A method for predicting the brittle-ductile transition temperature of a high-strength structural steel material

Abstract

The application provides a prediction and analysis method for the ductile-brittle transition temperature of high-strength structural steel material, which is determined by conducting Charpy impact tests and dynamic tear tests at a specific temperature, and establishing the ETT of the impact sample ductile-brittle transition temperature and the dynamic tear sample ductile-brittle transition temperature at the specific temperature 50 The correlation analysis establishes the impact ductile-brittle transition temperature and the dynamic tear ductile-brittle transition temperature and the specific temperature T 特定 The impact absorbed energy and the dynamic tear energy correlation model at the specific temperature. The prediction and analysis method for the ductile-brittle transition temperature of the high-strength structural steel material has a clear physical mechanism, greatly reduces the evaluation of the ductile-brittle transition test amount and calculation amount of the high-strength structural steel, is simple to construct, fast to use, and realizes the rapid prediction and evaluation of the impact sample ductile-brittle transition temperature and the dynamic tear sample ductile-brittle transition temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material fracture failure research, and particularly relates to a prediction and analysis method for ductile-brittle transition temperature of high-strength structural steel material. BACKGROUND

[0002] Fracture is one of the main reasons for the failure of metal materials. In a large number of damage accident researches, it is found that the fracture failure is often caused by low-stress brittle damage, which exposes that the traditional strength design method cannot completely guarantee the safety of metal materials and welded structures in use, thereby causing people's widespread attention to the fracture resistance of metal materials and welded structures, and gradually developing many fracture resistance evaluation methods, among which the ductile-brittle transition evaluation method based on the ductile-brittle transition temperature and the fracture mechanics evaluation method based on the fracture toughness parameter are the most representative.

[0003] The ductile-brittle transition evaluation method mainly evaluates metal materials with ductile-brittle transition characteristics, and the commonly used high-strength structural steel in engineering is mainly body-centered cubic structure. When the temperature is lower than a certain specific temperature, the fracture mode is changed from ductile fracture to brittle fracture, which has obvious ductile-brittle transition characteristics. Low-temperature brittle damage is generally low-stress damage, and the crack propagation speed is extremely fast. Once it occurs, it will cause serious safety accidents. Therefore, low-temperature brittle research is a crucial link in the safety evaluation of high-strength structural steel in service.

[0004] At present, there are many test methods for evaluating the ductile-brittle transition characteristics of high-strength structural steel, such as Charpy impact test, dynamic tear test, drop hammer tear test, etc. The ductile-brittle transition temperature value of the steel plate is measured through a series of temperature tests, and is compared with the lowest service temperature of the structure, so as to evaluate the feasibility of high-strength structural steel for low-temperature service environment structure.

[0005] The Charpy impact test has more sensitive advantages than other mechanical property test methods in testing material quality, internal defects, process quality, etc. It is the most commonly used test method for evaluating the ductile-brittle transition characteristics of steel plate at present. The dynamic tear test has larger sample size and higher notch sharpness than the impact test, and is closer to the actual use performance, which is an effective method for evaluating the actual ductile-brittle transition characteristics of high-strength structural steel. At present, the Charpy impact test and the dynamic tear test are the two most commonly used methods for evaluating the ductile-brittle transition characteristics of steel plate. However, both the Charpy impact test and the dynamic tear test need to first measure the impact absorbed energy or dynamic tear energy at different temperatures through a series of temperature tests, and then use the Boltzmann function (y=A2+(A1-A2) / (1+exp((x-x0) / dx))) to fit the ductile-brittle transition temperature and the impact absorbed energy or dynamic tear energy to obtain the ductile-brittle transition temperature value of the steel plate. The series of temperature tests require many samples and many test temperatures, and the test cycle is long, which not only consumes time, but also consumes a lot of manpower and material resources. SUMMARY

[0006] Therefore, the present application aims to provide a prediction analysis method for the ductile-brittle transition temperature of high-strength structural steel material, and relates to a rapid prediction model for determining the ductile-brittle transition temperature, which is a characteristic parameter of the ductile-brittle transition of high-strength structural steel material. 50 The calculation model realizes rapid prediction and evaluation of the ductile-brittle transition temperature of impact samples and the ductile-brittle transition temperature of dynamic tearing samples.

[0007] To achieve the above-mentioned purposes, the technical scheme of the present application is as follows:

[0008] A prediction analysis method for the ductile-brittle transition temperature of high-strength structural steel material, through conducting Charpy impact test and dynamic tearing test at a specific temperature, the ETT 50 of the ductile-brittle transition temperature of impact samples and the ductile-brittle transition temperature of dynamic tearing samples at the specific temperature is analyzed, a correlation model of the impact ductile-brittle transition temperature and the dynamic tearing ductile-brittle transition temperature and the impact absorbed energy and the dynamic tearing energy at the specific temperature T 特定 is established, and specifically includes the following steps:

[0009] S1: a calculation model of the impact absorbed energy at the specific temperature T 特定 and the ductile-brittle transition temperature is established, as shown in formula (1):

[0010]

[0011] In the formula, ETT 50 is the impact ductile-brittle transition temperature, with unit of ℃; is the impact absorbed energy at the specific temperature T 特定 , with unit of J; and α, β, θ are undetermined parameters.

[0012] S2: according to the correlation analysis of the dynamic tearing ductile-brittle transition temperature ETT 50 , a calculation model of the dynamic tearing energy at the specific temperature T 特定 is established, as shown in formula (2)

[0013]

[0014] In the formula, ETT 50 is the dynamic tearing ductile-brittle transition temperature, with unit of ℃; is the dynamic tearing energy at the specific temperature T 特定 , with unit of J; and γ, η are undetermined parameters.

[0015] S3: a series of temperature impact tests and a series of temperature dynamic tear tests are carried out on high-strength structural steels of different strength grades, Boltzmann function is used to fit the relationship between the test temperature and the impact absorbed energy, the relationship between the test temperature and the dynamic tear energy, and the ductile-brittle transition temperature value and the specific temperature T 特定 the lower impact absorbed energy the dynamic tear energy The calculation value or the calculation value range of the undetermined parameters α, β, θ, γ, η obtained by setting the fitting formula.

[0016] Further, step S1 includes the following steps:

[0017] S11: test analysis is carried out on the correlation between the impact absorbed energy and the ductile-brittle transition temperature of high-strength structural steels of different strength grades at typical temperatures A1-A2;

[0018] S12: according to the impact ductile-brittle transition temperature ETT 50 correlation analysis, the specific temperature T 特定 at which the ductile-brittle transition temperature presents an obvious power function relationship is determined.

[0019] S13: a calculation model of the impact absorbed energy at the specific temperature T 特定 temperature is established as formula (1);

[0020] Wherein, A1 and A2 are preset temperature values.

[0021] Further, step S2 includes the following steps:

[0022] S21: the correlation between the dynamic tear energy and the ductile-brittle transition temperature of high-strength structural steels of different strength grades at typical temperatures B1-B2 is analyzed;

[0023] S22: according to the impact ductile-brittle transition temperature ETT 50 correlation analysis, the specific temperature T 特定 at which the ductile-brittle transition temperature and the logarithm of the dynamic tear energy present an obvious linear relationship is determined.

[0024] S23: a calculation model of the dynamic tear energy at the specific temperature T 特定 temperature is established as formula (2);

[0025] Wherein, B1 and B2 are preset temperature values.

[0026] Further, in step S3, the least square method is used for fitting, and the calculation value or the calculation value range of the undetermined parameters α, β, θ, γ, η is calculated.

[0027] Further, the value range of A1-A2 is 20℃- -196℃.

[0028] Further, the value range of B1-B2 is 20℃- -196℃.

[0029] Further, the high-strength structural steel is a structural steel with a tensile strength of 355MPa-690MPa.

[0030] Further, the high-strength structural steel is a high-strength structural steel for ships and bridges.

[0031] Further, the value range of A1-A2 is 0℃- -120℃, and the value range of B1-B2 is 0℃- -120℃, and the specific temperature T 特定 is -120℃.

[0032] Compared with the prior art, the prediction and analysis method of the ductile-brittle transition temperature of the high-strength structural steel material has the following advantages:

[0033] (1) The prediction and analysis method of the ductile-brittle transition temperature of the high-strength structural steel material proposes a Charpy impact specimen ductile-brittle transition temperature and a dynamic tearing specimen ductile-brittle transition temperature prediction model of the high-strength structural steel. The calculation model can be established by measuring the impact absorbed energy or dynamic tearing energy at a fixed temperature, and the rapid prediction and evaluation of the ductile-brittle transition temperature of the high-strength structural steel can be realized, thereby providing a technical basis for the low-temperature brittleness tendency evaluation and anti-brittleness design of the high-strength structural steel.

[0034] (2) The prediction and analysis method of the ductile-brittle transition temperature of the high-strength structural steel material has a clear physical mechanism, greatly reduces the evaluation and calculation amount of the ductile-brittle transition test of the high-strength structural steel, and is simple to construct and fast to use. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which form a part of this application, are used to provide a further understanding of the application. The schematic embodiments of the application and their descriptions are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0036] Figure 1 is a structural diagram of the ductile-brittle transition curve related to the impact absorbed energy and temperature in the embodiment of the application;

[0037] Figure 2 is a structural diagram of the ductile-brittle transition curve related to the dynamic tearing energy and temperature in the embodiment of the application;

[0038] Figure 3 is a measured graph of the ductile-brittle transition temperature ETT 50 and the impact absorbed energy at 0℃ in the embodiment of the application;

[0039] Figure 4 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of impact absorption energy at -40°C;

[0040] Figure 5 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of impact absorption energy at -80°C;

[0041] Figure 6 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of impact absorption energy at -100°C;

[0042] Figure 7 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of impact absorption energy at -120°C;

[0043] Figure 8 Brittle-ductile transition temperature ETT in the embodiment of the present application

[0044] Figure 9 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of dynamic tear energy at 0°C;

[0045] Figure 10 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of dynamic tear energy at -40°C;

[0046] Figure 11 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of dynamic tear energy at -80°C;

[0047] Figure 12 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of dynamic tear energy at -100°C;

[0048] Figure 13 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured graph of dynamic tear energy at -120°C;

[0049] Figure 14 Brittle-ductile transition temperature ETT in the embodiment of the present application

[0050] Figure 15 Brittle-ductile transition temperature ETT in the embodiment of the present application 50 Actual measured ETT 50Analysis schematic of ductile-brittle transition temperature in impact test;

[0051] Figure 16 For predicting ETT in the embodiment of the present application 50 With the measured ETT 50 Analysis schematic of ductile-brittle transition temperature in dynamic tear test; DETAILED DESCRIPTION

[0052] In order to make the technical means and purposes of the present application easy to understand, the embodiments of the present application are described in detail below in combination with specific drawings.

[0053] It should be noted that all the terms for indicating directionality and positionality in the present application, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inner", "outer", "top", "low", "transverse", "longitudinal", "center", etc., are only used to explain the relative positional relationship, connection condition, etc. between components in a certain specific state (as shown in the drawings), and are only for the convenience of describing the present application, and thus cannot be understood as a limitation on the present application. In addition, the description of "first", "second", etc. in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features.

[0054] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", and "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection; can be directly connected, or indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The present application discloses a method for predicting and analyzing the ductile-brittle transition temperature of high-strength structural steel material. By conducting a Charpy impact test and a dynamic tear test at a specific temperature, the ETT of the ductile-brittle transition temperature of the impact test sample and the dynamic tear test sample at the specific temperature is determined.50 correlation analysis, the impact ductile-brittle transition temperature and the dynamic tearing ductile-brittle transition temperature and the specific temperature T 特定 impact absorbed energy and dynamic tearing energy correlation model at the specific temperature T

[0057] S1: establish the calculation model of the impact absorbed energy at the specific temperature T 特定 temperature, as formula (1):

[0058]

[0059] In the formula, ETT 50 impact ductile-brittle transition temperature, unit: ℃; impact absorbed energy at the specific temperature T 特定 , β, θ - undetermined parameters;

[0060] S2: according to the dynamic tearing ductile-brittle transition temperature ETT 50 correlation analysis, the impact ductile-brittle transition temperature and the dynamic tearing ductile-brittle transition temperature and the specific temperature T 特定 dynamic tearing energy calculation model at the specific temperature T

[0061]

[0062] In the formula, ETT 50 dynamic tearing ductile-brittle transition temperature, unit: ℃; dynamic tearing energy at the specific temperature T 特定 , γ, η - undetermined parameters;

[0063] S3: according to the series of temperature impact tests and the series of temperature dynamic tearing tests of the high-strength structural steel of different strength grades, the relationship between the test temperature and the impact absorbed energy, the relationship between the test temperature and the dynamic tearing energy is fitted by using Boltzmann function, and the ductile-brittle transition temperature value and the specific temperature T 特定 impact absorbed energy at the specific temperature T dynamic tearing energy at the specific temperature T The calculation values or the calculation value ranges of the undetermined parameters α, β, θ, γ, η are obtained by setting the fitting formula. As preferred, the fitting formula here is fitted by using the least square method.

[0064] The prediction analysis method of the ductile-brittle transition temperature of the high-strength structural steel material disclosed in the application starts from the characteristics of the high-strength structural steel ductile-brittle transition temperature curve itself, and the impact ductile-brittle transition temperature correlation analysis and the dynamic tearing ductile-brittle transition temperature correlation analysis are carried out, so as to establish the impact ductile-brittle transition temperature and the dynamic tearing ductile-brittle transition temperature at the specific temperature T 特定The model of the correlation between the lower impact absorbed energy and the dynamic tearing energy is used for predicting the ductile-brittle transition temperature of the high-strength structural steel, and the ductile-brittle transition temperature and ETT are obtained by analyzing the temperature Charpy impact test and the dynamic tearing test of the series of high-strength structural steel with different strength grades 50 and the specific temperature T 特定 The lower impact absorbed energy or the dynamic tearing energy is substituted into formula (1) and formula (2) to determine the parameters α, β, θ, γ and η. In the subsequent estimation of the ductile-brittle transition temperature of the high-strength structural steel, the series of temperature impact test or the series of temperature dynamic tearing test is not needed, and the ductile-brittle transition temperature of the high-strength structural steel can be evaluated only by testing the impact absorbed energy or the dynamic tearing energy at the specific temperature T 特定 .

[0065] The prediction analysis method of the ductile-brittle transition temperature of the high-strength structural steel material has clear physical mechanism, greatly reduces the evaluation test amount and calculation amount of the ductile-brittle transition of the high-strength structural steel, and has simple structure and fast use.

[0066] As an example of the present application, step S1 includes the following steps:

[0067] S11: performing test analysis on the correlation between the impact absorbed energy and the ductile-brittle transition temperature of the high-strength structural steel with different strength grades at the typical temperatures A1-A2;

[0068] S12: determining the specific temperature T 50 at which the ductile-brittle transition temperature presents obvious power function relationship according to the correlation analysis of the impact ductile-brittle transition temperature ETT 特定 .

[0069] S13: establishing the calculation model of the ductile-brittle transition temperature and the impact absorbed energy at the specific temperature T 特定 temperature according to formula (1).

[0070] As an example of the present application, step S2 includes the following steps:

[0071] S21: performing test analysis on the correlation between the dynamic tearing energy and the ductile-brittle transition temperature of the high-strength structural steel with different strength grades at the typical temperatures B1-B2;

[0072] S22: determining the specific temperature T 50 at which the logarithm of the ductile-brittle transition temperature and the dynamic tearing energy presents obvious linear relationship according to the correlation analysis of the impact ductile-brittle transition temperature ETT 特定 .

[0073] S23: establishing the calculation model of the ductile-brittle transition temperature and the dynamic tearing energy at the specific temperature T 特定 temperature according to formula (2).

[0074] The applicant conducted impact tests and dynamic tear tests on structural steel materials of different strengths, and the ductile-brittle transition curves of their impact absorption energy are shown below. Figure 1 As shown, the ductile-brittle transition curve of dynamic tearing energy is as follows: Figure 2 As shown, the ductile-brittle transition of high-strength structural steel is divided into three stages: the upper plateau region, the transition temperature region, and the lower plateau region. Above a certain temperature, the absorbed energy of the material remains essentially constant; this energy is called the "higher-order energy," and the fracture at this point is fully ductile fracture, which corresponds to the upper plateau region. Below a certain temperature, the absorbed energy of the material remains essentially constant; this energy is called the "lower-order energy," and the fracture at this point is fully brittle fracture, which corresponds to the lower plateau region. The temperature corresponding to the average of the "higher-order energy" and the "lower-order energy" is the ductile-brittle transition temperature (ETT). 50 Within this temperature range, the material fractures in a mixed elastoplastic manner.

[0075] ductile-brittle transition temperature ETT 50 As an important technical indicator of the low-temperature resistance to brittle fracture of steel plates, it is an important basis for the safety assessment of high-strength structural steel in low-temperature environments. However, the measurement process of ductile-brittle transition temperature is relatively cumbersome and complicated. Achieving rapid prediction and assessment of the ductile-brittle transition temperature of high-strength structural steel is of great significance to the service safety of steel plates.

[0076] For high-strength structural steel, the ductile-brittle transition is a process from fully ductile fracture to fully brittle fracture. Different materials have different ductile-brittle transition temperatures and ranges. At a specific temperature, the material may be in the upper plateau region, the ductile-brittle transition temperature region, or the lower plateau region. Materials in the upper plateau region have the lowest ductile-brittle transition temperature, followed by those in the ductile-brittle transition temperature region, and the highest in the lower plateau region. That is, the impact absorption energy or dynamic tearing energy of a material at a specific temperature can reflect the level of its ductile-brittle transition temperature to a certain extent.

[0077] Based on the above analysis, the applicant conducted a correlation analysis of the impact absorbed energy at a specific temperature with the dynamic tearing energy and the ductile-brittle transition temperature (ETT), and performed an ETT analysis for different specific temperatures. 50 The correlation between impact absorption energy and ductile-brittle transition temperature was analyzed. Specifically, the correlation between impact absorption energy and ductile-brittle transition temperature at typical temperatures for high-strength structural steels of different strength grades (A1-A2) was observed at a specific temperature T. 特定 The correlation between impact absorption energy and ductile-brittle transition temperature is most pronounced at certain temperatures. A1 and A2 are preset temperature values, with the range of A1 to A2 being 20℃ to -196℃. Figures 3 to 7 As shown, the range of values ​​for A1 to A2 is 0℃ to -120℃. Find the value as shown below. Figure 8The impact energy at -120℃ is related to the ductile-brittle transition temperature, and the ductile-brittle transition temperature and the impact energy at -120℃ temperature present a clear power function relationship, and the specific temperature T 特定 is -120℃, and a ductile-brittle transition temperature prediction model at the specific temperature is established according to the curve relationship; similarly, for different specific temperatures, the ductile-brittle transition temperature ETT 50 and the dynamic tear energy are analyzed, wherein the dynamic tear energy at a typical temperature of the different strength grades of high-strength structural steel B1-B2 and the ductile-brittle transition temperature have the most obvious correlation, B1 and B2 are preset temperature values, and the dynamic tear energy at the specific temperature T 特定 has the most obvious correlation with the ductile-brittle transition temperature, the value range of B1-B2 is 20℃- -196℃, as shown in Figures 9 to 13 , the value range of B1-B2 is 0℃- -120℃, and the dynamic tear energy at -120℃ and the ductile-brittle transition temperature are found, as shown in Figure 14 , the ductile-brittle transition temperature and the logarithm of the dynamic tear energy at -120℃ temperature present a clear linear relationship, and the specific temperature T 特定 is -120℃, and a dynamic tear ductile-brittle transition temperature prediction model at the specific temperature is established according to the curve relationship.

[0078] Through the above analysis, a correlation model of the impact ductile-brittle transition temperature and the dynamic tear ductile-brittle transition temperature at the specific temperature T 特定 is established, and in subsequent estimation of the ductile-brittle transition temperature value of the high-strength structural steel, a series of temperature impact tests or a series of temperature dynamic tear tests are not needed, and only the impact absorption energy or the dynamic tear energy at the specific temperature T 特定 can be used to evaluate the ductile-brittle transition temperature value of the high-strength structural steel.

[0079] As an example of the present application, the high-strength structural steel is a structural steel with a tensile strength of 355MPa-690MPa.

[0080] As an example of the present application, the high-strength structural steel is a high-strength structural steel for ships and bridges. Specific embodiments:

[0082] The working process of the present application is as follows:

[0083] 1. According to GB / T229-2020 “Metallic Materials Charpy Impact Test”, a series of temperature impact tests are carried out on high-strength structural steels of different strength grades, Boltzmann function is used to fit the test temperature and the impact absorption energy, the ductile-brittle transition temperature value and the impact absorption energy at -120℃ are determined, and the results are shown in Table 1.

[0084] Table 1 Impact toughness brittle transition temperature and energy value

[0085]

[0086] 2, the data in Table 1 is substituted into equation (1), and the least square method is used for fitting, the undetermined parameters are shown in Table 2, and the form of the prediction model is shown in equation (3).

[0087] Table 2 Values of undetermined parameters in calculation model

[0088] Parameter α β θ Value -22.0 -12.2 0.316

[0089]

[0090] 3, according to GB / T5482-2007 "metal material dynamic tearing test method", a series of temperature dynamic tearing tests are carried out on high strength structural steel of different strength grades, Boltzmann function is used to fit the test temperature and dynamic tearing energy, the toughness brittle transition temperature value and the dynamic tearing energy at-120℃ are determined, and the results are shown in Table 3.

[0091] Table 3 Dynamic tearing toughness brittle transition temperature and energy value

[0092]

[0093] 4, the data in Table 3 is substituted into equation (2), and the least square method is used for fitting, the undetermined parameters are shown in Table 4, and the form of the prediction model is shown in equation (4).

[0094] Table 4 Values of undetermined parameters in calculation model

[0095] Parameter γ η Range -67.0 88.7

[0096] ETT 50 = -67.0·logDT (-120℃) + 88.7 (4)

[0097] According to the prediction analysis method of toughness brittle transition temperature of high strength structural steel material described in the above embodiment, the predicted toughness brittle transition temperature ETT calculated by the formula of the calculation model recorded in the above embodiment 50 is compared with the measured ETT 50 . The analysis and comparison chart in the impact test and the dynamic tearing test is shown in Figure 15 , Figure 16 .

[0098] The high-strength structural steel material ductile-brittle transition temperature prediction analysis method relates to a rapid prediction model for determining a ductile-brittle transition characteristic parameter, i.e., a ductile-brittle transition temperature, of a high-strength structural steel material. The model realizes rapid prediction and evaluation of the ductile-brittle transition temperature of an impact sample and the ductile-brittle transition temperature of a dynamic tearing sample through a Charpy impact test at a specific temperature and a dynamic tearing test. The model can be established by using the impact absorbed energy or the dynamic tearing energy measured at a fixed temperature, and can realize rapid prediction and evaluation of the ductile-brittle transition temperature of the high-strength structural steel, thereby providing a technical basis for evaluation of the low-temperature brittleness tendency of the high-strength structural steel and anti-brittle fracture design.

[0099] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for predicting the ductile-to-brittle transition temperature of a high-strength structural steel material, characterized in that, The ETT of the impact toughness and ductile-brittle transition temperature of the impact sample and the dynamic tearing sample at the specific temperature is obtained by conducting the Charpy impact test and the dynamic tearing test at the specific temperature 50 Correlation analysis is conducted to establish the correlation model of the impact toughness and ductile-brittle transition temperature and the dynamic tearing toughness and ductile-brittle transition temperature at the specific temperature T 特定 Correlation analysis is conducted to establish the correlation model of the impact toughness and ductile-brittle transition temperature and the dynamic tearing toughness and ductile-brittle transition temperature at the specific temperature T S1: Establishing the ductile-to-brittle transition temperature and a specific temperature T 特定 A calculation model for impact absorbed energy at a temperature, such as Equation (1): wherein ETT 50 - impact ductility transition temperature in °C; - T 特定 impact absorption energy at time t in J; α, β, θ - parameters to be determined; S2: The dynamic tear embrittlement transition temperature ETT according to the dynamic tear test 50 Correlation analysis, establishing the embrittlement transition temperature and the specific temperature T 特定 The calculation model of the dynamic tear energy at the specific temperature T, as formula (2) where ETT 50 - dynamic tear brittle transition temperature in °C; - T 特定 dynamic tear energy in J; γ, η - parameters to be determined; S3: A series of temperature impact tests and a series of temperature dynamic tear tests are carried out on high-strength structural steels of different strength grades, Boltzmann functions are used to fit the relationship between test temperature and impact absorbed energy, and the relationship between test temperature and dynamic tear energy, and the ductile-brittle transition temperature value and the specific temperature T 特定 the lower impact absorbed energy the dynamic tear energy The calculation value or the calculation value range of the undetermined parameters α, β, θ, γ, η obtained by setting the fitting formula.

2. The method of claim 1, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 590 MPa or more. The step S1 comprises the following steps: S11: performing test analysis on the correlation between the impact absorbed energy and the ductile-brittle transition temperature of the high-strength structural steel of different strength grades at A1-A2 typical temperatures; S12: determining the ductile-brittle transition temperature ETT from the impact toughness 50 correlation analysis to determine the specific temperature T at which the ductile-brittle transition temperature exhibits a clear power function relationship 特定 ; S13: Establishing the ductile-to-brittle transition temperature and a specific temperature T 特定 The calculation model of impact absorbed energy at a temperature as formula (1); Wherein, A1 and A2 are preset temperature values.

3. The method of claim 1, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 1,000 MPa or more. The step S2 comprises the following steps: S21: performing test analysis on the correlation between the dynamic tearing energy and the ductile-brittle transition temperature of the high-strength structural steel of different strength grades at B1-B2 typical temperatures; S22 determining the ductile-brittle transition temperature ETT from the impact toughness 50 correlation analysis to determine the specific temperature T at which the ductile-brittle transition temperature and the logarithm of the dynamic tear energy exhibit a clear linear relationship 特定 ; S23: Establishing the ductile-to-brittle transition temperature and the specific temperature T 特定 The dynamic tear energy at the temperature is calculated as a model of formula (2). Wherein, B1 and B2 are preset temperature values.

4. The method of predicting the ductile-brittle transition temperature of a high-strength structural steel material according to claim 2 or 3, characterized in that, In the step S3, the least square method is used for fitting, and the calculation value or the calculation value range of the undetermined parameters α, β, θ, γ and η is obtained.

5. The method of claim 2, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 590 MPa or more. The value range of A1-A2 is 20℃- -196℃.

6. The method of claim 3, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 1,000 MPa or more. The value range of B1-B2 is 20℃- -196℃.

7. The method of claim 4, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 1,000 MPa or more. The high-strength structural steel is a structural steel with a tensile strength of 355MPa-690MPa.

8. The method of claim 7, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 1,000 MPa or more. The high-strength structural steel is a high-strength structural steel for ships and bridges.

9. The method of claim 8, wherein the high-strength structural steel material is a high-strength structural steel material having a tensile strength of 590 MPa or more. A1~A2 is in the range of 0°C to -120°C, B1~B2 is in the range of 0°C to -120°C, and the specific temperature T 特定 -120°C.

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