表面技术2025，Vol.54Issue(14)：37-47,11.DOI:10.16490/j.cnki.issn.1001-3660.2025.14.004
磁场和微生物对X80钢应力腐蚀开裂行为的影响
Effect of Magnetic Fields and Microorganisms on Stress Corrosion Cracking Behavior of X80 Steel
摘要
Abstract
The stress corrosion cracking(SCC)behavior of X80 pipeline steel buried in sea mud is often influenced by magnetic fields and sulfate reducing bacteria(SRB).By immersion experiments,electrochemical experiments,and characterization analysis,the influence of stresses and magnetic fields on the film formation law and the corrosion mechanism of SRB was studied,and the effects of SRB and magnetic fields on stress corrosion cracking of X80 steel under different stresses were further explored,providing a theoretical basis for pipeline protection in complex environments.The research results indicate that in a sterile environment,after applying a magnetic field,the Lorentz force enhances the transport process of substances in the solution,leading to the accumulation of nutrients in the solution on the steel surface,thereby hindering the corrosion of corrosive ions on the electrode surface.The magnetic field gradient force can attract particles such as oxygen and ferric chloride to the outside of the defect,and attract hydroxyl ions to the inside of the defect to form an oxide film with iron,thereby weakening the corrosion inside the defect and reducing the sensitivity of the metal to SCC.MF hinders the migration of corrosive ions to the electrode surface,thereby inhibiting the corrosion process.In a bacterial environment,the magnetic field changes the adhesion of SRB on the surface of X80 steel,making the distribution of the biofilm on the surface of the specimen more uneven,which leads to galvanic corrosion,where the biofilm is covered by the anode and surrounded by the cathode.With the densification of the biofilm,a complete biofilm prevents oxygen and corrosive anions(Cl-)from coming into contact with the steel surface,but leads to a local oxygen deficient environment on the steel surface,accelerating the cathodic depolarization process of SRB.Under the combined action of stress and SRB,pitting corrosion pits appear on the specimens.SRB significantly enhances the SCC sensitivity of X80 pipeline steel in simulated sea mud solution.The SCC sensitivity in SRB inoculation solution is several times higher than that in sterile solution,reaching 42％.The role of SRB in assisting pitting corrosion and promoting hydrogen infiltration into steel accelerates the initiation and propagation of cracks.SCC crack initiation usually starts within the pit.Once the crack is formed,magnetic field forces will also be generated inside the crack under the action of an external magnetic field.The magnetic field provides a carrier for the extracellular electron transfer process of SRB by attracting paramagnetic Fe3O4,thereby accelerating corrosion and causing the expansion of pitting corrosion pits.The expanded pitting will be subject to the action of the magnetic field and SRB again.In this cycle,SRB and the magnetic field will intensify the stress corrosion of steel.The corrosion rate of X80 steel specimens significantly increases under the synergistic effect of the three factors.关键词
磁场/硫酸盐还原菌/X80钢/应力腐蚀开裂/生物Key words
magnetic field/sulfate reducing bacteria/X80 steel/stress corrosion cracking/organism分类
矿业与冶金引用本文复制引用
申雨欣,王丹,郭大成,谢飞,王雨欣..磁场和微生物对X80钢应力腐蚀开裂行为的影响[J].表面技术,2025,54(14):37-47,11.基金项目
国家自然科学基金(52402428)National Natural Science Foundation(52402428) （52402428）
