Numerical simulation method for corrosion rate of high-strength steel under marine stress environment

Abstract

This invention discloses a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments, belonging to the field of corrosion and protection technology. The method includes the following steps: establishing a geometric model for simulation and meshing the model; setting material properties, including corrosion kinetic parameters and basic mechanical property parameters; applying boundary conditions to the geometric model to simulate the actual stress state of the high-strength steel plate; formulating a kinetic expression formula for the electrochemical reaction to describe the electrochemical behavior during corrosion; and performing a corrosion kinetic-mechanical coupling analysis to calculate the distribution of corrosion current, corrosion potential, and local corrosion rate. This invention, by constructing a multiphysics model, can accurately extrapolate and predict the dynamic corrosion rate of high-strength steel under different stresses and environmental parameters. It provides crucial theoretical basis and data support for the design, life assessment, and maintenance decisions of marine engineering structures.

Description

Technical Field

[0001] This invention relates to the field of corrosion and protection technology, and in particular to a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments. Background Technology

[0002] In the complex and harsh marine environment, the corrosion behavior of high-strength steel is diverse and dynamic. It not only undergoes uniform and localized corrosion caused by conventional, long-term static immersion, but also experiences more complex coupled damage processes under various loads. Currently, through extensive literature review and experimental data collection, we have preliminarily grasped basic data on the static corrosion rate, corrosion morphology, and main influencing factors of high-strength steel in simulated marine environments (such as salt spray and immersion). However, we are severely lacking in accurate corrosion data on high-strength steel under continuous or alternating stress and strain conditions, i.e., under actual service conditions.

[0003] The difficulty in filling this data gap stems primarily from the significant challenges in testing technology. Accurately simulating and monitoring the damage evolution and corrosion rate of materials under the combined effects of stress and corrosive media in a laboratory environment is technically extremely complex, costly, and time-consuming. The stress state significantly alters the electrochemical state of the material surface, the stability of the passivation film, and the behavior of crack initiation and propagation, making traditional static corrosion testing methods difficult to directly apply and obtain reliable data.

[0004] Therefore, in order to overcome this technical bottleneck, there is an urgent need for a method that can effectively predict the long-term safety and durability of high-strength steel in real marine engineering structures (such as offshore platforms, ships, and subsea pipelines). Summary of the Invention

[0005] The purpose of this invention is to provide a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments. This method utilizes data simulation and numerical simulation software to construct a multiphysics model that couples mechanical and electrochemical fields. Based on static corrosion data and material mechanical property parameters, this model is used to accurately extrapolate and predict the dynamic corrosion rate of high-strength steel under different stresses and environmental parameters.

[0006] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0007] This invention provides a numerical simulation method for the corrosion rate of high-strength steel under marine stress conditions, comprising the following steps:

[0008] Establish a geometric model for simulation and mesh the geometric model;

[0009] Set material properties, which include corrosion kinetic parameters and basic mechanical property parameters;

[0010] Boundary conditions are applied to the geometric model to simulate the actual stress state of the high-strength steel plate;

[0011] Develop kinetic formulas for electrochemical reactions to describe the electrochemical behavior during corrosion.

[0012] Corrosion kinetics-mechanics coupling analysis was performed to calculate the distribution of corrosion current, corrosion potential, and local corrosion rate.

[0013] Optionally, establishing the geometric model for simulation includes:

[0014] A geometric model including high-strength steel plates and seawater was established using finite element or finite volume simulation software.

[0015] Optionally, the surface of the high-strength steel plate is pre-determined to have corrosion defects.

[0016] Optionally, the corrosion defect is elliptical in shape.

[0017] Optionally, the meshing of the geometric model includes:

[0018] The geometric model is meshed using triangular mesh elements.

[0019] Optionally, the corrosion kinetic parameters include corrosion potential, anodic Tafel slope, cathode Tafel slope, and exchange current density obtained by electrochemical testing in a simulated marine environment;

[0020] The basic mechanical properties include stress-strain curve data, initial yield stress, Young's modulus, material density, and Poisson's ratio.

[0021] Optionally, applying boundary conditions to the geometric model includes:

[0022] The geometric model is set as a completely fixed constraint boundary at one end in the width direction, while different tensile displacement values ​​are applied to the other end.

[0023] Optionally, the formulation of the kinetic expression formula for the electrochemical reaction includes:

[0024] The Tafel equation is used as the kinetic expression for the electrochemical reaction.

[0025] Optionally, after formulating the kinetic expression of the electrochemical reaction and before performing the corrosion kinetic-mechanical coupling analysis, the method further includes:

[0026] The output results are set, including the distribution of the corrosion current, the distribution of the corrosion potential, and the local corrosion rate.

[0027] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: By constructing a multiphysics model, this invention can accurately deduce and predict the dynamic corrosion rate of high-strength steel under different stresses and environmental parameters based on existing static corrosion data and material mechanical property parameters. This provides crucial theoretical basis and data support for the design, life assessment, and maintenance decisions of marine engineering structures. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the method flow of Embodiment 1 provided by the present invention;

[0030] Figure 2 This is the corrosion current density diagram of the material under stress in a simulated seawater environment after simulation, as provided in Embodiment 2 of the present invention.

[0031] Figure 3 This is a corrosion rate diagram of the material under stress in a simulated seawater environment after simulation, as shown in Embodiment 2 of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure / invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0033] Example 1

[0034] This embodiment introduces a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments, referencing... Figure 1 The numerical simulation method for the corrosion rate of high-strength steel under marine stress environment in this embodiment includes:

[0035] S1. Establish the geometric model for simulation and perform mesh generation on the geometric model.

[0036] A geometric model including a high-strength steel plate and its surrounding sea area was established using finite element or finite volume simulation software. Elliptical corrosion defects were pre-defined on the upper surface of the high-strength steel plate. After the geometric model was established, it was finely meshed using triangular mesh elements to ensure sufficient mesh resolution in the corrosion defect areas.

[0037] S2 sets material properties, including corrosion kinetic parameters and basic mechanical property parameters.

[0038] Among them, the corrosion kinetic parameters are static corrosion data, including corrosion potential, anodic Tafel slope, cathodic Tafel slope and exchange current density obtained by electrochemical testing in a simulated marine environment;

[0039] The fundamental mechanical properties include stress-strain curve data, initial yield stress, Young's modulus, material density, and Poisson's ratio. These parameters are used for corrosion kinetic-mechanical coupling analysis.

[0040] S3 applies boundary conditions to the geometric model to simulate the actual stress state of the high-strength steel plate.

[0041] Appropriate boundary conditions are applied to the geometric model to simulate the actual stress state. Specifically, one end of the model is set as a completely fixed constraint boundary (displacement ux = uy = uz = 0), while a series of different tensile displacement values ​​are applied to the other end to simulate the stress and deformation process that the material may undergo in actual service and to study the influence of this mechanical state on corrosion development.

[0042] S4. Develop kinetic formulas for electrochemical reactions to describe the electrochemical behavior during corrosion.

[0043] To describe the electrochemical behavior during corrosion, the Tafel equation is used as the kinetic expression for the electrochemical reactions of materials. This equation effectively correlates corrosion current with overpotential and is a core mathematical tool for simulating the electrochemical processes of corrosion.

[0044] S5, perform corrosion kinetic-mechanical coupling analysis, and solve for the distribution of corrosion current, corrosion potential and local corrosion rate.

[0045] Before the simulation, the key output data are pre-defined. These outputs mainly include the distribution of corrosion current along the length of the corrosion defect, the distribution of corrosion potential, and the calculated local corrosion rate. These results are important indicators for assessing the severity and development trend of corrosion. After the settings are completed, a corrosion kinetic-mechanical coupling analysis is performed, and the calculation is completed. After the solution process is successfully completed, all calculation results are saved to the system, and the relevant data are exported to specified file formats (such as TXT, JPG, etc.) as needed for subsequent analysis, for further data processing and in-depth analysis.

[0046] Example 2

[0047] Based on the same inventive concept as Embodiment 1, refer to Figure 1 The numerical simulation method for the corrosion rate of high-strength steel under marine stress environment in this embodiment includes:

[0048] S1. Establish the geometric model for simulation and perform mesh generation on the geometric model.

[0049] A geometric model of a high-strength steel plate and its surrounding seawater was established using finite element simulation software. The high-strength steel plate is a cuboid with dimensions of 2m length, 1m width (ignoring edge effects in the width direction), and 20mm thickness. Elliptical corrosion defects with a major axis of 150mm and a depth of 10mm are pre-defined on the upper surface of the high-strength steel plate. The electrolyte temperature in the seawater is set to 288K, and its conductivity is set to 3S / m to characterize the ionic conductivity in a real seawater environment. After the geometric model was established, it was finely meshed using triangular mesh elements to ensure sufficient mesh resolution in the corrosion defect areas.

[0050] S2 sets material properties, including corrosion kinetic parameters and basic mechanical property parameters.

[0051] The corrosion kinetic parameters are static corrosion data, including corrosion potential, anodic Tafel slope, cathodic Tafel slope, and exchange current density obtained through electrochemical testing under simulated marine conditions. Specifically, the corrosion potential is 580 mV, the anodic Tafel slope is 60.6 mV, the cathodic Tafel slope is 960 mV, and the exchange current density is 15.3 μA / cm². 2 .

[0052] The basic mechanical properties include stress-strain curve data, initial yield stress, Young's modulus, material density, and Poisson's ratio. Specifically, the initial yield stress is 823 MPa, the Young's modulus is 207 GPa, and the material density is 7.85 g / cm³. 2 The Poisson's ratio is 0.33.

[0053] S3 applies boundary conditions to the geometric model to simulate the actual stress state of the high-strength steel plate.

[0054] Appropriate boundary conditions are applied to the geometric model to simulate the actual stress state. Specifically, one end of the model in the width direction is set as a completely fixed constraint boundary (displacement ux = uy = uz = 0), and tensile displacement values ​​of 1mm, 2mm, and 3mm are applied to the other end.

[0055] S4. Develop kinetic formulas for electrochemical reactions to describe the electrochemical behavior during corrosion.

[0056] To describe the electrochemical behavior during corrosion, the Tafel equation is used as the kinetic expression for the electrochemical reactions of materials. This equation effectively correlates corrosion current with overpotential and is a core mathematical tool for simulating the electrochemical processes of corrosion.

[0057] S5, perform corrosion kinetic-mechanical coupling analysis, and solve for the distribution of corrosion current, corrosion potential and local corrosion rate.

[0058] Before the simulation is performed, the key output data are pre-defined. These outputs mainly include the distribution of corrosion current along the length of the corrosion defect, the distribution of corrosion potential, and the local corrosion rate calculated from them.

[0059] The corrosion current distribution diagram was obtained through calculation. Figure 2 As shown, the corrosion rate diagram is as follows. Figure 3 As shown.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present disclosure / the present invention, and these improvements and modifications should also be considered within the scope of protection of the present disclosure / the present invention.

Claims

1. A numerical simulation method for the corrosion rate of high-strength steel in a marine stress environment, characterized by, Including the following steps: Establish a geometric model for simulation and mesh the geometric model; Set material properties, which include corrosion kinetic parameters and basic mechanical property parameters; Boundary conditions are applied to the geometric model to simulate the actual stress state of the high-strength steel plate; Develop kinetic formulas for electrochemical reactions to describe the electrochemical behavior during corrosion. Corrosion kinetics-mechanics coupling analysis was performed to calculate the distribution of corrosion current, corrosion potential, and local corrosion rate.

2. The method according to claim 1, wherein The establishment of the geometric model for simulation includes: A geometric model including high-strength steel plates and seawater was established using finite element or finite volume simulation software.

3. The method according to claim 2, wherein the method is characterized by, The surface of the high-strength steel plate is pre-determined to have corrosion defects.

4. The method of claim 2, wherein the method is characterized by, The corrosion defect is elliptical in shape.

5. The method of claim 3, wherein the method is characterized by: The meshing of the geometric model includes: The geometric model is meshed using triangular mesh elements.

6. The numerical simulation method for corrosion rate of high-strength steel under marine stress environment according to claim 1, characterized in that, The corrosion kinetic parameters include corrosion potential, anodic Tafel slope, cathode Tafel slope, and exchange current density obtained through electrochemical testing in a simulated marine environment. The basic mechanical properties include stress-strain curve data, initial yield stress, Young's modulus, material density, and Poisson's ratio.

7. The numerical simulation method for corrosion rate of high-strength steel under marine stress environment according to claim 1, characterized in that, Applying boundary conditions to the geometric model includes: The geometric model is set as a completely fixed constraint boundary at one end in the width direction, while different tensile displacement values ​​are applied to the other end.

8. The numerical simulation method for the corrosion rate of high-strength steel under marine stress environment according to claim 1, characterized in that, The formulation of the kinetic expression formula for the electrochemical reaction includes: The Tafel equation is used as the kinetic expression for the electrochemical reaction.

9. The numerical simulation method for corrosion rate of high-strength steel under marine stress environment according to claim 1, characterized in that, After formulating the kinetic expression of the electrochemical reaction and before performing the corrosion kinetic-mechanical coupling analysis, the following is also included: The output results are set, including the distribution of the corrosion current, the distribution of the corrosion potential, and the local corrosion rate.

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