scholarly journals Bulk phase resource ratio alters carbon steel corrosion rates and endogenously produced extracellular electron transfer mediators in a sulfate-reducing biofilm

Biofouling ◽  
2019 ◽  
Vol 35 (6) ◽  
pp. 669-683 ◽  
Author(s):  
Gregory P. Krantz ◽  
Kilean Lucas ◽  
Erica L.- Wunderlich ◽  
Linh T. Hoang ◽  
Recep Avci ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Carbon Steel ◽  
Steel Corrosion ◽  
Bulk Phase ◽  
Extracellular Electron Transfer ◽  
Sulfate Reducing ◽  
Corrosion Rates

scholarly journals The effect of volatile organic acids and CO2 on the corrosion rate of carbon steel from a Top-of-Line-Corrosion (TLC) perspective

2021 ◽  
Vol 1201 (1) ◽  
pp. 012079
Author(s):  
S B Gjertsen ◽  
A Palencsar ◽  
M Seiersten ◽  
T H Hemmingsen
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Organic Acid ◽  
Carbonic Acid ◽  
Acid Corrosion ◽  
Iron Concentration ◽  
Critical Factor ◽  
Steel Corrosion ◽  
Carbon Steels ◽  
Corrosion Rates

Abstract Models for predicting top-of-line corrosion (TLC) rates on carbon steels are important tools for cost-effectively designing and operating natural gas transportation pipelines. The work presented in this paper is aimed to investigate how the corrosion rates on carbon steel is affected by acids typically present in the transported pipeline fluids. This investigation may contribute to the development of improved models. In a series of experiments, the corrosion rate differences for pure CO2 (carbonic acid) corrosion and pure organic acid corrosion (acetic acid and formic acid) on X65 carbon steel were investigated at starting pH values; 4.5, 5.3, or 6.3. The experiments were conducted in deaerated low-salinity aqueous solutions at atmospheric pressure and temperature of 65 °C. The corrosion rates were evaluated from linear polarization resistance data as well as mass loss and released iron concentration. A correlation between lower pH values and increased corrosion rates was found for the organic acid experiments. However, the pH was not the most critical factor for the rates of carbon steel corrosion in these experiments. The experimental results showed that the type of acid species involved and the concentration of the undissociated acid in the solution influenced the corrosion rates considerably.

scholarly journals Formation of Biofilms and Biocorrosion on AISI-1020 Carbon Steel Exposed to Aqueous Systems Containing Different Concentrations of a Diesel/Biodiesel Mixture

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ivanilda Ramos de Melo ◽  
Severino Leopoldino Urtiga Filho ◽  
Fernando Jorge Santos Oliveira ◽  
Francisca Pessoa de França
Keyword(s):  
Carbon Steel ◽  
Sulfate Reducing Bacteria ◽  
Experimental Conditions ◽  
Exposed Area ◽  
Sulfate Reducing ◽  
Corrosion Rates ◽  
Biodiesel Blend ◽  
Corrosion Pits ◽  
Reducing Bacteria ◽  
Significant Concentration

Environmental and economic concerns accelerated biofuels research and industrial production. Many countries have been using diesel and biodiesel blends as fuels justifying research on biofilms formation and metals corrosion. Cylinders made of AISI-1020 carbon steel with an exposed area of 1587 mm2, water, and water associated with B3 fuel (diesel/biodiesel blend at 97 : 3 v/v) were used.The formation of biofilms was detected, and biocorrosion was detected on AISI-1020. The results showed a variation in sessile microflora during the experiments. In the biofilms, a significant concentration of aerobic, anaerobic, IOB,Pseudomonas aeruginosa, and sulfate-reducing bacteria was observed. The corrosion rates varied between0.45±0.01and0.12±0.01 mm/year, depending on the experimental conditions. The main corrosion products identified were various forms of FeOOH, magnetite, and all forms of FexSy. In systems where there were high levels of sulfate reducing bacteria, corrosion pits were observed. In addition, the aliphatic hydrocarbons present in the fluid containing 10% B3 were totally degraded.

scholarly journals Uniform and Pitting Corrosion of Carbon Steel byShewanella oneidensisMR-1 under Nitrate-Reducing Conditions

2018 ◽  
Vol 84 (12) ◽  
pp. e00790-18 ◽  
Author(s):  
Robert B. Miller ◽  
Kenton Lawson ◽  
Anwar Sadek ◽  
Chelsea N. Monty ◽  
John M. Senko
Keyword(s):  
Electron Transfer ◽  
Carbon Steel ◽  
Electron Donor ◽  
Pitting Corrosion ◽  
Nitrate Reduction ◽  
Steel Corrosion ◽  
Nitrite Accumulation ◽  
Content Type ◽  
Microbially Influenced Corrosion ◽  
Reducing Conditions

ABSTRACTDespite observations of steel corrosion in nitrate-reducing environments, processes of nitrate-dependent microbially influenced corrosion (MIC) remain poorly understood and difficult to identify. We evaluated carbon steel corrosion byShewanella oneidensisMR-1 under nitrate-reducing conditions using a split-chamber/zero-resistance ammetry (ZRA) technique. This approach entails the deployment of two metal (carbon steel 1018 in this case) electrodes into separate chambers of an electrochemical split-chamber unit, where the microbiology or chemistry of the chambers can be manipulated. This approach mimics the conditions of heterogeneous metal coverage that can lead to uniform and pitting corrosion. The current between working electrode 1 (WE1) and WE2 can be used to determine rates, mechanisms, and, we now show, extents of corrosion. WhenS. oneidensiswas incubated in the WE1 chamber with lactate under nitrate-reducing conditions, nitrite transiently accumulated, and electron transfer from WE2 to WE1 occurred as long as nitrite was present. Nitrite in the WE1 chamber (withoutS. oneidensis) induced electron transfer in the same direction, indicating that nitrite cathodically protected WE1 and accelerated the corrosion of WE2. WhenS. oneidensiswas incubated in the WE1 chamber without an electron donor, nitrate reduction proceeded, and electron transfer from WE2 to WE1 also occurred, indicating that the microorganism could use the carbon steel electrode as an electron donor for nitrate reduction. Our results indicate that under nitrate-reducing conditions, uniform and pitting carbon steel corrosion can occur due to nitrite accumulation and the use of steel-Fe(0) as an electron donor, but conditions of sustained nitrite accumulation can lead to more-aggressive corrosive conditions.IMPORTANCEMicrobially influenced corrosion (MIC) causes damage to metals and metal alloys that is estimated to cost over $100 million/year in the United States for prevention, mitigation, and repair. While MIC occurs in a variety of settings and by a variety of organisms, the mechanisms by which microorganisms cause this damage remain unclear. Steel pipe and equipment may be exposed to nitrate, especially in oil and gas production, where this compound is used for corrosion and “souring” control. In this paper, we show uniform and pitting MIC under nitrate-reducing conditions and that a major mechanism by which it occurs is via the heterogeneous cathodic protection of metal surfaces by nitrite as well as by the microbial oxidation of steel-Fe(0).

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