N. Larché, C. Leballeur, Sandra Le Manchet, Wenle He
Chlorination is widely used in seawater systems to avoid fouling. Free chlorine is a strong oxidizing agent that prevents the biofilm formation on immersed surfaces, when used above a certain content. However, the presence of residual chlorine associated with the high chloride content in seawater, significantly increases the risk of localized corrosion for most stainless steels. In the present study, a module initially developed to quantify the formation of electroactive biofilms on stainless steels has been used to assess the corrosivity of chlorinated seawater. Both the electrochemical potential and the cathodic current were measured on super-duplex stainless steel as a function of residual chlorine levels and seawater temperatures. In parallel, long term localized corrosion tests have been performed in simulated environments to assess the environmental limits for safe use of high-grade stainless steels in chlorinated seawater. It includes crevice corrosion exposure tests using adapted ISO18070:2015 crevice formers and internal tube pitting corrosion exposure tests in model tube heat exchangers simulating heat flux from 35°C to 170°C. The synergetic effect of residual chlorine content and temperature on the risk of localized corrosion has been quantified. Corrosion resistance properties are correlated to the electrochemical monitoring data, and the environmental limits of selected stainless steels have been established for duplex stainless steel UNS S32205, super-duplex stainless steel UNS S32750, hyper-duplex stainless steel UNS S32707 and the high-grade austenitic stainless steel UNS S31266.
{"title":"Localized Corrosion of High-Grade Stainless Steels in Chlorinated Seawater","authors":"N. Larché, C. Leballeur, Sandra Le Manchet, Wenle He","doi":"10.5006/4348","DOIUrl":"https://doi.org/10.5006/4348","url":null,"abstract":"Chlorination is widely used in seawater systems to avoid fouling. Free chlorine is a strong oxidizing agent that prevents the biofilm formation on immersed surfaces, when used above a certain content. However, the presence of residual chlorine associated with the high chloride content in seawater, significantly increases the risk of localized corrosion for most stainless steels. In the present study, a module initially developed to quantify the formation of electroactive biofilms on stainless steels has been used to assess the corrosivity of chlorinated seawater. Both the electrochemical potential and the cathodic current were measured on super-duplex stainless steel as a function of residual chlorine levels and seawater temperatures. In parallel, long term localized corrosion tests have been performed in simulated environments to assess the environmental limits for safe use of high-grade stainless steels in chlorinated seawater. It includes crevice corrosion exposure tests using adapted ISO18070:2015 crevice formers and internal tube pitting corrosion exposure tests in model tube heat exchangers simulating heat flux from 35°C to 170°C. The synergetic effect of residual chlorine content and temperature on the risk of localized corrosion has been quantified. Corrosion resistance properties are correlated to the electrochemical monitoring data, and the environmental limits of selected stainless steels have been established for duplex stainless steel UNS S32205, super-duplex stainless steel UNS S32750, hyper-duplex stainless steel UNS S32707 and the high-grade austenitic stainless steel UNS S31266.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47622082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
NACE impact report (2016) states that nearly 50% of reinforced concrete (RC) structures experience major repair in about ten years. The existing approach of patch repair does not address the root cause and may not be durable – resulting in re-repair and huge economic loss. Galvanic anodes (GAs) are gaining widespread acceptance to achieve maintenance-free repair life for a few decades. However, a few GAs with inadequate characteristics are prematurely failing (within a few months). There are no short-term test methods to evaluate the longevity of GAs. Therefore, this work focuses on developing a short-term test method (Galvanic Anode Performance (GAP) test) to assess the longevity of GAs. For this, the GAP specimen was designed by simulating CP-protected RC structure as follows: (i) GA embedded in bedding mortar (i.e., anode), (ii) Nichrome mesh (i.e., cathode simulating rebars in RC structures), (iii) position of anode and cathode, (iv) application of potential difference (0.5, 1, 5, 10, 20, and 30 V) to accelerate the degradation of GAs, and (v) electrolyte to simulate conductivity of concrete. Applied potentials > 5 V could not capture the difference in characteristics of GAs. However, potential differences of 0.5, 1, and 5 V could show the true behavior of GAs in various exposure conditions. Then, an approach is proposed to evaluate the service life of GAs. Possible reasons for the premature failure of anodes were investigated by evaluating pH and pore volume of encapsulating mortar. The GAP test can help practicing engineers to estimate the longevity of GAs.
{"title":"Development of galvanic anode performance (GAP) test for assessing the longevity of galvanic anodes for reinforced concrete structures","authors":"Deepak K. Kamde, R. Pillai","doi":"10.5006/4305","DOIUrl":"https://doi.org/10.5006/4305","url":null,"abstract":"NACE impact report (2016) states that nearly 50% of reinforced concrete (RC) structures experience major repair in about ten years. The existing approach of patch repair does not address the root cause and may not be durable – resulting in re-repair and huge economic loss. Galvanic anodes (GAs) are gaining widespread acceptance to achieve maintenance-free repair life for a few decades. However, a few GAs with inadequate characteristics are prematurely failing (within a few months). There are no short-term test methods to evaluate the longevity of GAs. Therefore, this work focuses on developing a short-term test method (Galvanic Anode Performance (GAP) test) to assess the longevity of GAs. For this, the GAP specimen was designed by simulating CP-protected RC structure as follows: (i) GA embedded in bedding mortar (i.e., anode), (ii) Nichrome mesh (i.e., cathode simulating rebars in RC structures), (iii) position of anode and cathode, (iv) application of potential difference (0.5, 1, 5, 10, 20, and 30 V) to accelerate the degradation of GAs, and (v) electrolyte to simulate conductivity of concrete. Applied potentials > 5 V could not capture the difference in characteristics of GAs. However, potential differences of 0.5, 1, and 5 V could show the true behavior of GAs in various exposure conditions. Then, an approach is proposed to evaluate the service life of GAs. Possible reasons for the premature failure of anodes were investigated by evaluating pH and pore volume of encapsulating mortar. The GAP test can help practicing engineers to estimate the longevity of GAs.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44802044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ying yan, mengting Li, peng chen, shuyuan Wang, chunjie Shi, hao zhou, laiming Wu, kun cai
Although the corrosion of iron-based alloys by ionic liquids (ILs) has been reported, the influence of trace water in ILs on its corrosion mechanism is often ignored. In this work, we investigated the corrosion behavior of Q235 carbon steel (Q235 CS) and 304 stainless steel (304 SS) exposed to 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) with trace water (0.5 wt% to 4.0 wt%) at 323 K. Electrochemical tests and surface analysis manifested that the increasing water content accelerated corrosion of the two iron-based alloys in [BMIM]BF4. A nontypical passivation zone was observed for Q235 CS, while 304 SS exhibited completely active dissolution and its corrosion situation was not as serious as Q235 CS. The occurrence of pitting corrosion is responsible for 304 SS behaviors in [BMIM]BF4. Some corrosion products accumulated on the surface of both iron-based alloys were similar, including FeF2, FeF3, FeO, Fe2O3, and/or FeOOH. Gas products during corrosion were also monitored to avoid the complicated cathodic depolarization process, and it was found to be composed of BF3, HF, and H2. Finally, the corrosion mechanism of iron-based alloys in ILs with trace water was proposed. The illustrated mechanism would be meaningful for understanding the similar corrosiveness to iron-based alloys.
{"title":"Reliance of Corrosion Characteristics for Two Iron-Based Alloys on the Water Content in 1-Butyl-3-Methylimidazolium Tetrafluoroborate","authors":"ying yan, mengting Li, peng chen, shuyuan Wang, chunjie Shi, hao zhou, laiming Wu, kun cai","doi":"10.5006/4292","DOIUrl":"https://doi.org/10.5006/4292","url":null,"abstract":"Although the corrosion of iron-based alloys by ionic liquids (ILs) has been reported, the influence of trace water in ILs on its corrosion mechanism is often ignored. In this work, we investigated the corrosion behavior of Q235 carbon steel (Q235 CS) and 304 stainless steel (304 SS) exposed to 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) with trace water (0.5 wt% to 4.0 wt%) at 323 K. Electrochemical tests and surface analysis manifested that the increasing water content accelerated corrosion of the two iron-based alloys in [BMIM]BF4. A nontypical passivation zone was observed for Q235 CS, while 304 SS exhibited completely active dissolution and its corrosion situation was not as serious as Q235 CS. The occurrence of pitting corrosion is responsible for 304 SS behaviors in [BMIM]BF4. Some corrosion products accumulated on the surface of both iron-based alloys were similar, including FeF2, FeF3, FeO, Fe2O3, and/or FeOOH. Gas products during corrosion were also monitored to avoid the complicated cathodic depolarization process, and it was found to be composed of BF3, HF, and H2. Finally, the corrosion mechanism of iron-based alloys in ILs with trace water was proposed. The illustrated mechanism would be meaningful for understanding the similar corrosiveness to iron-based alloys.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135381089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminum alloys are not immune to corrosion which can take the form of localized corrosion. Thus, the assessment of the corrosion behavior of aluminum alloys under atmospheric conditions is a major topic for the aerospace industry. One major difficulty in this task is the lack of robust and reliable accelerated corrosion test(s) in this field. Indeed, several tests as the Neutral Salt Spray test (ASTM B117) are used to assess the general corrosion resistance of aluminum, but these tests were not developed specifically for the aerospace industry and are not representative of service conditions. The aim of the present study was to compare the results of various accelerated corrosion tests conditions (ASTM B117, VDA 233-102, Volvo STD 423-0014) with newly developed test conditions. Hence different accelerated corrosion tests were designed by varying several parameters in the Volvo STD 423-0014 such as the salt concentration, the time of wetness and the relative humidity. The results obtained on 8 aluminum alloys (2xxx, 7xxx and Al-Li alloys) were then compared to marine exposures. From the results, one test provides the same type of corrosion attacks on the different alloys as under atmospheric exposures in the marine site and a good acceleration factor.
{"title":"Developement of reliable accelerated corrosion tests for aluminum alloys used in the aerospace industry","authors":"F. Peltier, D. Thierry","doi":"10.5006/4356","DOIUrl":"https://doi.org/10.5006/4356","url":null,"abstract":"Aluminum alloys are not immune to corrosion which can take the form of localized corrosion. Thus, the assessment of the corrosion behavior of aluminum alloys under atmospheric conditions is a major topic for the aerospace industry. One major difficulty in this task is the lack of robust and reliable accelerated corrosion test(s) in this field. Indeed, several tests as the Neutral Salt Spray test (ASTM B117) are used to assess the general corrosion resistance of aluminum, but these tests were not developed specifically for the aerospace industry and are not representative of service conditions. The aim of the present study was to compare the results of various accelerated corrosion tests conditions (ASTM B117, VDA 233-102, Volvo STD 423-0014) with newly developed test conditions. Hence different accelerated corrosion tests were designed by varying several parameters in the Volvo STD 423-0014 such as the salt concentration, the time of wetness and the relative humidity. The results obtained on 8 aluminum alloys (2xxx, 7xxx and Al-Li alloys) were then compared to marine exposures. From the results, one test provides the same type of corrosion attacks on the different alloys as under atmospheric exposures in the marine site and a good acceleration factor.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46540819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, a number of light rail systems have been built or extended in North America. Typical design lives of metallic and concrete transit structures are required to exceed 75 y, with exposure to de-icing salts, freeze/thaw, and the potential for stray currents. Measures to mitigate the risks of reinforcement corrosion to rail structures have progressed over the last century, with some diversion between the preferred practices in Europe and North America. One significant difference with large cost impacts on projects is the means and methods to achieve continuity of the reinforcing steel within rail structures to control stray currents to negligible levels. Herein we review the available standards and literature as it relates to the risks of stray current corrosion of reinforcing steel, specifically with respect to the requirement for welding reinforcing. Field measurements of steel resistivity taken during the construction of rail structures are presented to clarify the as-built condition. Taking into account the effect of stray currents on the chloride threshold for corrosion initiation, methods are recommended to achieve durability requirements for the least lifecycle cost to asset owners.
{"title":"Durability in Design of Light Rail Reinforced Concrete Structures","authors":"William Nash","doi":"10.5006/4167","DOIUrl":"https://doi.org/10.5006/4167","url":null,"abstract":"Recently, a number of light rail systems have been built or extended in North America. Typical design lives of metallic and concrete transit structures are required to exceed 75 y, with exposure to de-icing salts, freeze/thaw, and the potential for stray currents. Measures to mitigate the risks of reinforcement corrosion to rail structures have progressed over the last century, with some diversion between the preferred practices in Europe and North America. One significant difference with large cost impacts on projects is the means and methods to achieve continuity of the reinforcing steel within rail structures to control stray currents to negligible levels. Herein we review the available standards and literature as it relates to the risks of stray current corrosion of reinforcing steel, specifically with respect to the requirement for welding reinforcing. Field measurements of steel resistivity taken during the construction of rail structures are presented to clarify the as-built condition. Taking into account the effect of stray currents on the chloride threshold for corrosion initiation, methods are recommended to achieve durability requirements for the least lifecycle cost to asset owners.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42614154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anwar Sadek, Sai Prasanna Chinthala, J. Senko, C. Monty
Microbiologically influenced corrosion (MIC) impacts various industries such as oil/gas production and transmission, wastewater treatment, power generation, and chemical processing. In such settings, the combined impacts of microbiological activities and fluid flow dynamics could be primary controllers of metal corrosion. We examined the relative influences of fluid flow and the activities of the facultative Fe(III) reducing bacterium, Shewanella oneidensis MR-1, on the corrosion of carbon steel. Rotating cylinder electrode experiments were used to determine the shear stress and velocity at the surface of the metal coupon in a newly constructed flow system. The system was then used to study the impact of increasing fluid velocity and shear stress on the corrosion rate of coupons in O2-limited and O2-non-limited incubations. Confocal scanning laser microscopy was used to monitor biofilm development on the metal surface at increasing shear stress. We found that the activities of S. oneidensis inhibited corrosion, even under conditions of high shear stress and limited attachment, indicating that the respiratory consumption of O2 by planktonic S. oneidensis protects the metal surface from enhanced corrosion.
{"title":"Effects of Hydrodynamic Environment on the Interaction of Shewanella oneidensis with Low Carbon Steel and the Impacts on Corrosion","authors":"Anwar Sadek, Sai Prasanna Chinthala, J. Senko, C. Monty","doi":"10.5006/4313","DOIUrl":"https://doi.org/10.5006/4313","url":null,"abstract":"Microbiologically influenced corrosion (MIC) impacts various industries such as oil/gas production and transmission, wastewater treatment, power generation, and chemical processing. In such settings, the combined impacts of microbiological activities and fluid flow dynamics could be primary controllers of metal corrosion. We examined the relative influences of fluid flow and the activities of the facultative Fe(III) reducing bacterium, Shewanella oneidensis MR-1, on the corrosion of carbon steel. Rotating cylinder electrode experiments were used to determine the shear stress and velocity at the surface of the metal coupon in a newly constructed flow system. The system was then used to study the impact of increasing fluid velocity and shear stress on the corrosion rate of coupons in O2-limited and O2-non-limited incubations. Confocal scanning laser microscopy was used to monitor biofilm development on the metal surface at increasing shear stress. We found that the activities of S. oneidensis inhibited corrosion, even under conditions of high shear stress and limited attachment, indicating that the respiratory consumption of O2 by planktonic S. oneidensis protects the metal surface from enhanced corrosion.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47234381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. R. Rincon Troconis, S. Sharp, H. Ozyildirim, C. Demarest, Jacob Wright, Luis Perdomo-Hurtado, J. Scully
This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits superior corrosion resistance when compared to stranded cold-worked AISI 1080 (ASTM A416) steel and cold-worked modified austenitic stainless steel 201, making it a viable candidate for prestressing applications with extended service life. Laboratory and field testing were performed. The material microstructure was characterized using scanning electron microscopy/energy dispersive x-ray spectroscopy, transmission electron microscopy, and x-ray diffraction. Then, laboratory corrosion testing, including linear sweep voltammetry, pitting resistance exposure, and four-point bend stress corrosion cracking (SCC) testing, was performed under different conditions. These conditions included concrete pore solution saturated with chlorides, direct exposure to artificial seawater, various concentrations of NaCl and MgCl2, representative inland salt deposition conditions, and oxidizing conditions with high chloride concentrations. The laboratory studies were augmented with field testing (259 d), comprised of four-point bend SCC, U-bend SCC testing (ASTM G30), and atmospheric contaminant measurements. The pitting resistance results, corrosion morphology, stable pit safe range, SCC results in the lab and in the field, and hydrogen embrittlement (HE) testing by slow strain rate testing (SSRT) under cathodic polarization as a diagnostic showed that SCW2205 outperformed the other steels tested, in the case of marine atmospheric corrosive conditions. SCC in SCW2205 was characterized by a selective localized anodic dissolution of the ferrite matrix and environmentally assisted cracking in the austenite phase. However, SCC was only found in SCW2205 at or above 65°C. SSRTs confirmed susceptibility to hydrogen uptake and a hydrogen-assisted mechanism of HE given sufficient hydrogen. It is speculated that hydrogen uptake in pits or crevice sites might be a route to hydrogen absorption worth exploring further since the absence of cathodic polarization in application precludes hydrogen production and uptake.
{"title":"Corrosion-Resistant Stainless-Steel Strands for Prestressed Bridge Piles in Marine Atmospheric Environments","authors":"B. R. Rincon Troconis, S. Sharp, H. Ozyildirim, C. Demarest, Jacob Wright, Luis Perdomo-Hurtado, J. Scully","doi":"10.5006/4316","DOIUrl":"https://doi.org/10.5006/4316","url":null,"abstract":"This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits superior corrosion resistance when compared to stranded cold-worked AISI 1080 (ASTM A416) steel and cold-worked modified austenitic stainless steel 201, making it a viable candidate for prestressing applications with extended service life. Laboratory and field testing were performed. The material microstructure was characterized using scanning electron microscopy/energy dispersive x-ray spectroscopy, transmission electron microscopy, and x-ray diffraction. Then, laboratory corrosion testing, including linear sweep voltammetry, pitting resistance exposure, and four-point bend stress corrosion cracking (SCC) testing, was performed under different conditions. These conditions included concrete pore solution saturated with chlorides, direct exposure to artificial seawater, various concentrations of NaCl and MgCl2, representative inland salt deposition conditions, and oxidizing conditions with high chloride concentrations. The laboratory studies were augmented with field testing (259 d), comprised of four-point bend SCC, U-bend SCC testing (ASTM G30), and atmospheric contaminant measurements. The pitting resistance results, corrosion morphology, stable pit safe range, SCC results in the lab and in the field, and hydrogen embrittlement (HE) testing by slow strain rate testing (SSRT) under cathodic polarization as a diagnostic showed that SCW2205 outperformed the other steels tested, in the case of marine atmospheric corrosive conditions. SCC in SCW2205 was characterized by a selective localized anodic dissolution of the ferrite matrix and environmentally assisted cracking in the austenite phase. However, SCC was only found in SCW2205 at or above 65°C. SSRTs confirmed susceptibility to hydrogen uptake and a hydrogen-assisted mechanism of HE given sufficient hydrogen. It is speculated that hydrogen uptake in pits or crevice sites might be a route to hydrogen absorption worth exploring further since the absence of cathodic polarization in application precludes hydrogen production and uptake.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47989272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Santos, M. Serenario, Xi Wang, D. Young, M. Singer, Maalek Mohamed-Said, Shuai Ren, Yi He, A. Bueno
The occurrence of localized corrosion in carbon steel pipelines, even when the uniform corrosion rate remains low, is a major concern in the hydrocarbon production and transmission industry. The propagation of these pits, caused by the galvanic coupling between the inhibited surface and the active pit, can lead to serious consequences such as financial loss, environmental damage, production interruption, and even loss of life. To better understand this phenomenon, this work focuses on using the potentiostatic technique to evaluate the tendency of localized corrosion propagation. The experiments were conducted using a primarily imidazolinium-based corrosion inhibitor in produced water conditions (5 wt.% NaCl, pH 4.5, CO2-saturated) at 55°C and 80°C. The baseline results were obtained through linear polarization resistance and potentiodynamic polarization tests. The potentiostatic experiments were then conducted to artificially simulate different levels of galvanic coupling that could exist in case of active localized corrosion. The results showed that, at certain anodic potentials, increased inhibitor dosage was necessary to significantly decrease the current. However, at high current levels, further injections were insufficient, indicating that substrate dissolution may affect the adsorption of the inhibitor. This work provides insights into the role of inhibitors and important factors in stopping the propagation of localized corrosion of carbon steel. Further research, such as designing a proper zero-resistance ammeter setup, will be necessary to fully understand this complex phenomenon. The results show that the potentiostatic methodology can be a rapid and easy alternative to obtain electrochemical information and improve understanding of localized corrosion propagation.
{"title":"Inhibition of Localized Corrosion Propagation on Carbon Steel: a Potentiostatic Study","authors":"B. Santos, M. Serenario, Xi Wang, D. Young, M. Singer, Maalek Mohamed-Said, Shuai Ren, Yi He, A. Bueno","doi":"10.5006/4344","DOIUrl":"https://doi.org/10.5006/4344","url":null,"abstract":"The occurrence of localized corrosion in carbon steel pipelines, even when the uniform corrosion rate remains low, is a major concern in the hydrocarbon production and transmission industry. The propagation of these pits, caused by the galvanic coupling between the inhibited surface and the active pit, can lead to serious consequences such as financial loss, environmental damage, production interruption, and even loss of life. To better understand this phenomenon, this work focuses on using the potentiostatic technique to evaluate the tendency of localized corrosion propagation. The experiments were conducted using a primarily imidazolinium-based corrosion inhibitor in produced water conditions (5 wt.% NaCl, pH 4.5, CO2-saturated) at 55°C and 80°C. The baseline results were obtained through linear polarization resistance and potentiodynamic polarization tests. The potentiostatic experiments were then conducted to artificially simulate different levels of galvanic coupling that could exist in case of active localized corrosion. The results showed that, at certain anodic potentials, increased inhibitor dosage was necessary to significantly decrease the current. However, at high current levels, further injections were insufficient, indicating that substrate dissolution may affect the adsorption of the inhibitor. This work provides insights into the role of inhibitors and important factors in stopping the propagation of localized corrosion of carbon steel. Further research, such as designing a proper zero-resistance ammeter setup, will be necessary to fully understand this complex phenomenon. The results show that the potentiostatic methodology can be a rapid and easy alternative to obtain electrochemical information and improve understanding of localized corrosion propagation.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44968970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Santamaría, Ke Wang, M. Salasi, M. Salem, P. Lours, M. Iannuzzi, Z. Quadir
Austenitic stainless steel UNS S31603 (SS316L) is widely used in the resources industry due to its excellent corrosion resistance, ductility, and weldability. Recently, laser-based powder bed fusion (LPBF) manufacturing has gained popularity for creating SS316L components with complex geometries and superior mechanical properties. However, the rapid melting and solidification of the deposited layers during the thermal cycle of LPBF produce residual stresses. Components manufactured through LPBF are frequently used under applied stress in corrosive environments. Thus, it is crucial to understand their susceptibility to stress corrosion cracking (SCC) and the impact of residual stresses. This study investigated the combined effects of applied stress and temperature on the SCC behavior of LPBF SS316L using custom-made C-ring test specimens. Cold-drawn wrought SS316L was included for comparison. Stress relief heat treatment, microhardness testing, partial immersion testing, and microanalysis techniques, such as light optical microscopy (LOM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD), were used to quantify the SCC behavior. The outcomes of this study showed that stressed and unstressed LPBF SS316L specimens were highly susceptible to cracking around their printed holes. The SCC susceptibility was attributed to the residual stresses introduced by the printed supports, as both polished and as-printed holes showed similar cracking behavior. This work provides valuable insights and lays a foundation for further research into the impact of using C-ring samples to investigate SCC susceptibility and sheds light on the SCC susceptibility of as-printed components of complex geometry printed with supports due to the influence of residual stresses.
{"title":"Stress corrosion cracking behavior of austenitic stainless steel 316L produced using laser-based powder bed fusion","authors":"R. Santamaría, Ke Wang, M. Salasi, M. Salem, P. Lours, M. Iannuzzi, Z. Quadir","doi":"10.5006/4311","DOIUrl":"https://doi.org/10.5006/4311","url":null,"abstract":"Austenitic stainless steel UNS S31603 (SS316L) is widely used in the resources industry due to its excellent corrosion resistance, ductility, and weldability. Recently, laser-based powder bed fusion (LPBF) manufacturing has gained popularity for creating SS316L components with complex geometries and superior mechanical properties. However, the rapid melting and solidification of the deposited layers during the thermal cycle of LPBF produce residual stresses. Components manufactured through LPBF are frequently used under applied stress in corrosive environments. Thus, it is crucial to understand their susceptibility to stress corrosion cracking (SCC) and the impact of residual stresses. This study investigated the combined effects of applied stress and temperature on the SCC behavior of LPBF SS316L using custom-made C-ring test specimens. Cold-drawn wrought SS316L was included for comparison. Stress relief heat treatment, microhardness testing, partial immersion testing, and microanalysis techniques, such as light optical microscopy (LOM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD), were used to quantify the SCC behavior. The outcomes of this study showed that stressed and unstressed LPBF SS316L specimens were highly susceptible to cracking around their printed holes. The SCC susceptibility was attributed to the residual stresses introduced by the printed supports, as both polished and as-printed holes showed similar cracking behavior. This work provides valuable insights and lays a foundation for further research into the impact of using C-ring samples to investigate SCC susceptibility and sheds light on the SCC susceptibility of as-printed components of complex geometry printed with supports due to the influence of residual stresses.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47541652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The CO2 stream in a CCUS application generally includes impurities which could cause internal corrosion of CO2 pipelines. The general and localized corrosion behavior with a variety of O2 concentrations for X65 mild steel both in water-saturated CO2 and CO2-saturated water environments was evaluated using an autoclave. Corrosion tests were performed at 8 MPa and 25 °C, 8 MPa and 35 °C, 4 MPa and 35 °C to simulate the liquid, supercritical and gaseous CO2 transportation. Results indicate that notably higher general corrosion rates were recorded at each O2 concentration in the CO2-saturated water phase than those in the water-saturated CO2 environment. The general corrosion rates did not show gradual rise at 0-2000 ppm of O2; instead, a maximum was measured at 1000 ppm of O2 at 8 MPa and 25 °C, and 50 ppm O2 at 8 MPa and 35 °C in the water-saturated CO2 environment and 50 ppm at 8 MPa and 25 °C, and 100 ppm at 8 MPa and 35 °C in the CO2-saturated water environment. The general corrosion rate at 4 MPa and 35 °C followed a different changing trend with O2 content from that in 8 MPa, 25 °C and 35 °C both in the water-saturated CO2 and the CO2-saturated water environments. Localized corrosion or average corrosion rate of beyond 0.1 mm/y was identified in each test in the CO2-saturated water environment. When O2 was introduced, a more porous corrosion product scale was detected on the coupon surfaces. A final series of corrosion tests with 100 ppm and 2000 ppm O2 and 60% and 80% relative humidity (RH) in CO2 environment did not show any sign of localized corrosion attack, and the average corrosion rates were below 0.1 mm/y at 8 MPa, 25 °C and 35 °C, 4 MPa and 35 °C.
{"title":"Impact of O2 Content on the Corrosion Behavior of X65 Mild Steel in Gaseous, Liquid and Supercritical CO2 Environments","authors":"Xiu Jiang","doi":"10.5006/4196","DOIUrl":"https://doi.org/10.5006/4196","url":null,"abstract":"The CO2 stream in a CCUS application generally includes impurities which could cause internal corrosion of CO2 pipelines. The general and localized corrosion behavior with a variety of O2 concentrations for X65 mild steel both in water-saturated CO2 and CO2-saturated water environments was evaluated using an autoclave. Corrosion tests were performed at 8 MPa and 25 °C, 8 MPa and 35 °C, 4 MPa and 35 °C to simulate the liquid, supercritical and gaseous CO2 transportation. Results indicate that notably higher general corrosion rates were recorded at each O2 concentration in the CO2-saturated water phase than those in the water-saturated CO2 environment. The general corrosion rates did not show gradual rise at 0-2000 ppm of O2; instead, a maximum was measured at 1000 ppm of O2 at 8 MPa and 25 °C, and 50 ppm O2 at 8 MPa and 35 °C in the water-saturated CO2 environment and 50 ppm at 8 MPa and 25 °C, and 100 ppm at 8 MPa and 35 °C in the CO2-saturated water environment. The general corrosion rate at 4 MPa and 35 °C followed a different changing trend with O2 content from that in 8 MPa, 25 °C and 35 °C both in the water-saturated CO2 and the CO2-saturated water environments. Localized corrosion or average corrosion rate of beyond 0.1 mm/y was identified in each test in the CO2-saturated water environment. When O2 was introduced, a more porous corrosion product scale was detected on the coupon surfaces. A final series of corrosion tests with 100 ppm and 2000 ppm O2 and 60% and 80% relative humidity (RH) in CO2 environment did not show any sign of localized corrosion attack, and the average corrosion rates were below 0.1 mm/y at 8 MPa, 25 °C and 35 °C, 4 MPa and 35 °C.","PeriodicalId":10717,"journal":{"name":"Corrosion","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43614496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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