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: An all solid-state and roll-shape Ag/AgCl electrode for detecting chloride ions in concrete was prepared by electrochemical oxidation of high purity (99.99%) silver foil. Electrochemical measurement results indicate that in comparison with the conventional powder moulding Ag/AgCl electrode, the novel chloride ion selective electrode has a larger exchange current density, higher specific surface area and lower temperature coefficient; by means of the electrode a better linearity is revealed of the potential response slope (-58.2 mV) versus Cl- concentration in an artificial pore solution of concrete, which is close to the theoretical value; besides, the novel electrode also exhibits a rather stable potential for a period of 230 d with fluctuations less than 4 mV. The experimental results in concrete shows that the performance of the all solid-state and roll-shape electrode, such as its linearity of potential response to lg[Cl- ] and anti- interfere capability can significantly be improved by wrapping the electrode with a thin film of polyvinyl alcohol gel electrolyte. The mor-phology observation reveals that the novel Ag/AgCl electrode has a higher active surface area, which may be beneficial to the stability and the sensitivity of ion selection. In addition, the close stacked and layer by layer structure of the all solid-state and roll-shape AgCl/Ag electrode also enhances the adhesion of AgCl particulates to the Ag foil, which further improves its reliability on chloride detection and its service life in concrete.
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.