Grgur, Branimir N.

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orcid::0000-0003-4684-9053
  • Grgur, Branimir N. (3)
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Author's Bibliography

Corrosion of an austenite and ferrite stainless steel weld

Rajaković-Ognjanović, Vladana; Grgur, Branimir N.

(Srpsko hemijsko društvo, Beograd, 2011)

TY  - JOUR
AU  - Rajaković-Ognjanović, Vladana
AU  - Grgur, Branimir N.
PY  - 2011
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/418
AB  - Dissimilar metal connections are prone to frequent failures. These failures are attributed to the difference in the mechanical properties across the weld, the coefficients of thermal expansion of the two types of steels and the resulting creep at the interface. For the weld analyzed in this research, it was shown that corrosion measurements can be used for a proper evaluation of the quality of weld material and for the prediction of whether or not the material, after the applied welding process, can be in service without failures. It was found that the corrosion of the weld analyzed in this research resulted from the simultaneous activity of different types of corrosion. In this study, electrochemical techniques including polarization and metallographic analysis were used to analyze the corrosion of a weld material of ferrite and austenitic stainless steels. Based on surface, chemical and electrochemical analyses, it was concluded that corrosion occurrence was the result of the simultaneous activity of contact corrosion (ferrite and austenitic material conjuction), stress corrosion (originating from deformed ferrite structure) and inter-granular corrosion (due to chromium carbide precipitation). The value of corrosion potential of -0.53 V shows that this weld, after the thermal treatment, is not able to repassivate a protective oxide film.
AB  - Spojevi različitih metala dobijenih zavarivanjem skloni su propadanju uglavnom usled pojave različitih vidova korozije. Fizičko-hemijska, mehanička svojstva, kao i koeficijenti toplotnog širenja različitih čelika najčešći su uzrok pucanja materijala na zavarenim spojevima. Istraživanja u ovom radu su pokazala da se ispitivanje korozije materijala može koristiti za procenu kvaliteta spojeva zavarenih materijala. Različite analitičke, metalografske i elektrohemijske tehnike i metode analize su primenjene za ispitivanje korozije zavarenog spoja nerđajućih čelika feritne i austenitne strukture. Ustanovljeno je da do pojave korozije na zavarenom spoju ispitivanih materijala prevashodno dolazi usled: kontaktne korozije, naponske korozije (koja potiče od deformisane strukture ferita) i međukristalne korozije (posledica izluživanja hrom-karbida) u feritnom delu zavarenog spoja.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Corrosion of an austenite and ferrite stainless steel weld
T1  - Korozija zavarenog spoja austenitnog i feritnog nerđajućeg čelika
EP  - 1035
IS  - 7
SP  - 1027
VL  - 76
DO  - 10.2298/JSC100726090R
ER  - 
@article{
author = "Rajaković-Ognjanović, Vladana and Grgur, Branimir N.",
year = "2011",
abstract = "Dissimilar metal connections are prone to frequent failures. These failures are attributed to the difference in the mechanical properties across the weld, the coefficients of thermal expansion of the two types of steels and the resulting creep at the interface. For the weld analyzed in this research, it was shown that corrosion measurements can be used for a proper evaluation of the quality of weld material and for the prediction of whether or not the material, after the applied welding process, can be in service without failures. It was found that the corrosion of the weld analyzed in this research resulted from the simultaneous activity of different types of corrosion. In this study, electrochemical techniques including polarization and metallographic analysis were used to analyze the corrosion of a weld material of ferrite and austenitic stainless steels. Based on surface, chemical and electrochemical analyses, it was concluded that corrosion occurrence was the result of the simultaneous activity of contact corrosion (ferrite and austenitic material conjuction), stress corrosion (originating from deformed ferrite structure) and inter-granular corrosion (due to chromium carbide precipitation). The value of corrosion potential of -0.53 V shows that this weld, after the thermal treatment, is not able to repassivate a protective oxide film., Spojevi različitih metala dobijenih zavarivanjem skloni su propadanju uglavnom usled pojave različitih vidova korozije. Fizičko-hemijska, mehanička svojstva, kao i koeficijenti toplotnog širenja različitih čelika najčešći su uzrok pucanja materijala na zavarenim spojevima. Istraživanja u ovom radu su pokazala da se ispitivanje korozije materijala može koristiti za procenu kvaliteta spojeva zavarenih materijala. Različite analitičke, metalografske i elektrohemijske tehnike i metode analize su primenjene za ispitivanje korozije zavarenog spoja nerđajućih čelika feritne i austenitne strukture. Ustanovljeno je da do pojave korozije na zavarenom spoju ispitivanih materijala prevashodno dolazi usled: kontaktne korozije, naponske korozije (koja potiče od deformisane strukture ferita) i međukristalne korozije (posledica izluživanja hrom-karbida) u feritnom delu zavarenog spoja.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Corrosion of an austenite and ferrite stainless steel weld, Korozija zavarenog spoja austenitnog i feritnog nerđajućeg čelika",
pages = "1035-1027",
number = "7",
volume = "76",
doi = "10.2298/JSC100726090R"
}
Rajaković-Ognjanović, V.,& Grgur, B. N.. (2011). Corrosion of an austenite and ferrite stainless steel weld. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 76(7), 1027-1035.
https://doi.org/10.2298/JSC100726090R
Rajaković-Ognjanović V, Grgur BN. Corrosion of an austenite and ferrite stainless steel weld. in Journal of the Serbian Chemical Society. 2011;76(7):1027-1035.
doi:10.2298/JSC100726090R .
Rajaković-Ognjanović, Vladana, Grgur, Branimir N., "Corrosion of an austenite and ferrite stainless steel weld" in Journal of the Serbian Chemical Society, 76, no. 7 (2011):1027-1035,
https://doi.org/10.2298/JSC100726090R . .
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Improvement of chemical control in the water-steam cycle of thermal power plants

Rajaković-Ognjanović, Vladana; Živojinović, Dragana Z.; Grgur, Branimir N.; Rajaković, Ljubinka V.

(2011)

TY  - JOUR
AU  - Rajaković-Ognjanović, Vladana
AU  - Živojinović, Dragana Z.
AU  - Grgur, Branimir N.
AU  - Rajaković, Ljubinka V.
PY  - 2011
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/410
AB  - A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and by the most convenient analytical tools. The necessity for the stricter chemical control is demonstrated through a concrete example of the TPP Nikola Tesla, Serbia. After a thorough analysis of the chemical control system of the WSC, diagnostic and control parameters were chosen for continuous systematic measurements. Sodium and chloride ions were recognized as the ions which indicate the corrosion potential of the water and give insight into the proper production and maintenance of water within the WSC. Chemical transformations of crucial corrosion elements, iron and silica, were considered and related to their quantitative values.
T2  - Applied Thermal Engineering
T1  - Improvement of chemical control in the water-steam cycle of thermal power plants
EP  - 128
IS  - 1
SP  - 119
VL  - 31
DO  - 10.1016/j.applthermaleng.2010.08.028
ER  - 
@article{
author = "Rajaković-Ognjanović, Vladana and Živojinović, Dragana Z. and Grgur, Branimir N. and Rajaković, Ljubinka V.",
year = "2011",
abstract = "A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and by the most convenient analytical tools. The necessity for the stricter chemical control is demonstrated through a concrete example of the TPP Nikola Tesla, Serbia. After a thorough analysis of the chemical control system of the WSC, diagnostic and control parameters were chosen for continuous systematic measurements. Sodium and chloride ions were recognized as the ions which indicate the corrosion potential of the water and give insight into the proper production and maintenance of water within the WSC. Chemical transformations of crucial corrosion elements, iron and silica, were considered and related to their quantitative values.",
journal = "Applied Thermal Engineering",
title = "Improvement of chemical control in the water-steam cycle of thermal power plants",
pages = "128-119",
number = "1",
volume = "31",
doi = "10.1016/j.applthermaleng.2010.08.028"
}
Rajaković-Ognjanović, V., Živojinović, D. Z., Grgur, B. N.,& Rajaković, L. V.. (2011). Improvement of chemical control in the water-steam cycle of thermal power plants. in Applied Thermal Engineering, 31(1), 119-128.
https://doi.org/10.1016/j.applthermaleng.2010.08.028
Rajaković-Ognjanović V, Živojinović DZ, Grgur BN, Rajaković LV. Improvement of chemical control in the water-steam cycle of thermal power plants. in Applied Thermal Engineering. 2011;31(1):119-128.
doi:10.1016/j.applthermaleng.2010.08.028 .
Rajaković-Ognjanović, Vladana, Živojinović, Dragana Z., Grgur, Branimir N., Rajaković, Ljubinka V., "Improvement of chemical control in the water-steam cycle of thermal power plants" in Applied Thermal Engineering, 31, no. 1 (2011):119-128,
https://doi.org/10.1016/j.applthermaleng.2010.08.028 . .
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Corroded scale analysis from water distribution pipes

Rajaković-Ognjanović, Vladana; Grgur, Branimir N.

(Savez hemijskih inženjera, Beograd, 2011)

TY  - JOUR
AU  - Rajaković-Ognjanović, Vladana
AU  - Grgur, Branimir N.
PY  - 2011
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/420
AB  - The subject of this study were the steel pipes that are part of Belgrade's drinking water supply network. In order to investigate the mutual effects of corrosion and water quality, the corrosion scales on the pipes were analyzed. The idea was to improve control of corrosion processes and prevent impact of corrosion on water quality degradation. The instrumental methods for corrosion scales characterization used were: scanning electron microscopy (SEM), for the investigation of corrosion scales of the analyzed samples surfaces, X-ray diffraction (XRD), for the analysis of the presence of solid forms inside scales, scanning electron microscopy (SEM), for the microstructural analysis of the corroded scales, and BET adsorption isotherm for the surface area determination. Depending on the composition of water next to the pipe surface, corrosion of iron results in the formation of different compounds and solid phases. The composition and structure of the iron scales in the drinking water distribution pipes depends on the type of the metal and the composition of the aqueous phase. Their formation is probably governed by several factors that include water quality parameters such as pH, alkalinity, buffer intensity, natural organic matter (NOM) concentration, and dissolved oxygen (DO) concentration. Factors such as water flow patterns, seasonal fluctuations in temperature, and microbiological activity as well as water treatment practices such as application of corrosion inhibitors can also influence corrosion scale formation and growth. Therefore, the corrosion scales found in iron and steel pipes are expected to have unique features for each site. Compounds that are found in iron corrosion scales often include goethite, lepidocrocite, magnetite, hematite, ferrous oxide, siderite, ferrous hydroxide, ferric hydroxide, ferrihydrite, calcium carbonate and green rusts. Iron scales have characteristic features that include: corroded floor, porous core that contains both fluid and solid, relatively dense shell-like layer that covers the porous core and provides structural integrity to the scale, and surface layer that is present on top of the shell-like layer at scale-water interface and loosely attached to the shell-like layer. Iron(II) deposits are formed under reducing conditions. The presence of relatively soluble Fe(II) deposits such as siderite and ferrous hydroxide was confirmed by XRD and SEM analysis. In the presence of carbonic species, siderite (FeCO3) is prevailing ferrous deposit. Further studies are needed for obtaining greater knowledge on the mechanism of iron release from corroded pipes and the influence of water quality to iron corrosion.
AB  - Tema ovog istraživanja bile su čelične cevi koje su deo beogradske vodovodske mreže. Da bi se ispitalo međusobno dejstvo korozije i kvaliteta vode analizirane su korozione ljuske na cevima. Cilj istraživanja bio je poboljšanje kontrole procesa korozije da bi se smanjio uticaj korozije na degradaciju kvaliteta vode. Utvrđeno je da u zavisnosti od sastava vode, korozione ljuske predstavljaju različita jedinjenja gvožđa. Prisustvo teško rastvornih jedinjenja gvožđa(II) i gvožđa(III) utvrđeno je savremenim instrumentalnim metodama i tehnikama.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Corroded scale analysis from water distribution pipes
T1  - Analiza korozionih ljuski u vodovodskim cevima
EP  - 515
IS  - 5
SP  - 507
VL  - 65
DO  - 10.2298/HEMIND110523049R
ER  - 
@article{
author = "Rajaković-Ognjanović, Vladana and Grgur, Branimir N.",
year = "2011",
abstract = "The subject of this study were the steel pipes that are part of Belgrade's drinking water supply network. In order to investigate the mutual effects of corrosion and water quality, the corrosion scales on the pipes were analyzed. The idea was to improve control of corrosion processes and prevent impact of corrosion on water quality degradation. The instrumental methods for corrosion scales characterization used were: scanning electron microscopy (SEM), for the investigation of corrosion scales of the analyzed samples surfaces, X-ray diffraction (XRD), for the analysis of the presence of solid forms inside scales, scanning electron microscopy (SEM), for the microstructural analysis of the corroded scales, and BET adsorption isotherm for the surface area determination. Depending on the composition of water next to the pipe surface, corrosion of iron results in the formation of different compounds and solid phases. The composition and structure of the iron scales in the drinking water distribution pipes depends on the type of the metal and the composition of the aqueous phase. Their formation is probably governed by several factors that include water quality parameters such as pH, alkalinity, buffer intensity, natural organic matter (NOM) concentration, and dissolved oxygen (DO) concentration. Factors such as water flow patterns, seasonal fluctuations in temperature, and microbiological activity as well as water treatment practices such as application of corrosion inhibitors can also influence corrosion scale formation and growth. Therefore, the corrosion scales found in iron and steel pipes are expected to have unique features for each site. Compounds that are found in iron corrosion scales often include goethite, lepidocrocite, magnetite, hematite, ferrous oxide, siderite, ferrous hydroxide, ferric hydroxide, ferrihydrite, calcium carbonate and green rusts. Iron scales have characteristic features that include: corroded floor, porous core that contains both fluid and solid, relatively dense shell-like layer that covers the porous core and provides structural integrity to the scale, and surface layer that is present on top of the shell-like layer at scale-water interface and loosely attached to the shell-like layer. Iron(II) deposits are formed under reducing conditions. The presence of relatively soluble Fe(II) deposits such as siderite and ferrous hydroxide was confirmed by XRD and SEM analysis. In the presence of carbonic species, siderite (FeCO3) is prevailing ferrous deposit. Further studies are needed for obtaining greater knowledge on the mechanism of iron release from corroded pipes and the influence of water quality to iron corrosion., Tema ovog istraživanja bile su čelične cevi koje su deo beogradske vodovodske mreže. Da bi se ispitalo međusobno dejstvo korozije i kvaliteta vode analizirane su korozione ljuske na cevima. Cilj istraživanja bio je poboljšanje kontrole procesa korozije da bi se smanjio uticaj korozije na degradaciju kvaliteta vode. Utvrđeno je da u zavisnosti od sastava vode, korozione ljuske predstavljaju različita jedinjenja gvožđa. Prisustvo teško rastvornih jedinjenja gvožđa(II) i gvožđa(III) utvrđeno je savremenim instrumentalnim metodama i tehnikama.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Corroded scale analysis from water distribution pipes, Analiza korozionih ljuski u vodovodskim cevima",
pages = "515-507",
number = "5",
volume = "65",
doi = "10.2298/HEMIND110523049R"
}
Rajaković-Ognjanović, V.,& Grgur, B. N.. (2011). Corroded scale analysis from water distribution pipes. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 65(5), 507-515.
https://doi.org/10.2298/HEMIND110523049R
Rajaković-Ognjanović V, Grgur BN. Corroded scale analysis from water distribution pipes. in Hemijska industrija. 2011;65(5):507-515.
doi:10.2298/HEMIND110523049R .
Rajaković-Ognjanović, Vladana, Grgur, Branimir N., "Corroded scale analysis from water distribution pipes" in Hemijska industrija, 65, no. 5 (2011):507-515,
https://doi.org/10.2298/HEMIND110523049R . .
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