Effect Of Magnetic Field On Corrosion Behavior Of Carbon Steel Pipeline In Seawater Pumped Storage Power Station

In order to ensure that the power system is economical,reliable,and capable of safe operation,the power generation of seawater pumped storage power stations has become the main source of support for the national economy.However,seawater is one of the strongest corrosive electrolytes,and the metal structures in seawater pumped storage power stations are subject to a lot of corrosion,which is not only prone to accidents,but also affects the rapid development of power engineering.Therefore,metal protection technology is very important.Carbon steel is widely used in seawater pumped storage power stations due to its cost-effectiveness in corrosion resistance.Therefore,the research on the corrosion resistance of carbon steel in seawater is of great significance to power engineering.In order to suppress the corrosion behavior of carbon steel in seawater,researchers have proposed many technical solutions based on numerical simulation and electrochemical experiments.Recently,it was discovered that magnetic fields can affect the corrosion behavior of metals in seawater environments.Because the magnetic field does not pollute the marine environment and is conducive to the green development of marine resources,this article takes the carbon steel pipelines of seawater pumped storage power stations as the research goal to investigate whether the magnetic field can inhibit the corrosion of carbon steel in seawater.Aiming at the carbon steel pipelines of seawater pumped storage power stations,this paper selects Q235 carbon steel in seawater as the research object.First,numerical simulation is used to analyze whether the magnetic flux density distribution inside the surface of carbon steel pipelines is uniform and the magnetic field is applied under different magnetic field layout methods.Whether the method is reasonable.Then electrochemical experiments were used to investigate whether the magnetic field had an effect on the corrosion degree of carbon steel pipelines.This section selects three types of magnetic field layouts: the electromagnetic field generated by the conductive wires laid on the pipe surface,the electromagnetic field generated by the energized spiral coil wound on the pipe surface,and the static magnetic field generated by Nd Fe B permanent magnets.According to the results of the magnetic field layout,it was found that because carbon steel is a paramagnetic material,when a permanent magnet is applied to the surface of a carbon steel pipe,most of the applied magnetic field is absorbed by the carbon steel,and there is little magnetic leakage.According to the results of electrochemical experiments,it was found that the corrosion of carbon steel was suppressed under an external magnetic field.Corrosion of carbon steel is suppressed to a certain extent by means of applying an external magnetic field to a permanent magnet.However,in order to make better use of the soft magnetism of carbon steel and explore the influence of magnetic field on its corrosion,the corrosion area of carbon steel pipelines is too large to study the corrosion mechanism.Therefore,the effect of magnetic field on the corrosion mechanism of carbon steel was studied by using a small Q235 test piece.First,based on the actual experimental model,the magnetic field intensity distribution of the surface magnetized by Nd Fe B was analyzed and calculated.In order to avoid the error between the simulated magnetic field intensity distribution and the actual experimental value being too large,a Gauss meter was used to actually measure several points near the surface of the carbon steel.Magnetic field strength.Based on the results of simulation calculations,further electrochemical experiments were performed.The open-circuit potential method,chronoamperometry,and X-ray diffraction corrosion intermediates were used to explain the influence of the magnetic field on the corrosion process of carbon steel.In the electrochemical experiments,it was found that the main factors affecting the electrochemical corrosion of carbon steel in seawater are electromagnetic forces,and the electromagnetic forces that play a major role are the magnetic field gradient force and the Lorentz force.A strong magnetic field gradient exists on the surface of the magnetized carbon steel,and the magnetic field gradient force inhibits the corrosion process of the carbon steel.In order to understand the principle of Lorentz force on the electrochemical reaction process,the anode surface potential is affected by Lorentz force using the electrochemical experiment Tafel linear extrapolation method,electrochemical numerical simulation analysis and AC impedance spectrum analysis under a uniform magnetic field.Because the Lorentz force accelerates the flow of ions in the solution,the corrosion of carbon steel is accelerated.The full text mainly proves that the soft magnetism of carbon steel is conducive to its magnetization by permanent magnets,causing the carbon steel itself to have a magnetism equal to or even greater than that of the original permanent magnet.There are magnetic field gradient force and Lorentz force on the surface of magnetized carbon steel.Lorentz force accelerates the solution ions in seawater,resulting in active ion movement and accelerated corrosion of carbon steel.The existence of the magnetic field gradient caused the magnetic ions in the solution to be adsorbed on the surface of the carbon steel,hindering the reaction and inhibiting corrosion.Therefore,the reasonable use of magnetic field layout in seawater to avoid Lorentz force can inhibit the corrosion process of carbon steel.