| 摘要: |
| 目的 高强度管线钢在含硫酸盐还原菌（SRB）的海洋环境中极易发生电化学腐蚀行为，若管线钢中渗入大量H原子，腐蚀将会更严重，因此探究了充氢条件下X70管线钢在SRB环境中的电化学腐蚀问题。方法 采用电化学技术和表面分析技术，系统地研究了在南海模拟溶液中，电化学充氢条件下X70管线钢在SRB环境中的电化学行为。通过模拟不同含量的H原子进入α-Fe的扩散，差分电荷密度图和Fe—Fe的键能，分析了不同含量的H原子进入到Fe原子之间后对其造成的影响。结果 在SRB环境中，随充氢量的增多腐蚀加剧，增大充氢电流密度和充氢时间都能促进腐蚀正向进行。结论 在南海模拟溶液中，氢是促使X70管线钢腐蚀加剧的重要因素；第一性原理的计算结果表明H原子的存在降低了Fe原子之间的电荷密度，从而削弱了H原子附近的Fe—Fe键能，在腐蚀介质中整个结构会在这个削弱的位置失效，使此处更容易发生腐蚀。 |
| 关键词: X70管线钢 硫酸盐还原菌（SRB） 充氢条件 电化学行为 第一性原理 |
| DOI：10.3969/j.issn.1007-3426.2025.03.015 |
| 分类号: |
| 基金项目:国家自然科学基金“南海干湿交替中多因素耦合作用下X80管线钢应力腐蚀行为与机理研究”（52274062）；辽宁石油化工大学创新创业训练计划项目“高强度钢在深海多因素耦合作用下析氢及渗氢机理研究”（202310148010） |
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| Electrochemical behavior of X70 pipeline steel in SRB-containing environment under hydrogen-charged conditions |
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DU Rongjia1, WANG Dan1,2, ZHANG Ying3, XIE Fei1,2, LI Tianjiao1, WU Ming1,2
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1.College of Petroleum Engineering, Liaoning Petrochemical University, Fushun, Liaoning, China;2.Liaoning Provincial Key Laboratory of Oil and Gas Storage and Transportation Technology, Fushun, Liaoning, China;3.Institute of Engineering and Technology, PetroChina Xinjiang Oilfield Company, Keramay, Xinjiang, China
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| Abstract: |
| Objective High-strength pipeline steel is highly susceptible to electrochemical corrosion in the marine environment containing sulfate reducing bacteria (SRB). If a large number of hydrogen atoms are infiltrated into the pipeline steel, the corrosion will be more serious, so it is necessary to investigate the electrochemical corrosion of X70 pipeline steel in the SRB environment under hydrogen-charged conditions. Method The electrochemical behavior of X70 pipeline steel under hydrogen-charged conditions in a simulated marine solution containing SRB of the South China Sea was systematically studied by electrochemical and surface analysis techniques. Through simulating the diffusion of different concentrations of hydrogen atoms into α-Fe, differential charge density maps and Fe—Fe bond energies, the effects of different concentrations of hydrogen atoms entering between Fe atoms were analyzed. Result When SRB were present, corrosion levels rose in tandem with increases in hydrogen charging. Additionally, higher hydrogen charging current density and longer hydrogen charging duration could promote forward corrosion. Conclusion The simulation of the South China Sea marine solution reveals that hydrogen is an important factor in the corrosion of X70 pipeline steel. The results of first principle calculations indicate that the presence of hydrogen atoms decreases the charge density between iron atoms, thereby weakening the Fe—Fe bonds in close proximity to the hydrogen atoms. As a consequence, in a corrosive environment, the structural integrity of the entire system will fail at these weakened locations, making them more susceptible to corrosion. |
| Key words: X70 pipeline steel sulfate reducing bacteria(SRB) hydrogen-charged conditions electrochemical behavior first principle |
