A method for predicting tensile strength of high-strength crack-arrest thick plates

Abstract

The present invention provides a method for predicting the tensile strength of a high-strength crack arrest thick plate, which relates to the technical field of material fracture failure research. The method comprises: performing a correlation analysis between the tensile strength Rm and the alloy composition, Ceq, grain size, and plate thickness t; calculating the Rm / t 2 and Ceq / t 2 , grain size / t 2 、Si content / t 2 、Ni content / t 2 Carry out correlation analysis respectively; establish a tensile strength prediction model for high-strength crack arrest thick plates; when predicting the tensile strength of the high-strength crack arrest thick plates, obtain Rm, nickel content, silicon content, grain size, plate thickness t, and calculate Ceq; substitute Rm, Si content, Ni content, grain size, t, and Ceq into the model to determine parameters α, β, γ, μ, and ρ; the tensile strength prediction method for high-strength crack arrest thick plates described in the present invention can more accurately predict the tensile strength of high-strength crack arrest thick plates, and provide guidance for the evaluation of crack arrest toughness of steel plates and the development of crack arrest thick plates with higher strength grades.

Description

Technical Field

[0001] The invention relates to the technical field of material fracture failure research, and in particular to a method for predicting the tensile strength of a high-strength crack arrest thick plate, and more particularly to a rapid prediction model for determining the tensile strength of a high-strength crack arrest steel. Background Art

[0002] Since the beginning of the 21st century, in order to improve efficiency and reduce operating costs, the development of container ships has become increasingly large and ultra-large. With the large and ultra-large structure, in order to meet the rigidity and strength requirements, the strength grade and thickness specifications of the steel plates used in the hull structure have also been continuously increased. The highest strength level has reached 460MPa, and the maximum plate thickness specification is approaching 100mm. With the increase in strength and the increase in plate thickness, the fracture resistance of the steel plate decreases, and its safety and reliability issues are prominent.

[0003] In order to ensure the safety of the structure, it is often required that the high-strength thick steel plates used in key parts of large container ships must have crack arresting properties, that is, once brittle cracks occur in the structure, the steel plates can stop them, thereby avoiding catastrophic damage. To this end, the IACS Hull Committee has specially established a PT52 working group to formulate relevant standards for the safe application of 50-100mm thick high-strength steel plates for ships, and proposed a crack arresting performance evaluation test method and technical indicators for crack arresting performance (plate thickness ≤ 80mm, Kca ≥ 6000N / mm at -10℃) 3 / 2 ; Plate thickness>80mm, Kca≥8000N / mm at -10℃ 3 / 2 ).

[0004] A large number of studies have been carried out at home and abroad to address the issues of how to evaluate and regulate crack arrest performance, and a variety of correlation models between crack arrest toughness / crack arrest temperature and small-size specimen characterization parameters have been established, such as the correlation model between crack arrest toughness and core tensile strength and side non-plastic transition temperature, the correlation model between crack arrest temperature and side non-plastic transition temperature, the correlation model between crack arrest temperature and core dynamic tearing ductile-brittle transition temperature, etc. By establishing the correlation between large-scale crack arrest tests and small-scale tests, the basic mechanical property parameters that affect crack arrest performance have been clarified, which has pointed out the direction for the regulation and improvement of crack arrest performance and has effectively guided the development of domestic crack arrest steels.

[0005] The above-mentioned large number of research results show that the crack arrest performance of the crack arrest thick plate not only depends on the characteristic temperature of the ductile-brittle transition of the material, but also has a close relationship with the tensile strength of the core of the material. When the ductile-brittle transition temperature is the same, the higher the tensile strength, the higher the crack arrest toughness of the material. In addition, the development of container ships is becoming larger and larger, but due to the limitation of strength level, the thickness of the plate used on the 24000TEU container ship is as high as 95mm, which brings a series of problems such as difficult production, increased weight of the hull, and low welding efficiency of the shipyard. This has put forward a clear demand for improving the strength grade of steel plates and reducing the thickness of plates.

[0006] Therefore, for the tensile strength which is closely related to the crack arrest performance of the crack arrest thick plate, finding out the factors affecting the tensile strength of the crack arrest thick plate can not only provide support for improving the crack arrest toughness of the steel plate, but also provide effective guidance for the development of crack arrest steel with higher strength grades. However, there is no public report on the research on the factors affecting the tensile strength of the crack arrest thick plate and the prediction model. Summary of the invention

[0007] In view of this, the present invention aims to propose a method for predicting the tensile strength of high-strength crack-arrest thick plates, which can realize the predictive evaluation of the tensile strength of the core of the crack-arrest thick plates by measuring the alloy composition and grain size of the materials, so as to provide a technical basis for improving the crack arrest toughness and strength grade of the crack-arrest thick plates, and fill the gap in the research on the influencing factors and prediction models of the tensile strength of the crack-arrest thick plates in the prior art.

[0008] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0009] A method for predicting tensile strength of high-strength crack-arrest thick plates, comprising:

[0010] S1. Correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the single element content in the alloy composition; correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the carbon equivalent Ceq, grain size, and plate thickness t;

[0011] S2. Introducing parameter t 2 The relationship between tensile strength Rm and carbon equivalent Ceq, grain size, Si content, and Ni content was corrected respectively. 2 and Ceq / t 2 , grain size / t 2 、Si content / t 2 、Ni content / t 2 Correlation analysis was performed separately;

[0012] S3. Establishment of tensile strength prediction model for high-strength crack-arrest thick plates Rm=α×Ceq+β×GS+γ×Ni+μ×Si+ρ×t 2 ;

[0013] S4. When predicting the tensile strength of the high-strength crack arrest thick plate, the tensile test, alloy element analysis, and grain size grade assessment of the high-strength crack arrest thick plate are carried out to obtain Rm, nickel content, silicon content, grain size, and plate thickness t, and the carbon equivalent Ceq is calculated according to the alloy element analysis results; Rm, nickel content, silicon content, grain size, t, and Ceq are substituted into the model expression of step S3 to determine the parameters α, β, γ, μ, and ρ;

[0014] Among them, Rm is the tensile strength of high-strength crack arrest thick plate, MPa; Ceq is carbon equivalent, %; GS is grain size, grade; Ni is nickel element content, %; Si is silicon element content, %; t is plate thickness, mm; α, β, γ, μ, ρ are parameters to be determined.

[0015] Furthermore, in step S1, the alloy components include at least C, Si, Mn, Ni, Cr, Mo, Cu, Al, Nb, and P.

[0016] Furthermore, in step S1, the tensile strength Rm and alloy composition are data corresponding to the core position of the high-strength crack-arresting thick plate.

[0017] Furthermore, the calculation formula of Ceq is Ceq=C+Mn / 6+(Cr+Mo+V) / 5+(Ni+Cu) / 15; wherein C, Mn, Cr, Mo, V, Ni, and Cu are the mass percentages of the corresponding elements, respectively.

[0018] Furthermore, in step S4, by substituting t of 50 mm to 90 mm, Ceq of 0.359% to 0.484%, nickel content of 0.089% to 3.35%, silicon content of 0.134% to 0.284%, grain size of 7 to 12, and Rm of 517 MPa to 679 MPa into the model expression of step S3, the least squares method was used for fitting, and the parameters α=1399.3, β=5.4, γ=-48.6, μ=274.5, ρ=-0.011 were determined, and the tensile strength prediction model of high-strength crack arrest thick plate Rm=1399.3Ceq+5.4GS-48.6Ni+274.5Si-0.011t was obtained. 2 .

[0019] Furthermore, the method is used to predict the tensile strength of high-strength crack-arresting thick plates with a tensile strength of 390MPa~460MPa and a thickness of 50mm~90mm.

[0020] Compared with the prior art, the method for predicting the tensile strength of a high-strength crack-arrest thick plate described in the present invention has the following advantages:

[0021] The tensile strength prediction method of the high-strength crack arrest thick plate of the present invention is based on the correlation between the tensile strength of the core of the high-strength crack arrest thick plate and the alloy composition and grain size. 2 After correction, through the correlation analysis of tensile strength with alloy composition and grain size, a correlation model of tensile strength of high-strength crack arrest thick plate and carbon equivalent, Si content, Ni content, grain size and plate thickness was established. This prediction model can predict the tensile strength of high-strength crack arrest thick plate more accurately, and has the advantages of clear physical mechanism, simple construction and quick use.

[0022] When the tensile strength of the core of the high-strength crack-arrest thick plate needs to be predicted, the tensile strength of the core, carbon equivalent, Si content, Ni content, grain size grade, and plate thickness are obtained by conducting tensile tests, alloy composition tests, and grain size grade assessments of the crack-arrest thick plate, and the parameters α, β, γ, μ, and ρ are substituted into the model expression of step S3 to determine the parameters. In the subsequent prediction and design of the tensile strength of the core of the high-strength crack-arrest thick plate, the tensile strength of the core of the high-strength thick plate can be predicted by alloy composition design and target grain size, which can provide guidance for the evaluation of crack-arrest toughness of steel plates and the development of crack-arrest thick plates with higher strength grades. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the correlation between the core tensile strength and the C element of the present invention;

[0025] Figure 2 It is a schematic diagram of the correlation between the core tensile strength and the Si element of the present invention;

[0026] Figure 3 This is a schematic diagram of the correlation between the core tensile strength and the Mn element of the present invention;

[0027] Figure 4 This is a schematic diagram of the correlation between the core tensile strength and the Ni element of the present invention;

[0028] Figure 5 It is a schematic diagram of the correlation between the core tensile strength and the Cr element of the present invention;

[0029] Figure 6 It is a schematic diagram of the correlation between the core tensile strength and the Mo element of the present invention;

[0030] Figure 7 This is a schematic diagram of the correlation between the core tensile strength and the Cu element of the present invention;

[0031] Figure 8 It is a schematic diagram of the correlation between the tensile strength of the core and the Al element of the present invention;

[0032] Fig. 9 It is a schematic diagram of the correlation between the core tensile strength and the Nb element of the present invention;

[0033] Fig.10 It is a schematic diagram of the correlation between the core tensile strength and the P element of the present invention;

[0034] Fig.11 This is a schematic diagram of the correlation between the core tensile strength and the carbon equivalent of the present invention;

[0035] Fig.12 It is a schematic diagram of the correlation between the core tensile strength and the grain size of the present invention;

[0036] Fig.13 It is a schematic diagram of the correlation between the core tensile strength and the plate thickness of the present invention;

[0037] Fig.14 This is a schematic diagram of the correlation between the core tensile strength and the carbon equivalent after considering the plate thickness effect in the present invention;

[0038] Fig.15 It is a schematic diagram of the correlation between the core tensile strength and the grain size after considering the plate thickness effect in the present invention;

[0039] Fig.16 This is a schematic diagram of the correlation between the core tensile strength and the Si element after considering the plate thickness effect in the present invention;

[0040] Fig.17 This is a schematic diagram of the correlation between the core tensile strength and Ni after considering the plate thickness effect in the present invention;

[0041] Fig.18 Graph showing the relationship between the predicted tensile strength value and the actual measured tensile strength value in Example 1 of the present invention. DETAILED DESCRIPTION

[0042] The inventive concepts of the present disclosure will be described below using terms commonly used by those skilled in the art to convey the essence of their work to other persons skilled in the art. However, these inventive concepts can be embodied in many different forms and should not be considered limited to the embodiments described herein.

[0043] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0044] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0045] As for the tensile strength which is closely related to the crack arrest performance of the crack arrest thick plate, finding out the factors affecting the tensile strength of the crack arrest thick plate can not only provide support for improving the crack arrest toughness of the steel plate, but also provide effective guidance for the development of crack arrest steel with higher strength grades. However, there is no public report on the research on the factors affecting the tensile strength of the crack arrest thick plate and the prediction model.

[0046] Based on this, as attached Figure 1-18 As shown, this embodiment proposes a method for predicting the tensile strength of a high-strength crack-arrest thick plate, comprising:

[0047] S1. Correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the single element content in the alloy composition; correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the carbon equivalent Ceq, grain size, and plate thickness t;

[0048] Among them, the alloy components include multiple elements such as C, Si, Mn, Ni, Cr, Mo, Cu, Al, Nb, and P; the tensile strength Rm and alloy components are data measured at the core position of the high-strength crack-arresting thick plate, that is, the tensile strength can be regarded as the core tensile strength, and the alloy component can also be regarded as the core alloy component.

[0049] In step S1, the sample of the high-strength crack-arresting thick plate is a 390MPa~460MPa grade crack-arresting thick plate with a plate thickness specification of 50mm~90mm. Accordingly, the method of the present application is also applicable to high-strength crack-arresting thick plates of this specification.

[0050] In step S1, the specific correlation analysis result is:

[0051] Depend on Figure 1-10 It can be seen that there is no obvious correlation between a single element and the tensile strength, and it is undoubtedly difficult to effectively improve the tensile strength by adjusting the composition of a single element.

[0052] Depend on Fig.11 It can be seen that as the carbon equivalent increases, the tensile strength of the material increases, but there is a certain degree of discreteness in the data correlation, indicating that the carbon equivalent is a factor that affects the tensile strength of the core of the steel plate.

[0053] Depend on Fig.12 It can be seen that as the grain size grade increases, the tensile strength tends to increase, but the data is highly discrete, indicating that the grain size (grain size) is also a factor affecting the tensile strength of the core of the steel plate.

[0054] Depend on Fig.13 It can be seen that as the plate thickness increases, the strength of the steel plate shows a certain downward trend.

[0055] Therefore, through the correlation analysis in step S1, it can be determined that the carbon equivalent, grain size and plate thickness are all factors that affect the tensile strength of the material.

[0056] Similarly, this application also briefly introduces the applicant's theoretical exploration at the beginning of the research to help understand the technical content of this application.

[0057] The alloy composition and microstructure of the material are often the core factors affecting its strength. The main alloy elements are C, Si, Mn, Cr, Mo, V, Ni, Cu, Ti, Nb, and impurity elements P, S, etc. Among them, C is a necessary element to ensure strength, and the strength of the material is mainly improved through solid solution strengthening and precipitation strengthening. Si is the main deoxidizing component in the steelmaking process. Si in the form of solid solution can increase the toughness-brittle transition temperature while improving the strength. Mn is a necessary element to ensure the strength and toughness of the steel plate. Mn combines with S to form MnS to avoid hot cracks caused by the formation of FeS at the grain boundary. At the same time, Mn is also a good deoxidizer. Cu can improve the strength of the material, Ni has a solid solution strengthening effect, which can promote the steel plate to form a stable austenite structure and improve the strength and toughness of the steel plate. Al is a deoxidation and grain refinement element. Nb can effectively refine the grain size of steel. As an element added to improve the strength and toughness of steel, Ti can improve the toughness of steel and the toughness of the welding heat affected zone. It mainly exists in the form of TiN and plays a role. P is an element that is unfavorable to the toughness of the material. It can segregate in the center of the slab and aggregate at the grain boundary, which damages the low-temperature toughness. S is also an element that is unfavorable to the toughness of the material. It can form sulfide inclusions and become a crack source. At the same time, the grain size also has a significant effect on the strength of the material. The smaller the grain size, the higher the strength of the material. Based on this, the foundation has been laid for the research direction of this application. The applicant has gradually studied and established a prediction model for the tensile strength of the core of the high-strength crack arrest thick plate through correlation analysis between the tensile strength of the core and the alloy composition and grain size.

[0058] S2. Introducing parameter t 2 The relationship between tensile strength Rm and carbon equivalent Ceq, grain size, Si content, and Ni content was corrected respectively. 2 and Ceq / t 2 , grain size / t 2 、Si content / t 2 、Ni content / t 2 Correlation analysis was performed separately;

[0059] In order to avoid misunderstanding, the parameter t 2 It is the square of the plate thickness t. The purpose is to introduce this influencing factor based on the influence of plate thickness on tensile strength and to correct other related parameters.

[0060] In step S2, the specific correlation analysis result is:

[0061] Depend on Fig.14 It can be seen that Rm / t 2 and Ceq / t 2 There is an obvious linear relationship between them;

[0062] Depend on Fig.15 It can be seen that Rm / t 2 and grain size / t 2 There is also an obvious linear relationship between them;

[0063] Depend on Fig.16 , 17 It can be seen that Rm / t 2 and Si content / t 2 、Ni content / t 2 There is a certain linear correlation.

[0064] Among them, since the carbon equivalent Ceq includes 7 types of elements such as alloying elements C, Mn, Cr, Mo, V, Ni, and Cu, but does not include Si elements that affect the strength of the material, and Ni is an alloying element that can both enhance the strength of the material and improve the toughness of the material, it is a core element that affects the toughness of the material. For this reason, the applicant focused on the study of Si elements, Ni elements and tensile strength, and it was effectively verified in the correlation analysis in step S2.

[0065] S3. Establishment of tensile strength prediction model for high-strength crack-arrest thick plates Rm=α×Ceq+β×GS+γ×Ni+μ×Si+ρ×t 2 ;

[0066] Among them, Rm is the tensile strength of high-strength crack arrest thick plate, MPa; Ceq is carbon equivalent, %, and the calculation formula of Ceq is Ceq=C+Mn / 6+(Cr+Mo+V) / 5+(Ni+Cu) / 15; GS is grain size, grade; Ni is nickel element content, %; Si is silicon element content, %; t is plate thickness, mm; α, β, γ, μ, ρ are parameters to be determined.

[0067] Based on the correlation analysis results of steps S1 and S2, the parameter t 2 After correction, the tensile strength is closely related to the carbon equivalent, grain size, Si element content and Ni element content. That is, the tensile strength of the crack arrest thick plate mainly depends on the carbon equivalent, grain size, Si element content, Ni element content and plate thickness.

[0068] S4. When predicting the tensile strength of the high-strength crack-arresting thick plate, the tensile test, alloy element analysis and grain size grade assessment of the high-strength crack-arresting thick plate are carried out to obtain Rm, nickel content, silicon content, grain size and plate thickness t, and the carbon equivalent Ceq is calculated based on the alloy element analysis results; Rm, nickel content, silicon content, grain size, t and Ceq are substituted into the model expression of step S3 to determine the parameters α, β, γ, μ and ρ.

[0069] Among them, the tensile test can be carried out on the high-strength crack arrest thick plate according to GB / T228.1 "Metallic Material Tensile Test Part 1 Room Temperature Test Method", the alloy element analysis can be carried out on the high-strength crack arrest thick plate according to ASTM E1019, GB / T 20125, GB / T 22382 and SN / T 3806 and other standards, and the grain size grade of the high-strength crack arrest thick plate can be evaluated according to GB / T 6394 to determine the grain size grade; for the calculation of Ceq, it can be calculated according to the calculation formula of Ceq in step S3. At the same time, not only in step S4, the acquisition of relevant data in this application is the same, and no further elaboration is made.

[0070] After determining the parameters α, β, γ, μ, and ρ, the model expression of the present application becomes a clear mathematical relationship. The subsequent process of predicting the tensile strength of the high-strength crack-arresting thick plate no longer requires tensile testing. The tensile strength of the high-strength crack-arresting thick plate can be predicted by simply performing alloy element analysis and grain size grade assessment on the high-strength crack-arresting thick plate, and substituting the carbon equivalent, Si content, Ni content, grain size grade, and plate thickness into this clear mathematical relationship (i.e., the final prediction model of the present application).

[0071] The present invention starts from the correlation between the tensile strength of the core of the high-strength crack arrest thick plate and the alloy composition and grain size, and introduces the parameter t 2 After correction, through the correlation analysis of tensile strength with alloy composition and grain size, a correlation model of tensile strength of high-strength crack arrest thick plate and carbon equivalent, Si content, Ni content, grain size and plate thickness was established. This prediction model can predict the tensile strength of high-strength crack arrest thick plate more accurately, and has the advantages of clear physical mechanism, simple construction and quick use.

[0072] When the tensile strength of the core of the high-strength crack-arrest thick plate needs to be predicted, the tensile strength of the core, carbon equivalent, Si content, Ni content, grain size grade, and plate thickness are obtained by conducting tensile tests, alloy composition tests, and grain size grade assessments of the crack-arrest thick plate, and the parameters α, β, γ, μ, and ρ are substituted into the model expression of step S3 to determine the parameters α, β, γ, μ, and ρ. In the subsequent prediction and design of the tensile strength of the core of the high-strength crack-arrest thick plate, the tensile strength of the core of the high-strength thick plate can be predicted by alloy composition design and target grain size, which can provide guidance for the evaluation of crack-arrest toughness of steel plates and the development of crack-arrest thick plates with higher strength grades.

[0073] Example 1

[0074] Since the specific analysis process of steps S1-S3 is described in detail in the foregoing text, and the same content is also adopted in this embodiment, the specific implementation process of steps S1-S3 is not described in detail in this embodiment.

[0075] This embodiment focuses on the specific implementation content of step S4 for introduction.

[0076] Step a, according to GB / T228.1 "Metallic Materials Tensile Test Part 1 Room Temperature Test Method" tensile test was carried out on different batches of high-strength crack arrest thick plates to obtain the core tensile strength, and the alloy element analysis of the steel plate core was carried out according to ASTM E1019, GB / T 20125, GB / T 22382 and SN / T 3806 standards to calculate the carbon equivalent Ceq, and at the same time, the grain size of the steel plate core was evaluated according to GB / T 6394 to determine the grain size grade, and the data are shown in Table 1. It should be noted that in the actual implementation of step a, due to the large number of data groups detected, it is difficult to display them one by one, and Table 1 only displays the range of the acquired data.

[0077] Table 1 Test data of high strength crack arrest thick plate

[0078]

[0079] Step b, substitute the data measured in step a into the model expression of step S3, and fit it using the least squares method to obtain the undetermined parameters α=1399.3, β=5.4, γ=-48.6, μ=274.5, ρ=-0.011; accordingly, the tensile strength prediction model of the high-strength crack arrest thick plate is obtained: Rm=1399.3Ceq+5.4GS-48.6Ni+274.5Si-0.011t 2 (Formula A);

[0080] Substitute the individual data groups in step a into formula A, calculate the predicted Rm values ​​respectively, and compare them with the corresponding measured Rm values. The comparison results of some groups are shown in Table 2.

[0081] Table 2 Comparison of predicted and measured Rm values ​​of high-strength crack-arrest thick plates

[0082]

[0083] The relative deviation is the difference between the measured value of Rm and the predicted value of Rm, divided by the measured value of Rm.

[0084] It can be seen from the results in Table 2 that the absolute value of the relative deviation between the Rm predicted value and the Rm measured value obtained by the tensile strength prediction method of the high-strength crack-arrest thick plate of the present application is no more than 6.5%.

[0085] At the same time, the specific comparison can also be found in the attached Fig.18 , attached Fig.18 In the above equation, the predicted value of Rm is used as the horizontal coordinate, and the measured value of Rm is used as the vertical coordinate. A point can be determined in the coordinate system by using a set of corresponding predicted values ​​of Rm and measured values ​​of Rm. Fig.18 It can be seen that: through the tensile strength prediction method of the high-strength crack arrest thick plate of the present application, the relative deviation between the predicted value of Rm and the measured value of Rm is small, which can meet the deviation range requirements of the design research requirements (the deviation range requirements correspond to the attached Fig.18 The range between the top and bottom slashes in the .

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for predicting the tensile strength of a high-strength crack-arrest thick plate, characterized in that: The method comprises: S1. Correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the single element content in the alloy composition; correlation analysis is performed on the tensile strength Rm of the high-strength crack arrest thick plate and the carbon equivalent Ceq, grain size, and plate thickness t; S2. Introducing parameter t 2 The relationship between tensile strength Rm and carbon equivalent Ceq, grain size, Si content, and Ni content was corrected respectively. 2 and Ceq / t 2 , grain size / t 2 、Si content / t 2 、Ni content / t 2 Correlation analysis was performed separately; S3. Establishment of tensile strength prediction model for high-strength crack-arrest thick plates Rm=α×Ceq+β×GS+γ×Ni+μ×Si+ρ×t 2 ; S4. When predicting the tensile strength of the high-strength crack arrest thick plate, the tensile test, alloy element analysis, and grain size grade assessment of the high-strength crack arrest thick plate are carried out to obtain Rm, nickel content, silicon content, grain size, and plate thickness t, and the carbon equivalent Ceq is calculated according to the alloy element analysis results; Rm, nickel content, silicon content, grain size, t, and Ceq are substituted into the model expression of step S3 to determine the parameters α, β, γ, μ, and ρ; Among them, Rm is the tensile strength of high-strength crack arrest thick plate, MPa; Ceq is carbon equivalent, %; GS is grain size, grade; Ni is nickel content, %; Si is silicon content, %; t is plate thickness, mm; α, β, γ, μ, ρ are parameters to be determined; In step S1, the alloy composition includes at least C, Si, Mn, Ni, Cr, Mo, Cu, Al, Nb, and P; In step S4, by substituting t of 50 mm to 90 mm, Ceq of 0.359% to 0.484%, nickel content of 0.089% to 3.35%, silicon content of 0.134% to 0.284%, grain size of 7 to 12, and Rm of 517 MPa to 679 MPa into the model expression of step S3, the least squares method is used for fitting, and the parameters α=1399.3, β=5.4, γ=-48.6, μ=274.5, ρ=-0.011 are determined, and the tensile strength prediction model of high-strength crack arrest thick plate Rm=1399.3Ceq+5.4GS-48.6Ni+274.5Si-0.011t is obtained. 2 .

2. A method for predicting tensile strength of high-strength crack arrest thick plates according to claim 1, characterized in that: In step S1, the tensile strength Rm and alloy composition are data corresponding to the core position of the high-strength crack-arresting thick plate.

3. A method for predicting tensile strength of high-strength crack arrest thick plates according to claim 1, characterized in that: The calculation formula for Ceq is Ceq=C+Mn / 6+(Cr+Mo+V) / 5+(Ni+Cu) / 15; among them, C, Mn, Cr, Mo, V, Ni, and Cu are the mass percentages of the corresponding elements respectively.

4. A method for predicting tensile strength of high-strength crack arrest thick plates according to claim 1, characterized in that: The method is used to predict the tensile strength of high-strength crack-arrest thick plates with a tensile strength of 390MPa-460MPa and a thickness of 50mm-90mm.

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