Interface Failure Behavior Of X80 Pipeline Steel Under The Synergistic Effect Of Leakage Magnetic Field And Microbe

Modern technologies such as magnetic flux leakage detection often used on construction sites will inevitably have residual magnetic fields after construction.Because buried pipelines are in the soil environment all year round,they will be affected by various complex soil environmental factors and cause corrosion behavior.Microbes and magnetic fields,as common corrosion factors in construction sites,have varying degrees of influence on the corrosion behavior of pipelines.It is of great significance to study the synergistic effect of magnetic field and microorganisms on the corrosion failure behavior of X80 steel..In this paper,sulfate-reducing bacteria were extracted as experimental strains.By simulating the soil environment of Shenyang under aseptic and bacterium conditions,the electrochemical corrosion behavior and stress corrosion failure rules of X80 steel at 0m T,10 m T,20 m T and 30 m T were studied.By constructing a static magnetic field system combined with absorbance analysis,the activity of sulfate reducing bacteria(SRB)will be inhibited by the magnetic field,and as the strength of the magnetic field increases,the inhibition is more obvious.The electrochemical corrosion behavior of X80 steel in the simulated environment of Shenyang soil was studied using polarization curve and AC impedance spectroscopy combined with weightlessness method.The polarization curve and the law analyzed by the AC impedance diagram remained similar.The comparison of corrosion rate is: 20 m T> 30 m T> 10 m T> 0m T.The comparison of the degree of corrosion in the presence of bacteria is: 20 m T> 10 m T> 30 m T> 0m T.The addition of the magnetic field promotes the corrosion behavior as a whole,but when the magnetic field strength reaches a certain level(30m T),it plays a counter-productive effect.The introduction of SRB promoted the occurrence of corrosion behavior,that is,SRB and magnetic field cooperated to promote the corrosion behavior of X80 steel in the simulated solution in Shenyang.Through the slow strain tensile rate experiment combined with the electronic scanning pattern,the stress corrosion cracking behavior under the synergistic effect of magnetic field and microorganism was explored.It was found that the stress corrosion sensitivity I under a sterile environment showed a certain trend: I(0m T)<I(10m T)<I(30m T)<I(20m T).The comparison of I value in the presence of bacteria is: I(0m T)<I(30m T)<I(10m T)<I(20m T)The introduction of magnetic field and SRB makes the X80 steel sample have a certain stress corrosion sensitivity,and the overall elongation and shrinkage of the bacteria group are lower than the sterile group,indicating that the introduction of SRB promotes the synergy of magnetic field and stress to a certain extent.The following corrosion effects on X80 pipeline steel.