Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《中国腐蚀与防护学报》
Abstract： A FeCO3 film and FeS film were prepared on carbon steel L360 by anodic electrolyzing the steel in NaHCO3 solution and immersing the steel in Na2S solution respectively in air at 80 ℃. Then, the corrosion performance of the steel covered with the two films beneath sulfur-deposition in an artificial formation water was studied by means of electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and environmental scanning electron microscope (ESEM). The results indicated that for the case without S deposits, the two films showed good protectiveness in the artificial solutions with pH 7 and 3 respectively, and the FeCO3 film was better than the FeS film. The two films were better in the neutral solution than in acidic solution. However, for the case with S deposits, the two films loosed their protectiveness in the two solutions. Moreover, in the solution with pH 7, the steel beneath FeCO3 film suffered from local corrosion seriously, while the steel beneath FeS film suffered from uniform corrosion. Besides, in the solution with pH 3, the steels with or without films all suffered from uniform corrosion.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Research progress on corrosion of carbon steels induced by SRB is reviewed in terms of the formation mechanism of biofilm, the traditional corrosion mechanism of SRB, mechanism of biocatalysis cathodic sulfate reduction, and the corrosion of carbon steels under the deposit scale induced by SRB biomineralization. In addition, the paper focused on the key role of the theory of bioenergetics and bioelectrochemistry in understanding the mechanism of MIC induced by SRB. The novel technologies and methods for control of SRB biofilm which provide reference for control of SRB corrosion are introduced.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Corrosion inhibition performance of common inhibitors such as lauric acid and thioure for carbon steel in a CO2-saturated and SRB-containing artificial sewage was studied by means of electrochemical methods, mass loss method, three-dimensional stereoscopic microscope and quantitative measurement of the bacteria amount. The results show that in a sterilized and CO2-saturated medium, the inhibition efficiencies of lauric acid and thiourea were 98.6%, 94.6% respectively; the two inhibitors lauric acid and thiourea were all mix-type inhibitors which mainly suppress the cathodic process. In the SRB-containing and CO2-saturated medium, lauric acid and thiourea exhibit low inhibition efficiency: 62.9% and 53.5%, respectively, while there exist a lot of corrosion pits on the steel surface; and the inhibitors lauric acid and thiourea can promote the growth of SRB, while the metabolites of SRB prevent the adsorption of lauric acid and thiourea on the metal surface. Therefore, the two inhibitors may not be suitable to apply in those SRB-containing environments.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： The situatuion concering corrosion and scaling of the inner wall of sewage gathering pipelines in oil field was investigated by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), X-ray diffracmeter (XRD) and three-dimensional stereoscopic microscopy. The results indicated that after exposure to the sewage for 30 d a scale of deposits ca 169.6 μm in thickness could be observed on the surface of test samples, which consisted maily of extracellular polymeric substance with iron sulfides, the product of sulfate reducing bacteria metabolism, while beneath the scale the pipeline steel suffered from pitting corrosion with a maximum pit depth 23.96 μm; however after exposure for the same period in the same medium but with continuously adding organic guanidine bactericide of a dose 100 mg/L, the thickness of corrosion products scale was lowed to only ca 48.6 μm, besides, the corrosion of the substrate beneath the scale was light. It may be concluded that one of the reasons responsible to the localized perforation of pipelines was the SRB induced corrosion.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract： People realized that microbes can cause serious microbiologically influenced corrosion (MIC) attack on metals since a century ago. In the past 20 years, the research relevant to MIC became more and more important due to severe damages and huge economic losses caused by microorganisms. Due to a lack of understanding, MIC has even been considered to be a“myth”in the field of corrosion, therefore, a theory which can cogently explain MIC phenomena is needed. The latest research result indicated that MIC is a bioelectrochemical process in essence. When the organic carbon is not available or fully consumed, metal such as iron would replace organic carbons as an electron donor for microorganisms, resulting in the occurrence of MIC. In addition, another theory related with the mechanism of MIC is that microbes could secrete corrosive metabolites such as organic acids. It is well known that corrosion is an exergonic process, and the microorganisms would utilize the energy released by the corrosion of metal to obtain their maintenance energy. Currently, electrochemical methods are widely used in MIC research, and the classical cathodic depolarization theory (CDT) was proposed based on electrochemistry. However, if only from the perspective of the electrochemistry, many phenomena of MIC can not be cogently explained. Researchers realized that the knowledge of bioenergetics and bioelectrochemistry may be the key to better understand the interactions between microorganisms and metals and then the process of MIC. This review is to summarize the recent works, and introduce the latest theories concerning the mechanism of MIC emphatically, such as biocatalytic cathodic sulfate reduction (BCSR) and electrical microbial influenced corrosion (EMIC). The introduction of the novel perspective to study MIC from bioenergetics and bioelectrochemistry is also provided in this review. Based on bioenergetics and bioelectrochemistry, the BCSR theory can cogently explain how and why MIC happens, which has been a longterm unsolved research problem.
Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract：采用电化学方法、腐蚀失重法及表面分析手段研究了X80钢在含有铁细菌（IOB）的油田产出水中的腐蚀行为研究。结果表明，IOB明显的促进了X80钢的均匀腐蚀及局部腐蚀。在空白的油田产出水中，X80钢腐蚀速率随时间延长先减小后增大。含有菌的油田产出水介质中，X80碳钢腐蚀速率先快速减小后又快速增大。含有铁细菌(IOB)的体系形成的生物膜较为疏松，同时可以看到大量的腐蚀产物及IOB细胞。而且通过3D三维立体显微镜可以看出含有IOB体系表面腐蚀较为严重且具有点蚀坑产生。极化曲线分析和失重分析都表明IOB的存在促进了X80碳钢的腐蚀。铁氧化菌可以加速X80管线碳钢的腐蚀。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-14 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：采用腐蚀失重法、电化学测量技术和表面分析技术研究了硫酸盐还原菌（SRB）在外加磁场下对Q235钢的腐蚀行为。研究结果表明： 磁场下SRB对Q235钢的腐蚀作用较空白组减轻，其阻抗值先减小后增大，而空白组的阻抗值先增大后减小，说明磁场下试样表面的生物膜形成滞后。扫描电子显微镜（SEM）的分析结果显示，磁场下Q235钢表面的生物膜均匀致密，并且紧密的黏附在金属表面，腐蚀产物主要以铁的氧化物为主，而空白组的腐蚀产物则以铁的硫化物为主，清除腐蚀产物后，表面呈现均匀腐蚀状态，实验组相对平整，有效地抑制了腐蚀过程。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-11 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：采用失重法、电化学测量和表面分析技术研究了有无静磁场环境下在含有硫酸盐还原菌（SRB）的培养基中铜合金的腐蚀行为。结果表明：SRB条件下，铜合金腐蚀失重最大，无磁场下的腐蚀电流密度远大于有磁场存在下，磁场的加入可以有效地减缓铜合金的腐蚀。SEM及能谱分析表明：静磁场下铜合金表面腐蚀产物膜均匀致密，腐蚀产物为金属硫化物，XPS进一步分析表明，铜的化合价以一价化合物为主；而无磁场时腐蚀产物疏松，腐蚀产物硫化物中，主要为二价铜。静磁场条件下所形成的致密的硫化亚铜腐蚀产物层阻碍腐蚀的发生，有效地减小了铜合金的腐蚀。
Hits
Hits
Downloads
Comment