P. Amoah, Sandyson Owusu-Poku, Gordon Asartenga Ajubala
In this study, radiographic techniques were used to inspect large-diameter pipes that are used for transporting fluids in some industries in Ghana. Radiographic approaches such as the double wall technique (DWT) and tangential radiographic technique (TRT) were used to evaluate the remaining wall thickness, deposits, and corrosion in the pipes. Two steel pipes with known varying wall thicknesses ranging from 4.00 mm to 13.00 mm with a diameter of 150.00 mm were examined to authenticate the accuracy and reliability of the tangential method that was used to measure the remaining wall thickness. The tangential configuration resulted in a higher material thickness, which therefore required more time of exposure compared to the DWT method. The exposure angle of the source to the tangential part of the specimen was approximately 87°. The film generated was compared with a normal pipe piece that was not machined to serve as a control. From the radiograph obtained, an average of 6 and 7 rounded indications depicting pitting corrosion were revealed on the radiograph of the internally and externally fabricated pipe, respectively. Radiographs after the TRT revealed that the recorded wall thickness obtained from the film is about twice the value of the calculated true wall thickness.
{"title":"Investigation of Wall Thickness, Corrosion, and Deposits in Industrial Pipelines Using Radiographic Technique","authors":"P. Amoah, Sandyson Owusu-Poku, Gordon Asartenga Ajubala","doi":"10.1155/2023/4924399","DOIUrl":"https://doi.org/10.1155/2023/4924399","url":null,"abstract":"In this study, radiographic techniques were used to inspect large-diameter pipes that are used for transporting fluids in some industries in Ghana. Radiographic approaches such as the double wall technique (DWT) and tangential radiographic technique (TRT) were used to evaluate the remaining wall thickness, deposits, and corrosion in the pipes. Two steel pipes with known varying wall thicknesses ranging from 4.00 mm to 13.00 mm with a diameter of 150.00 mm were examined to authenticate the accuracy and reliability of the tangential method that was used to measure the remaining wall thickness. The tangential configuration resulted in a higher material thickness, which therefore required more time of exposure compared to the DWT method. The exposure angle of the source to the tangential part of the specimen was approximately 87°. The film generated was compared with a normal pipe piece that was not machined to serve as a control. From the radiograph obtained, an average of 6 and 7 rounded indications depicting pitting corrosion were revealed on the radiograph of the internally and externally fabricated pipe, respectively. Radiographs after the TRT revealed that the recorded wall thickness obtained from the film is about twice the value of the calculated true wall thickness.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"1 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46505167","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}
Pub Date : 2023-01-01DOI: 10.1137/1.9781611977554.ch187
Dominik Kempa, Tomasz Kociumaka
<p><p>The suffix array, describing the lexicographical order of suffixes of a given text, and the suffix tree, a path-compressed trie of all suffixes, are the two most fundamental data structures for string processing, with plethora of applications in data compression, bioinformatics, and information retrieval. For a length-<math><mi>n</mi></math> text, however, they use <math><mi>Θ</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>n</mi><mo>)</mo></math> bits of space, which is often too costly. To address this, Grossi and Vitter [STOC 2000] and, independently, Ferragina and Manzini [FOCS 2000] introduced space-efficient versions of the suffix array, known as the <i>compressed suffix array</i> (CSA) and the <i>FM-index</i>. Sadakane [SODA 2002] then showed how to augment them to obtain the <i>compressed suffix tree</i> (CST). For a length-<math><mi>n</mi></math> text over an alphabet of size <math><mi>σ</mi></math>, these structures use only <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>)</mo></math> bits. Nowadays, these structures are part of the standard toolbox: modern textbooks spend dozens of pages describing their applications, and they almost completely replaced suffix arrays and suffix trees in space-critical applications. The biggest remaining open question is how efficiently they can be constructed. After two decades, the fastest algorithms still run in <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mo>)</mo></math> time [Hon et al., FOCS 2003], which is <math><mi>Θ</mi><mfenced><mrow><msub><mrow><mtext>log</mtext></mrow><mrow><mi>σ</mi></mrow></msub><mi>n</mi></mrow></mfenced></math> factor away from the lower bound of <math><mi>Ω</mi><mfenced><mrow><mi>n</mi><mo>/</mo><msub><mrow><mtext>log</mtext></mrow><mrow><mi>σ</mi></mrow></msub><mi>n</mi></mrow></mfenced></math> (following from the necessity to read the input). In this paper, we make the first in 20 years improvement in <math><mi>n</mi></math> for this problem by proposing a new compressed suffix array and a new compressed suffix tree which admit <math><mi>o</mi><mo>(</mo><mi>n</mi><mo>)</mo></math>-time construction algorithms while matching the space bounds and the query times of the original CSA/CST and the FM-index. More precisely, our structures take <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>)</mo></math> bits, support SA queries and full suffix tree functionality in <math><mi>𝒪</mi><mfenced><mrow><msup><mrow><mtext>log</mtext></mrow><mrow><mi>ϵ</mi></mrow></msup><mi>n</mi></mrow></mfenced></math> time per operation, and can be constructed in <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>min</mtext><mo>(</mo><mn>1</mn><mo>,</mo><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>/</mo><msqrt><mtext>log</mtext><mspace></mspace><mi>n</mi></msqrt><mo>)</mo><mo>)</mo></math> time using <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><msp
{"title":"<ArticleTitle xmlns:ns0=\"http://www.w3.org/1998/Math/MathML\">Breaking the <ns0:math><ns0:mi>O</ns0:mi><ns0:mo>(</ns0:mo><ns0:mi>n</ns0:mi><ns0:mo>)</ns0:mo></ns0:math>-Barrier in the Construction of Compressed Suffix Arrays and Suffix Trees.","authors":"Dominik Kempa, Tomasz Kociumaka","doi":"10.1137/1.9781611977554.ch187","DOIUrl":"10.1137/1.9781611977554.ch187","url":null,"abstract":"<p><p>The suffix array, describing the lexicographical order of suffixes of a given text, and the suffix tree, a path-compressed trie of all suffixes, are the two most fundamental data structures for string processing, with plethora of applications in data compression, bioinformatics, and information retrieval. For a length-<math><mi>n</mi></math> text, however, they use <math><mi>Θ</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>n</mi><mo>)</mo></math> bits of space, which is often too costly. To address this, Grossi and Vitter [STOC 2000] and, independently, Ferragina and Manzini [FOCS 2000] introduced space-efficient versions of the suffix array, known as the <i>compressed suffix array</i> (CSA) and the <i>FM-index</i>. Sadakane [SODA 2002] then showed how to augment them to obtain the <i>compressed suffix tree</i> (CST). For a length-<math><mi>n</mi></math> text over an alphabet of size <math><mi>σ</mi></math>, these structures use only <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>)</mo></math> bits. Nowadays, these structures are part of the standard toolbox: modern textbooks spend dozens of pages describing their applications, and they almost completely replaced suffix arrays and suffix trees in space-critical applications. The biggest remaining open question is how efficiently they can be constructed. After two decades, the fastest algorithms still run in <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mo>)</mo></math> time [Hon et al., FOCS 2003], which is <math><mi>Θ</mi><mfenced><mrow><msub><mrow><mtext>log</mtext></mrow><mrow><mi>σ</mi></mrow></msub><mi>n</mi></mrow></mfenced></math> factor away from the lower bound of <math><mi>Ω</mi><mfenced><mrow><mi>n</mi><mo>/</mo><msub><mrow><mtext>log</mtext></mrow><mrow><mi>σ</mi></mrow></msub><mi>n</mi></mrow></mfenced></math> (following from the necessity to read the input). In this paper, we make the first in 20 years improvement in <math><mi>n</mi></math> for this problem by proposing a new compressed suffix array and a new compressed suffix tree which admit <math><mi>o</mi><mo>(</mo><mi>n</mi><mo>)</mo></math>-time construction algorithms while matching the space bounds and the query times of the original CSA/CST and the FM-index. More precisely, our structures take <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>)</mo></math> bits, support SA queries and full suffix tree functionality in <math><mi>𝒪</mi><mfenced><mrow><msup><mrow><mtext>log</mtext></mrow><mrow><mi>ϵ</mi></mrow></msup><mi>n</mi></mrow></mfenced></math> time per operation, and can be constructed in <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><mspace></mspace><mtext>min</mtext><mo>(</mo><mn>1</mn><mo>,</mo><mtext>log</mtext><mspace></mspace><mi>σ</mi><mo>/</mo><msqrt><mtext>log</mtext><mspace></mspace><mi>n</mi></msqrt><mo>)</mo><mo>)</mo></math> time using <math><mi>𝒪</mi><mo>(</mo><mi>n</mi><msp","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2010 1","pages":"5122-5202"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11149104/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86311282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work we investigated the inhibiting effect of sodium citrate, an environmentally safe corrosion inhibitor, on low-alloy steel 09G2S in a neutral environment using electrochemical methods. Potentiodynamic studies showed that sodium citrate reduces corrosion currents of 09G2S steel in a 0.1% NaCl solution and reaches its maximum efficiency at a concentration of 2.5 g/l. Electrochemical impedance spectroscopy results indicate the adsorption of citrate ions and the formation of a protective film, which probably consists of Fe-citrate complexes. The formation of a protective film on the steel surface in sodium citrate-inhibited solutions was confirmed by the results of scanning electron microscopy and EDX analysis. Hence, our research shows that sodium citrate has satisfactory anticorrosion properties and can be used as a basic component during the development of environmentally safe inhibitor compositions for the protection of low-alloyed carbon steels in neutral environments of recirculating water supply systems in petroleum refineries, petrochemical plants, and other industries.
{"title":"Sodium Citrate as an Environmentally Friendly Corrosion Inhibitor of Steel in a Neutral Environment","authors":"M. Danyliak, I. Zin, Yuliia Rizun, S. Korniy","doi":"10.1155/2022/1442537","DOIUrl":"https://doi.org/10.1155/2022/1442537","url":null,"abstract":"In this work we investigated the inhibiting effect of sodium citrate, an environmentally safe corrosion inhibitor, on low-alloy steel 09G2S in a neutral environment using electrochemical methods. Potentiodynamic studies showed that sodium citrate reduces corrosion currents of 09G2S steel in a 0.1% NaCl solution and reaches its maximum efficiency at a concentration of 2.5 g/l. Electrochemical impedance spectroscopy results indicate the adsorption of citrate ions and the formation of a protective film, which probably consists of Fe-citrate complexes. The formation of a protective film on the steel surface in sodium citrate-inhibited solutions was confirmed by the results of scanning electron microscopy and EDX analysis. Hence, our research shows that sodium citrate has satisfactory anticorrosion properties and can be used as a basic component during the development of environmentally safe inhibitor compositions for the protection of low-alloyed carbon steels in neutral environments of recirculating water supply systems in petroleum refineries, petrochemical plants, and other industries.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48238153","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}
Based on the macrocell corrosion theory and by alternating the microcell corrosion state and macrocell corrosion state, the influence of mineral admixtures, such as fly ash, slag, and limestone powder, on the macrocell corrosion behaviors of steel bars embedded in chloride-contaminated concrete were investigated and clarified. The results indicated that the inhibition effect induced by slag on macrocell corrosion and microcell corrosion was obviously better than that induced by fly ash or limestone powder. The presence of slag in chloride-contaminated concrete could remarkably decrease the corrosion area ratios of anodic steel, even if the replacement levels of slag to cement reached 70%. With the addition of mineral admixtures into concrete, the ratio of macrocell current density to microcell current density was decreased to some extent, depending on the types, replacement levels, and replacement ways of mineral admixtures. The use of slag and fly ash in chloride-contaminated concrete can effectively weaken the macrocell corrosion and make the corrosion be dominated by microcell corrosion. The types and replacement levels of mineral admixtures also had a remarkable influence on the control mode of macrocell corrosion. The use of slag was more effective than that of fly ash or limestone to weaken the cathode control mode of macrocell corrosion and made the control mode of macrocell corrosion be dominated by jointed control.
{"title":"Effects of Mineral Admixtures on Macrocell Corrosion Behaviors of Steel Bars in Chloride-Contaminated Concrete","authors":"Z. Cao, Zhongfu Su, M. Hibino, H. Goda","doi":"10.1155/2022/3332123","DOIUrl":"https://doi.org/10.1155/2022/3332123","url":null,"abstract":"Based on the macrocell corrosion theory and by alternating the microcell corrosion state and macrocell corrosion state, the influence of mineral admixtures, such as fly ash, slag, and limestone powder, on the macrocell corrosion behaviors of steel bars embedded in chloride-contaminated concrete were investigated and clarified. The results indicated that the inhibition effect induced by slag on macrocell corrosion and microcell corrosion was obviously better than that induced by fly ash or limestone powder. The presence of slag in chloride-contaminated concrete could remarkably decrease the corrosion area ratios of anodic steel, even if the replacement levels of slag to cement reached 70%. With the addition of mineral admixtures into concrete, the ratio of macrocell current density to microcell current density was decreased to some extent, depending on the types, replacement levels, and replacement ways of mineral admixtures. The use of slag and fly ash in chloride-contaminated concrete can effectively weaken the macrocell corrosion and make the corrosion be dominated by microcell corrosion. The types and replacement levels of mineral admixtures also had a remarkable influence on the control mode of macrocell corrosion. The use of slag was more effective than that of fly ash or limestone to weaken the cathode control mode of macrocell corrosion and made the control mode of macrocell corrosion be dominated by jointed control.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42880288","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}
PDL (Phoenix dactylifera leaves) is widely spread in Iraq and is known to be rich in phytochemicals as flavonoids, saponins, tannins, glycosides, oils, and lipids. The effect of PDL extract in reducing the corrosion of Aluminium in 1 M HCl solution using a weight loss technique, and computational chemistry calculations were investigated in this study. The study carried out at different temperatures (20, 30, 40, and 50) in the presence of plant extract and the absence of extract. A number of parameters were included to be detected in this study according to the density functional theory (DFT)/P3LYP/6-311G, including the highest occupied molecular orbital EHOMO, the lowest unoccupied molecular orbital ELUMO, energy gap Δ E , softness S , hardness η , dipole moment μ , electronegativity χ , electrophilicity ω , inhibitor-metal interaction energy ∆ ψ , and electrons transferred fraction Δ N . Two adsorption isotherms were used to explain inhibitor adsorption behavior. Two adsorption isotherms were used to explain inhibitor adsorption behavior, the Freundlich adsorption isotherm and the Langmuir adsorption isotherm, the Freundlich adsorption isotherm was discovered to be followed by the inhibitor with correlation coefficient values ranging from 0.98 to 0.94 with temperature increased from 20 to 50 degrees Celsius. The adsorption mechanism includes a physical adsorption process. The results showed that with the increment of the inhibitors concentration, there was an improvement of the inhibition efficiency. The most outstanding inhibitor efficiency was 97.7% at 10 mL/L inhibitor concentration.
PDL（Phoenix dactylifera leaves）在伊拉克广泛分布，富含黄酮、皂苷、单宁、糖苷、油和脂质等植物化学物质。PDL提取物降低铝在1中的腐蚀作用 M HCl溶液的重量损失技术和计算化学计算在本研究中进行了研究。该研究在不同温度（20、30、40和50）下，在存在植物提取物和不存在提取物的情况下进行。根据密度泛函理论（DFT）/P3LYP/6-311G，本研究包括了许多待检测的参数，包括最高占据分子轨道EHOMO、最低占据分子轨道ELUMO、能隙ΔE、柔软度S、硬度η、偶极矩μ、电负性χ、亲电性ω，抑制剂-金属相互作用能∆ψ和电子转移分数ΔN。用两条吸附等温线来解释缓蚀剂的吸附行为。使用两条吸附等温线来解释抑制剂的吸附行为，Freundlich吸附等温线和Langmuir吸附等温线，发现随着温度从20摄氏度增加到50摄氏度，Freundrich吸附等温线之后是抑制剂，相关系数在0.98到0.94之间。吸附机理包括物理吸附过程。结果表明，随着缓蚀剂浓度的增加，缓蚀效果有所提高。在10 mL/L抑制剂浓度。
{"title":"Computational and Experimental Evaluation of Inhibition Potential of a New Ecologically Friendly Inhibitor Leaves of Date Palm (Phoenix dactylifera L.) for Aluminium Corrosion in an Acidic Media","authors":"O. Hatem","doi":"10.1155/2022/5953561","DOIUrl":"https://doi.org/10.1155/2022/5953561","url":null,"abstract":"PDL (Phoenix dactylifera leaves) is widely spread in Iraq and is known to be rich in phytochemicals as flavonoids, saponins, tannins, glycosides, oils, and lipids. The effect of PDL extract in reducing the corrosion of Aluminium in 1 M HCl solution using a weight loss technique, and computational chemistry calculations were investigated in this study. The study carried out at different temperatures (20, 30, 40, and 50) in the presence of plant extract and the absence of extract. A number of parameters were included to be detected in this study according to the density functional theory (DFT)/P3LYP/6-311G, including the highest occupied molecular orbital EHOMO, the lowest unoccupied molecular orbital ELUMO, energy gap \u0000 \u0000 Δ\u0000 E\u0000 \u0000 , softness \u0000 \u0000 S\u0000 \u0000 , hardness \u0000 \u0000 η\u0000 \u0000 , dipole moment \u0000 \u0000 μ\u0000 \u0000 , electronegativity \u0000 \u0000 χ\u0000 \u0000 , electrophilicity \u0000 \u0000 ω\u0000 \u0000 , inhibitor-metal interaction energy \u0000 \u0000 ∆\u0000 ψ\u0000 \u0000 , and electrons transferred fraction \u0000 \u0000 Δ\u0000 N\u0000 \u0000 . Two adsorption isotherms were used to explain inhibitor adsorption behavior. Two adsorption isotherms were used to explain inhibitor adsorption behavior, the Freundlich adsorption isotherm and the Langmuir adsorption isotherm, the Freundlich adsorption isotherm was discovered to be followed by the inhibitor with correlation coefficient values ranging from 0.98 to 0.94 with temperature increased from 20 to 50 degrees Celsius. The adsorption mechanism includes a physical adsorption process. The results showed that with the increment of the inhibitors concentration, there was an improvement of the inhibition efficiency. The most outstanding inhibitor efficiency was 97.7% at 10 mL/L inhibitor concentration.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43596233","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}
L. Popoola, A. Yusuff, O. Ikumapayi, Onyemaechi Melford Chima, A. Ogunyemi, B. A. Obende
In this study, corrosion inhibition efficiency of Cucumeropsis mannii shell extract (CMSE) was tested on A515 Grade 70 carbon steel in 1.0 M NaCl solution. Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and weight loss (WL) measurements were used to investigate the inhibition efficiency. Scanning electron microscopy, Fourier transform infrared spectroscopy, atomic adsorption spectroscopy, and energy dispersive spectroscopy were used to characterize the carbon steel and extract. PDP and EIS measurements revealed maximum inhibition efficiency of 91.2% and 92.2%, respectively. Tafel plot confirmed inhibitor to be a mixed type. A monolayer adsorption of CMSE molecules occurred spontaneously by physisorption. Polarization resistance increased with increasing inhibitor concentration. WL measurement revealed decrease in corrosion rate with increasing concentration of corrosion inhibitor. Maximum Young modulus and hardness of 202.4 GPa and 112.3 BHN, respectively, were recorded for the carbon steel at a minimum corrosion rate and load. Pitting and uniform corrosion were formed on the carbon steel in the absence of CMSE. CMSE contains –OH, –OCH3, and –C-NH3 as active functional groups. In conclusion, Cucumeropsis mannii shell extract acted excellently as corrosion inhibitor for A515 Grade 70 carbon steel in 1.0 M NaCl.
本研究以A515 70级碳钢为试材，在1.0 M NaCl溶液。使用电位动态极化（PDP）、电化学阻抗谱（EIS）和重量损失（WL）测量来研究抑制效率。利用扫描电子显微镜、傅立叶变换红外光谱、原子吸附光谱和能量色散光谱对碳钢和提取物进行了表征。PDP和EIS测量显示最大抑制效率分别为91.2%和92.2%。塔菲尔图证实抑制剂为混合型。CMSE分子的单层吸附通过物理吸附自发发生。极化电阻随抑制剂浓度的增加而增加。WL测量显示腐蚀速率随着缓蚀剂浓度的增加而降低。最大杨氏模量和硬度为202.4 在最小腐蚀速率和载荷下，碳钢分别记录了GPa和112.3BHN。在没有CMSE的情况下，碳钢上形成了点蚀和均匀腐蚀。CMSE含有–OH、–OCH3和–C-NH3作为活性官能团。综上所述，曼氏Cucumeropsis壳提取物对A515 70级碳钢在1.0 M NaCl。
{"title":"Electrochemical, Isotherm, and Material Strength Studies of Cucumeropsis mannii Shell Extract on A515 Grade 70 Carbon Steel in NaCl Solution","authors":"L. Popoola, A. Yusuff, O. Ikumapayi, Onyemaechi Melford Chima, A. Ogunyemi, B. A. Obende","doi":"10.1155/2022/3189844","DOIUrl":"https://doi.org/10.1155/2022/3189844","url":null,"abstract":"In this study, corrosion inhibition efficiency of Cucumeropsis mannii shell extract (CMSE) was tested on A515 Grade 70 carbon steel in 1.0 M NaCl solution. Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and weight loss (WL) measurements were used to investigate the inhibition efficiency. Scanning electron microscopy, Fourier transform infrared spectroscopy, atomic adsorption spectroscopy, and energy dispersive spectroscopy were used to characterize the carbon steel and extract. PDP and EIS measurements revealed maximum inhibition efficiency of 91.2% and 92.2%, respectively. Tafel plot confirmed inhibitor to be a mixed type. A monolayer adsorption of CMSE molecules occurred spontaneously by physisorption. Polarization resistance increased with increasing inhibitor concentration. WL measurement revealed decrease in corrosion rate with increasing concentration of corrosion inhibitor. Maximum Young modulus and hardness of 202.4 GPa and 112.3 BHN, respectively, were recorded for the carbon steel at a minimum corrosion rate and load. Pitting and uniform corrosion were formed on the carbon steel in the absence of CMSE. CMSE contains –OH, –OCH3, and –C-NH3 as active functional groups. In conclusion, Cucumeropsis mannii shell extract acted excellently as corrosion inhibitor for A515 Grade 70 carbon steel in 1.0 M NaCl.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47511657","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}
Xudong Zhou, Xinmin Zhang, Ruiwen Xu, Bin Li, X. Ren, Jinyang Zhu, Ying Jin
The corrosion tendency and fatigue behavior of a SM480C welded joint in a sea-crossing suspension bridge after twenty-year exposure to a marine environment was investigated in this work. It was found that the corrosion product on the whole surface of the welded joint is loose, with many holes and cracks, which allowing corrosive media enter and reach the surface of the substrate. Localized corrosion occurred in the weld zone (WZ) and the heat-affected zone (HAZ), the maximum depth of localized corrosion in the HAZ reached 1.8 mm, and the maximum local corrosion rate is 0.082 mm/y. By using Bimetallic Conjugation Theory calculations, the galvanic effect of the welded joint was qualified, indicates that HAZ was the most corrosion susceptible area in the welded joint. The galvanic corrosion current on HAZ reached approximately 2 μA, which is much higher than the corrosion of isolated HAZ by about 6.5 times. The corrosion has an obvious influence on the fatigue performance, the elongation of the bridge deck decreases by 40%~70%, and the tensile strength decreases by 4.5%~31.33%. In order to ensure the service safety and avoid premature failure, the average thickness of the corroded bridge deck should not be less than 10 mm under the stress amplitude of 115 MPa.
{"title":"Galvanic Corrosion and Fatigue Behavior of a SM480C Welded Joint Steel in a Sea-Crossing Suspension Bridge","authors":"Xudong Zhou, Xinmin Zhang, Ruiwen Xu, Bin Li, X. Ren, Jinyang Zhu, Ying Jin","doi":"10.1155/2022/2665663","DOIUrl":"https://doi.org/10.1155/2022/2665663","url":null,"abstract":"The corrosion tendency and fatigue behavior of a SM480C welded joint in a sea-crossing suspension bridge after twenty-year exposure to a marine environment was investigated in this work. It was found that the corrosion product on the whole surface of the welded joint is loose, with many holes and cracks, which allowing corrosive media enter and reach the surface of the substrate. Localized corrosion occurred in the weld zone (WZ) and the heat-affected zone (HAZ), the maximum depth of localized corrosion in the HAZ reached 1.8 mm, and the maximum local corrosion rate is 0.082 mm/y. By using Bimetallic Conjugation Theory calculations, the galvanic effect of the welded joint was qualified, indicates that HAZ was the most corrosion susceptible area in the welded joint. The galvanic corrosion current on HAZ reached approximately 2 μA, which is much higher than the corrosion of isolated HAZ by about 6.5 times. The corrosion has an obvious influence on the fatigue performance, the elongation of the bridge deck decreases by 40%~70%, and the tensile strength decreases by 4.5%~31.33%. In order to ensure the service safety and avoid premature failure, the average thickness of the corroded bridge deck should not be less than 10 mm under the stress amplitude of 115 MPa.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"1 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42088875","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}
Win Thandar, Y. Win, T. Khaing, Yasuo Suzuki, K. Sugiura, I. Nishizaki
This research is aimed at studying the corrosion rates of carbon and weathering steels due to exposure at three urban exposure sites and the characteristics of corrosion products of carbon steel in Yangon, Myanmar. The ISO 9223 standard was used to classify the corrosion aggressiveness of the atmosphere. There is a high level of time of wetness (TOW) class which is τ 4 in the south and τ 3 in the central part of Myanmar. At the recent exposure sites in Myanmar, the atmospheric impurities are low, so the corrosion rates of carbon and weathering steels are mainly governed by TOW. The corrosion rates of test sites fall into the ISO C2 category. It appears that corrosion kinetics fit the power model well, since the correlation coefficient is high. Various morphologies of corrosion products including globular, flowery, and sandy lepidocrocite emerged in the early stage of exposure. The longer TOW conditions resulted in the formation of lepidocrocite and goethite. The growth of goethite products on carbon steel was discovered after nine months of exposure.
{"title":"Investigation of Initial Atmospheric Corrosion of Carbon and Weathering Steels Exposed to Urban Atmospheres in Myanmar","authors":"Win Thandar, Y. Win, T. Khaing, Yasuo Suzuki, K. Sugiura, I. Nishizaki","doi":"10.1155/2022/4301767","DOIUrl":"https://doi.org/10.1155/2022/4301767","url":null,"abstract":"This research is aimed at studying the corrosion rates of carbon and weathering steels due to exposure at three urban exposure sites and the characteristics of corrosion products of carbon steel in Yangon, Myanmar. The ISO 9223 standard was used to classify the corrosion aggressiveness of the atmosphere. There is a high level of time of wetness (TOW) class which is \u0000 \u0000 \u0000 \u0000 τ\u0000 \u0000 \u0000 4\u0000 \u0000 \u0000 \u0000 in the south and \u0000 \u0000 \u0000 \u0000 τ\u0000 \u0000 \u0000 3\u0000 \u0000 \u0000 \u0000 in the central part of Myanmar. At the recent exposure sites in Myanmar, the atmospheric impurities are low, so the corrosion rates of carbon and weathering steels are mainly governed by TOW. The corrosion rates of test sites fall into the ISO C2 category. It appears that corrosion kinetics fit the power model well, since the correlation coefficient is high. Various morphologies of corrosion products including globular, flowery, and sandy lepidocrocite emerged in the early stage of exposure. The longer TOW conditions resulted in the formation of lepidocrocite and goethite. The growth of goethite products on carbon steel was discovered after nine months of exposure.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45397041","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 under insulation (CUI) refers to the external corrosion of piping and vessels when they are encapsulated in thermal insulation. To date, very limited information (especially electrochemical data) is available for these “difficult-to-test” CUI conditions. This study was aimed at developing a novel electrochemical sensing method for in situ CUI monitoring and analysis. Pt-coated Ti wires were used to assemble a three-electrode electrochemical cell over a pipe surface covered by thermal insulation. The CUI behavior of X70 carbon steel (CS) and 304 stainless steel (SS) under various operating conditions was investigated using mass loss, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. It was found that both the consecutive wet and dry cycles and cyclic temperatures accelerated the progression of CUI. LPR and EIS measurements revealed that the accelerated CUI by thermal cycling was due to the reduced polarization resistance and deteriorated corrosion film. Enhanced pitting corrosion was observed on all tested samples after thermal cycling conditions, especially for CS samples. The proposed electrochemical technique demonstrated the ability to obtain comparable corrosion rates to conventional mass loss data. In addition to its potential for in situ CUI monitoring, this design could be further applied to rank alloys, coatings, and inhibitors under more complex exposure conditions.
{"title":"In Situ Monitoring of Corrosion under Insulation Using Electrochemical and Mass Loss Measurements","authors":"Mingzhang Yang, Jing Liu","doi":"10.1155/2022/6681008","DOIUrl":"https://doi.org/10.1155/2022/6681008","url":null,"abstract":"Corrosion under insulation (CUI) refers to the external corrosion of piping and vessels when they are encapsulated in thermal insulation. To date, very limited information (especially electrochemical data) is available for these “difficult-to-test” CUI conditions. This study was aimed at developing a novel electrochemical sensing method for in situ CUI monitoring and analysis. Pt-coated Ti wires were used to assemble a three-electrode electrochemical cell over a pipe surface covered by thermal insulation. The CUI behavior of X70 carbon steel (CS) and 304 stainless steel (SS) under various operating conditions was investigated using mass loss, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. It was found that both the consecutive wet and dry cycles and cyclic temperatures accelerated the progression of CUI. LPR and EIS measurements revealed that the accelerated CUI by thermal cycling was due to the reduced polarization resistance and deteriorated corrosion film. Enhanced pitting corrosion was observed on all tested samples after thermal cycling conditions, especially for CS samples. The proposed electrochemical technique demonstrated the ability to obtain comparable corrosion rates to conventional mass loss data. In addition to its potential for in situ CUI monitoring, this design could be further applied to rank alloys, coatings, and inhibitors under more complex exposure conditions.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49122697","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}
J. Pereyra-Hernández, I. Rosales-Cadena, R. Guardián-Tapia, J. González-Rodríguez, R. López‐Sesenes
<jats:p>Al-based alloys named M1, M2, M3, M4, and M5 doped with different atomic percentage (at%) of cobalt and manganese as cast and submitted at two heat treatments (600°C and 1100°C) were analyzed by using electrochemical techniques to evaluate their corrosion resistance immersed in 3 M KOH. With the heat treatments applied to the alloys, the sample M2 (65% Al, 20% Co, and 15% Mn) observed the highest corrosion resistance with <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <msub> <mrow> <mi>R</mi> </mrow> <mrow> <mi>p</mi> </mrow> </msub> </math> </jats:inline-formula> values of <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2"> <mn>3.0</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </math> </jats:inline-formula>, <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3"> <mn>6.2</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </math> </jats:inline-formula>, and <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4"> <mn>1.61</mn> <mo>×</mo> <msup> <mrow> <mn>10</mn> </mrow> <mrow> <mn>3</mn> </mrow> </msup> <mtext> </mtext> <mi>Ω</mi> <mo>·</mo> <mtext>c</mtext> <msup> <mrow> <mtext>m</mtext> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </math> </jats:inline-formula> as cast, 600°C, and 1100°C, respectively. The latter was in agreement wit
{"title":"Heat Treatment Effect in the Corrosion Resistance of the Al-Co-Mn Alloys Immersed in 3 M KOH","authors":"J. Pereyra-Hernández, I. Rosales-Cadena, R. Guardián-Tapia, J. González-Rodríguez, R. López‐Sesenes","doi":"10.1155/2021/3458957","DOIUrl":"https://doi.org/10.1155/2021/3458957","url":null,"abstract":"<jats:p>Al-based alloys named M1, M2, M3, M4, and M5 doped with different atomic percentage (at%) of cobalt and manganese as cast and submitted at two heat treatments (600°C and 1100°C) were analyzed by using electrochemical techniques to evaluate their corrosion resistance immersed in 3 M KOH. With the heat treatments applied to the alloys, the sample M2 (65% Al, 20% Co, and 15% Mn) observed the highest corrosion resistance with <jats:inline-formula>\u0000 <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\">\u0000 <msub>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>p</mi>\u0000 </mrow>\u0000 </msub>\u0000 </math>\u0000 </jats:inline-formula> values of <jats:inline-formula>\u0000 <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\">\u0000 <mn>3.0</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mrow>\u0000 <mn>10</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </math>\u0000 </jats:inline-formula>, <jats:inline-formula>\u0000 <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\">\u0000 <mn>6.2</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mrow>\u0000 <mn>10</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </math>\u0000 </jats:inline-formula>, and <jats:inline-formula>\u0000 <math xmlns=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\">\u0000 <mn>1.61</mn>\u0000 <mo>×</mo>\u0000 <msup>\u0000 <mrow>\u0000 <mn>10</mn>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>3</mn>\u0000 </mrow>\u0000 </msup>\u0000 <mtext> </mtext>\u0000 <mi>Ω</mi>\u0000 <mo>·</mo>\u0000 <mtext>c</mtext>\u0000 <msup>\u0000 <mrow>\u0000 <mtext>m</mtext>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </math>\u0000 </jats:inline-formula> as cast, 600°C, and 1100°C, respectively. The latter was in agreement wit","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43409625","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：