M. Thieme, U. Bergmann, Anja Kiesewetter, Tobias Wehry, K. Potzger, A. Zarzycki, M. Marszalek, H. Worch
The present work deals with the corrosion of mild steel (1.0037) used as the outer construction material of the preheater of a modern industrial cement production facility. The facility uses secondary fuels, which introduce considerable amounts of corrosive species. The situation at the examination sites in the preheater zone is tracked over a period of two years including operation and shut-down periods. The investigation is focused on (i) the acquisition of the underlying physicochemical conditions, such as moisture, temperature, and contamination data at the examination site of the preheater, (ii) the multianalytical identification of the formed corrosion products using scanning electron microscopy combined with energy-dispersive X-ray analysis, infrared spectrometry, Raman spectrometry, X-ray diffractometry, and Möβbauer spectrometry, and (iii) voltammetric and EIS laboratory investigations using model solutions. It was evidenced that corrosion takes place at a temperature level of about 100°C in the presence of moisture and oxygen as well as chloride ion as a consequence of the usage of secondary fuels. Typical hot-gas corrosion could be excluded under the current conditions. Appearance, structure, and nature of the corrosion products were found to be not mainly dependent on the varied length of exposure, but on the conditions of the hosting preheater intake. In addition to different FeOOH phases and hematite, magnetite was found, dependent on the oxygen concentration in the process gas. The decisive role of oxygen as key factor for the corrosion rate was electrochemically confirmed.
{"title":"Investigation of Mild Steel Corrosion in the Cement Production Associated with the Usage of Secondary Fuels","authors":"M. Thieme, U. Bergmann, Anja Kiesewetter, Tobias Wehry, K. Potzger, A. Zarzycki, M. Marszalek, H. Worch","doi":"10.1155/2020/7341029","DOIUrl":"https://doi.org/10.1155/2020/7341029","url":null,"abstract":"The present work deals with the corrosion of mild steel (1.0037) used as the outer construction material of the preheater of a modern industrial cement production facility. The facility uses secondary fuels, which introduce considerable amounts of corrosive species. The situation at the examination sites in the preheater zone is tracked over a period of two years including operation and shut-down periods. The investigation is focused on (i) the acquisition of the underlying physicochemical conditions, such as moisture, temperature, and contamination data at the examination site of the preheater, (ii) the multianalytical identification of the formed corrosion products using scanning electron microscopy combined with energy-dispersive X-ray analysis, infrared spectrometry, Raman spectrometry, X-ray diffractometry, and Möβbauer spectrometry, and (iii) voltammetric and EIS laboratory investigations using model solutions. It was evidenced that corrosion takes place at a temperature level of about 100°C in the presence of moisture and oxygen as well as chloride ion as a consequence of the usage of secondary fuels. Typical hot-gas corrosion could be excluded under the current conditions. Appearance, structure, and nature of the corrosion products were found to be not mainly dependent on the varied length of exposure, but on the conditions of the hosting preheater intake. In addition to different FeOOH phases and hematite, magnetite was found, dependent on the oxygen concentration in the process gas. The decisive role of oxygen as key factor for the corrosion rate was electrochemically confirmed.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"1 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2020-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/7341029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44259489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The biological activity, biocompatibility, and corrosion resistance of implants depend primarily on titanium dioxide (TiO2) film on biomedical titanium alloy (Ti6Al4V). This research is aimed at getting an ideal temperature range for forming a dense titanium dioxide (TiO2) film during titanium alloy cutting. This article is based on Gibbs free energy, entropy changes, and oxygen partial pressure equations to perform thermodynamic calculations on the oxidation reaction of titanium alloys, studies the oxidation reaction history of titanium alloys, and analyzes the formation conditions of titanium dioxide. The heat oxidation experiment was carried out. The chemical composition was analyzed with an energy dispersive spectrometer (EDS). The results revealed that titanium dioxide (TiO2) is the main reaction product on the surface below 900°C. Excellent porous oxidation films can be obtained between 670°C and 750°C, which is helpful to improve the bioactivity and osseointegration of implants.
{"title":"Oxidation Mechanism of Biomedical Titanium Alloy Surface and Experiment","authors":"Kai‐Wen Ma, Rui Zhang, Junlong Sun, Chang-kui Liu","doi":"10.1155/2020/1678615","DOIUrl":"https://doi.org/10.1155/2020/1678615","url":null,"abstract":"The biological activity, biocompatibility, and corrosion resistance of implants depend primarily on titanium dioxide (TiO2) film on biomedical titanium alloy (Ti6Al4V). This research is aimed at getting an ideal temperature range for forming a dense titanium dioxide (TiO2) film during titanium alloy cutting. This article is based on Gibbs free energy, entropy changes, and oxygen partial pressure equations to perform thermodynamic calculations on the oxidation reaction of titanium alloys, studies the oxidation reaction history of titanium alloys, and analyzes the formation conditions of titanium dioxide. The heat oxidation experiment was carried out. The chemical composition was analyzed with an energy dispersive spectrometer (EDS). The results revealed that titanium dioxide (TiO2) is the main reaction product on the surface below 900°C. Excellent porous oxidation films can be obtained between 670°C and 750°C, which is helpful to improve the bioactivity and osseointegration of implants.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2020 1","pages":"1-9"},"PeriodicalIF":3.1,"publicationDate":"2020-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/1678615","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49517473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdulhammed K. Hamzat, I. A. Adediran, L. Alhems, M. Riaz
Although little attention is paid to corrosion study in food processing and production industry, it is highly important to take a critical look at what transpires at the production stages and how these can affect human health due to contamination of the final product. This research employs the design of experiment module of a Minitab software to analyze the corrosion effect of mild steel in fruit juice environment. Coupon method was adopted to calculate the rate of corrosion in orange, pineapple, and cashew fluid for a duration of 25 days with measurement taken at 5-day intervals. The highest corrosion rate of 0.71 mmpy was observed in cashew fluid followed by pineapple fluid, and the least rate of 0.08 mmpy was observed in orange fluid. The generalized model equation was obtained to predict corrosion rate of mild steel in a similar environment. In general, design of experiment offers a better way to analyze corrosion experiment result, and this innovative idea is shown in this work.
{"title":"Investigation of Corrosion Rate of Mild Steel in Fruit Juice Environment Using Factorial Experimental Design","authors":"Abdulhammed K. Hamzat, I. A. Adediran, L. Alhems, M. Riaz","doi":"10.1155/2020/5060817","DOIUrl":"https://doi.org/10.1155/2020/5060817","url":null,"abstract":"Although little attention is paid to corrosion study in food processing and production industry, it is highly important to take a critical look at what transpires at the production stages and how these can affect human health due to contamination of the final product. This research employs the design of experiment module of a Minitab software to analyze the corrosion effect of mild steel in fruit juice environment. Coupon method was adopted to calculate the rate of corrosion in orange, pineapple, and cashew fluid for a duration of 25 days with measurement taken at 5-day intervals. The highest corrosion rate of 0.71 mmpy was observed in cashew fluid followed by pineapple fluid, and the least rate of 0.08 mmpy was observed in orange fluid. The generalized model equation was obtained to predict corrosion rate of mild steel in a similar environment. In general, design of experiment offers a better way to analyze corrosion experiment result, and this innovative idea is shown in this work.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2020 1","pages":"1-10"},"PeriodicalIF":3.1,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/5060817","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43444819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Bouhlal, N. Labjar, F. Abdoun, Aimad Mazkour, M. Serghini-Idrissi, M. El Mahi, E. Lotfi, S. El hajjaji
The present work investigates the influence of temperature on C38 steel corrosion in a 1 M HCl medium with and without different concentrations of a hydro-alcoholic extract of used coffee grounds (HECG). The potentiodynamic polarization technique and the electrochemical impedance spectroscopy were performed in temperatures ranging from 293.15 to 323.15 K. It was observed that the inhibition efficiency decreased with increased temperature and inhibitor concentration. The HECG adsorption process on C38 steel surface was found to be spontaneous and obeyed to Langmuir isotherm at all studied temperatures. The associated thermodynamic parameters of adsorption led to suggest the occurrence of physical adsorption of the HECG compounds on the C38 steel surface.
{"title":"Electrochemical and Thermodynamic Investigation on Corrosion Inhibition of C38 Steel in 1M Hydrochloric Acid Using the Hydro-Alcoholic Extract of Used Coffee Grounds","authors":"F. Bouhlal, N. Labjar, F. Abdoun, Aimad Mazkour, M. Serghini-Idrissi, M. El Mahi, E. Lotfi, S. El hajjaji","doi":"10.1155/2020/4045802","DOIUrl":"https://doi.org/10.1155/2020/4045802","url":null,"abstract":"The present work investigates the influence of temperature on C38 steel corrosion in a 1 M HCl medium with and without different concentrations of a hydro-alcoholic extract of used coffee grounds (HECG). The potentiodynamic polarization technique and the electrochemical impedance spectroscopy were performed in temperatures ranging from 293.15 to 323.15 K. It was observed that the inhibition efficiency decreased with increased temperature and inhibitor concentration. The HECG adsorption process on C38 steel surface was found to be spontaneous and obeyed to Langmuir isotherm at all studied temperatures. The associated thermodynamic parameters of adsorption led to suggest the occurrence of physical adsorption of the HECG compounds on the C38 steel surface.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2020 1","pages":"1-14"},"PeriodicalIF":3.1,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/4045802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48719130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Zaher, A. Chaouiki, R. Salghi, A. Boukhraz, B. Bourkhiss, M. Ouhssine
The chemical composition of the methanolic extract of Ammi visnaga (Khella) seeds from the Sidi Slimane region is determined for the first time by Gas Chromatography coupled with Mass Spectrometry (GC/MS). Ten compounds representing 99.638% of the total extract were identified. Khellin (49.011%), Visnagin (26.537%) and Dimethylethylamine (15.108%) are the major components. Moreover, the inhibitory effect of the Methanolic extract of the seeds of Ammi visnaga on the corrosion of mild steel in a solution of 1M HCl is determined using weight loss measurements, the potentiodynamic technique as well as the technique of electrochemical impedance spectroscopy (EIS). It is found that the extract reduces the corrosion rate of the steel in the acid solution. Inhibition efficiency increases as the concentration of the extract increases. The tested compound has an inhibition efficiency of 84% for a concentration equal to 1.0 g/L. The polarization measurements indicate that the examined extract acts as a mixed inhibitor with predominant anodic efficacy. The data obtained from EIS studies are analyzed to model this process using appropriate equivalent circuit models. The adsorption of the extract on the surface of the mild steel obeys the Langmuir adsorption isotherm in acidic medium and the activation is determined and discussed.
{"title":"Inhibition of Mild Steel Corrosion in 1M Hydrochloric Medium by the Methanolic Extract of Ammi visnaga L. Lam Seeds","authors":"A. Zaher, A. Chaouiki, R. Salghi, A. Boukhraz, B. Bourkhiss, M. Ouhssine","doi":"10.1155/2020/9764206","DOIUrl":"https://doi.org/10.1155/2020/9764206","url":null,"abstract":"The chemical composition of the methanolic extract of Ammi visnaga (Khella) seeds from the Sidi Slimane region is determined for the first time by Gas Chromatography coupled with Mass Spectrometry (GC/MS). Ten compounds representing 99.638% of the total extract were identified. Khellin (49.011%), Visnagin (26.537%) and Dimethylethylamine (15.108%) are the major components. Moreover, the inhibitory effect of the Methanolic extract of the seeds of Ammi visnaga on the corrosion of mild steel in a solution of 1M HCl is determined using weight loss measurements, the potentiodynamic technique as well as the technique of electrochemical impedance spectroscopy (EIS). It is found that the extract reduces the corrosion rate of the steel in the acid solution. Inhibition efficiency increases as the concentration of the extract increases. The tested compound has an inhibition efficiency of 84% for a concentration equal to 1.0 g/L. The polarization measurements indicate that the examined extract acts as a mixed inhibitor with predominant anodic efficacy. The data obtained from EIS studies are analyzed to model this process using appropriate equivalent circuit models. The adsorption of the extract on the surface of the mild steel obeys the Langmuir adsorption isotherm in acidic medium and the activation is determined and discussed.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":"1-10"},"PeriodicalIF":3.1,"publicationDate":"2020-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/9764206","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44521483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.
{"title":"Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel","authors":"Z. Tian, Lijun Song, Xinmin Li","doi":"10.1155/2019/1206098","DOIUrl":"https://doi.org/10.1155/2019/1206098","url":null,"abstract":"Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/1206098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49085694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nitrite inhibitor is a kind of most effective inhibitory corrosion additive used in reinforced concrete. This paper expounded the inhibiting mechanism and physical property of nitrite in concrete. Moreover, the recent progress and application condition at home and abroad were summarized. Meanwhile, corresponding methods for detecting nitrite ion concentration is proposed. Additionally, the inhibition practice on corrosion protection of reinforcing bar in concrete was presented. The long-term inhibiting effectiveness of nitrite ion in concrete when the n(NO2-)/n(Cl-) ratios were above the threshold values in concrete was obtained. Finally it is confirmed that critical molar ratio of n(NO2-)/n(Cl-) increased with differential nitrite ion concentration, higher cathode, and anode area ratio in steel bar.
{"title":"Research Progress of Nitrite Corrosion Inhibitor in Concrete","authors":"Yilin Song, Junzhe Liu, Hui Wang, Haibin Shu","doi":"10.1155/2019/3060869","DOIUrl":"https://doi.org/10.1155/2019/3060869","url":null,"abstract":"Nitrite inhibitor is a kind of most effective inhibitory corrosion additive used in reinforced concrete. This paper expounded the inhibiting mechanism and physical property of nitrite in concrete. Moreover, the recent progress and application condition at home and abroad were summarized. Meanwhile, corresponding methods for detecting nitrite ion concentration is proposed. Additionally, the inhibition practice on corrosion protection of reinforcing bar in concrete was presented. The long-term inhibiting effectiveness of nitrite ion in concrete when the n(NO2-)/n(Cl-) ratios were above the threshold values in concrete was obtained. Finally it is confirmed that critical molar ratio of n(NO2-)/n(Cl-) increased with differential nitrite ion concentration, higher cathode, and anode area ratio in steel bar.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2019-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/3060869","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44640416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To obtain the influence mechanism of epoxy resin content, curing time, and other external factors on the compressive strength and seawater corrosion resistance of geopolymer, the NaOH and Na2SiO3 were used as activators; the effect of epoxy resin concentration on the corrosion resistance of metakaolin-based geopolymer was investigated by experiments. The mechanism of epoxy resin concentration affecting the polymerization process and the properties of geopolymer was analyzed by X-ray diffraction, scanning electron microscopy-energy spectrum, and Fourier transform infrared spectroscopy. It was shown that the epoxy resin slowed down the polymerization. The presence of epoxy resin had a beneficial effect on compact structure. Furthermore, compared with the noncorrosive specimen, mixed with 30% specimen’s average compressive strength increased by 4.77MPa and 4.24MPa after curing for 1d and 3d and soaking for 56d.
{"title":"Epoxy Resin’s Influence in Metakaolin-Based Geopolymer’s Antiseawater Corrosion Performance","authors":"Wen-feng Bian, Zhongchang Wang, Moaxin Zhang","doi":"10.1155/2019/5470646","DOIUrl":"https://doi.org/10.1155/2019/5470646","url":null,"abstract":"To obtain the influence mechanism of epoxy resin content, curing time, and other external factors on the compressive strength and seawater corrosion resistance of geopolymer, the NaOH and Na2SiO3 were used as activators; the effect of epoxy resin concentration on the corrosion resistance of metakaolin-based geopolymer was investigated by experiments. The mechanism of epoxy resin concentration affecting the polymerization process and the properties of geopolymer was analyzed by X-ray diffraction, scanning electron microscopy-energy spectrum, and Fourier transform infrared spectroscopy. It was shown that the epoxy resin slowed down the polymerization. The presence of epoxy resin had a beneficial effect on compact structure. Furthermore, compared with the noncorrosive specimen, mixed with 30% specimen’s average compressive strength increased by 4.77MPa and 4.24MPa after curing for 1d and 3d and soaking for 56d.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2019-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5470646","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43473633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of AC stray current density on corrosion behavior of X80 steel with stripped coating defects was studied by electrochemical method. The experimental results showed that the open circuit potential of X80 steel was shifted negatively due to the existence of AC interference. The degree of negative shift increased with the increasing of AC stray current density. And the potential after the cut of AC interference was still more negative than before. That is, the corrosion interference continued after cutting the AC power. In the initial stage of the experiment, the corrosion current density with 30A/m2 AC stray current interference was about 1.4 times of that without AC interference, while the corrosion current density with 50A/m2 AC stray current interference was about two times of that without AC interference.
{"title":"Study on the Influence of AC Stray Current on X80 Steel under Stripped Coating by Electrochemical Method","authors":"Yanyu Cui, Tao Shen, Qing-Miao Ding","doi":"10.1155/2019/4372430","DOIUrl":"https://doi.org/10.1155/2019/4372430","url":null,"abstract":"The effect of AC stray current density on corrosion behavior of X80 steel with stripped coating defects was studied by electrochemical method. The experimental results showed that the open circuit potential of X80 steel was shifted negatively due to the existence of AC interference. The degree of negative shift increased with the increasing of AC stray current density. And the potential after the cut of AC interference was still more negative than before. That is, the corrosion interference continued after cutting the AC power. In the initial stage of the experiment, the corrosion current density with 30A/m2 AC stray current interference was about 1.4 times of that without AC interference, while the corrosion current density with 50A/m2 AC stray current interference was about two times of that without AC interference.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/4372430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43856060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cementitious materials are subject to degradation when subjected to corrosive chloride media. This paper reports the experimental results on corrosion studies conducted on a potential cementitious material, PCDC, made from a blend of 55 % Ordinary Portland Cement (OPC), Dried Calcium Carbide Residue (DCCR), and an incineration mix of Rice Husks (RH), Spent Beaching Earth (SBE), and Ground Reject Bricks (BB). The experiments were run along 100 % OPC. Different w/c were used. Corrosion current densities using linear polarisation resistance (LPR) and corrosion potentials measurements versus saturated calomel electrode were used for the determination of corrosion rates and potentials, respectively, for simulated reinforcement at different depths of cover in the cement mortars. The results showed that PCDC exhibited higher corrosion current densities over all depths of covers and early attainment of active corrosion than the control cements. In conclusion, PCDC and OPC can be used in a similar corrosive media during construction.
{"title":"Effects of Chlorides on Corrosion of Simulated Reinforced Blended Cement Mortars","authors":"J. Wachira","doi":"10.1155/2019/2123547","DOIUrl":"https://doi.org/10.1155/2019/2123547","url":null,"abstract":"Cementitious materials are subject to degradation when subjected to corrosive chloride media. This paper reports the experimental results on corrosion studies conducted on a potential cementitious material, PCDC, made from a blend of 55 % Ordinary Portland Cement (OPC), Dried Calcium Carbide Residue (DCCR), and an incineration mix of Rice Husks (RH), Spent Beaching Earth (SBE), and Ground Reject Bricks (BB). The experiments were run along 100 % OPC. Different w/c were used. Corrosion current densities using linear polarisation resistance (LPR) and corrosion potentials measurements versus saturated calomel electrode were used for the determination of corrosion rates and potentials, respectively, for simulated reinforcement at different depths of cover in the cement mortars. The results showed that PCDC exhibited higher corrosion current densities over all depths of covers and early attainment of active corrosion than the control cements. In conclusion, PCDC and OPC can be used in a similar corrosive media during construction.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2019-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/2123547","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49045892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}