges from 0.3 to 1.6, with the values ​​increasing from bottom to top; and the right vertical axis C ranges from 1 to 1.3, with the values ​​decreasing from bottom to top. This design of different directions of change for the left and right vertical axes allows the β curve and the C curve to be separated, preventing the two curves from partially overlapping.

[0022] Preferably, the horizontal coordinate β 2 The numerical range of Fo is 0–4; the numerical range of the abscissa β is 0–1.6; exponential function The ordinate of the function value of the trigonometric function cosβ varies from 0 to 1, so they can share the same ordinate.

[0023] Preferably, the horizontal coordinate β 2 Fo uses a variable scale to clearly represent [the information] within the graphic space. The curve's numerical range is such that the scale division between 0 and 1 is 5 times that between 1 and 4.

[0024] Preferably, the horizontal and vertical sliders are slidably connected to the curve plate via a tenon and mortise structure.

[0025] Preferably, the horizontal and vertical sliders are made of transparent material, with marking lines engraved in the middle and colored, used to locate the position of the curve plate. The thickness of the horizontal and vertical sliders should be as thin as possible while ensuring strength, so that the horizontal slider has good visibility and the marking lines can be as close as possible to the curve plate, thereby improving the accuracy of locating the curve plate using the marking lines.

[0026] Preferably, horizontal slider grooves are provided on the upper and lower sides of the curved plate, and horizontal slider tenons are respectively provided inside the upper and lower ends of the horizontal slider, which are interference fit with the horizontal slider grooves. This allows the horizontal slider to form a tenon-and-mortise connection with the curved plate, and also allows the horizontal slider to slide in the horizontal direction of the curved plate.

[0027] Preferably, vertical slider mortises are provided on the left and right sides of the curve plate, and vertical slider tenons are provided inside the left and right ends of the vertical slider, which are interference fit with the vertical slider mortises. This allows the vertical slider to form a tenon-and-mortise connection with the curve plate, and also allows the vertical slider to slide in the horizontal direction of the curve plate.

[0028] Preferably, the ends of the horizontal and vertical slide grooves are provided with eight sealing members. The sealing members are provided with sealing member tenons that connect to the curve plate. The sealing member tenons are tightly fitted with the horizontal and vertical slide grooves, and the sealing members are fixed in position after installation.

[0029] A method for using an apparatus for calculating the temperature difference during the heat treatment process of a steel billet includes the following steps:

[0030] ①Based on the values ​​of the abscissas on the front or back of the curve plate, including Bi and β values. 2 By selecting either the Fo value or the β value, and sliding the horizontal slider until its marker line aligns with this x-axis value, while keeping the horizontal slider fixed, you can obtain the intersection point of the marker line with the curves on the coordinate graph, including the β curve and the C curve. One of the curves or the cosβ curve.

[0031] ② Slide the vertical slider. When the marker line of the vertical slider passes through the above intersection point, keep the vertical slider fixed. Obtain the intersection point of the vertical slider and the vertical coordinate. From this intersection point, the vertical coordinate value can be obtained, including the β value and the C value. One of the values ​​or cosβ.

[0032] ③ Through the obtained C, The value of cosβ is calculated using equations (A) and (B), which yields the surface temperature θ of the steel plate. s and center temperature θ m :

[0033] Surface temperature:

[0034] Core temperature: Beneficial effects

[0035] 1. The present invention relates to a device mainly composed of a front side and a back side of a curve plate, with a total of 4 coordinate curves engraved on both sides. Compared with the existing technology of the Heisler diagram which requires dozens of curves, the number of curves is greatly reduced. By looking up these four curves and using the calculation formula, the surface temperature and center temperature of the steel plate can be obtained through simple multiplication calculation.

[0036] 2. The coordinate curves involved in this invention use only one independent variable to retrieve the ordinate value of each curve, making the lookup process simple, fast, convenient, and accurate. In contrast, the existing Heisler graph requires two independent variables, making the lookup process cumbersome and inconvenient.

[0037] 3. The calculation principle involved in this invention is simple. By operating this device, the values ​​on the right side of the surface temperature equation (A) and the center temperature equation (B) can be obtained, and then the surface temperature and center temperature can be obtained by multiplication. In contrast, the existing Heisler chart is based on a transformed surface temperature equation and center temperature equation, which has a complex calculation principle, and the surface temperature cannot be obtained independently from the chart.

[0038] 4. This invention relates to a horizontal and vertical slider, which are auxiliary mechanisms for map lookup. By sliding the horizontal and vertical sliders and using the marker lines on the sliders, the horizontal, vertical, and curve positions can be accurately located. The horizontal and vertical sliders and marker lines not only make map lookup convenient and quick but also improve its accuracy. Existing Heisler charts rely on visual judgment of the graphic position, making map lookup inconvenient, slow, and with poor accuracy. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 For the existing technology of flat plate θ m / θ0 is a curve relating Fo and Bi.

[0041] Figure 2 For the existing technology of flat plate θ / θ m Relationship curves between Bi and η.

[0042] Figure 3 This is a schematic diagram of the front structure of the curve plate in the device for calculating the temperature difference during the heat treatment process of steel billets according to the present invention.

[0043] Figure 4 This is a schematic diagram of the reverse side structure of the curve plate in the device for calculating the temperature difference during the heat treatment process of steel billets according to the present invention.

[0044] Figure 5 This is an enlarged cross-sectional view of the apparatus for calculating the temperature difference during the heat treatment process of steel billets according to the present invention.

[0045] Figure 6 This is an enlarged cross-sectional view of the device BB for calculating the temperature difference during the heat treatment process of steel billets according to the present invention.

[0046] Figure 7 This is a schematic diagram of the connection structure between the horizontal slider and the curve plate of the device of the present invention.

[0047] Figure 8 This is a schematic diagram of the connection structure between the vertical slider and the curve plate of the device of the present invention.

[0048] Figure 9 This is a schematic diagram of the sealing component structure of the device of the present invention.

[0049] In the attached image:

[0050] 1. Curve board 101. Front of curve board 102. Back of curve board 2. Horizontal slider

[0051] 201. Horizontal slider mortise; 202. Horizontal slider tenon; 3. Vertical slider; 301. Vertical slider mortise.

[0052] 302. Vertical sliding tenon; 4. Closure component; 401. Closure component tenon. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0054] Example 1:

[0055] like Figure 3 and Figure 4 As shown, a device for calculating the temperature difference during the heat treatment of steel billets includes a curve plate (1), a horizontal slider (2), and a vertical slider (3); the front side (101) of the curve plate is engraved with a β curve and a C curve, with the horizontal axis being Bi, the left vertical axis being β, and the right vertical axis being C. The function of the β curve is to find the β value corresponding to the horizontal axis Bi value based on the left vertical axis β, and the function of the C curve is to find the C value corresponding to the horizontal axis Bi value based on the right vertical axis C; the back side (102) of the curve plate is engraved with The curve and the cosβ curve, with the bottom x-axis being β. 2 Fo, with β as the top x-axis and the exponential function as the left y-axis. And the function value of the trigonometric function cosβ, The function of the curve is to find the relationship between the vertical coordinate and the horizontal coordinate β based on the function value on the left. 2 The corresponding Fo value The function value; the function of the cosβ curve is to find the cosβ function value corresponding to the β value on the horizontal axis based on the vertical axis of the function value on the left; the horizontal slider (2) is perpendicular to the horizontal axis, runs through the entire front and back of the curve plate (1), and slides along the direction of the horizontal axis; the vertical slider (3) is perpendicular to the vertical axis, runs through the entire front and back of the curve plate (1), and slides along the direction of the vertical axis; there is no connection between the horizontal slider (2) and the vertical slider (3), and they are set independently of each other.

[0056] The horizontal axis Bi ranges from 0.1 to 100, and the scale is logarithmic. The left vertical axis β ranges from 0.3 to 1.6, with values ​​increasing from bottom to top. The right vertical axis C ranges from 1 to 1.3, with values ​​decreasing from bottom to top. This design, with different directions of change for the left and right vertical axes, separates the curve and the C-curve, preventing partial overlap between the two curves.

[0057] x-coordinate β 2 The numerical range of Fo is 0–4; the numerical range of the abscissa β is 0–1.6; exponential function The ordinate of the function value of the trigonometric function cosβ varies from 0 to 1, so they can share the same ordinate.

[0058] x-coordinate β 2 Fo uses a variable scale to clearly represent [the information] within the graphic space. The curve's numerical range is such that the scale division between 0 and 1 is 5 times that between 1 and 4.

[0059] like Figure 5 and Figure 6 As shown, the horizontal slider (2) and the vertical slider (3) are slidably connected to the curve plate (1) through a mortise and tenon structure. The horizontal slider (2) and the vertical slider (3) are made of transparent material, and each has a marking line engraved in the middle and colored. The position of the curve plate (1) is located by the marking line. The thickness of the horizontal slider (2) and the vertical slider (3) should be as thin as possible while ensuring strength, so that the horizontal slider has good visibility and the marking line can be as close as possible to the curve plate, thereby improving the accuracy of locating the position of the curve plate by the marking line.

[0060] like Figure 5 and Figure 7 As shown, horizontal slider mortises (201) are provided on the upper and lower sides of the curve plate (1), and horizontal slider tenons (202) are provided in the upper and lower ends of the horizontal slider (2), which are interference fit with the horizontal slider mortises (201). This allows the horizontal slider to form a tenon-and-mortise connection with the curve plate, and also allows the horizontal slider to slide in the horizontal direction of the curve plate.

[0061] like Figure 6 and Figure 8 As shown, vertical slider mortises (301) are provided on the left and right sides of the curve plate (1), and vertical slider tenons (302) are provided in the interior of the left and right ends of the vertical slider (3), which are interference fit with the vertical slider mortises (301), so that the vertical slider can form a tenon-and-mortise connection with the curve plate, and the vertical slider can slide in the horizontal direction of the curve plate.

[0062] like Figure 9 As shown, the ends of the horizontal slide groove (201) and the vertical slide groove (301) are provided with eight closing parts (4). The closing parts (4) are provided with closing part tenons (401) that are connected to the curve plate (1). The closing part tenons (401) are tightly fitted with the horizontal slide groove (201) and the vertical slide groove (301). The closing parts are fixed in position after installation.

[0063] A method for using an apparatus for calculating the temperature difference during the heat treatment process of a steel billet includes the following steps:

[0064] ①Based on the values ​​of the abscissas of the front (101) or back (102) of the curve plate, including the Bi value and β value. 2 By selecting either the Fo value or the β value, sliding the horizontal slider (2) to align the marker line of the horizontal slider (2) with this horizontal coordinate value, and then keeping the horizontal slider (2) fixed, the intersection point of the marker line and the curve in the coordinate graph can be obtained, including the β curve, the C curve, and the curve. One of the curves or the cosβ curve.

[0065] ② Slide the vertical slider (3). When the marker line of the vertical slider (3) passes through the above intersection point, keep the vertical slider (3) fixed to obtain the intersection point of the vertical slider (3) and the vertical coordinate. From this intersection point, the vertical coordinate value can be obtained, including the β value, C value, One of the values ​​or cosβ.

[0066] ③ Through the obtained C, The value of cosβ is calculated using equations (A) and (B), which yields the surface temperature θ of the steel plate. s and center temperature θ m :

[0067] Surface temperature:

[0068] Core temperature:

[0069] Example 2:

[0070] The apparatus for calculating the temperature difference during the heat treatment process of steel billets, as described in this invention, is prepared by the following method:

[0071] 1. Making a curve board

[0072] ①According to the appendix Figure 3 and attached Figure 4 To make the curve plate (1) as shown, a rectangular plate with appropriate length and width dimensions should be constructed. The material for making the curve plate (1) can be a wood board, an opaque acrylic sheet, or an opaque plastic sheet, or any other material that is easy to machine. The purpose of using an opaque material is to have coordinate scales, curves, text symbols, and other information engraved on both the front and back of the curve plate. Using an opaque material can prevent the information on one side from being interfered with by the information on the other side. The curve plate (1) should have a suitable thickness so that mortises can be made on the four sides of the curve plate (1).

[0073] ②According to the appendix Figure 3 As shown, the abscissa Bi, ordinate β, and ordinate C are engraved on the front side (101) of the curve plate, and the β curve and C curve are also engraved; according to the attached... Figure 4 As shown, β is etched on the reverse side (102) of the curve plate. 2Fo (horizontal axis), β (horizontal axis), and function value (vertical axis) are marked. The curve and the cosβ curve.

[0074] ③ Make horizontal slide grooves (201) and vertical slide grooves (301) on the four sides of the curve plate (1). The horizontal slide grooves (201) and vertical slide grooves (301) on the four sides are interconnected.

[0075] ④ Color the coordinate scales, curves and text symbols engraved on the front (101) and back (102) of the curve plate so that this information is clearly distinguishable.

[0076] 2. Make a horizontal slider

[0077] ①According to the appendix Figure 3 and attached Figure 4 To make the horizontal slider (2) as shown, two rectangular plates with appropriate length and width dimensions should be made. The material for making the horizontal slider should be a transparent material that is easy to machine, such as transparent acrylic sheet or transparent plastic sheet. The reason for using a transparent material for the horizontal slider (2) is that the coordinate scale, curve, and text symbols on the front or back of the curve board can be observed through the horizontal slider. The thickness of the horizontal slider (2) should be as thin as possible while ensuring strength, so that the horizontal slider (2) has good visibility and the marking line can be as close as possible to the curve board, thereby improving the accuracy of locating the position of the curve board with the marking line.

[0078] ②As attached Figure 3 and attached Figure 4 As shown, a marker line is engraved in the middle of the horizontal slider (2), and the marker line is colored so that the marker line is clearly distinguishable.

[0079] ③According to the appendix Figure 7 Two connectors with horizontal slider tenons (202) are fabricated. The thickness of the connectors is slightly thicker than that of the curved plate (1) so that there is a certain distance between the installed horizontal slider (2) and the curved plate (1), which can ensure that the horizontal slider can slide freely. The dimensions of the horizontal slider tenons (202) and the dimensions of the horizontal slider mortises (201) are interference fit so that the horizontal slider tenons (202) can not only be installed into the horizontal slider mortises (201), but also slide in the horizontal slider mortises (201).

[0080] ④ Glue the two rectangular plates prepared above to the same side of the two connectors respectively, forming the shape shown in the attached figure. Figure 3 and attached Figure 4 The horizontal slider shown is the whole.

[0081] 3. Fabricate the vertical slider and vertical slider connector.

[0082] ①According to the appendix Figure 3 and attached Figure 4 To create the shape of the vertical slider (3), make two rectangular plates with appropriate length and width. The material for making the vertical slider should be a transparent material that is easy to machine, such as transparent acrylic sheet or transparent plastic sheet. The reason for using a transparent material for the vertical slider (3) is that the coordinate scale, curve, and text symbols on the front or back of the curve board can be observed through the vertical slider. The thickness of the vertical slider (3) should be as thin as possible while ensuring strength, so that the vertical slider (3) has good visibility and the marking line can be as close as possible to the curve board, thereby improving the accuracy of locating the position of the curve board with the marking line.

[0083] ②As attached Figure 3 and attached Figure 4 As shown, a marker line is engraved in the middle of the vertical slider (3), and the marker line is colored so that the marker line is clearly distinguishable.

[0084] ③According to the appendix Figure 8 Two connectors with vertical slider tenons (302) are fabricated. The thickness of the connectors is slightly thicker than that of the curved plate (1) so that there is a certain distance between the installed vertical slider (3) and the curved plate (1), which can ensure that the vertical slider can slide freely. The dimensions of the vertical slider tenon (302) and the vertical slider mortise (301) are interference fit so that the vertical slider tenon (302) can not only be installed in the vertical slider mortise (301), but also slide in the vertical slider mortise (301).

[0085] ④ Glue the two rectangular plates prepared above to the same side of the two connectors respectively, forming the shape shown in the attached figure. Figure 3 and attached Figure 4 The vertical slider shown is a whole.

[0086] 4. Fabricate the corner mortise sealing parts of the curved plate.

[0087] According to the appendix Figure 9 Eight closures (4) are made as shown. The thickness of the closure (4) is the same as the thickness of the curved plate. The size of the tenon (401) of the closure is tight-fitting with the horizontal slide groove (201) and the vertical slide groove (301) so that the position of the closure (4) is fixed after it is installed into the horizontal slide groove (201) and the vertical slide groove (301).

[0088] 5. Device Assembly

[0089] ① Install the horizontal slider tenon (202) into the horizontal slider groove (201) on the upper and lower sides of the curve plate (1) to complete the installation of the horizontal slider (2).

[0090] ② Install the vertical slider tenon (302) into the vertical slider mortise (301) on the left and right sides of the curve plate (1) to complete the installation of the vertical slider (3).

[0091] ③ Install the eight closure components (4) into the horizontal slide groove (201) and the vertical slide groove (301) to complete the entire device.

[0092] Example 3:

[0093] The working principle of this invention is to transform the calculation equations for the surface temperature and center temperature of the steel billet during the heat treatment process into a method of looking up curves for calculation, and to imprint these curves on the device involved in this invention. By operating the device, the unknown terms in the calculation equations for the surface temperature and center temperature can be found, thereby realizing the rapid calculation of the steel billet temperature.

[0094] Steel billets undergoing heat treatment are generally in the form of steel strips (thin steel plates), square steel bars with square cross-sections, and rectangular steel bars (hereinafter referred to as rectangular steel columns). The surface temperature and core temperature of all three shapes of steel billets can be calculated using the following equations:

[0095] Surface temperature:

[0096] Core temperature:

[0097] The following describes how to use the apparatus involved in this invention to solve for the surface temperature and center temperature of these three types of steel billets.

[0098] 1. Steel strip (thin steel plate)

[0099] The maximum temperature difference during steel strip heat treatment is the difference between the surface temperature and the center temperature. Therefore, the maximum temperature difference can be obtained by using this device to determine these two temperatures.

[0100] (1) Use the front of the curve plate (101), as shown in the attached figure. Figure 3 As shown. Using the known heating intensity Bi value, slide the horizontal slider until its mark is at the corresponding mark on the Bi x-axis, keeping the horizontal slider fixed. Then slide the vertical slider until its mark intersects the horizontal slider mark with the β curve, keeping the vertical slider fixed. Find and record the β value based on the intersection of the vertical slider mark with the left β y-axis. Next, keeping the horizontal slider fixed, slide the vertical slider again until its mark intersects the horizontal slider mark with the C curve, keeping the vertical slider fixed. Find and record the C value based on the intersection of the vertical slider mark with the right C y-axis.

[0101] (2) Use the reverse side of the curve plate (102), as shown in the attached figure. Figure 4 As shown. First, using the known heat treatment time Fo and the β obtained above, calculate β.2 The value of Fo. Then slide the horizontal slider so that its marker line is at β. 2 At the corresponding mark on the horizontal axis (F), keep the horizontal slider fixed. Slide the vertical slider until its mark aligns with the horizontal slider's mark. The intersection of the curves. Locate and record the intersection of the vertical slider mark and the left-hand function value's ordinate. Find the value. Then, keeping the horizontal slider fixed, slide the vertical slider again until its marker line intersects the horizontal slider marker line and the cosβ curve, keeping the vertical slider fixed. Based on the intersection of the vertical slider marker line and the left-hand function value's ordinate, find and record the cosβ value.

[0102] (3) From the obtained C value, Substituting the numerical values ​​of cosβ and θ0, along with the known θ0, into equations (A) and (B) yields the surface temperature θ of the steel strip. s and center temperature θ m .

[0103] 2. Square steel

[0104] The maximum temperature difference during the heat treatment of square steel is the difference between the temperature at the edge of the square steel and the temperature at the center of the square steel. Therefore, the maximum temperature difference can be obtained by using this device to determine these two temperatures.

[0105] (1) Use the front of the curve plate (101), as shown in the attached figure. Figure 3 As shown, following the same steps as the steel strip above, the values ​​of β and C are found and recorded.

[0106] (2) Use the reverse side of the curve plate (102), as shown in the attached figure. Figure 4 As shown, follow the same steps as for the steel strip described above to find and record... Numerical value and cosβ value.

[0107] (3) From the obtained C value, Given the numerical values ​​of cosβ and θ0, calculate The result is the center temperature of the square steel; calculation The result is the temperature at the edge of the square steel.

[0108] 3. Rectangular steel column

[0109] The maximum temperature difference during heat treatment of a rectangular steel column is the difference between the temperature at the edge of the rectangular steel column and the temperature at the center of the rectangular steel column. Therefore, the maximum temperature difference can be obtained by using this device to determine these two temperatures.

[0110] Unlike square steel, rectangular steel columns have two heating intensities, Bi1 and Bi2, corresponding to the two sides of the rectangular cross-section, during heat treatment.

[0111] (1) Use the front of the curve plate (101), as shown in the attached figure. Figure 3 As shown, following the same steps as the steel strip described above, the values ​​of β1 and C1 are obtained and recorded using the Bi1 value.

[0112] (2) Use the reverse side of the curve plate (102), as shown in the attached figure. Figure 4 As shown, following the same steps as the steel strip described above, respectively using... Find and record the numerical value and β1 value. Numerical values ​​and cosβ1 values.

[0113] (3) Using the Bi2 value, find and record the β2 and C2 values ​​using the same method as above. Numerical value and cosβ2 value.

[0114] (4) Based on the obtained values ​​of C1 and C2, Given the numerical values ​​of cosβ1 and cosβ2, and the known θ0, calculate... The result is the temperature at the center of the rectangular steel column; calculation The result is the temperature at the edge of the rectangular steel column.

Claims

1. An apparatus for calculating the temperature difference during the heat treatment of steel billets, characterized in that: Includes a curve plate (1), a horizontal slider (2), and a vertical slider (3); the front (101) of the curve plate is engraved with a β curve and a C curve, with the horizontal axis being Bi, the left vertical axis being β, and the right vertical axis being C. The function of the β curve is to find the β value corresponding to the horizontal axis Bi value based on the left vertical axis β, and the function of the C curve is to find the C value corresponding to the horizontal axis Bi value based on the right vertical axis C; the back (102) of the curve plate is engraved with The curve and the cosβ curve, with the bottom x-axis being β. 2 Fo, with β as the top x-axis and the exponential function as the left y-axis. And the function value of the trigonometric function cosβ, The function of the curve is to find the relationship between the vertical coordinate and the horizontal coordinate β based on the function value on the left. 2 The corresponding Fo value The function value; the function of the cosβ curve is to find the cosβ function value corresponding to the β value on the horizontal axis based on the vertical axis of the function value on the left; the horizontal slider (2) is perpendicular to the horizontal axis, runs through the entire front and back of the curve plate (1), and slides along the direction of the horizontal axis; the vertical slider (3) is perpendicular to the vertical axis, runs through the entire front and back of the curve plate (1), and slides along the direction of the vertical axis; the horizontal slider (2) and the vertical slider (3) are not connected and are set independently of each other.

2. The apparatus for calculating the temperature difference during the heat treatment process of steel billets according to claim 1, characterized in that: The horizontal axis Bi ranges from 0.1 to 100, and the scale is logarithmic; the left vertical axis β ranges from 0.3 to 1.6, with the scale value increasing from bottom to top; the right vertical axis C ranges from 1 to 1.3, with the scale value decreasing from bottom to top.

3. The apparatus for calculating the temperature difference during the heat treatment process of steel billets according to claim 1, characterized in that: The horizontal coordinate β 2 The numerical range of Fo is 0–4; the numerical range of the abscissa β is 0–1.6; exponential function The value of the ordinate of the trigonometric function cosβ varies from 0 to 1.

4. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to claim 3, characterized in that: Horizontal axis β 2 Fo The variable scale is used, and the scale ratio of the numerical value range of 0-1 is 5 times the scale of 1-4.

5. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to claim 1, characterized in that: The horizontal slider (2) and the vertical slider (3) are slidably connected to the curve plate (1) by a tenon and mortise structure.

6. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to claim 1, characterized in that: The horizontal slider (2) and the vertical slider (3) are both engraved with marking lines in the middle, and the position of the curve plate (1) is located by the marking lines.

7. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to claim 5, characterized in that: The upper and lower sides of the curved plate (1) are provided with horizontal slide grooves (201), and the upper and lower ends of the horizontal slide (2) are respectively provided with horizontal slide tenons (202), which are interference fit with the horizontal slide grooves (201).

8. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to claim 5, characterized in that: The curve plate (1) has vertical slide grooves (301) on its left and right sides. The vertical slide (3) has vertical slide tenons (302) inside its left and right ends, which are interference fit with the vertical slide grooves (301).

9. The apparatus for calculating the temperature difference during the heat treatment process of a steel billet according to any one of claims 7 and 8, characterized in that: The ends of the horizontal slide groove (201) and the vertical slide groove (301) are provided with eight closing members (4). The closing members (4) are provided with closing member tenons (401) that are connected to the curve plate (1). The closing member tenons (401) and the horizontal slide groove (201) and the vertical slide groove (301) are tightly fitted.

10. A method of using a device for calculating the temperature difference during the heat treatment process of a steel billet, characterized in that, Includes the following steps: ①Based on the values ​​of the abscissas of the front (101) or back (102) of the curve plate, including the Bi value and β value. 2 By selecting either the Fo value or the β value, sliding the horizontal slider (2) to align the marker line of the horizontal slider (2) with this horizontal coordinate value, and then keeping the horizontal slider (2) fixed, the intersection point of the marker line and the curve in the coordinate graph can be obtained, including the β curve, the C curve, and the curve. One of the curves or the cosβ curve; ② Slide the vertical slider (3). When the marker line of the vertical slider (3) passes through the above intersection point, keep the vertical slider (3) fixed to obtain the intersection point of the vertical slider (3) and the vertical coordinate. From this intersection point, the vertical coordinate value can be obtained, including the β value, C value, One of the values ​​of either value or cosβ; ③ Through the obtained C, The value of cosβ is calculated using equations (A) and (B), which yields the surface temperature θ of the steel plate. s and center temperature θ m : Surface temperature: Core temperature: .

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