Method, system and equipment for predicting ultimate tensile strength of high-temperature alloy and medium
By constructing the strain energy density model using Hollomon constitutive equation, the problem of difficulty in constructing the ultimate tensile strength prediction model of high-temperature alloy is solved, and quantitative prediction of the ultimate tensile strength of high-temperature alloy at different temperatures is achieved.
Patent Information
- Application Number
- CN202510151328.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-05-30
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
It is difficult to build the existing high-temperature alloy ultimate tensile strength prediction model and requires a large amount of experimental data, which makes it very difficult to build the theoretical model.
The tensile flow process and strain hardening behavior of high-temperature alloys under uniaxial tensile tension were used to describe the tensile flow process and strain hardening behavior of high-temperature alloys under uniaxial tensile strength prediction model, and based on this model, the ultimate tensile strength prediction model of high-temperature alloys was constructed.
Through this method, the ultimate tensile strength prediction model of high-temperature alloy can be simply constructed, which can be achieved with only a small amount of data, and quantitatively predict the ultimate tensile strength of high-temperature alloy at different temperatures.
Smart Images
Figure CN120072145A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of advanced materials, and particularly relates to a method, system, device and medium for predicting the ultimate tensile strength of superalloys. Background Art
[0002] With the development of modern industry, many materials will be affected by different temperatures in their service environments. For example, when nickel-based superalloys are used in pressure vessels and nuclear reactors, they need to withstand harsh high-temperature environments. Therefore, they are required to have good mechanical properties in a wide temperature range. And the ultimate strength or ultimate tensile strength (UTS) represents the maximum load-bearing capacity of a structure. Therefore, predicting the ultimate tensile strength of superalloys at different temperatures is very important for structural design.
[0003] Currently, some existing models also consider the influence of temperature on the macroscopic ultimate tensile strength of materials. However, the fitting of these models requires a large amount of experimental data. Generally speaking, experimental data in the full temperature range are needed, which makes it very difficult to construct a theoretical model. Summary of the Invention
[0004] In order to overcome the deficiency of the difficult construction of the prediction model for the ultimate tensile strength of superalloys, the present invention provides a method for predicting the ultimate tensile strength of superalloys, including the following steps:
[0005] Use the Hollomon constitutive equation to describe the tensile flow process and strain hardening behavior of superalloys under uniaxial tension, and construct a strain energy density model; construct a prediction model for the ultimate tensile strength of superalloys according to the strain energy density model;
[0006] Obtain the melting point of the superalloy, the strength coefficient and strain hardening index of the superalloy at room temperature, input the melting point of the superalloy, the strength coefficient and strain hardening index of the superalloy at room temperature into the prediction model for the ultimate tensile strength, and quantitatively predict the ultimate tensile strength of the superalloy at different temperatures.
[0007] The strain energy density model is:
[0008]
[0009] In the formula, K(T 0 ) and N(T 0 ) are the strength coefficient and strain hardening index at the reference temperature T 0 respectively, σ t (T 0 ) is the stress at the reference temperature T 0 , T m is the melting point of the material, and T is the temperature.
[0010] The prediction model for the ultimate tensile strength of the superalloy is as follows:
[0011]
[0012] In the formula, σ u (T) is the ultimate tensile strength at a certain temperature, σ u (T 0 ) is the ultimate tensile strength at the reference temperature T 0 , K(T 0 ) and N(T 0 ) are the strength coefficient and strain hardening exponent at the reference temperature T 0 respectively, T m is the melting point of the material, and T is the temperature.
[0013] The present invention also provides a prediction system for the ultimate tensile strength of a superalloy, including:
[0014] A model construction module, which is used to describe the tensile flow process and strain hardening behavior of the superalloy under uniaxial tension using the Hollomon constitutive equation, and construct a strain energy density model; construct a prediction model for the ultimate tensile strength of the superalloy according to the strain energy density model;
[0015] An ultimate tensile strength prediction module, which is used to obtain the melting point of the superalloy, the strength coefficient and strain hardening exponent of the superalloy at room temperature, input the melting point of the superalloy, the strength coefficient and strain hardening exponent of the superalloy at room temperature into the ultimate tensile strength prediction model, and quantitatively predict the ultimate tensile strength of the superalloy at different temperatures.
[0016] The present invention also provides a computer device, including a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the method for predicting the ultimate tensile strength of the superalloy.
[0017] The present invention also provides a computer-readable storage medium, which stores a computer program, and the computer program is suitable for being loaded by a processor to execute the method for predicting the ultimate tensile strength of the superalloy.
[0018] The method for predicting the ultimate tensile strength of the superalloy provided by the present invention has the following beneficial effects:
[0019] The present invention can construct a strain energy density model by using the Hollomon constitutive equation to describe the tensile flow process and strain hardening behavior of superalloys under uniaxial tension, and the model construction process is very simple; according to the strain energy density model, a prediction model for the ultimate tensile strength of superalloys can be constructed, and this process can be achieved with only a small amount of data; by inputting the melting point of the superalloy, the strength coefficient and strain hardening index of the superalloy at room temperature into the ultimate tensile strength prediction model, the ultimate tensile strength of the superalloy at different temperatures can be predicted. Description of the Drawings
[0020] In order to more clearly illustrate the embodiments of the present invention and their design schemes, the accompanying drawings required for this embodiment will be briefly introduced below. The drawings in the following description are only partial embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0021] Figure 1 Flowchart of the method for predicting the ultimate tensile strength of the superalloy in the embodiment of the invention;
[0022] Figure 2 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 600 and Inconel 690;
[0023] Figure 3 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 718;
[0024] Figure 4 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 625;
[0025] Figure 5 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 617;
[0026] Figure 6 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 750 in a certain temperature range;
[0027] Figure 7 Schematic diagram of the comparison between the prediction results and experimental data of Inconel 750 in another temperature range;
[0028] Figure 8 Schematic diagram of the comparison between the prediction results and experimental data of the iron-based alloy Incoloy 800H;
[0029] Figure 9 Schematic diagram of the comparison between the prediction results and experimental data of a certain cobalt-based alloy;
[0030] Figure 10Schematic diagram of the comparison between the predicted results and experimental data of another cobalt-based alloy. Detailed implementation mode
[0031] In order to enable those skilled in the art to better understand the technical solution of the present invention and be able to implement it, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.
[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the technical solution of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.
[0033] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified or limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In the description of the present invention, unless otherwise stated, the meaning of "plurality" is two or more, and details are not described herein again.
[0034] Embodiment
[0035] The present invention provides a method for predicting the ultimate tensile strength of a superalloy, specifically as Figure 1 shown, including the following steps:
[0036] Step 1: Use the Hollomon constitutive equation to describe the tensile flow process and strain hardening behavior of the superalloy under uniaxial tension, and construct a strain energy density model; construct a prediction model for the ultimate tensile strength of the superalloy according to the strain energy density model. The specific process is as follows:
[0037] The strain energy (per unit volume) required to reach the ultimate tensile strength of the material can be calculated by integrating the constitutive equation and can be written as follows:
[0038]
[0039] The Hollomon constitutive equation is described as follows:
[0040]
[0041] Where, σ t (T) is the true stress, ε(T) is the true strain, E is the elastic modulus, σ ty is the yield stress, K is the strength coefficient, and N is the strain hardening index or work hardening index.
[0042] After derivation and simplification, the strain energy density model at the reference temperature T 0 (room temperature in this embodiment) is:
[0043]
[0044] The process of obtaining the ultimate tensile strength prediction model is as follows:
[0045] First, the true stress tensile strength model is:
[0046]
[0047] Where, K(T) and N(T) are the strength coefficient and strain hardening index at temperature T respectively, and K(T 0 ) and N(T 0 ) are the strength coefficient and strain hardening index at the reference temperature T 0 respectively.
[0048] (2) According to the relationship between engineering strain and hardening index (Formulas (5) and (6)):
[0049]
[0050] 1 + ε u (T) = e N (6);
[0051] Based on Formula (4), we can obtain:
[0052]
[0053] The evolution functions of the strength coefficient and hardening index with temperature are:
[0054]
[0055] Substituting Formula (8) into Formula (7), we can obtain the ultimate tensile strength prediction model of the superalloy:
[0056]
[0057] wherein, σ u (T) is the ultimate tensile strength at a certain temperature, σ u (T 0 ) is the ultimate tensile strength at the reference temperature T 0 , ε u (T) is the strain at a certain temperature, ε u (T 0 ) is the strain at the reference temperature T 0 , K(T 0 ) and N(T 0 ) are respectively the strength coefficient and the strain hardening exponent at the reference temperature T 0 , T m is the melting point of the material, and T is the temperature.
[0058] Step 2: Obtain the melting point of the superalloy, construct a prediction model for the ultimate tensile strength of the superalloy based on the melting point of the superalloy and the strength coefficient and strain hardening exponent at different temperatures, and use the prediction model for the ultimate tensile strength to quantitatively predict the ultimate tensile strength of the superalloy at different temperatures.
[0059] The present invention also provides a prediction system for the ultimate tensile strength of a superalloy, including a model construction module and an ultimate tensile strength prediction module. The model construction module is used to describe the tensile flow process and strain hardening behavior of the superalloy under uniaxial tension using the Hollomon constitutive equation, construct a strain energy density model, and obtain the strength coefficient and strain hardening exponent of the superalloy at different temperatures according to the strain energy density model; the ultimate tensile strength prediction module is used to obtain the melting point of the superalloy, construct a prediction model for the ultimate tensile strength of the superalloy based on the strain energy density model, the melting point of the superalloy, and the strength coefficient and strain hardening exponent at different temperatures, and use the prediction model for the ultimate tensile strength to quantitatively predict the ultimate tensile strength of the superalloy at different temperatures.
[0060] The present invention also provides a computer device, including a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the method for predicting the ultimate tensile strength of the superalloy.
[0061] The present invention also provides a computer-readable storage medium, which stores a computer program, and the computer program is suitable for being loaded by a processor to execute the method for predicting the ultimate tensile strength of the superalloy.
[0062] To verify the accuracy of the prediction model for the ultimate tensile strength constructed by the present invention ×, the present invention compares the prediction results of the constructed prediction model for the ultimate tensile strength with the experimental data of 10 groups of superalloys at different temperatures. Figure 2The comparison results of Inconel 600 and Inconel 690 Figure 3 The comparison results of Inconel 718 Figure 4 The comparison results of Inconel 625; Figure 5 For Inconel 617; Figure 6 and Figure 7 The comparison results of Inconel 750 at different temperature ranges respectively. It can be seen from the model prediction results and experimental data that the prediction results of the ultimate tensile strength prediction model of the present invention are basically consistent with the experimental data. Generally speaking, the UTS value decreases with the increase of temperature; this can be attributed to the softening effect of high temperature on the material, and the hardening behavior gradually weakens. However, some experimental results also show abnormal changes, and the prediction results reveal some deviations from the experimental data. For example, the reason for the lack of accurate prediction of Inconel 750 at 1173K is due to dynamic recovery and dynamic recrystallization, which affect strain hardening. After reaching a certain temperature, dynamic recovery and dynamic recrystallization dominate, and at this time the strain hardening of the material becomes very weak or non-existent, which causes deviations in the model prediction. The research object of the present invention is the temperature-related UTS after work hardening of the material. However, at these temperatures, the strain hardening of the material has disappeared. Therefore, considering these facts, it is reasonable that there are certain deviations in the prediction results within this temperature range. Considering similar service environments, the model of the invention is also applicable to iron-based and cobalt-based alloys. Figure 8 Shows the prediction results of the ultimate tensile strength prediction model of the present invention for the UTS of the iron-based alloy Incoloy 800H and the experimental comparison results. Figure 9 and Figure 10The predicted results of the ultimate tensile strength prediction model of the present invention for the UTS of two cobalt-based alloys and the experimental comparison results are shown respectively. The comparison results show that the effectiveness of the model for predicting the temperature-dependent UTS of nickel-based and cobalt-based alloys is valid in a wide temperature range (approximately from room temperature to 800 °C). The verification results for iron-based alloys show better prediction from room temperature to 700 °C. The model of the present invention only requires a few easily obtainable parameters, and all parameters have physical meanings, which is more advantageous than fitting experimental data in all temperature ranges. The inventive model can predict the temperature-dependent UTS only using the UTS, strength coefficient, and strain hardening exponent at a reference temperature (usually room temperature). The present invention has achieved good results using this simple model. For the strain hardening exponent (N) and strength coefficient (K) at room temperature, according to the stress-strain relationship of the material, they can be conveniently determined from the true stress-strain experimental results in a double logarithmic coordinate system through the Hollomon relationship. In fact, as long as the material conforms to the Hollomon constitutive equation, N and K can be obtained before the material reaches the UTS, and the specific measurement method can refer to ASTM standard E646. In addition, the present invention also notes the development of the automated ball indentation technique, which allows K and N to be obtained in a non-destructive manner at room temperature. If this technique can be combined with the model proposed by the present invention, it will be easier to obtain the mechanical material properties at high temperatures.
[0063] It should be noted that the inventive model does not directly consider the evolution of micro-mechanisms (such as grain size and dislocation density) with temperature, although the present invention indirectly considers their effects using the strain hardening exponent, strength coefficient, and UTS at the reference temperature. However, dynamic recovery and recrystallization occur at relatively high temperatures, which have a great impact on the UTS of the material, resulting in certain deviations in the prediction. However, it is necessary to explain that generally, for safety and service life, materials are recommended to be used within a certain temperature range. At temperatures where strong dynamic recovery and recrystallization occur, this has exceeded the optimal use temperature of the material. Therefore, most materials are not allowed to be used at such temperatures. The present invention does not deny that there are some deviations in the prediction at very high temperatures, but the ultimate tensile strength prediction model of the superalloy constructed by the present invention can effectively predict the UTS of the material in the temperature environment that the material often faces in practice, and has met the application requirements under engineering conditions.
[0064] The above-described embodiments are only the preferred specific embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope disclosed by the present invention all belong to the protection scope of the present invention.
Claims
1. A method for predicting the ultimate tensile strength of a high-temperature alloy over a wide temperature range, characterized in that: The steps include: The Hollomon constitutive equation is used to describe the tensile flow process and strain hardening behavior of the high-temperature alloy under uniaxial tension, and a strain energy density model is constructed. Based on the strain energy density model, a prediction model for the ultimate tensile strength of the high-temperature alloy is constructed. The melting point, strength coefficient and strain hardening exponent of the high-temperature alloy are obtained, the melting point, strength coefficient and strain hardening exponent of the high-temperature alloy are input into the ultimate tensile strength prediction model, and the ultimate tensile strength of the high-temperature alloy at different temperatures is quantitatively predicted.
2. The method for predicting the ultimate tensile strength of a high-temperature alloy according to claim 1, characterized in that: The strain energy density model is: Where K(T0) and N(T0) are the strength coefficient and strain hardening exponent at the reference temperature T0, respectively, and σ t (T0) is the stress at reference temperature T0, T m is the melting point of the material and T is the temperature.
3. The method for predicting the ultimate tensile strength of a high-temperature alloy according to claim 1, characterized in that: The temperature-dependent high-temperature alloy ultimate tensile strength prediction model is: In the formula, σ u (T) is the ultimate tensile strength at a certain temperature, σ u (T0) is the ultimate tensile strength at the reference temperature T0, K(T0) and N(T0) are the strength coefficient and strain hardening exponent at the reference temperature T0, respectively. m is the melting point of the material and T is the temperature.
4. A high temperature alloy ultimate tensile strength prediction system, characterized in that: include: Model building module, used to describe the tensile flow process and strain hardening behavior of high-temperature alloys under uniaxial tension using the Hollomon constitutive equation, and to construct a strain energy density model; based on the strain energy density model, a prediction model for the ultimate tensile strength of high-temperature alloys is constructed; The ultimate tensile strength prediction module is used to obtain the melting point, strength coefficient and strain hardening exponent of the high-temperature alloy at room temperature, input the melting point, strength coefficient and strain hardening exponent of the high-temperature alloy at room temperature into the ultimate tensile strength prediction model, and quantitatively predict the ultimate tensile strength of the high-temperature alloy at different temperatures.
5. A computer device, characterized in that: It comprises a memory and a processor; the memory stores a computer program, and the processor is used to run the computer program in the memory to execute the method for predicting the ultimate tensile strength of a high-temperature alloy according to any one of claims 1 to 3.
6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded by a processor to execute the method for predicting the ultimate tensile strength of a high-temperature alloy according to any one of claims 1 to 3.