scholarly journals A study of bacteria adhesion and microbial corrosion on different stainless steels in environment containing Desulfovibrio vulgaris

2021 ◽  
Vol 8 (1) ◽  
pp. 201577
Author(s):  
T. T. T. Tran ◽  
K. Kannoorpatti ◽  
A. Padovan ◽  
S. Thennadil
Keyword(s):  
Stainless Steel ◽  
Surface Properties ◽  
Passive Film ◽  
Stainless Steels ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Bacterial Attachment ◽  
Alloying Elements ◽  
Desulfovibrio Vulgaris ◽  
Microbial Corrosion

Stainless steel is an important material used in many applications due to its mechanical strength and corrosion-resistant properties. The high corrosion resistance of stainless steel is provided by the passive film. Different stainless steels have different alloy elements and surface properties which could have a significant influence on bacterial attachment to the surface and thus might result in different microbial corrosion behaviours. In this study, the effect of adhesion of sulfate-reducing bacteria (SRB) on corrosion behaviour in artificial seawater on different stainless steels was investigated. Stainless steel materials used were SS 410, SS 420, SS 316 and DSS 2205 and pure chromium. The contact angle was measured to study the effect of surface properties of materials. Adhesion was measured by counting cells attached to the surface of materials. The corrosion behaviour of the materials was measured by electrochemical testing including measuring open circuit potential, electrochemical impedance spectroscopy and potentiodynamic behaviour. The long-term corrosion behaviour of each material was studied after six months of exposure by measuring weight loss and surface analysis with scanning electron microscope with energy-dispersive X-ray analysis. Hydrophobicity had a strong effect on bacterial attachment. Alloying elements e.g. nickel also had shown its ability to attract bacteria to adhere on the surface. However, the corrosion rate of different materials is determined not only by bacterial attachment but also by the stability of the passive film which is determined by the alloying elements, such as Mo and Cr. Chromium showed high resistance to corrosion, possibly due to toxicity on bacterial attachment. The nature of bacterial attachment and corrosion behaviour of the materials are discussed.

scholarly journals Microbial corrosion of DSS 2205 in an acidic chloride environment under continuous flow

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251524
Author(s):  
Thi Thuy Tien Tran ◽  
Krishnan Kannoorpatti ◽  
Anna Padovan ◽  
Suresh Thennadil ◽  
Khai Nguyen
Keyword(s):  
Biofilm Formation ◽  
Electrochemical Impedance ◽  
Positive Impact ◽  
Corrosion Behaviour ◽  
Open Circuit ◽  
Bacterial Attachment ◽  
Desulfovibrio Vulgaris ◽  
Flow Conditions ◽  
Microbial Corrosion ◽  
The Impact

Corrosion under flow conditions is a major problem in the transportation industry. Various studies have shown the direct impact of different flow rates on bacteria biofilm formation, mass transfer and resulting different corrosion behaviour of materials in neutral environments. However, little is understood on corrosion under acidic flow conditions. This study investigated the impact of an acidic artificial seawater environment containing Desulfovibrio vulgaris on DSS 2205 microbial corrosion under different velocities (0.25 m.s-1 and 0.61 m.s-1). Experiments containing no bacteria were performed as controls. Bacterial attachment was observed by optical and scanning electron microscope (SEM). Materials corrosion was assessed using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Pits formed after potentiodynamic test were observed under SEM. The largest area of bacterial attachment was found on coupons immersed at a velocity of 0.25 m.s-1; however, the corrosion rate was lower than at higher velocity. Shallow pits occurred in the metal coupons when bacteria were present, while deep pits occurred in the controls. The study indicates the positive impact of biofilm formation in corrosion prevention of materials under acidic condition. The nature of corrosion behaviour of duplex stainless is discussed.

scholarly journals Effect of Alkaline Artificial Seawater Environment on the Corrosion Behaviour of Duplex Stainless Steel 2205

2020 ◽  
Vol 10 (15) ◽  
pp. 5043
Author(s):  
Tien Tran Thi Thuy ◽  
Krishnan Kannoorpatti ◽  
Anna Padovan ◽  
Suresh Thennadil
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Hydrogen Sulphide ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Artificial Seawater ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Desulfovibrio Vulgaris ◽  
Alkaline Environments

Sulphate reducing bacteria (SRB) can be found in alkaline environments. Due to their metabolite products such as hydrogen sulphide, the corrosion behaviour of materials in alkaline environments may be affected by the presence of SRB. This study focuses on the investigation of corrosion behaviour of duplex stainless steel DSS 2205 in nutrient rich artificial seawater containing SRB species, Desulfovibrio vulgaris, at different alkaline conditions with pH range from 7 to 10. The open circuit potential value (OCP), sulphide level and pH were recorded daily. Confocal laser scanning microscopy (CLSM) was used to study the adhesion of SRB on the DSS 2205 surface. Electrochemical impedance spectroscopy (EIS) was used to study the properties of the biofilm. Potentiodynamic polarization was used to study the corrosion behaviour of material. Inductively coupled plasma mass was used to measure the concentration of cations Fe, Ni, Mo, Mn in the experimental solution after 28 days. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used for surface analysis. The results showed that D. vulgaris are active in an alkaline environment with pH 7–9. However, at pH 10, D. vulgaris activity exhibited an 8-day lag. The corrosion rate of DSS 2205 at pH 9 was higher than at other pH environments due to a higher dissolved concentration of hydrogen sulphide.

scholarly journals Composition equivalents of stainless steels understood via gamma stabilizing efficiency

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuqi Zhang ◽  
Qing Wang ◽  
Rui Yang ◽  
Chuang Dong
Keyword(s):  
Stainless Steel ◽  
Phase Boundary ◽  
Stainless Steels ◽  
Alloying Elements ◽  
Positive Sign ◽  
Equivalent Scheme ◽  
Α Phase ◽  
Phase Type ◽  
Boundary Lines

AbstractThe phase-type of a stainless steel is generally predicted by equivalent equations in terms of a major austenitic (γ) or ferritic (α) stabilizer Ni or Cr. The present paper attempts to understand the equivalent methods in stainless steels via the slopes of the phase boundary lines separating γ and γ + α phase zones. The prevailing equivalent coefficients are well interpreted using the slope ratios of the alloying elements divided by that of Ni or Cr, after analyzing over one hundred common stainless steels. Different from traditional composition equivalents which evaluate γ stabilizers and α stabilizers separately; the new equivalent scheme provides a unified phase stabilizing parameter for all alloying elements in stainless steels. This parameter is defined as γ stabilizing efficiency. Its negative or positive sign indicates γ stabilizer or α stabilizer, and its value represents the stabilizing efficiency.

Low velocity oxy fuel spraying of hydroxyapatite coating on a multifunctional UNS S31254 austenitic stainless steel

2021 ◽  
pp. 095441192110157
Author(s):  
Srikant Tiwari ◽  
Suryanarayan B Mishra
Keyword(s):  
Stainless Steel ◽  
Calcium Phosphate ◽  
Austenitic Stainless Steel ◽  
Bacterial Adhesion ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
The Body ◽  
Low Velocity ◽  
Uncoated Steel

Artificial material such as stainless steel (SS) is widely used for orthopaedic applications owing to its superior properties, ease of fabrication and lower cost. However, in the body environment, stainless steel can leach toxic elements such as nickel and chromium. To prevent this, a hydroxyapatite (HAp) coating having chemical characteristics very similar to the human bone was deposited on a medical-grade UNS S31254 austenitic stainless steel by a Low-velocity oxy-fuel spray gun (LVOF). The coating was characterised by using a field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Fourier transform infrared spectroscope (FTIR). The adhesion strength, microhardness and corrosion behaviour were studied using the Tensometre, Vickers microhardness tester and potentiodynamic polarisation with electrochemical impedance spectroscope. The bacterial adhesion and bioactivity of the coating were also evaluated. The LVOF sprayed HAp coating has shown better corrosion resistance, higher bioactivity and higher hardness than the uncoated steel. The presence of tricalcium phosphate, octa-calcium phosphate (OCP) and tetra-calcium phosphate (TTCP) was found in the coating. LVOF sprayed HAp coating is also found suitable in lowering the bacterial adhesion on the steel substrate.

Corrosion behavior of a new 25Cr-3Ni-7Mn-0.66 N duplex stainless steel in artificial seawater

2021 ◽  
Vol 63 (6) ◽  
pp. 505-511
Author(s):  
Songkran Vongsilathai ◽  
Anchaleeporn Waritswat Lothongkum ◽  
Gobboon Lothongkum
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Melting Furnace ◽  
Artificial Seawater ◽  
Vacuum Arc ◽  
Significant Difference ◽  
Type Semiconductor

Abstract A new duplex 25Cr-3Ni-7Mn-0.66 N alloy was prepared in a vacuum arc re-melting furnace and characterized by metallographic and EPMA methods. Its corrosion behavior was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and a Mott-Schottky (M-S) analysis in artificial seawater at room temperature and compared with those of super and normal commercial duplex stainless steel (SDSS and DSS). No significant difference in the open circuit potentials and pitting potentials was observed. Its passive film current density lies between those of SDSS and DSS. This was confirmed by EIS analysis. A pit attack was observed on the δ-phase for all duplex samples, because the PREN16 of the δ-phase was lower than that of the γ-phase. From the Mott-Schottky analysis, the passive films were found to be composed of bi-layer structures, a p-type semiconductor inner layer, and a n-type semiconductor outer layer. The degree of defect as well as the effect of nitrogen in passive film layer are discussed with respect to the point defect model.

Examination of the Orientation Relationships between the Main Phases of Duplex Stainless Steel by EBSD

2007 ◽  
Vol 537-538 ◽  
pp. 297-302
Author(s):  
Tibor Berecz ◽  
Péter János Szabó
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Electron Backscatter Diffraction ◽  
Duplex Stainless Steels ◽  
Alloying Elements ◽  
Orientation Relationships ◽  
Σ Phase ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Duplex stainless steels are a famous group of the stainless steels. Duplex stainless steels consist of mainly austenitic and ferritic phases, which is resulted by high content of different alloying elements and low content of carbon. These alloying elements can effect a number of precipitations at high temperatures. The most important phase of these precipitation is the σ-phase, what cause rigidity and reduced resistance aganist the corrosion. Several orientation relationships have been determined between the austenitic, ferritic and σ-phase in duplex stainless steels. In this paper we tried to verify them by EBSD (electron backscatter diffraction).

scholarly journals Effect of Heat Treatment of Martensitic Stainless Steel on Passive Layer Growth Kinetics Studied by Electrochemical Impedance Spectroscopy in Conjunction with the Point Defect Model

2020 ◽  
Vol 1 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Ingmar Bösing ◽  
Georg Marquardt ◽  
Jorg Thöming
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Passive Film ◽  
Growth Kinetics ◽  
Martensitic Stainless Steel ◽  
Electrochemical Impedance ◽  
Defect Model ◽  
Point Defect Model

Martensitic stainless steels are widely used materials. Their mechanical and corrosion properties are strongly influenced by their microstructure and thereby can be affected by heat treatment. In the present study, the effect of different austenitizing temperatures on the passive film growth kinetics of martensitic stainless steel is studied by electrochemical impedance spectroscopy. The data was further fitted by the point defect model to determine kinetic parameters. We show that an increasing austenitizing temperature leads to a more protective passive film and slows down passive film dissolution in sulfuric acid.

Uniformity Analysis of the Passive Film for SS316 Stainless Steel

2007 ◽  
Vol 364-366 ◽  
pp. 215-220
Author(s):  
Shuo Jen Lee ◽  
J.J. Lai ◽  
Yu Ming Lee ◽  
Ming Der Ger ◽  
S.W. Cheng
Keyword(s):  
Stainless Steel ◽  
Passive Film ◽  
Stainless Steels ◽  
Traditional Method ◽  
Local Corrosion ◽  
Pitting Potential ◽  
Corrosion Resistant ◽  
Potential Test

Passive film of stainless steels possesses good corrosion resistant property. However, the passive film formed in nature is not uniform and the quality is not consistent. It is the major causes for local corrosion. The pitting potential test is a traditional method to test local corrosion of stainless steels. The local corrosion is usually induced by the break-down of the passive film. Therefore, it can be utilized to evaluate the quality of the passive film. Also, because the pitting test is quick and inexpensive, many tests can be performed to evaluate the uniformity of the passive film. This study focuses on SS316 stainless steel. The specimens were treated with electropolishing processes. The original and the processed specimens were tested by pitting potential tests. From these results, the distribution and the uniformity of passive film could be evaluated. An efficient and inexpensive index of the uniformity of the passive film is proposed.

scholarly journals Stochasticity of Bacterial Attachment and Its Predictability by the Extended Derjaguin-Landau-Verwey-Overbeek Theory

2011 ◽  
Vol 77 (11) ◽  
pp. 3757-3764 ◽  
Author(s):  
Teck Wah R. Chia ◽  
Vu Tuan Nguyen ◽  
Thomas McMeekin ◽  
Narelle Fegan ◽  
Gary A. Dykes
Keyword(s):  
Stainless Steel ◽  
Physicochemical Properties ◽  
Surface Properties ◽  
Bacterial Attachment ◽  
Bacterial Cells ◽  
Initial Ratio ◽  
Content Type ◽  
Initial Inoculum ◽  
Serovar Typhimurium ◽  
Attachment Process

ABSTRACTBacterial attachment onto materials has been suggested to be stochastic by some authors but nonstochastic and based on surface properties by others. We investigated this by attaching pairwise combinations of twoSalmonella entericaserovar Sofia (S. Sofia) strains (with different physicochemical and attachment properties) with one strain each ofS. entericaserovar Typhimurium,S. entericaserovar Infantis, orS. entericaserovar Virchow (all with similar physicochemical and attachment abilities) in ratios of 0.428, 1, and 2.333 onto glass, stainless steel, Teflon, and polysulfone. Attached bacterial cells were recovered and counted. If the ratio of attached cells of eachSalmonellaserovar pair recovered was the same as the initial inoculum ratio, the attachment process was deemed stochastic. Experimental outcomes from the study were compared to those predicted by the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. Significant differences (P< 0.05) between the initial and the attached ratios for serovar pairs containingS. Sofia S1296a for all different ratios were apparent for all materials. ForS. Sofia S1635-containing pairs, 7 out of 12 combinations of serovar pairs and materials had attachment ratios not significantly different (P> 0.05) from the initial ratio of 0.428. Five out of 12 and 10 out of 12 samples had attachment ratios not significantly different (P> 0.05) from the initial ratios of 1 and 2.333, respectively. These results demonstrate that bacterial attachment to different materials is likely to be nonstochastic only when the key physicochemical properties of the bacteria were significantly different (P< 0.05) from each other. XDLVO theory could successfully predict the attachment of some individual isolates to particular materials but could not be used to predict the likelihood of stochasticity in pairwise attachment experiments.

scholarly journals Corrosion Behaviour of a Highly Alloyed Austenitic Alloy UB6 in Contaminated Phosphoric Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
M. Boudalia ◽  
A. Guenbour ◽  
A. Bellaouchou ◽  
R. M. Fernandez-Domene ◽  
J. Garcia-Anton
Keyword(s):  
Stainless Steel ◽  
Phosphoric Acid ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Electrochemical Behaviour ◽  
Phosphoric Acid Solution ◽  
Flat Band ◽  
Potential Range ◽  
Potentiodynamic Curves ◽  
P Type

The influence of temperature (20–80°C) on the electrochemical behaviour of passive films anodically formed on UB6 stainless steel in phosphoric acid solution (5.5 M H3PO4) has been examined by using potentiodynamic curves, electrochemical impedance spectroscopy, and Mott-Schottky analysis. UB6 stainless steel in contaminated phosphoric acid is characterised by high interfacial impedance, thereby, illustrating its high corrosion resistance. The obtained results show that the films behave as n-type and p-type semiconductors in the potential range above and below the flat band potential, respectively. This behaviour is assumed to be the consequence of the semiconducting properties of the iron oxide and chromium oxide regions which compose the passive film.

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