Evaluation of corrosion inhibitors in acid medium

2015 ◽  
Vol 62 (4) ◽  
pp. 241-245
Author(s):  
Fernando Benedicto Mainier ◽  
Raphaela de Melo Baêsso e Silva
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Acid Medium ◽  
Design Methodology ◽  
Corrosion Inhibitors ◽  
Experimental Conditions ◽  
Content Type ◽  
Steel Pipes ◽  
Kinetics Of

Purpose – The purpose of this paper is to evaluate the corrosion inhibitor performance in acid medium through the determination of Fe2+ ions present based on reaction kinetics of steel with the acid. The use of corrosion inhibitors has been an excellent technique for protecting carbon steel pipes acidizing operations in oil wells. The inhibitor forms a chemical barrier on the metal surface that prevents or reduces attack by the acidic media. Design/methodology/approach – The experimental study provides a methodology to evaluate the performance of corrosion inhibitors in an acid medium, preferentially of concentrated hydrochloric acid. The process consists essentially of total immersion coupons of carbon steel, with continuous stirring, controlled temperature and quantitative determinations of iron ions from the dissolution of steel. The additions of commercial corrosion inhibitor base of ethoxylated amines of high molecular weight in an acid medium showed excellent performance at a temperature ranging from 25 to 45°C. Findings – This paper presents the mechanisms of protection, performance graphs and calculations of the activation energies of the addition of corrosion inhibitors in an acidic medium. Originality/value – The originality of this essay is to evaluate and correlate the performance of corrosion inhibitors with the activation energy in experimental conditions.

Investigation of some parameters affecting the cathodic protection of steel pipelines

2014 ◽  
Vol 61 (4) ◽  
pp. 250-254
Author(s):  
Adnan S. Jabur
Keyword(s):  
Carbon Steel ◽  
Current Density ◽  
Cathodic Protection ◽  
Design Methodology ◽  
Electrochemical Cell ◽  
Content Type ◽  
Steel Pipes ◽  
Experimental Apparatus ◽  
Impressed Current ◽  
Full Protection

Purpose – This work aimed to study the effect of environment resistivity and distance between cathode and anode on the required cathodic protection current density of buried carbon steel pipes and determine the impressed current that gives full protection to bare and coated pipes by two different coatings. Design/methodology/approach – The experimental apparatus is an electrochemical cell composed of carbon steel pipe of 10 cm in length as a working electrode in addition to reference and auxiliary electrodes and direct current power supply. The cathodic protection tests were carried out in five solutions of different concentrations of sodium chloride and distilled water with different resistivities. Findings – It was found that the cathodic protection current density increased with a decrease in environment resistivity and increase in the distance between cathode and anode. Additionally, the cathodic protection current density of coated pipes by two different polymers increased with a decrease in the environment resistivity and increasing number of coating defects. Originality/value – icp = D/A + B?2, where: icp = cathodic protection current density; D = distance between anode and cathode; ? = environment resistivity; A = constant (0.2104); and B = constant (0.864 × 10−6).

Locating complex eigenvalues for analytical eddy-current models used to detect flaws

2019 ◽  
Vol 38 (6) ◽  
pp. 1800-1809
Author(s):  
Grzegorz Tytko ◽  
Łukasz Dawidowski
Keyword(s):  
Eddy Current ◽  
Design Methodology ◽  
Complex Function ◽  
Precise Determination ◽  
Argument Principle ◽  
Content Type ◽  
Conductive Material ◽  
Complex Roots ◽  
Complex Eigenvalues

Purpose Discrete eigenvalues occur in eddy current problems in which the solution domain was truncated on its edge. In case of conductive material with a hole, the eigenvalues are complex numbers. Their computation consists of finding complex roots of a complex function that satisfies the electromagnetic interface conditions. The purpose of this paper is to present a method of computing complex eigenvalues that are roots of such a function. Design/methodology/approach The proposed approach involves precise determination of regions in which the roots are found and applying sets of initial points, as well as the Cauchy argument principle to calculate them. Findings The elaborated algorithm was implemented in Matlab and the obtained results were verified using Newton’s method and the fsolve procedure. Both in the case of magnetic and nonmagnetic materials, such a solution was the only one that did not skip any of the eigenvalues, obtaining the results in the shortest time. Originality/value The paper presents a new effective method of locating complex eigenvalues for analytical solutions of eddy current problems containing a conductive material with a hole.

The inhibitive properties of Nopal slime on the corrosion of steel in chloride-contaminated mortar

2015 ◽  
Vol 63 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Wilfrido Martinez-Molina ◽  
Andres Torres-Acosta ◽  
Rosalba Hernández-Leos ◽  
Elia Alonso-Guzman ◽  
Itzel Mendoza-Pérez ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Electrochemical Impedance ◽  
Experimental Period ◽  
Experimental Program ◽  
Content Type ◽  
Industry Applications ◽  
Cactus Mucilage ◽  
Electrochemical Monitoring ◽  
Chloride Contaminated

Purpose – The purpose of this paper is to determine if a type of cactus mucilage, Opuntia ficus-indica (OFI), may act as a corrosion inhibitor for carbon steel in cement-based materials (mortar) exposed to chloride-laden environment. Design/methodology/approach – Mortar prisms, reinforced with carbon steel rods, were immersed in sodium chloride (NaCl) solution for five wet – dry cycles. The experimentation included electrochemical monitoring (corrosion potential, Ecorr, and polarization resistance, Rp) of carbon steel during the time of exposure until corrosion-induced cracking appeared at the mortar surface. Crack survey on the mortar prisms was performed. Carbon steel rods were retrieved from the mortar after crack survey and steel mass loss at the end of the experimental period was estimated. A comparison between the different mixtures was also performed. Findings – OFI mucilage did perform as a corrosion inhibitor of steel in chloride contaminated mortar. Research limitations/implications – The experimental program needs to be corroborated in concrete specimens with typical dimensions. The surface oxide/hydroxide formation of the carbon steel in contact with the OFI mucilage is still unknown; thus, electrochemical impedance spectroscopy (EIS) and X-ray diffraction (XRD) analyses are needed. Practical implications – OFI mucilage is a suitable natural product that can be used to increase durability of concrete structures not only in countries where OFI cactus is produced, but also in many other countries where this plant is considered a plague. Originality/value – The new information obtained from this paper is the innovative use of a by-product of this cactus plant for construction industry applications.

Corrosion inhibition of some azole derivatives on carbon steel in hydrochloric acid solution

2014 ◽  
Vol 61 (5) ◽  
pp. 300-306 ◽  
Author(s):  
B.P. Markhali ◽  
R. Naderi ◽  
M. Sayebani ◽  
M. Mahdavian
Keyword(s):  
Carbon Steel ◽  
Hydrochloric Acid ◽  
Organic Compounds ◽  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Acid Corrosion ◽  
Molecular Structures ◽  
Inhibition Mechanism ◽  
Content Type

Purpose – The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole (BTH) on carbon steel in 1 M hydrochloric acid (HCl) solution. Organic inhibitors are widely used to protect metals in acidic media. Among abundant suggestions for acid corrosion inhibitors, azole compounds have gained attention. Design/methodology/approach – The inhibition efficiency of the three organic compounds was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Findings – Superiorities of BTH and BTAH corrosion inhibitors were shown by EIS data and polarization curves. Moreover, the results revealed that BTAH and BTH can function as effective mixed-type adsorptive inhibitors, whereas no inhibition behavior was observed for BI. Both BTAH and BTH obeyed Longmuir adsorption isotherm. The results obtained from this isotherm showed that both inhibitors adsorbed on the specimen surface physically and chemically. The difference in inhibition efficiencies of BTAH, BTH and BI was related to the presence of nitrogen and sulfur hetero atoms on their molecular structures. Originality/value – This study evaluated inhibition efficiency of BI, BTAH and BTH using electrochemical methods. In addition, the study attempted to find inhibition mechanism of the inhibitors and to find modes of adsorption of the inhibitors, correlating effects of heteroatoms and inhibition efficiency.

Electrochemical behaviour of acetyl G as corrosion inhibitor for mild steel in acid medium

2015 ◽  
Vol 44 (6) ◽  
pp. 371-378 ◽  
Author(s):  
Y. Sangeetha ◽  
S. Meenakshi ◽  
C. Sairam Sundaram
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Acid Medium ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Green Inhibitor ◽  
Content Type ◽  
Mild Steel Surface

Purpose – The purpose of this paper is to develop an eco-friendly corrosion inhibitor for mild steel in 1 M HCl. Design/methodology/approach – A pharmaceutical drug acetyl G was investigated for its corrosion inhibition efficiency using weight loss method, potentiodynamic polarisation and electrochemical impedance spectroscopy. Findings – The inhibition efficiency increased with increase in inhibitor concentration. Results from polarisation studies revealed mixed type of inhibition. Impedance studies, scanning electron microscopy and Fourier transform spectroscopy confirm the adsorption of inhibitor on the mild steel surface. Research limitations/implications – The drug acetyl G has sulphur and nitrogen atoms which effectively block the corrosion of mild steel and is non-toxic and has good inhibition efficiency. Practical implications – This method provides an excellent, non-toxic and cost-effective material as a corrosion inhibitor for mild steel in acid medium. Originality/value – Application of this drug as a corrosion inhibitor has not been reported yet in the literature. Replacing the organic inhibitors, this green inhibitor shows excellent inhibition efficiency. This is adsorbed excellently on the mild steel surface due to the presence of long chain and hetero atoms. Thus, the drug retards the corrosion reaction.

Study on fine lines and undercut suppression of printed circuit board prepared by electrolytic etching

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Denglin Fu ◽  
Yanan Wen ◽  
Jida Chen ◽  
Lansi Lu ◽  
Ting Yan ◽  
...  
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibitors ◽  
Printed Circuit Board ◽  
Copper Surface ◽  
Etching Process ◽  
Circuit Board ◽  
Content Type ◽  
Printed Circuit ◽  
Etching Method ◽  
Electrolytic Etching

Purpose The purpose of this paper is to study an electrolytic etching method to prepare fine lines on printed circuit board (PCB). And the influence of organics on the side corrosion protection of PCB fine lines during electrolytic etching is studied in detail. Design/methodology/approach In this paper, the etching factor of PCB fine lines produced by new method and the traditional method was analyzed by the metallographic microscope. In addition, field emission scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to study the inhibition of undercut of the four organometallic corrosion inhibitors with 2,5-dimercapto-1,3,4-thiadiazole, benzotriazole, l-phenylalanine and l-tryptophan in the electrolytic etching process. Findings The SEM results show that corrosion inhibitors can greatly inhibit undercut of PCB fine lines during electrolytic etching process. XPS results indicate that N and S atoms on corrosion inhibitors can form covalent bonds with copper during electrolytic etching process, which can be adsorbed on sidewall of PCB fine lines to form a dense protective film, thereby inhibiting undercut of PCB fine lines. Quantum chemical calculations show that four corrosion inhibitor molecules tend to be parallel to copper surface and adsorb on copper surface in an optimal form. COMSOL Multiphysics simulation revealed that there is a significant difference in the amount of corrosion inhibitor adsorbed on sidewall of the fine line and the etching area. Originality/value As a clean production technology, electrolytic etching method has a good development indicator for the production of high-quality fine lines in PCB industry in the future. And it is of great significance in saving resources and reducing environmental pollution.

Variety perception and attitude toward digital assortments

2019 ◽  
Vol 47 (12) ◽  
pp. 1353-1363 ◽  
Author(s):  
Yolande Piris ◽  
Nathalie Guibert
Keyword(s):  
Design Methodology ◽  
Positive Attitude ◽  
Experimental Approach ◽  
Product Category ◽  
Experimental Conditions ◽  
Content Type ◽  
Perceptions And Attitudes ◽  
Practical Implications ◽  
Real Product ◽  
The Way

Purpose The purpose of this paper is to investigate consumers’ variety perception for online grocery assortments and, more generally, to better understand consumers’ attitude toward digital assortments. In particular, this research examines the influence of the organization of products that results from assortment structure and display. Design/methodology/approach Starting from the observation that previous work on traditional assortments is not sufficient to understand consumers’ perceptions and attitudes, the paper adopts a hypothetico-deductive approach and develops four hypotheses. These hypotheses are tested using an experimental approach. Findings This research enables us to see that both attitude and variety perception are affected by the way products are organized on a website. Furthermore, contrary to what the literature on traditional assortments allows one to assume, the assortment corresponding to a more positive attitude is not perceived as being the more varied. As a result, our findings reconsider the link between variety perception and consumer assortment evaluation for digital assortments. Research limitations/implications The work is based on data collected for only one product category. It would be interesting to explore other categories also, to determine if the structure of the assortment and variety perception have stable effects. Practical implications The results inform retailers that they must carefully design the display of their digital assortments. If a retailer wants to enhance variety perception, the authors recommend using an assortment organized by brand, or presenting all the products together. If, instead, the goal is to encourage a positive attitude, the retailer should opt for assortments sorted by attribute or that present all products together. Originality/value This research adopts a new orientation on assortment perception and evaluation, considering the specificities involved in digitizing assortments. In addition, this research studies a real product category and puts respondents in experimental conditions close to reality.

Causality in qualitative market and social research

2019 ◽  
Vol 22 (3) ◽  
pp. 405-413
Author(s):  
Clive Roland Boddy
Keyword(s):  
Qualitative Research ◽  
Design Methodology ◽  
Social Research ◽  
Pragmatic Approach ◽  
Social Phenomena ◽  
Content Type ◽  
The Past ◽  
The Moment ◽  
Practical Implications

Purpose Academic qualitative researchers have been criticized for rejecting the idea that their research can establish causality while market and social researchers, with their realist and pragmatic approach to research, take for granted that it can. This paper aims to explore the ability of qualitative research to determine cause and effect in terms of market and social phenomena. Design/methodology/approach The literature on causality in qualitative research is reviewed and discussed. The discussion is further informed by the author’s own experience of undertaking commercial and academic market and social qualitative research over the past 33 years. Findings In qualitative market and social research, the determination of causality is often needed but rarely discussed. This paper explores this occurrence and brings to the fore, via discussion and the use of example, the ways in which causality can be determined by qualitative research. Practical implications A determination of what events bring about predictable changes in social and market environments can be established via qualitative research particularly at a probabilistic level of causality. This implies that policymakers should give a greater emphasis to qualitative findings than then sometimes do at the moment. Originality/value Causality in market and social research is rarely discussed by practitioners but is nevertheless a premise of much of the qualitative research that is undertaken. This paper is therefore distinctive in that it examines whether this premise is justifiable.

Corrosion behavior of carbon steel in chloride contaminated simulated concrete pore solution with carboxylate of benzoic acid and dimethylethanolamine

2017 ◽  
Vol 64 (5) ◽  
pp. 555-562 ◽  
Author(s):  
J.Z. Liu ◽  
Jing Shun Cai ◽  
L. Shi ◽  
D. Zhao ◽  
C.C. Chen ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Benzoic Acid ◽  
Corrosion Inhibitor ◽  
Steel Surface ◽  
Threshold Level ◽  
Initial Time ◽  
Inhibition Mechanism ◽  
Content Type ◽  
Chloride Threshold

Purpose The purpose of this study is to investigate the inhibition efficiency and mechanism of a specific carboxylate corrosion inhibitor which consists of benzoic acid and dimethylethanolamine on steel surface. Design/methodology/approach The performance of carbon steel influenced by this organic inhibitor under different concentration of Cl− and immersion time was studied by linear polarization resistance and electrochemical impedance spectroscopy in a simulated concrete pore (SCP) solution. The surface morphology and composition of steel was also analyzed by optical microscopy, SEM and EDS to investigate the effect of inhibitor on the pattern of the steel surface after long-term immersion. Findings Carboxylate of benzoic acid and dimethylethanolamine can increase the chloride threshold level and decrease the corrosion area of carbon steel in SCP solution with 0.6 mol/L Cl− even after 120 days exposure. The inhibition mechanism of inhibitor lies in quick adsorption and buffering effect at initial time then formed deposited layer on steel surface after long-term immersion in chloride-rich environment. Originality/value It demonstrated that the carboxylate corrosion inhibitor not only can improve the chloride threshold level for carbon steel but also effectively decrease the corrosion rate even in chloride-rich SCP solution after long-term immersion, which is different form the conventional amino alcohol.

Analysis of the Electrode Kinetics of Ni(II) Reduction in Thiocyanate Media on the Dropping Mercury Electrode

2000 ◽  
Vol 65 (3) ◽  
pp. 326-342
Author(s):  
María S. Crespo-Pinilla ◽  
Fernando Mata-Pérez ◽  
Rosa M. Villamañán
Keyword(s):  
Ionic Strength ◽  
Compensation Effect ◽  
Supporting Electrolyte ◽  
Mercury Electrode ◽  
Electrode Kinetics ◽  
Surface Process ◽  
Experimental Conditions ◽  
Dropping Mercury Electrode ◽  
Kinetics Of

A study of two prewaves of the Ni(II)-SCN- system was carried out under the experimental conditions when the influence of electroreduction of SCN- is negligible. Kinetics of Ni(II) reduction in thiocyanate media on the dropping mercury electrode was studied by DC Tast Polarography (DCTP) via determination of Koutecký's parameter χ; the influence of different variables was analyzed. The study of prewaves was performed using various polarographic techniques. Values of χ depend on the SCN- concentration, pH, ionic strength (Ψ-effect) and on the nature of the supporting electrolyte. The number of electrons n, the transfer coefficient α, the stoichiometric number ν, ∆H≠, and ∆S≠ were determined (compensation effect). The first prewave has character of a reaction in the solution, the second prewave is a surface process. Main features of both mechanisms are common: catalytic nature, one-electron step discharge and the rate-determining process between species of opposite charges.

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