I.R. Ramos, S.B. Valdez, K.R. Zlatev, W.M Schorr, B.M. Carrillo, M.S. Stoytcheva, I.R. Garcia and M.M. Martinez
– The purpose of this investigation was to develop a digital instrument for the quantitative evaluation of pitting corrosion in metals.
Abstract
Purpose
The purpose of this investigation was to develop a digital instrument for the quantitative evaluation of pitting corrosion in metals.
Design/methodology/approach
This investigation comprised two central parts: research, testing and monitoring of the formation of pitting by conventional methods and applying American Society for Testing and Materials (ASTM) Standards, and the development of a virtual instrument based on the LabVIEW 2010 platform.
Findings
The methodology used was suitable for the analysis of pitting on carbon steel and aluminum alloy UNS A96061, used in the aerospace industry.
Practical implications
This technique allows pits to be to localized, measured and quantified on metallic surfaces, for corrosion evaluation in atmospheric and industrial environments.
Originality/value
This combination of conventional and digital methods can assist in corrosion control of pitting in industrial equipment.
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Keywords
O.L. Vargas, S.B. Valdez, M.L. Veleva, K.R. Zlatev, W.M. Schorr and G.J. Terrazas
The purpose of this paper is to evaluate the corrosion of silver due to hydrogen sulphide pollutant in indoor conditions at a microelectronics plant located in Mexicali, Baja…
Abstract
Purpose
The purpose of this paper is to evaluate the corrosion of silver due to hydrogen sulphide pollutant in indoor conditions at a microelectronics plant located in Mexicali, Baja California, a semi‐arid zone in the northwest of Mexico.
Design/methodology/approach
Silver coupons and silver plated on to copper‐lead frames are exposed in the assembly process building of a microelectronics company during a period of 60 days and also in a sheltered test chamber that simulates indoor conditions with ambient concentrations of atmospheric pollutants, temperature and relative humidity (rH). Other exposures are made in the test chamber to study the corrosion behaviour of silver coupons over a duration of 24 months. The corrosion products were analysed using the Scanning Electron Microscope (SEM) and Energy Dispersive X‐ray Spectroscopy (EDS). Corrosion rates were measured by Quartz Crystal Microbalance (QCM) under laboratory‐controlled conditions.
Findings
The presence of silver sulphide corrosion products, dendrites and whiskers is observed on the exposed samples using SEM and EDS analysis.
Practical implications
The paper is designed to establish whether the company, where the exposure is taking place, constituted an indoor environment with outdoor hydrogen sulphide pollutant in sufficient concentration to induce silver corrosion.
Originality/value
The methodology used in this work can be applied to study the indoor corrosion behaviour of other metals, which will be of interest to the microelectronics industry.
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Keywords
S.B. Valdez, R.K. Zlatev, W.M. Schorr, G.N. Rosas, Ts. Dobrev, M. Monev and I. Krastev
To develop and test a rapid method for evaluation of the corrosion protection (CP) of carbon steel (CS) by vapour corrosion inhibitors (VCI) films.
Abstract
Purpose
To develop and test a rapid method for evaluation of the corrosion protection (CP) of carbon steel (CS) by vapour corrosion inhibitors (VCI) films.
Design/methodology/approach
The determination of the CP by VCI on CSs is commonly carried out in a chamber applying neutral salt spray (NSS) and usually it takes many days. The common disadvantage of the various rapid methods created until now is the need of special laboratory equipment making their application complicated and inconvenient for field tests. The method for CP measurement of VCI films on CS described in this study is based on measurement of the height of the anodic peak under galvanostatic condition applied earlier on other types of films and coatings. By means of a calibration plot: peak height (V) vs NSS protection time (s), CP of VCI films on CS specimens expressed in hours NSS is determined in a few seconds without using an NSS chamber. Measurements of CP by VCI films under field conditions are performed applying a hand held tester.
Findings
Two groups of CS UNS G10180 steel specimens with increasing thickness of VCI films were studied – one in an NSS chamber and the second by the application of a corrosion tester. The correlation between the results obtained for the two groups of specimens was found and a calibration plot was made.
Practical implications
Based on this method, a special corrosion tester was developed, able to measure under field conditions as well.
Originality/value
The method subject of the paper is a further development of a galvanostatic method developed by the authors for CP evaluation of chromate films of Zn and Cd coatings. The method was modified according to the properties of VCI films
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Keywords
B.G. Lopez, S.B. Valdez, K.R. Zlatev, P.J. Flores, B.M. Carrillo and W.M. Schorr
Aggressive environments that enhance indoor corrosion in industrial plants decrease the yielding of electronic equipment, causing electrical failures. The purpose of the present…
Abstract
Purpose
Aggressive environments that enhance indoor corrosion in industrial plants decrease the yielding of electronic equipment, causing electrical failures. The purpose of the present paper is to evaluate corrosion rates in metals used in electronic devices as a function of temperature, humidity and the concentrations of some air pollutants in order to predict the optimal conditions preventing or minimizing corrosion.
Design/methodology/approach
Atmospheric pollutants mainly sulphur oxides, penetrating through small crevices and holes into electronic plants in combination with climatic factors such as humidity and heat, promote corrosion. The corrosion rate of the five most used metals in the electronics industry: carbon steel, copper, nickel, silver, and tin, were studied gravimetrically as a function of variations in humidity, temperature and air pollutant concentrations from 2003 to 2005. The samples were exposed in an instrumented boot to indoor conditions and gravimetric measurements were performed together with measurements of the above‐mentioned parameters. Mathematical simulation applying Math Lab software was carried out as well. The ternary diagrams for pollutants, temperature and relative humidity were applied as a useful tool to correlate these parameters in indoor conditions with the corrosion rate of metals applied in the electronics industry.
Findings
The obtained results have shown that the presence of even small concentrations of air pollutants promoted corrosion processes when time of wetness conditions were reached.
Practical implications
The study was carried out in order to minimize the corrosion losses of the electronic plants situated especially in Mexicali City located on a semi‐desert zone in the Northwest of Mexico.
Originality/value
This paper establishes the relationship of variations of pollutants concentration, temperature and the relative humidity with the corrosion rate of metals in indoor conditions in the electronics industry located in the semi‐arid zone of Mexicali. Design was characterized and simulated using the MathLab software.
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Gustavo Lopez, Hugo Tiznado, Gerardo Soto Herrera, Wencel De la Cruz, Benjamin Valdez, Miguel Schorr and Zlatev Roumen
The electronics industry has grown over the past 50 years, mostly in developed countries, contributing to their economic progress. Particularly in the Baja California State…
Abstract
Purpose
The electronics industry has grown over the past 50 years, mostly in developed countries, contributing to their economic progress. Particularly in the Baja California State located in the northwest of Mexico, these companies have prospered in the industrial parks of Mexicali considered as an arid zone and Ensenada, a port and city on the Pacific Ocean considered as a marine region. In both environments, during winter and summer, the climate impacts on indoor conditions, affecting humidity and temperature, and generating corrosion which decreases the yields of the electronic devices and industrial machines. The purpose of this paper is to investigate the effects of corrosion on electronic devices in these arid and marine environments.
Design/methodology/approach
The paper determines the corrosivity levels inside industrial plants of desertic and coast regions in Mexico, to evaluate the deterioration of electronic metals.
Findings
Relative humidity, temperature, time of wetness, are recorded and related to the corrosion process in arid and marine environments.
Research limitations/implications
Some missing information about air pollution in Ensenada from some Environmental Monitoring Stations was a limitation, and the need to use complex atmospheric techniques.
Originality/value
The paper shows that it is very important to control metallic corrosion generated by climate factors and air pollution in indoor industrial plants: the corrosion of electronic devices and equipments depletes their yield and can lead to loss‐making failures.
Details
Keywords
Jørgen Brandt, Jesper H. Christensen and Zahari Zlatev
Describes a tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model), developed for studying transport, dispersion, and deposition of air pollution caused by…
Abstract
Describes a tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model), developed for studying transport, dispersion, and deposition of air pollution caused by a single but strong source. The model is based on a combination of a Lagrangian short‐range puff model and a Eulerian long‐range transport model. It has been run and validated against measurements from the two European Tracer Experiment (ETEX) releases and from the Chernobyl accident. An air pollution forecast system, THOR, is under development, to make forecasts of various air pollutants on a European scale. Some preliminary results are shown. DREAM will be implemented in THOR for calculations of real time predictions of transport, dispersion and deposition of radioactive material from accidental releases (e.g. Chernobyl). Some applications of the DREAM model and examples of model results are described.
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Keywords
Mario Celso Genovez, Luiz Henrique Araujo, Tiago Dinis Pinto and Radim Hrdina
This paper aims to describe the results of lab testing of a newly developed organic inhibitor V-active VCIs. The findings demonstrate that it is possible to eliminate or reduce…
Abstract
Purpose
This paper aims to describe the results of lab testing of a newly developed organic inhibitor V-active VCIs. The findings demonstrate that it is possible to eliminate or reduce the oxidizing action of water, thereby extending the allowable time before painting after hydrojetting, and that the new corrosion inhibitor technology does not interfere with the final quality of paint adhesion.
Design/methodology/approach
Metallic specimens were treated/washed in standard lab condition. A 2 per cent V-active VCI SPH1712 water solution was prepared by diluting the inhibitor in industrial water. Metal sample plates were examined after blasting and after subsequent drying, and were submitted to the paint adhesion tests, cathodic disbondment, total soluble salts, time for formation of flash rust and cyclic corrosion test type III (20 cycles), to evaluate the duration of temporary protection and oxidation prevention and influence on paint adherence.
Findings
Using the V-active VCI proposed technology, it was possible to minimize or eliminate the oxidizing action of the water when the metal is exposed to saline moisture in a closed environment, extending the acceptable time before painting without interfering with the final quality of painting.
Practical implications
The proposed technology allows an increase in the prepared (wet blasted) steel surface during cleaning and preparation, thereby reducing labor and product costs, and reduces water consumption during the preparation process. Practical applications in the shipbuilding, ship maintenance and oil and gas production industries include the preservation of internal tubes and pipes, protection during hydrostatic test processes and cleaning with water and corrosion prevention in diesel tanks contaminated with water.
Originality/value
The intent of this paper is to present the obtained results for a new formulation of organic chemical inhibitors that use water as the application medium. In addition to this property, this group of organic inhibitors maintains the properties of volatile inhibitors. Thus, these compounds are generically known as V-active VCIs.
Details
Keywords
Lopez Badilla Gustavo, Valdez Salas Benjamin, Schorr Wiener Miguel, Rosas Gonzalez Navor, Tiznado Vazquez Hugo and Soto Herrara Gerardo
The purpose of this paper is to study the indoor corrosion of metals used in the electronics industry, as influenced by climate factors.
Abstract
Purpose
The purpose of this paper is to study the indoor corrosion of metals used in the electronics industry, as influenced by climate factors.
Design/methodology/approach
Corrosivity levels inside industrial plants were evaluated to evaluate the deterioration of metals.
Findings
Relative humidity, temperature, and time of wetness are recorded and related to the corrosion process.
Originality/value
Control of climate factors indoors in industrial plants to reduce and control the corrosion process of metals used in the electronics industry.
Details
Keywords
Mário Celso Genovez, Luiz Henrique Araújo, Tiago Dinis Pinto and Radim Hrdina
This work describes test results that were obtained using a newly-developed type of organic inhibitor: V-active VCIs. The findings demonstrate that is possible to eliminate or…
Abstract
Purpose
This work describes test results that were obtained using a newly-developed type of organic inhibitor: V-active VCIs. The findings demonstrate that is possible to eliminate or reduce the oxidizing action of water, thereby extending the allowable time before painting after hydrojetting, and that the new corrosion inhibitor technology does not interfere with the final quality of paint adhesion.
Design/methodology/approach
Metallic specimens were treated/washed by hydrojet (35000 Psi). It was employed as a 2 per cent V-active VCI SPH 1,712 water solution by dilution of the inhibitor in industrial water. Metal sample plates were examined after blasting and after subsequent drying, and were submitted to the paint adhesion tests, to evaluate the duration of temporary protection, oxidation prevention and influence on the adherence of paint (pull off).
Findings
Using the V-active VCI proposed technology, it was possible to minimize or eliminate the oxidizing action of the water when the metal is exposed to the saline moisture in a closed environment, extending the acceptable time before painting without interference in the final quality of painting.
Practical implications
The proposed technology allows to the area of prepared (wet blasted) steel surface to be increased during cleaning and preparation, thereby reducing labor and product costs, and reduces water consumption during the preparation process. Practical applications in the shipbuilding, ship maintenance and oil and gas production industries, include the preservation of internal tubes and pipes, protection during hydrostatic test processes and cleaning with water and corrosion prevention in diesel tanks contaminated with water.
Originality/value
The intent of this paper is to present the obtained results for a new formulation of organic chemical inhibitors that use water medium as the application method. In addition to this property, this group of organic inhibitors maintains the property of volatile inhibitors. Thus, these compounds are generically known as V-active VCI.
Details
Keywords
Jesper Clement, Viktor Smith, Jordan Zlatev, Kerstin Gidlöf and Joost van de Weijer
The purpose of this paper is to present an experimental study which aims at assessing the potentially misleading effect of graphic elements on food packaging. The authors call…
Abstract
Purpose
The purpose of this paper is to present an experimental study which aims at assessing the potentially misleading effect of graphic elements on food packaging. The authors call these elements potentially misleading elements (PMEs) as they can give customers false expectations. They are either highlighted numerical information (30 per cent fibre, 8 per cent fat, 100 per cent natural […]) or pictorial information with no relation to the product (e.g. images of happy people).
Design/methodology/approach
In a combined decision task monitored by eye-tracking and a subsequence survey, the authors tested the impact of PMEs on common products. Combining different pairs of products, where one product had a PME, whereas the other did not, the authors could evaluate if preference correlated with the presence of a PME.
Findings
The authors found both types of PMEs to have analogous effects on participants’ preferences and correlate with participants’ visual attention. The authors also found evidence for a positive influence on a later explicit justification for the specific choice.
Research limitations/implications
This study was conducted in a lab environment and solely related to health-related decisions. The authors still need to know if these findings are transferable to real in-store decisions and other needs such as high quality or low price. This calls for further research.
Practical implications
The topic is important for food companies, and it might become a priority in managing brand equity, combining consumer preferences, loyalty and communicative fairness.
Originality/value
Using eye-tracking and retrospective interviews brings new insights to consumer’s decision-making and how misleading potentially occurs.