Prediction method suitable for deformation resistance of invar alloy in hot rolling process and application thereof

Abstract

The invention relates to a forecasting method suitable for deformation resistance in the invar alloy hot rolling process and application thereof, belongs to the field of hot rolling, and solves the problems that in the prior art, in the invar alloy hot rolling process, especially in the hot rolling and finish rolling process, deformation resistance forecasting is low in precision and large in deviation, and the plate shape and quality after hot rolling are difficult to guarantee. And a large amount of time and cost are required. The forecasting method comprises the following steps: collecting main equipment and process parameters of a hot rolling unit; invar alloy incoming material parameters and hot rolling process parameters are given; the outlet temperature of the jth pass is calculated; and determining the deformation resistance of the invar alloy in the jth pass. According to the method, accurate prediction of the deformation resistance in the invar alloy hot rolling process is achieved, and the accuracy error is small.

Description

Technical Field

[0001] This invention relates to the field of hot rolling technology, and in particular to a method for predicting deformation resistance in the hot rolling process of Invar alloys and its application. Background Technology

[0002] Invar alloy, also known as low-expansion alloy, is a magnetic metal alloy composed of iron and nickel. Due to its unique low expansion characteristics and good dimensional stability, Invar alloy has an irreplaceable position in fields that require high precision and stability.

[0003] In the hot rolling process of Invar alloy, it is necessary to determine the reasonable hot rolling force parameters through deformation resistance in order to control the strip shape. Therefore, deformation resistance is one of the important parameters in the hot rolling process. Thus, it is crucial to accurately know the deformation resistance of Invar alloy strip before hot rolling production.

[0004] However, in the existing technology, there is no publicly available method for accurately predicting the deformation resistance of Invar alloys during the hot rolling process. Currently, the hot rolling deformation resistance of Invar alloys mainly relies on empirical estimation or trial rolling methods. These methods fail to fully consider the unique characteristics of Invar alloys and do not comprehensively consider the various process parameters that may affect the deformation resistance during the hot rolling process. Therefore, the predicted hot rolling deformation resistance of Invar alloys by existing methods deviates significantly from the actual situation, which directly affects the accuracy of rolling force settings. For hot-rolled Invar alloy strip steel, especially ultra-wide and thin-gauge products, this inaccurate deformation resistance prediction can easily lead to poor strip shape, resulting in significant quality losses and wasting a lot of time and resources. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a method for predicting deformation resistance in the hot rolling process of Invar alloys and its application, in order to solve at least one of the following problems in the prior art: low accuracy and large deviation in the prediction of deformation resistance of Invar alloys during hot rolling, especially hot finishing rolling, which makes it difficult to guarantee the shape and quality of the hot-rolled plate, and requires a lot of time and cost.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a method for predicting deformation resistance in the hot rolling process of Invar alloys, comprising the following steps:

[0008] (a) Collect the main equipment and process parameters of the hot rolling mill, including: the number of passes N, and the diameter D of the rolls in each pass. j The rolling speed ν of each pass j Rolling pressure P in each pass j Roll surface temperature T gThe distance between racks, L; the cooling water temperature between racks, T. w water flow density q w j represents the j-th pass;

[0009] (b) Given the incoming parameters and hot rolling process parameters of the Invar alloy, including: the initial width B, initial thickness h0, density ρ, specific heat capacity c, initial deformation resistance σ0, and the deformation resistance σ of the Invar alloy in the j-th pass. j The exit thickness h of the j-th pass j The inlet temperature T of the j-th pass 0j The exit temperature T of the j-th pass 1j ;

[0010] (c) Based on the parameters from steps (a) and (b), calculate the outlet temperature T of the j-th pass. 1j =T 1j-1 +ΔT Hj +ΔT fj -ΔT tj -ΔT cj ;

[0011] Where, ΔT Hj The temperature rise caused by plastic deformation, ΔT fj For frictional temperature rise, ΔT tj ΔT is the temperature drop caused by contact with the rolls. cj The temperature drop is caused by the cooling water; 1 < j ≤ N;

[0012] (d) Based on the exit temperature T of the j-th pass 1j The deformation resistance σ of the Invar alloy in the j-th pass is determined according to the following formula. j ;

[0013]

[0014] In the formula, u mj The average deformation rate of the Invar alloy in the j-th pass is expressed in seconds. -1 e j For the actual deformation degree of the Invar alloy in the j-th pass, a1 = -1.89 to -2.05, a2 = 2.4 to 2.6, a3 = 0.2 to 0.6, a4 = -0.2 to -0.4, a5 = 0.1 to 0.2, a6 = 1.0 to 1.3; T 1j The unit is ℃, and the unit of σ0 is MPa;

[0015] Repeat steps (c) to (d) to calculate the deformation resistance for passes 1 to N.

[0016] Furthermore, in step (c), the frictional temperature rise ΔT is determined according to the following formula. fj :

[0017]

[0018] In the formula, A is the friction temperature rise influence coefficient, which is taken as 4.0 to 4.5;

[0019] K1 is the influence coefficient of the roll material, and the value of K1 ranges from 0.8 to 1.0;

[0020] K2 is the rolling speed influence coefficient, B = 0.1~0.2, D = 1~2, E = 1.5~2.5, x0 = 5~6, ν j The unit is m / s;

[0021] K3 is the influence coefficient of the rolled material, and the value of K3 is 1.40 to 1.45;

[0022] l j T represents the length of the deformation zone in the j-th pass, in mm. 0j The unit is ℃;

[0023] h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm.

[0024] σ j-1 The deformation resistance for the (j-1)th pass is expressed in MPa.

[0025] h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm.

[0026] The unit of ρ is kg / m³ 3 The unit of c is J / (kg×K), ν j The unit is m / s.

[0027] Furthermore, in step (c), the temperature drop ΔT caused by the cooling water is determined according to the following formula. cj :

[0028]

[0029] In the formula, T 0j and T w The unit is ℃, the unit of L is m, and the unit of h is h. j The unit is mm, ν j The unit is m / s, q w The unit is m 3 / (m 2×h), α is the water-cooled heat transfer coefficient, e is the actual deformation degree of the Invar alloy in the j-th pass, x, y, and z are all regression coefficients, x = 197~200, y = 2.28~2.34, z = -0.00030~-0.00035.

[0030] Furthermore, in step (c), the temperature drop ΔT caused by the contact roll is determined according to the following formula. tj :

[0031]

[0032] In the formula, s is the thickness of the iron oxide scale, in μm;

[0033] λ is the thermal conductivity of Invar alloy, with units of cal / (cm×s×℃);

[0034] h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm.

[0035] l j The length of the deformation zone in the j-th pass is in mm.

[0036] ν j The unit is m / s; T 0j and T g The unit is ℃; the unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

[0037] Furthermore, the thickness of the iron oxide scale is s = 7 μm to 14 μm; and / or,

[0038] The thermal conductivity of the Invar alloy is λ = 0.02 to 0.04 cal / (cm×s×℃).

[0039] Further, in step (c), the temperature rise ΔT caused by the plastic deformation is determined according to the following formula. Hj :

[0040]

[0041] In the formula, η j For absorption efficiency, η j The range is 50% to 90%, satisfying η j-1 ≥η j , 1 < j ≤ N;

[0042] h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm.

[0043] P jThe rolling pressure for the j-th pass is expressed in kN.

[0044] J1 is the mechanical equivalent of heat, J1 = 9.81;

[0045] The unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

[0046] Furthermore, in step (b), the initial deformation resistance σ0 is experimentally measured under certain test conditions, including a strip temperature of 950–1100°C and a deformation rate of 5–10 s. -1 And the degree of deformation is 0.1 to 0.3.

[0047] Furthermore, in step (a), the surface temperature T of the roll is... g =55~75℃; and / or,

[0048] The inter-rack cooling water temperature T w =20~30℃; and / or,

[0049] The water flow density q w =1.5~2.0m 3 / (m 2 ×h).

[0050] Furthermore, the length l of the deformation zone in the j-th pass is determined according to the following formula. j :

[0051]

[0052] In the formula, h j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. j The diameter of the j-th rolling mill roll is in mm.

[0053] Furthermore, the average deformation rate u of the Invar alloy in the j-th pass is determined according to the following formula. mj :

[0054]

[0055] In the formula, ν j h is the rolling speed of the j-th pass, in m / s. j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. j The diameter of the j-th rolling mill roll is in mm.

[0056] Furthermore, in step (a), the rolling speed ν for each pass... jThe value range is 1.49–9.19 m / s; and / or,

[0057] Rolling pressure P in each pass j The value range is 14000~37000kN.

[0058] This invention provides the application of the aforementioned forecasting method in the preparation of Invar alloys for precision optics, semiconductors, LNG transportation, and consumer electronics.

[0059] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0060] (1) This invention discloses a method for predicting the deformation resistance of Invar alloy during hot rolling. This method comprehensively considers the characteristics of Invar alloy and the combined effects of multiple factors during hot rolling. By analyzing the production process parameters during the incoming material and hot rolling process, the four key factors affecting the rolling temperature are comprehensively evaluated, thereby accurately determining the exit temperature of each pass. Based on the established mathematical model between the exit temperature and the deformation resistance, the deformation resistance of each pass is further determined. This method can accurately predict the deformation resistance of Invar alloy during the hot rolling process, especially during the hot finishing rolling process, when the incoming material and hot rolling conditions change. The accuracy error range is controlled below 7.8%, and the average accuracy error per pass is controlled below 4.9%, providing a reliable basis for formulating reasonable hot rolling strategies and controlling the quality of product sheet shape.

[0061] (2) This invention discloses a method for predicting the hot rolling deformation resistance of Invar alloys, which comprehensively evaluates four key factors affecting the rolling temperature, namely the temperature rise (ΔT) caused by plastic deformation. Hj Frictional temperature rise (ΔT) fj Temperature drop (ΔT) caused by contact rolls tj ) and the temperature drop (ΔT) caused by cooling water cj Based on the aforementioned temperature rise and fall, this invention can dynamically and accurately determine the exit temperature (T) of each rolling pass. 1j To obtain the accurate outlet temperature (T) 1j Based on this, the present invention further constructs a mathematical model between the outlet temperature and the deformation resistance, which reflects the relationship between the outlet temperature (T) and the deformation resistance. 1j ), average deformation rate (u) mj ), actual degree of deformation (e) j ) and deformation resistance (σ jBased on the inherent physical relationship between the materials and the parameters, the advantages of this invention lie in its strong adaptability and prediction accuracy. The method of this invention can better adapt to changes in the incoming material characteristics or hot rolling parameters of Invar alloys. Based on the established prediction model, through iterative calculations (steps c to d), it can efficiently and accurately predict the deformation resistance from the 1st to the Nth pass. Experimental verification shows that the prediction results of the prediction method provided by this invention are in high agreement with the measured values, with the accuracy error of a single pass controlled below 7.8%, and the average accuracy error of all passes controlled below 4.9%.

[0062] (3) By accurately predicting the deformation resistance during hot rolling, this invention effectively overcomes the limitations of existing empirical or trial rolling methods: regardless of the material characteristics of Invar alloy or the hot rolling conditions, this invention can efficiently and accurately predict the deformation resistance, thereby providing an important basis for formulating a reasonable hot rolling procedure. This not only significantly saves time and costs, but also greatly improves rolling efficiency and provides reliable technical support for hot rolling production.

[0063] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0064] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0065] Figure 1 This is a flowchart illustrating a method for predicting deformation resistance in the hot rolling process of Invar alloys, as provided in an embodiment of the present invention. Detailed Implementation

[0066] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0067] Accurate prediction of the deformation resistance of Invar alloys during hot rolling faces numerous challenges, among which the complexity of temperature changes and the coupling of multiple factors are particularly prominent. The temperature change of Invar alloys is a complex dynamic process, mainly influenced by factors such as deformation heat, frictional heat, and cooling water temperature drop. These temperature changes are closely related to process parameters such as rolling speed, rolling force, roll temperature, and cooling water, which are dynamically changing in actual production, thus affecting the deformation resistance.

[0068] Existing empirical and trial rolling methods have significant limitations in predicting the hot-rolling deformation resistance of Invar alloys, making it difficult to meet the requirements for high-precision prediction. Therefore, developing a dynamic prediction model that comprehensively considers the influence of multiple factors and is based on real-time data is of great significance for improving the prediction accuracy of the hot-rolling deformation resistance of Invar alloys, ensuring plate quality, reducing production costs, and improving rolling efficiency.

[0069] Therefore, the present invention provides a method for predicting the deformation resistance of Invar alloys during hot rolling, comprising the following steps:

[0070] (a) Collect the main equipment and process parameters of the hot rolling mill, including: the number of passes N, and the diameter D of the rolls in each pass. j The rolling speed ν of each pass j Rolling pressure P in each pass j Roll surface temperature T g The distance between racks, L; the cooling water temperature between racks, T. w water flow density q w j represents the j-th pass;

[0071] (b) Given the incoming parameters and hot rolling process parameters of the Invar alloy, including: the initial width B, initial thickness h0, density ρ, specific heat capacity c, initial deformation resistance σ0, and the deformation resistance σ of the Invar alloy in the j-th pass. j The exit thickness h of the j-th pass j The inlet temperature T of the j-th pass 0j The exit temperature T of the j-th pass 1j ;

[0072] (c) Based on the parameters from steps (a) and (b), calculate the outlet temperature T of the j-th pass. 1j =T 1j-1 +ΔT Hj +ΔT fj -ΔT tj -ΔT cj ;

[0073] Where, ΔT Hj The temperature rise caused by plastic deformation, ΔT fj For frictional temperature rise, ΔT tj ΔT is the temperature drop caused by contact with the rolls. cj The temperature drop is caused by the cooling water.

[0074] (d) Based on the exit temperature T of the j-th pass 1j The deformation resistance σ of the Invar alloy in the j-th pass is determined according to the following formula. j ;

[0075]

[0076] In the formula, u m The average deformation rate of the Invar alloy in the j-th pass is expressed in seconds. -1 , e represents the actual deformation degree of the Invar alloy in the j-th pass, a1 = -1.89 to -2.05, a2 = 2.4 to 2.6, a3 = 0.2 to 0.6, a4 = -0.2 to -0.4, a5 = 0.1 to 0.2, a6 = 1.0 to 1.3; T 1j The unit is ℃, and the unit of σ0 is MPa;

[0077] Repeat steps (c) to (d) to calculate the deformation resistance for the first to Nth passes in sequence.

[0078] It can be understood that in the above formula, a1, a2, a3, a4, a5, and a6 are regression coefficients in the deformation resistance model of Invar alloy.

[0079] For example, the values ​​of a1 are -1.89, -1.91, -1.93, -1.95, -1.97, -1.99, -2.01, -2.03, and -2.05.

[0080] For example, the values ​​of a2 are 2.40, 2.42, 2.44, 2.46, 2.48, 2.50, 2.52, 2.54, 2.56, 2.58, and 2.60.

[0081] For example, the values ​​of a3 are 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60.

[0082] For example, the values ​​of a4 are -0.20, -0.22, -0.24, -0.26, -0.28, -0.30, -0.32, -0.34, -0.36, -0.38, and -0.40.

[0083] For example, the values ​​of a5 are 0.10, 0.12, 0.14, 0.16, 0.18, and 0.20.

[0084] For example, the values ​​of a6 are 1.0, 1.05, 1.10, 1.15, 1.20, 1.25, and 1.3.

[0085] Compared with existing technologies, this invention discloses a method for predicting the deformation resistance of Invar alloy during hot rolling. This method comprehensively considers the characteristics of Invar alloy and the combined effects of multiple factors during hot rolling. By analyzing the production process parameters during the incoming material and hot rolling process, it comprehensively evaluates four key factors affecting the rolling temperature, thereby accurately determining the exit temperature of each pass. Based on the established mathematical model between the exit temperature and deformation resistance, the deformation resistance of each pass is further determined. This method can accurately predict the deformation resistance during the hot rolling process, especially during the hot finishing rolling process, even when the incoming material and hot rolling conditions of Invar alloy change. The accuracy error range is controlled below 7.8%, and the average accuracy error per pass is controlled below 4.9%. Therefore, this invention achieves accurate prediction of the deformation resistance during the hot rolling process of Invar alloy with small accuracy error, providing a reliable basis for formulating reasonable hot rolling strategies and controlling product sheet quality.

[0086] This invention effectively overcomes the limitations of existing empirical or trial rolling methods by accurately predicting the deformation resistance during hot rolling. Regardless of the characteristics of the incoming Invar alloy or the hot rolling conditions, this invention can efficiently and accurately predict the deformation resistance, thus providing an important foundation for formulating reasonable hot rolling procedures. This not only significantly saves time and costs but also greatly improves rolling efficiency, providing reliable technical support for hot rolling production.

[0087] The technical concept of this invention is to utilize the incoming material parameters and material characteristics of Invar alloy, combined with the equipment and process parameters for hot rolling, to fully consider the multi-factor coupling of rolling temperature during hot rolling of Invar alloy (including the temperature rise ΔT caused by plastic deformation). Hj Frictional temperature rise ΔT fj Temperature drop ΔT caused by contact with the rolls tj Temperature drop ΔT caused by cooling water cj The exit temperature of each rolling pass is determined, and the exit temperature is substituted into the deformation resistance calculation model to realize the prediction of the hot rolling deformation resistance of Invar alloy strip. This enables efficient and accurate prediction of the deformation resistance of strip when encountering Invar alloy strip in subsequent production processes.

[0088] In some embodiments, the average deformation rate u of the Invar alloy in the j-th pass is determined according to the following formula. mj :

[0089]

[0090] In the formula, ν j h is the rolling speed of the j-th pass, in m / s. j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. jThe diameter of the j-th rolling mill roll is in mm.

[0091] In some embodiments, the actual deformation degree e of the Invar alloy in the j-th pass is determined according to the following formula. j :

[0092]

[0093] In the formula, h j-1 and h j The inlet and outlet thicknesses are for the j-th pass, in mm.

[0094] In some embodiments, in step (c), the frictional temperature rise ΔT is determined according to the following formula. fj :

[0095]

[0096] In the formula, A is the friction temperature rise influence coefficient, A = 4.0~4.5;

[0097] K1 is the influence coefficient of the roll material, K1 = 0.8~1.0;

[0098] K2 is the rolling speed influence coefficient, B = 0.1~0.2, D = 1~2, E = 1.5~2.5, x0 = 5~6, ν j The unit is m / s;

[0099] K3 is the influence coefficient of the rolled material, and the value of K3 is 1.4 to 1.45;

[0100] l j T represents the length of the deformation zone in the j-th pass, in mm. 0j The unit is ℃;

[0101] h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm.

[0102] σ j-1 The deformation resistance for the (j-1)th pass is expressed in MPa.

[0103] h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm.

[0104] The unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K);

[0105] ν j The rolling speed for the j-th pass is expressed in m / s.

[0106] For example, the values ​​of A are 4.0, 4.05, 4.10, 4.15, 4.20, 4.25, 4.30, 4.35, 4.40, 4.45, and 4.5.

[0107] For example, the value of K1 can be 0.8, 0.85, 0.90, 0.95, or 1.0.

[0108] For example, in the formula for calculating K2, the values ​​of B are 0.10, 0.12, 0.14, 0.16, 0.18, and 0.20. The values ​​of D are 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0. The values ​​of E are 1.5, 1.7, 1.9, 2.1, 2.3, and 2.5. The values ​​of x0 are 5.0, 5.2, 5.4, 5.6, 5.8, and 6.0.

[0109] For example, the values ​​of K3 are 1.40, 1.41, 1.42, 1.43, 1.44, and 1.45.

[0110] For example, h mj =(h j-1 +h j ) / 2.

[0111] For example, the inlet temperature T of the j-th pass 0j Equal to the exit temperature T of the (j-1)th pass (the previous pass) 1j-1 .

[0112] In some embodiments, in step (c), the frictional temperature rise ΔT is determined according to the following formula. cj :

[0113]

[0114] In the formula, T 0j and T w The unit is ℃, the unit of L is m, and the unit of h is h. j The unit is mm, ν j The unit is m / s, q w The unit is m 3 / (m 2 ×h), α is the water-cooled heat transfer coefficient, e is the actual deformation degree of the Invar alloy in the j-th pass, x, y, and z are all regression coefficients, x = 197~200, y = 2.28~2.34, z = -0.00030~-0.00035.

[0115] For example, in the formula for calculating the water-cooled heat transfer coefficient α, the regression coefficient x takes values ​​such as 197.5, 198.0, 198.2, 198.5, 198.6, 198.8, 199.0, 199.5, and 200.0. Preferably, x = 198.5 to 198.6.

[0116] For example, in the formula for calculating the water-cooled heat transfer coefficient α, the regression coefficient y takes values ​​such as 2.28, 2.285, 2.29, 2.295, 0.301, 0.304, 0.308, 0.312, 0.316, 0.321, 0.325, 0.330, 0.335, and 0.34. Preferably, y = 2.301 to 2.321.

[0117] For example, in the formula for calculating the water-cooled heat transfer coefficient α, the regression coefficient z can take values ​​such as -0.00030, -0.000305, -0.000310, -0.000314, -0.000317, -0.000320, -0.000322, -0.000325, -0.000330, -0.000335, -0.000340, -0.000345, and -0.00035. Preferably, z = -0.000317 to -0.000322.

[0118] In some embodiments, in step (c), the temperature drop ΔT caused by the contact roll is determined according to the following formula. tj :

[0119]

[0120] In the formula, s is the thickness of the iron oxide scale, in μm;

[0121] λ is the thermal conductivity of Invar alloy, with units of cal / (cm×s×℃);

[0122] h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm.

[0123] l j The length of the deformation zone in the j-th pass is in mm.

[0124] ν j The unit is m / s; T 0j and T g The unit is ℃; the unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

[0125] In some embodiments, the thickness s of the iron oxide scale is 70 μm to 140 μm. Exemplarily, the values ​​of the iron oxide scale thickness s are 70 μm, 90 μm, 100 μm, 110 μm, 130 μm, and 140 μm.

[0126] In some embodiments, the thermal conductivity λ of the Invar alloy is 3.5–4.5 cal / (cm·s·℃). Exemplary examples include values ​​of λ for the thermal conductivity of the Invar alloy such as 3.5 cal / (cm·s·℃), 3.7 cal / (cm·s·℃), 3.9 cal / (cm·s·℃), 4.2 cal / (cm·s·℃), and 4.4 cal / (cm·s·℃).

[0127] In some embodiments, the length l of the deformation zone in the j-th pass is determined according to the following formula. j :

[0128]

[0129] In the formula, h j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. j The diameter of the j-th rolling mill roll is in mm.

[0130] In some embodiments, in step (c), the temperature rise ΔT caused by the plastic deformation is determined according to the following formula. Hj :

[0131]

[0132] In the formula, η j For absorption efficiency, η j The range is 50% to 90%, satisfying η j-1 ≥η j , 1 < j ≤ N;

[0133] h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm.

[0134] P j The rolling pressure for the j-th pass is expressed in kN.

[0135] J1 is the mechanical equivalent of heat, J1 = 9.81;

[0136] The unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

[0137] It is understandable that the absorption efficiency η jIt refers to the percentage of deformation heat that is converted into heat generated by the rolled piece, out of the total deformation heat.

[0138] The inventors discovered through research that during the hot rolling process of Invar alloys, the initial temperature of the strip is relatively high during the first few stands of rolling, resulting in better plasticity and relatively lower deformation resistance. At this stage, the heat generated during deformation is more easily absorbed by the strip, leading to higher absorption efficiency. However, during the later stands, the strip temperature gradually decreases, and heat dissipation accelerates. This means that some of the deformation heat needs to be used to compensate for the temperature drop, reducing the amount that can be absorbed and converted into heat, thus lowering the absorption efficiency. Based on this discovery, this invention controls the absorption efficiency within a reasonable range and sets the absorption efficiency of the preceding pass to be no less than that of the following pass. This allows the mathematical model to more accurately reflect the actual working conditions, thereby improving the accuracy of deformation resistance prediction.

[0139] For example, the difference in absorption efficiency between each pass is the same, and 0 ≤ η j-1 -η j ≤40% / (N-1).

[0140] For example, η j Values ​​such as 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, and 90% are given.

[0141] In some embodiments, in step (b), the initial deformation resistance σ0 is experimentally measured under certain test conditions, including a strip temperature of 950–1100°C and a deformation rate of 5–10 s. -1 And the degree of deformation is 0.1 to 0.3.

[0142] For example, in the test conditions, the strip temperature is taken as 950℃, 980℃, 1000℃, 1020℃, 1040℃, 1060℃, 1080℃, or 1100℃. The deformation speed is 5s. -1 6s -1 7s -1 7.5s -1 8.09s -1 8.5s -1 9s -1 10s -1 The degrees of deformation are 0.10, 0.13, 0.15, 0.18, 0.21, 0.23, 0.25, 0.28, and 0.30.

[0143] Preferably, the test conditions include a strip temperature of 1000–1100°C and a deformation rate of 7–9 s. -1 And the degree of deformation is 0.15 to 0.25.

[0144] For example, the experiment is a high-temperature, high-speed deformation resistance test.

[0145] In some embodiments, the initial deformation resistance σ0 is 150–240 MPa.

[0146] In some embodiments, in step (a), the surface temperature T of the roll is... g =55~75℃. For example, T g The values ​​are 55℃, 60℃, 65℃, 70℃, and 75℃.

[0147] In some embodiments, in step (a), the temperature T of the inter-rack cooling water is... w =20~30℃. For example, T w The values ​​are 20℃, 22℃, 25℃, 28℃, and 30℃.

[0148] In some embodiments, in step (a), the water flow density q w =1.5~2.0m 3 / (m 2 ×h). For example, q w The value is 1.5m. 3 / (m 2 ×h), 1.6m 3 / (m 2 ×h), 1.7m 3 / (m 2 ×h), 1.8m 3 / (m 2 ×h), 1.9m 3 / (m 2 ×h), 2.0m 3 / (m 2 ×h).

[0149] In some embodiments, in step (a), the number of passes N is 5 to 7; for example, N = 5, 6, 7.

[0150] In some embodiments, in step (a), the diameter D of each pass roll is... j The value range is 600–800 mm; for example, D j The sizes are 600mm, 650mm, 700mm, 750mm, and 800mm.

[0151] In some embodiments, in step (a), the rolling speed ν of each pass... j The value range is 1.49–9.19 m / s; for example, ν jThe rolling pressures are 1.49 m / s, 2.0 m / s, 3.0 m / s, 4.0 m / s, 5.0 m / s, 6.0 m / s, 7.0 m / s, 8.0 m / s, and 9.0 m / s. In some embodiments, in step (a), the rolling pressure P for each pass... j The value range is 14000~37000kN; for example, P j The values ​​are 14000kN, 20000kN, 25000kN, 30000kN, 35000kN, and 37000kN.

[0152] In some embodiments, in step (a), the distance L between the racks ranges from 3 to 5 m. For example, L is 3 m, 3.5 m, 4 m, 4.5 m, or 5 m.

[0153] In some embodiments, in step (b), the initial width B of the Invar alloy is ≥ 1200 mm, for example, B = 1200 mm to 2000 mm. The initial thickness h0 of the Invar alloy is ≤ 40 mm, for example, h0 = 35 to 40 mm. Exemplarily, B is 1200 mm, 1400 mm, 1600 mm, 1800 mm, or 2000 mm; h0 is 35 mm, 36 mm, 38 mm, or 40 mm.

[0154] In some embodiments, in step (b), the exit thickness h of the j-th pass... j and the exit thickness h of the (j-1)th pass j-1 Satisfy: (h) j-1 -h j ) / h j-1 = 0.10~0.40. For example, (h j-1 -h j ) / h j-1 =0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40.

[0155] In some embodiments, in step (b), the inlet temperature T of the first pass is... 01 The temperature is 950–1050℃. For example, T 01 The temperatures are 950℃, 980℃, 1000℃, 1020℃, and 1050℃.

[0156] In some embodiments, in step (b), the density ρ and specific heat capacity c of the Invar alloy can be obtained by consulting existing technical data.

[0157] This invention provides the application of the aforementioned forecasting method in the preparation of Invar alloys for precision optics, semiconductors, LNG transportation, and consumer electronics.

[0158] The deformation resistance prediction method provided by this invention has significant application value and beneficial effects in the field of precision electronics, such as the manufacturing of Invar alloy photomasks for OLED displays. In OLED display manufacturing, whether it's an open-face photomask or a fine metal photomask (FMM), the substrate is typically made of Invar alloy with low expansion characteristics. These photomasks undergo critical plastic processing steps such as hot rolling during manufacturing to achieve the required thickness and flatness. Traditional empirical or trial-and-error rolling parameter settings are difficult to accurately match the unique deformation behavior of Invar alloy, easily leading to problems such as poor strip shape, uneven thickness, and high internal residual stress after hot rolling, directly affecting the final dimensional accuracy and pattern transfer quality of the photomask.

[0159] The forecasting method of this invention provides a scientific basis for the rational setting of rolling force by accurately predicting the deformation resistance of Invar alloy during hot rolling. This helps to achieve proactive and precise control over the shape and size of Invar alloy strip during the hot rolling process, thereby significantly improving the shape quality, thickness uniformity, and dimensional stability of the hot-rolled Invar alloy strip, thus providing a reliable raw material guarantee for the subsequent precision processing of photomasks. The forecasting method of this invention is also applicable to the forecasting of deformation resistance in the hot rolling and finishing stage of ultra-wide and thin-gauge Invar alloy strip, effectively solving the problem of the difficulty in accurately predicting the deformation resistance of ultra-wide and thin-gauge Invar alloy strip during the hot rolling and finishing stage. This lays the technological foundation for manufacturing ultra-large-size, high-precision photomasks, and thus supports the research and development and production of ultra-large-size OLED display panels. By improving the precision and consistency of the material preparation stage, this invention helps to improve the final quality and production yield of display products, which is of great significance for promoting the development of the high-end display industry.

[0160] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0161] Example 1:

[0162] This embodiment provides a method for predicting the deformation resistance during the hot rolling process of Invar alloys, including the following steps:

[0163] (a) Collect the main equipment and process parameters of the hot rolling mill, including: number of passes N=7, diameter D of the rolls in each pass. j = (809.56, 826.07, 794.82, 777.91, 659.94, 610.87, 634.87) mm, where v is the rolling speed v of Invar alloy in each pass. j = (1.492, 2.193, 3.166, 4.488, 6.039, 7.822, 9.189) m / s, where P is the rolling pressure P of Invar alloy in each pass. j= (34794, 33846, 32802, 28897, 24292, 18082, 14441) kN, roll surface temperature T g =65℃, inter-rack cooling water temperature T w =25℃, water flow density q w =1.7m 3 / (m 2 ×h), the distance between the racks is L=4m.

[0164] (b) Given the in-situ parameters and hot rolling process parameters of the invar alloy, including: the initial width of the invar alloy B = 1572 mm, the initial thickness of the invar alloy h0 = 36.91 mm, and the density of the invar alloy ρ = 8100 kg / m³. 3 The specific heat capacity of the Invar alloy is c = 515 J / (kg×K), and the initial deformation resistance is σ0 = 211.21 MPa (i.e., at a temperature of 1000℃, a deformation degree of 0.21, and a deformation rate of 8.09 s). -1 Under the test conditions, the deformation resistance (measured by high temperature and high speed deformation resistance test) of Invar alloy at the exit thickness h in the j-th pass. j = (24.2648, 15.8409, 10.9747, 7.8089, 5.9477, 4.6572, 4.0520) mm, inlet temperature T of the first pass. 01 =980℃.

[0165] (c) Based on the parameters from steps (a) and (b), calculate the outlet temperature T of the j-th pass. 1j =T 1j-1 +ΔT Hj +ΔT fj -ΔT tj -ΔT cj ;

[0166] The temperature rise ΔT caused by the plastic deformation is determined according to the following formula (1). Hj :

[0167]

[0168] In equation (1), the absorption efficiency η for passes 1 to 7 is... j The values ​​are (0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6), and J1 = 9.81.

[0169] The frictional temperature rise ΔT is determined according to the following formula (2). fj :

[0170]

[0171] In equation (2), A = 4.184;

[0172] K1 = 1.0; K3 = 1.42;

[0173] In the formula for calculating K2, B = 0.10629, D = 1.07628, E = 2.09331, and x0 = 5.42754;

[0174] The temperature drop ΔT caused by the contact roll is determined according to the following formula (3). tj :

[0175]

[0176] In formula (3), the thickness of the iron oxide scale is s = 100 μm; the thermal conductivity of the Invar alloy is λ = 3.9 cal / (cm × s × ℃).

[0177] The frictional temperature rise ΔT is determined according to the following formula (4). cj :

[0178]

[0179] In Equation (4), the formula for calculating the water-cooled heat transfer coefficient α contains x, y, and z, which are all regression coefficients: x = 198.54, y = 2.312, and z = -0.00032.

[0180] The length l of the deformation zone in the j-th pass is determined according to the following formula. j :

[0181]

[0182] The actual deformation degree e of the Invar alloy in the j-th pass is determined according to the following formula. j :

[0183]

[0184] The average deformation rate u of the Invar alloy in the j-th pass is determined according to the following formula. mj :

[0185]

[0186] (d) Based on the exit temperature T of the j-th pass 1j The deformation resistance σ of the Invar alloy in the j-th pass is determined according to the following formula (5). j ;

[0187]

[0188] In equation (5), the regression coefficients {a1,a2,a3,a4,a5,a6} of the deformation resistance model of Invar alloy are {-1.900,2.641,0.433,-0.427,0.175,1.360}.

[0189] Repeat steps (c) and (d) to calculate the outlet temperature T for 7 passes. 1j and deformation resistance σ j :

[0190] The first pass, the inlet temperature of the Invar alloy is T. 01 =980℃, calculate ΔT H1 =0.321℃, ΔT f1 =0.0010℃, ΔT t1 =0.037℃, ΔT c1 =10.81℃, then the first pass exit temperature T 11 =T 01 +ΔT H1 +ΔT f1 -ΔT t1 -ΔT c1 =969.46℃, in formula (5), e1 = 1.52, u m1 =8.58, K s =-0.68; Substituting into formula (5), the deformation resistance of the first pass of Invar alloy σ1 is calculated to be 229.61MPa.

[0191] The second pass, the inlet temperature of the Invar alloy is T. 02 =969.46℃, calculate ΔT H2 =0.29℃, ΔT f2 =0.0022℃, ΔT t2 =0.031℃, ΔT c2 =11.18℃, then the outlet temperature T of the second pass is... 12 =T 02 +ΔT H2 +ΔT f2 -ΔT t2 -ΔT c2 =958.54℃, in formula (5), e2 = 1.53, u m2 =15.61, K s =-7.0; Substituting into formula (5), the deformation resistance of the second pass Invar alloy σ2 = 247.44 MPa is calculated.

[0192] The third pass, with an inlet temperature of T for the Invar alloy. 03 =958.5℃, calculate ΔT H3 =0.23℃, ΔT f3 =0.0027℃, ΔTt3 =0.024℃, ΔT c3 =11.09℃, then the outlet temperature T of the third pass is... 13 =T 03 +ΔT H3 +ΔT f3 -ΔT t3 -ΔT c3 =947.66℃, in formula (5), e3 = 1.44, u m3 =25.21, K s =-0.56; Substituting into formula (5), the deformation resistance of the third pass Invar alloy σ3 = 284.65 MPa is calculated.

[0193] The fourth pass, the inlet temperature of the Invar alloy is T. 04 =947.66℃, calculate ΔT H4 =0.18℃, ΔT f4 =0.0034℃, ΔT t4 =0.019℃, ΔT c4 =11.90℃, then the fourth pass exit temperature T 14 =T 04 +ΔT H4 +ΔT f4 -ΔT t4 -ΔT c4 =936.92℃, in formula (5), e4=1.40, u m4 =40.95, K s =-0.51; Substituting into formula (5), the fourth deformation resistance σ4 = 311.99 MPa is calculated.

[0194] The fifth pass, the inlet temperature of the Invar alloy is T. 05 =936.92℃, calculate ΔT H5 =0.11℃, ΔT f5 =0.0033℃, ΔT t5 =0.014℃, ΔT c5 =10.55℃, then the outlet temperature T of the fifth pass is... 15 =T 05 +ΔT H5 +ΔT f5 -ΔT t5 -ΔT c5 =926.47℃, in formula (5), e5 = 1.31, u m5 =60.25, K s =-0.37; Substituting into formula (5), the deformation resistance of the fifth pass Invar alloy σ5 = 349.23 MPa is calculated.

[0195] For the sixth pass, the inlet temperature of the Invar alloy is T. 06 =926.47℃, calculate ΔT H6 =0.07℃, ΔT f6 =0.0033℃, ΔT t6 =0.011℃, ΔT c6 =10.32℃, then the outlet temperature T of the sixth pass is... 16 =T 06 +ΔT H6 +ΔT f6 -ΔT t6 -ΔT c6 =916.21℃, in formula (5), e6 = 1.27, u m6 =86.24, K s =-0.32; Substituting into formula (5), the deformation resistance of the sixth pass Invar alloy σ6 = 372.28 MPa is calculated.

[0196] The seventh pass, the inlet temperature of the Invar alloy is T. 07 =916.21℃, calculate ΔT H7 =0.02℃, ΔT f7 =0.0021℃, ΔT t7 =0.01℃, ΔT c7 =10.01℃, then the outlet temperature T of the seventh pass is... 17 =T 07 +ΔT H7 +ΔT f7 -ΔT t7 -ΔT c7 =906.21℃, in formula (5), e7 = 1.49, u m7 =78.22, K s =-0.13; Substituting into formula (5), the deformation resistance of the seventh pass Invar alloy σ7 = 391.35 MPa is calculated.

[0197] Example 2:

[0198] The difference between this embodiment and Embodiment 1 is that:

[0199] In step (a), the diameter D of each pass of the rolling mill... j = (809.56, 826.07, 794.82, 777.91, 659.94, 610.87, 634.87) mm, where v is the rolling speed v of Invar alloy in each pass. j = (2.031, 3.188, 4.559, 6.336, 8.342, 10.514, 12.036) m / s, where P is the rolling pressure P of Invar alloy in each pass. j= (26123,28958,23829,20652,17613,12037,9691) kN, water flow density q w =1.6m 3 / (m 2 ×h);

[0200] In step (b), the initial thickness h0 of the Invar alloy is 34.6653 mm, and the outlet thickness h of the Invar alloy in the j-th pass is... j = (22.7598, 14.4369, 10.1590, 7.3804, 5.6845, 4.5570, 4.0460) mm; Inlet temperature T of the first pass. 01 =980℃;

[0201] In step (c), in the formula for calculating K2 in formula (2), B = 0.10629, D = 1.07628, E = 2.09331, x0 = 5.42754;

[0202] The remaining parameters and formulas for steps (a) to (d) are the same as in Example 1.

[0203] Repeat steps (c) and (d) to calculate the outlet temperature T for 7 passes. 1j and deformation resistance σ j :

[0204] The first pass, the inlet temperature of the Invar alloy is T. 01 =980℃, calculate ΔT H1 =0.241℃, ΔT f1 =0.00095℃, ΔT t1 =0.028℃, ΔT c1 = 8.484℃, then the first pass exit temperature T 11 =T 01 +ΔT H1 +ΔT f1 -ΔT t1 -ΔT c1 =971.73℃, in formula (5), e1 = 1.52, u m1 =12.09, K s =-0.6874; Substituting into formula (5), the deformation resistance of the first pass of Invar alloy σ1 is calculated to be 237.17MPa.

[0205] The second pass, the inlet temperature of the Invar alloy is T. 02 =971.73℃, calculate ΔT H2 =0.273℃, ΔT f2 =0.0023℃, ΔT t2 =0.023℃, ΔTc2 = 8.46℃, then the outlet temperature T of the second pass is... 12 =T 02 +ΔT H2 +ΔT f2 -ΔT t2 -ΔT c2 =963.51℃, in formula (5), e2 = 1.57, u m2 =24.76, K s =-0.7673; Substituting into formula (5), the deformation resistance of the second pass Invar alloy σ2 is calculated to be 247.94MPa.

[0206] The third pass, with an inlet temperature of T for the Invar alloy. 03 =963.51℃, calculate ΔT H3 =0.16℃, ΔT f3 =0.0027℃, ΔT t3 =0.017℃, ΔT c3 = 8.36℃, then the outlet temperature T of the third pass is... 13 =T 03 +ΔT H3 +ΔT f3 -ΔT t3 -ΔT c3 =955.29℃, in formula (5), e3 = 1.42, u m3 =36.78, K s =-0.5357; Substituting into formula (5), the deformation resistance of the third pass Invar alloy σ3 = 298.15MPa is calculated.

[0207] The fourth pass, the inlet temperature of the Invar alloy is T. 04 =955.29℃, calculate ΔT H4 =0.12℃, ΔT f4 =0.0030℃, ΔT t4 =0.013℃, ΔT c4 = 8.23℃, then the fourth pass exit temperature T 14 =T 04 +ΔT H4 +ΔT f4 -ΔT t4 -ΔT c4 =947.17℃, in formula (5), e4=1.37, u m4 =57.32, K s =-0.4698; Substituting into formula (5), the fourth deformation resistance σ4 = 325.73 MPa is calculated.

[0208] The fifth pass, the inlet temperature of the Invar alloy is T. 05=947.17℃, calculate ΔT H5 =0.07℃, ΔT f5 =0.0028℃, ΔT t5 =0.010℃, ΔT c5 = 8.07℃, then the fifth pass exit temperature T 15 =T 05 +ΔT H5 +ΔT f5 -ΔT t5 -ΔT c5 =939.17℃, in formula (5), e5 = 1.29, u m5 =83.11, K s =-0.3551; Substituting into formula (5), the deformation resistance of the fifth pass Invar alloy σ5 = 359.01 MPa is calculated.

[0209] For the sixth pass, the inlet temperature of the Invar alloy is T. 06 =939.17℃, calculate ΔT H6 =0.04℃, ΔT f6 =0.0026℃, ΔT t6 =0.0079℃, ΔT c6 =7.93℃, then the outlet temperature T of the sixth pass is... 16 =T 06 +ΔT H6 +ΔT f6 -ΔT t6 -ΔT c6 =931.27℃, in formula (5), e6 = 1.24, u m6 =110.74, K s =-0.2808; Substituting into formula (5), the deformation resistance of the sixth Invar alloy is calculated to be σ6 = 382.27 MPa.

[0210] The seventh pass, the inlet temperature of the Invar alloy is T. 07 =931.27℃, calculate ΔT H7 =0.016℃, ΔT f7 =0.0015℃, ΔT t7 =0.0056℃, ΔT c7 =7.76℃, then the outlet temperature T of the seventh pass is... 17 =T 07 +ΔT H7 +ΔT f7 -ΔT t7 -ΔT c7 =923.52℃, in formula (5), e7 = 1.12, u m7 =94.29, K s=-0.1061; Substituting into formula (5), the deformation resistance of the seventh pass Invar alloy σ7 = 391.94 MPa is calculated.

[0211] Example 3:

[0212] The difference between this embodiment and embodiment 1 is that in formula (2), A = 4.0; K3 = 1.45;

[0213] In the formula for calculating K2, B = 0.1, D = 2, E = 1.5, and x0 = 6;

[0214] The remaining parameters and formulas for steps (a) to (d) are the same as in Example 1.

[0215] Example 4:

[0216] The difference between this embodiment and embodiment 1 is that in formula (2), A = 4.5; K3 = 1.40;

[0217] In the formula for calculating K2, B = 0.2, D = 1, E = 2.5, and x0 = 5;

[0218] The remaining parameters and formulas for steps (a) to (d) are the same as in Example 1.

[0219] Example 5:

[0220] The difference between this embodiment and embodiment 1 is that in formula (4), x = 197, y = 2.34, z = -0.00030; the remaining parameters and formulas in steps (a) to (d) are the same as in embodiment 1.

[0221] Example 6:

[0222] The difference between this embodiment and embodiment 1 is that in formula (4), x = 200, y = 2.28, z = -0.00035; the remaining parameters and formulas in steps (a) to (d) are the same as in embodiment 1.

[0223] Comparative Example 1

[0224] The difference between this embodiment and embodiment 1 is that in formula (5), the regression coefficients {a1,a2,a3,a4,a5,a6} of the deformation resistance model of Invar alloy are {-1.900, 2.581, 0.493, -0.472, 0.185, 1.345}; the remaining parameters and formulas of steps (a) to (d) are the same as those in embodiment 1.

[0225] Comparative Example 2

[0226] The difference between this embodiment and embodiment 1 is that in formula (5), the regression coefficients {a1,a2,a3,a4,a5,a6} of the deformation resistance model of Invar alloy are {-1.925, 2.466, 0.493, -0.409, 0.153, 1.231}; the remaining parameters and formulas of steps (a) to (d) are the same as those in embodiment 1.

[0227] Comparative Example 3

[0228] The difference between this embodiment and embodiment 1 is that in formula (5), the regression coefficients {a1,a2,a3,a4,a5,a6} of the deformation resistance model of Invar alloy are {-1.935, 2.466, 0.493, -0.403, 0.157, 1.231}; the remaining parameters and formulas of steps (a) to (d) are the same as those in embodiment 1.

[0229] Comparative Example 4

[0230] The difference between this embodiment and embodiment 1 is that in formula (5), the regression coefficients {a1,a2,a3,a4,a5,a6} of the deformation resistance model of Invar alloy are {-2.010, 2.566, 0.493, -0.409, 0.163, 1.231}; the remaining parameters and formulas of steps (a) to (d) are the same as those in embodiment 1.

[0231] Table 1. Predicted values ​​of deformation resistance in the embodiments and comparative examples of the present invention.

[0232]

[0233] Table 2 Predicted values ​​of deformation resistance in embodiments of the present invention

[0234]

[0235] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for predicting deformation resistance in the hot rolling process of Invar alloys, characterized in that, Includes the following steps: (a) Collect the main equipment and process parameters of the hot rolling mill, including: the number of passes N, and the diameter D of the rolls in each pass. j The rolling speed ν of each pass j Rolling pressure P in each pass j Roll surface temperature T g The distance between racks, L; the cooling water temperature between racks, T. w water flow density q w j represents the j-th pass; (b) Given the incoming parameters and hot rolling process parameters of the Invar alloy, including: the initial width B, initial thickness h0, density ρ, specific heat capacity c, initial deformation resistance σ0, and the deformation resistance σ of the Invar alloy in the j-th pass. j The exit thickness h of the j-th pass j The inlet temperature T of the j-th pass 0j The exit temperature T of the j-th pass 1j ; (c) Based on the parameters from steps (a) and (b), calculate the outlet temperature T of the j-th pass. 1j =T 1j-1 +ΔT Hj +ΔT fj -ΔT tj -ΔT cj ; Where, ΔT Hj The temperature rise caused by plastic deformation, ΔT fj For frictional temperature rise, ΔT tj The temperature drop caused by contact with the rolls, ΔT cj Temperature drop caused by cooling water; 1 < j ≤ N; (d) Based on the exit temperature T of the j-th pass 1j The deformation resistance σ of the Invar alloy in the j-th pass is determined according to the following formula. j ; In the formula, u mj The average deformation rate of the Invar alloy in the j-th pass is expressed in seconds. -1 e j For the actual deformation degree of the Invar alloy in the j-th pass, a1 = -1.89 to -2.05, a2 = 2.4 to 2.6, a3 = 0.2 to 0.6, a4 = -0.2 to -0.4, a5 = 0.1 to 0.2, a6 = 1.0 to 1.3; T 1j The unit is ℃, and the unit of σ0 is MPa; Repeat steps (c) to (d) to calculate the deformation resistance from the first pass to the Nth pass.

2. The forecasting method according to claim 1, characterized in that, In step (c), the frictional temperature rise ΔT is determined according to the following formula. fj : In the formula, A is the friction temperature rise influence coefficient, which is taken as 4.0 to 4.5; K1 is the influence coefficient of the roll material, and the value of K1 ranges from 0.8 to 1.0; K2 is the rolling speed influence coefficient, B = 0.1~0.2, D = 1~2, E = 1.5~2.5, x0 = 5~6, ν j The unit is m / s; K3 is the influence coefficient of the rolled material, and the value of K3 is 1.40 to 1.45; l j T represents the length of the deformation zone in the j-th pass, in mm. 0j The unit is ℃; h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm. σ j-1 The deformation resistance for the (j-1)th pass is expressed in MPa. h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm. The unit of ρ is kg / m³ 3 The unit of c is J / (kg×K), ν j The unit is m / s.

3. The forecasting method according to claim 1, characterized in that, In step (c), the temperature drop ΔT caused by the cooling water is determined according to the following formula. cj : In the formula, T 0j and T w The unit is ℃, the unit of L is m, and the unit of h is h. j The unit is mm, ν j The unit is m / s, q w The unit is m 3 / (m 2 ×h), α is the water-cooled heat transfer coefficient, e is the actual deformation degree of the Invar alloy in the j-th pass, x, y, and z are all regression coefficients, x = 197~200, y = 2.28~2.34, z = -0.00030~-0.00035.

4. The forecasting method according to claim 1, characterized in that, In step (c), the temperature drop ΔT caused by the contact roll is determined according to the following formula. tj : In the formula, s is the thickness of the iron oxide scale, in μm; λ is the thermal conductivity of Invar alloy, with units of cal / (cm×s×℃); h mj This represents the average inlet and outlet thicknesses for the j-th pass, in mm. l j The length of the deformation zone in the j-th pass is in mm. ν j The unit is m / s; T 0j and T g The unit is ℃; the unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

5. The forecasting method according to claim 4, characterized in that, The thickness of the iron oxide scale is s = 7 μm to 14 μm; and / or, The thermal conductivity of the Invar alloy is λ = 0.02 to 0.04 cal / (cm×s×℃).

6. The forecasting method according to claim 1, characterized in that, In step (c), the temperature rise ΔT caused by the plastic deformation is determined according to the following formula. Hj : In the formula, η j For absorption efficiency, η j The range is 50% to 90%, satisfying η j-1 ≥η j , 1 < j ≤ N; h j-1 and h j Here are the inlet and outlet thicknesses for the j-th pass, in mm. P j The rolling pressure for the j-th pass is expressed in kN. J1 is the mechanical equivalent of heat, J1 = 9.81; The unit of density ρ is kg / m³. 3 The unit of specific heat capacity c is J / (kg×K).

7. The forecasting method according to claim 1, characterized in that, In step (b), the initial deformation resistance σ0 is obtained experimentally under certain test conditions, including a strip temperature of 950–1100°C and a deformation rate of 5–10 s. -1 And the degree of deformation is 0.1 to 0.

3.

8. The forecasting method according to claim 1, characterized in that, In step (a), the surface temperature T of the roll is... g =55~75℃; and / or, The inter-rack cooling water temperature T w =20~30℃; and / or, The water flow density q w =1.5~2.0m 3 / (m 2 ×h).

9. The forecasting method according to claim 2 or 4, characterized in that, The length l of the deformation zone in the j-th pass is determined according to the following formula. j : In the formula, h j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. j The diameter of the j-th rolling mill roll is in mm.

10. The forecasting method according to claim 1, characterized in that, The average deformation rate u of the Invar alloy in the j-th pass is determined according to the following formula. mj : In the formula, ν j h is the rolling speed of the j-th pass, in m / s. j-1 and h j D represents the inlet and outlet thicknesses for the j-th pass, in mm. j The diameter of the j-th rolling mill roll is in mm.

11. The forecasting method according to claim 1, characterized in that, In step (a), the rolling speed ν for each pass j The value range is 1.49–9.19 m / s; and / or, Rolling pressure P in each pass j The value range is 14000~37000kN.

12. The application of the forecasting method according to any one of claims 1-11 in the preparation of Invar alloys for use in precision optics, semiconductors, LNG transportation and consumer electronics.

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