Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Influence of Sulfate-Reducing Bacteria on the Corrosion Residual Strength of an AZ91D Magnesium Alloy.

ABSTRACT: In this paper, the corrosion residual strength of the AZ91D magnesium alloy in the presence of sulfate-reducing bacteria is studied. In the experiments, the chemical composition of corrosion film was analyzed by a scanning electron microscope with energy dispersive X-ray spectroscopy. In addition, a series of instruments, such as scanning electronic microscope, pH-meter and an AG-10TA materials test machine, were applied to test and record the morphology of the corrosion product, fracture texture and mechanical properties of the AZ91D magnesium alloy. The experiments show that the sulfate-reducing bacteria (SRB) play an important role in the corrosion process of the AZ91D magnesium alloy. Pitting corrosion was enhanced by sulfate-reducing bacteria. Corrosion pits are important defects that could lead to a significant stress concentration in the tensile process. As a result, sulfate-reducing bacteria influence the corrosion residual strength of the AZ91D magnesium alloy by accelerating pitting corrosion.

SUBMITTER: Zhu X

PROVIDER: S-EPMC5456009 | biostudies-other | 2014 Oct

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Influence of Sulfate-Reducing Bacteria on the Corrosion Behavior of High Strength Steel EQ70 under Cathodic Polarization.

Project description:Certain species of sulfate-reducing bacteria (SRB) use cathodes as electron donors for metabolism, and this electron transfer process may influence the proper protection potential choice for structures. The interaction between SRB and polarized electrodes had been the focus of numerous investigations. In this paper, the impact of cathodic protection (CP) on Desulfovibrio caledoniens metabolic activity and its influence on highs trength steel EQ70 were studied by bacterial analyses and electrochemical measurements. The results showed that EQ70 under -0.85 VSCE CP had a higher corrosion rate than that without CP, while EQ70 with -1.05 VSCE had a lower corrosion rate. The enhanced SRB metabolic activity at -0.85 VSCE was most probably caused by the direct electron transfer from the electrode polarized at -0.85 VSCE. This direct electron transfer pathway was unavailable in -1.05 VSCE. In addition, the application of cathodic protection led to the transformation of sulfide rusts into carbonates rusts. These observations have been employed to provide updated recommendations for the optimum CP potential for steel structures in the presence of SRB.

| S-EPMC5014316 | biostudies-literature

Mitigation of Corrosion on Magnesium Alloy by Predesigned Surface Corrosion.

Project description:Rapid corrosion of magnesium alloys is undesirable in structural and biomedical applications and a general way to control corrosion is to form a surface barrier layer isolating the bulk materials from the external environment. Herein, based on the insights gained from the anticorrosion behavior of corrosion products, a special way to mitigate aqueous corrosion is described. The concept is based on pre-corrosion by a hydrothermal treatment of Al-enriched Mg alloys in water. A uniform surface composed of an inner compact layer and top Mg-Al layered double hydroxide (LDH) microsheet is produced on a large area using a one-step process and excellent corrosion resistance is achieved in saline solutions. Moreover, inspired by the super-hydrophobic phenomenon in nature such as the lotus leaves effect, the orientation of the top microsheet layer is tailored by adjusting the hydrothermal temperature, time, and pH to produce a water-repellent surface after modification with fluorinated silane. As a result of the trapped air pockets in the microstructure, the super-hydrophobic surface with the Cassie state shows better corrosion resistance in the immersion tests. The results reveal an economical and environmentally friendly means to control and use the pre-corrosion products on magnesium alloys.

| S-EPMC4663789 | biostudies-literature

Microbiologically influenced corrosion of stainless steel independent of sulfate-reducing bacteria.

Project description:The presence and activities of microorganisms on metal surfaces can affect corrosion. Microbial communities after such corrosion incidents have been frequently analyzed, but little is known about the dynamics of microbial communities in biofilms on different types of stainless steels, such as austenitic, martensitic, and duplex stainless steels. Here, we conducted immersion experiments on 10 types of stainless steels in a freshwater environment, where microbiologically influenced corrosion was observed. During 22-month of immersion, severe localized corrosions were observed only on martensitic S40300 stainless steel. Microbial community analysis showed notable differences between non-corroded and corroded stainless steels. On the surfaces of non-corroded stainless steels, microbial communities were slowly altered and diversity decreased over time; in particular, relative abundance of Nitrospira sp. notably increased. Whereas microbial communities in corrosion products on corroded stainless steels showed low diversity; in particular, the family Beggiatoaceae bacteria, iron-oxidizing bacteria, and Candidatus Tenderia sp. were enriched. Furthermore, sulfur enrichment during localized corrosion was observed. Since there was no enrichment of sulfate-reducing bacteria, the sulfur enrichment may be derived from the presence of family Beggiatoaceae bacteria with intracellular sulfur inclusion. Our results demonstrated slow and drastic changes in microbial communities on the healthy and corroded metal surfaces, respectively, and microbial communities on the healthy metal surfaces were not affected by the composition of the stainless steel.

| S-EPMC9597249 | biostudies-literature

Corrosion of iron by sulfate-reducing bacteria: new views of an old problem.

Project description:About a century ago, researchers first recognized a connection between the activity of environmental microorganisms and cases of anaerobic iron corrosion. Since then, such microbially influenced corrosion (MIC) has gained prominence and its technical and economic implications are now widely recognized. Under anoxic conditions (e.g., in oil and gas pipelines), sulfate-reducing bacteria (SRB) are commonly considered the main culprits of MIC. This perception largely stems from three recurrent observations. First, anoxic sulfate-rich environments (e.g., anoxic seawater) are particularly corrosive. Second, SRB and their characteristic corrosion product iron sulfide are ubiquitously associated with anaerobic corrosion damage, and third, no other physiological group produces comparably severe corrosion damage in laboratory-grown pure cultures. However, there remain many open questions as to the underlying mechanisms and their relative contributions to corrosion. On the one hand, SRB damage iron constructions indirectly through a corrosive chemical agent, hydrogen sulfide, formed by the organisms as a dissimilatory product from sulfate reduction with organic compounds or hydrogen ("chemical microbially influenced corrosion"; CMIC). On the other hand, certain SRB can also attack iron via withdrawal of electrons ("electrical microbially influenced corrosion"; EMIC), viz., directly by metabolic coupling. Corrosion of iron by SRB is typically associated with the formation of iron sulfides (FeS) which, paradoxically, may reduce corrosion in some cases while they increase it in others. This brief review traces the historical twists in the perception of SRB-induced corrosion, considering the presently most plausible explanations as well as possible early misconceptions in the understanding of severe corrosion in anoxic, sulfate-rich environments.

| S-EPMC3911074 | biostudies-literature

sulfate reducing bacteria

Project description:sulfate reducing bacteria Metagenome

| PRJNA421399 | ENA

sulfate-reducing bacteria

Project description:The presence of O2 in wastewater affects the abundance of SRB species

| PRJNA903667 | ENA

Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy.

Project description:The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

| S-EPMC5456170 | biostudies-other

Marine sulfate-reducing bacteria cause serious corrosion of iron under electroconductive biogenic mineral crust.

Project description:Iron (Fe(0) ) corrosion in anoxic environments (e.g. inside pipelines), a process entailing considerable economic costs, is largely influenced by microorganisms, in particular sulfate-reducing bacteria (SRB). The process is characterized by formation of black crusts and metal pitting. The mechanism is usually explained by the corrosiveness of formed H(2) S, and scavenge of 'cathodic' H(2) from chemical reaction of Fe(0) with H(2) O. Here we studied peculiar marine SRB that grew lithotrophically with metallic iron as the only electron donor. They degraded up to 72% of iron coupons (10?mm?×?10?mm?×?1?mm) within five months, which is a technologically highly relevant corrosion rate (0.7?mm?Fe(0) year(-1) ), while conventional H(2) -scavenging control strains were not corrosive. The black, hard mineral crust (FeS, FeCO(3) , Mg/CaCO(3) ) deposited on the corroding metal exhibited electrical conductivity (50?S?m(-1) ). This was sufficient to explain the corrosion rate by electron flow from the metal (4Fe(0) ???4Fe(2+) ?+?8e(-) ) through semiconductive sulfides to the crust-colonizing cells reducing sulfate (8e(-) ?+?SO(4) (2-) ?+?9H(+) ???HS(-) ?+?4H(2) O). Hence, anaerobic microbial iron corrosion obviously bypasses H(2) rather than depends on it. SRB with such corrosive potential were revealed at naturally high numbers at a coastal marine sediment site. Iron coupons buried there were corroded and covered by the characteristic mineral crust. It is speculated that anaerobic biocorrosion is due to the promiscuous use of an ecophysiologically relevant catabolic trait for uptake of external electrons from abiotic or biotic sources in sediments.

| S-EPMC3429863 | biostudies-other

Microstructure and Corrosion of Cast Magnesium Alloy ZK60 in NaCl Solution.

Project description:In this work, the effects of the microstructure and phase constitution of cast magnesium alloy ZK60 (Mg-5.8Zn-0.57Zr, element concentration in wt.%) on the corrosion behavior in aqueous NaCl (0.1 mol dm-3) were investigated by weight-loss measurements, hydrogen evolution tests, and electrochemical techniques. The alloy was found to be composed of ?-Mg matrix, with large second-phase particles of MgZn2 deposited along grain boundaries and a Zr-rich region in the central area of the grains. The large second-phase particles and the Zr-rich regions were more stable than the Mg matrix, resulting in a strong micro-galvanic effect. A filiform corrosion was found. It originated from the second-phase particles in the grain boundary regions in the early corrosion period. The filaments gradually occupied most areas of the alloy surface, and the general corrosion rate decreased significantly. Corrosion pits were developed under filaments. The pit growth rate decreased over time; however, it was about eight times larger than the general corrosion rate. A schematic model is presented to illustrate the corrosion mechanism.

| S-EPMC7504006 | biostudies-literature

sulfate-reducing bacteria consortium

Project description:a sulfate-reducing bacteria consortium

| PRJNA607572 | ENA