Omar Rosas - Academia.edu (original) (raw)

Papers by Omar Rosas

Research paper thumbnail of FeCO3 layer evolution for API 5L X52 steel in carbon dioxide-saturated NaCl brine in the presence of 1-decyl-3-methylimidazolium chloride

Corrosion Science, 2014

ABSTRACT The FeCO3 layer evolution process for API 5L X52 carbon steel in CO2-saturated NaCl brin... more ABSTRACT The FeCO3 layer evolution process for API 5L X52 carbon steel in CO2-saturated NaCl brine in the presence of 1-decyl-3-methylimidazolium chloride ionic liquid was characterized using electrochemical techniques. Four layer-formation stages were described: active-adsorption, porous layer, compact layer-formation, and the compact layer state. The ionic liquid slowed the layering process by influencing both crystal precipitation and structural changes. Two models were developed to account for the interfacial evolution: the first model considered the balance of positive and negative charges at the interface of the metal and electrolyte in blank solution, while the second one considered the layer coverage and evolution with the imidazolium compound.

Research paper thumbnail of Effect of chloride ions on the electrochemical performance of LDX 2003 alloy in concrete and simulated concrete-pore solutions

Journal of Applied Electrochemistry, 2014

ABSTRACT The aim of this work is to study the effect of chloride ions in the performance of LDX 2... more ABSTRACT The aim of this work is to study the effect of chloride ions in the performance of LDX 2003 alloy and to characterize the interface formed in simulated concrete and simulated concrete-pore solutions. In order to have a baseline for analyzing LDX 2003 performance, this alloy is compared with two commonly used materials, AISI 1008 and SAE 316L. Electrochemical techniques such as potentiodynamic scan and electrochemical impedance spectroscopy are used to analyze the qualitative characteristics of the passive layer in four different chloride concentrations for the simulated concrete solutions: 0, 0.05, 0.7, and 3.5 wt%; and four different ratios of [Cl−]/[OH−] for the simulated concrete-pore solution: 0, 0.1, 1.0, and 10. For long-term experimental condition, equivalent circuits analogs were applied and the results were analyzed to describe and quantify meaningful parameters for corrosion performance. The electrochemical techniques are complemented by high resolution techniques, such as scanning electron microscopy, atomic force microscopy, and 3D optical microscopy.

Research paper thumbnail of Electrochemical and fractographic analysis of Microbiologically Assisted Stress Corrosion Cracking of carbon steel

Research paper thumbnail of Corrosion of low carbon steel by microorganisms from the ‘pigging’ operation debris in water injection pipelines

Bioelectrochemistry, 2014

Research paper thumbnail of Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: Laboratory investigation

Bioelectrochemistry, 2014

Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion ... more Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -800<E(OCP)/mV (vs. SCE)<-700. Generally, the overall corrosion rate, expressed as 1/(Rp/Ω), was lower in the inoculated seawater though they varied significantly on both reactors. Initial and final corrosion rates were virtually identical, namely initial 1/(Rp/Ω)=2×10(-6)±5×10(-7) and final 1/(Rp/Ω)=1.1×10(-5)±2.5×10(-6). Measured data, including electrochemical noise transients and statistical parameters (0.05<Localized Index<1; -5<Skewness<-5; Kurtosis>45), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.

Research paper thumbnail of FeCO3 layer evolution for API 5L X52 steel in carbon dioxide-saturated NaCl brine in the presence of 1-decyl-3-methylimidazolium chloride

Corrosion Science, 2014

ABSTRACT The FeCO3 layer evolution process for API 5L X52 carbon steel in CO2-saturated NaCl brin... more ABSTRACT The FeCO3 layer evolution process for API 5L X52 carbon steel in CO2-saturated NaCl brine in the presence of 1-decyl-3-methylimidazolium chloride ionic liquid was characterized using electrochemical techniques. Four layer-formation stages were described: active-adsorption, porous layer, compact layer-formation, and the compact layer state. The ionic liquid slowed the layering process by influencing both crystal precipitation and structural changes. Two models were developed to account for the interfacial evolution: the first model considered the balance of positive and negative charges at the interface of the metal and electrolyte in blank solution, while the second one considered the layer coverage and evolution with the imidazolium compound.

Research paper thumbnail of Effect of chloride ions on the electrochemical performance of LDX 2003 alloy in concrete and simulated concrete-pore solutions

Journal of Applied Electrochemistry, 2014

ABSTRACT The aim of this work is to study the effect of chloride ions in the performance of LDX 2... more ABSTRACT The aim of this work is to study the effect of chloride ions in the performance of LDX 2003 alloy and to characterize the interface formed in simulated concrete and simulated concrete-pore solutions. In order to have a baseline for analyzing LDX 2003 performance, this alloy is compared with two commonly used materials, AISI 1008 and SAE 316L. Electrochemical techniques such as potentiodynamic scan and electrochemical impedance spectroscopy are used to analyze the qualitative characteristics of the passive layer in four different chloride concentrations for the simulated concrete solutions: 0, 0.05, 0.7, and 3.5 wt%; and four different ratios of [Cl−]/[OH−] for the simulated concrete-pore solution: 0, 0.1, 1.0, and 10. For long-term experimental condition, equivalent circuits analogs were applied and the results were analyzed to describe and quantify meaningful parameters for corrosion performance. The electrochemical techniques are complemented by high resolution techniques, such as scanning electron microscopy, atomic force microscopy, and 3D optical microscopy.

Research paper thumbnail of Electrochemical and fractographic analysis of Microbiologically Assisted Stress Corrosion Cracking of carbon steel

Research paper thumbnail of Corrosion of low carbon steel by microorganisms from the ‘pigging’ operation debris in water injection pipelines

Bioelectrochemistry, 2014

Research paper thumbnail of Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: Laboratory investigation

Bioelectrochemistry, 2014

Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion ... more Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -800<E(OCP)/mV (vs. SCE)<-700. Generally, the overall corrosion rate, expressed as 1/(Rp/Ω), was lower in the inoculated seawater though they varied significantly on both reactors. Initial and final corrosion rates were virtually identical, namely initial 1/(Rp/Ω)=2×10(-6)±5×10(-7) and final 1/(Rp/Ω)=1.1×10(-5)±2.5×10(-6). Measured data, including electrochemical noise transients and statistical parameters (0.05<Localized Index<1; -5<Skewness<-5; Kurtosis>45), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.