TY  - JOUR
AU  - Musrati, Walid
AU  - Međo, Bojan
AU  - Cvijović-Alagić, Ivana
AU  - Gubeljak, Nenad
AU  - Štefane, Primož
AU  - Radosavljević, Zoran
AU  - Rakin, Marko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6607
AB  - Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed.
AB  - Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters
T1  - Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1
EP  - 165
IS  - 2
SP  - 155
VL  - 77
DO  - 10.2298/HEMIND230222016M
ER  - 

@article{
author = "Musrati, Walid and Međo, Bojan and Cvijović-Alagić, Ivana and Gubeljak, Nenad and Štefane, Primož and Radosavljević, Zoran and Rakin, Marko",
year = "2023",
abstract = "Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed., Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters, Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1",
pages = "165-155",
number = "2",
volume = "77",
doi = "10.2298/HEMIND230222016M"
}

Musrati, W., Međo, B., Cvijović-Alagić, I., Gubeljak, N., Štefane, P., Radosavljević, Z.,& Rakin, M.. (2023). Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 77(2), 155-165.
https://doi.org/10.2298/HEMIND230222016M

Musrati W, Međo B, Cvijović-Alagić I, Gubeljak N, Štefane P, Radosavljević Z, Rakin M. Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija. 2023;77(2):155-165.
doi:10.2298/HEMIND230222016M .

Musrati, Walid, Međo, Bojan, Cvijović-Alagić, Ivana, Gubeljak, Nenad, Štefane, Primož, Radosavljević, Zoran, Rakin, Marko, "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters" in Hemijska industrija, 77, no. 2 (2023):155-165,
https://doi.org/10.2298/HEMIND230222016M . .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Mladenović, Mladen
AU  - Savić, Zoran
AU  - Grabulov, Vencislav
AU  - Radosavljević, Zoran
AU  - Rakin, Marko
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4567
AB  - Topic of this work is the integrity assessment of the pipeline section from hydropower plant Pirot. Crack-like defect size, maximum depth, is determined based on non-destructive evaluation - the largest crack depth is taken as the initial value for load carrying capacity estimation. Also, the crack dimensions (both length and depth) are varied. Limit pressure values are determined from 3D and 2D models of pipes with axial cracks on external surface. The influence of tensile loading on the load carrying capacity of the pipes with circumferential cracks is also examined. Integrity of pipes with both types of defects (axial and circumferential) is assessed through application of FAD diagrams.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Structural Integrity and Life
T1  - Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'
EP  - 86
IS  - 1
SP  - 82
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_4567
ER  - 

@article{
author = "Međo, Bojan and Arsić, Miodrag and Mladenović, Mladen and Savić, Zoran and Grabulov, Vencislav and Radosavljević, Zoran and Rakin, Marko",
year = "2020",
abstract = "Topic of this work is the integrity assessment of the pipeline section from hydropower plant Pirot. Crack-like defect size, maximum depth, is determined based on non-destructive evaluation - the largest crack depth is taken as the initial value for load carrying capacity estimation. Also, the crack dimensions (both length and depth) are varied. Limit pressure values are determined from 3D and 2D models of pipes with axial cracks on external surface. The influence of tensile loading on the load carrying capacity of the pipes with circumferential cracks is also examined. Integrity of pipes with both types of defects (axial and circumferential) is assessed through application of FAD diagrams.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Structural Integrity and Life",
title = "Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'",
pages = "86-82",
number = "1",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_4567"
}

Međo, B., Arsić, M., Mladenović, M., Savić, Z., Grabulov, V., Radosavljević, Z.,& Rakin, M.. (2020). Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'. in Structural Integrity and Life
Society for Structural Integrity and Life, Institute for Material Testing., 20(1), 82-86.
https://hdl.handle.net/21.15107/rcub_technorep_4567

Međo B, Arsić M, Mladenović M, Savić Z, Grabulov V, Radosavljević Z, Rakin M. Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'. in Structural Integrity and Life. 2020;20(1):82-86.
https://hdl.handle.net/21.15107/rcub_technorep_4567 .

Međo, Bojan, Arsić, Miodrag, Mladenović, Mladen, Savić, Zoran, Grabulov, Vencislav, Radosavljević, Zoran, Rakin, Marko, "Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'" in Structural Integrity and Life, 20, no. 1 (2020):82-86,
https://hdl.handle.net/21.15107/rcub_technorep_4567 .

TY  - JOUR
AU  - Bajić, Darko
AU  - Mrdak, Mihailo
AU  - Bajić, Nikola
AU  - Veljić, Darko
AU  - Rakin, Marko
AU  - Radosavljević, Zoran
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4534
AB  - In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.
PB  - MDPI, Basel
T2  - Materials
T1  - Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding
IS  - 9
VL  - 13
DO  - 10.3390/ma13092152
ER  - 

@article{
author = "Bajić, Darko and Mrdak, Mihailo and Bajić, Nikola and Veljić, Darko and Rakin, Marko and Radosavljević, Zoran",
year = "2020",
abstract = "In this paper, we will present our investigation of the quality of J55 microalloyed steel welds that were formed by a basic flux-cored wire electrodes that were of appropriate quality and alloyed with Ni and Mo. Based on the comparison and analysis of the obtained results related to the testing of the chemical composition, mechanical properties, toughness at test temperatures, and the microstructure of welding joints formed by a classic and specially coated rutile flux-cored electrode, we assessed the justification to switch from solid wire electrodes to flux-cored alloyed wire electrodes of appropriate quality. The research aim for the application of flux-cored wire electrodes instead of solid wire electrodes is based on the advantages pertaining to a flux-cored wire: molten metal from electrode wire is transferred in the form of fine droplets, easy welding and maximum productivity within all spatial positions related to welding, improved properties of welding joints, and increased productivity when compared to a classic solid wire. Our research encompasses the development of the experimental production at the Research and Development Center IHIS Belgrade (Development Institute for Chemical Power Sources), Serbia, of the new type of a coated electrode with improved welding properties when compared to a classic electrode intended for microalloyed steel welding.",
publisher = "MDPI, Basel",
journal = "Materials",
title = "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding",
number = "9",
volume = "13",
doi = "10.3390/ma13092152"
}

Bajić, D., Mrdak, M., Bajić, N., Veljić, D., Rakin, M.,& Radosavljević, Z.. (2020). Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials
MDPI, Basel., 13(9).
https://doi.org/10.3390/ma13092152

Bajić D, Mrdak M, Bajić N, Veljić D, Rakin M, Radosavljević Z. Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding. in Materials. 2020;13(9).
doi:10.3390/ma13092152 .

Bajić, Darko, Mrdak, Mihailo, Bajić, Nikola, Veljić, Darko, Rakin, Marko, Radosavljević, Zoran, "Development of Coated Electrodes with Solid Wire and Flux-Cored Alloyed Wire for Microalloyed Steel Welding" in Materials, 13, no. 9 (2020),
https://doi.org/10.3390/ma13092152 . .

TY  - JOUR
AU  - Musraty, Walid
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Stefane, Primoz
AU  - Radosavljević, Zoran
AU  - Burzić, Zijah
AU  - Rakin, Marko
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4027
AB  - Pipelines are commonly used in process industry for transport of fluids, as well as granular solids, due to their numerous advantages in comparison to other transportation means. Pipe integrity is essential for a reliable work of the entire plant, as well as for safety assurance. Also, serious ecological consequences may follow the pipeline failure in some cases, i.e. due to the leak of toxic, flammable or otherwise dangerous fluids in a chemical or some other plant. Therefore, it is very important to examine the fracture behaviour of pipelines, which is done here by testing the recently proposed ring-shaped specimens exposed to bending. The specimens were fabricated from a seam pipe for pressure applications (allowed for usage on temperatures up to 300 degrees C). Initial defects, very narrow notches, were machined either in the base metal and weld metal (seam) or in the base metal only. Regardless of the defect position, ductile fracture mechanism is observed in all specimens. The results show that the ring-shaped specimen can be successfully used for fracture characterisation of pipeline material, especially for thin-walled pipes which are not suitable for production of standard fracture mechanics specimens due to the insufficient wall thickness.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Seam pipes for process industry - Fracture analysis by using ring-shaped specimens
EP  - 46
IS  - 1
SP  - 39
VL  - 72
DO  - 10.2298/HEMIND170530014M
ER  - 

@article{
author = "Musraty, Walid and Međo, Bojan and Gubeljak, Nenad and Stefane, Primoz and Radosavljević, Zoran and Burzić, Zijah and Rakin, Marko",
year = "2018",
abstract = "Pipelines are commonly used in process industry for transport of fluids, as well as granular solids, due to their numerous advantages in comparison to other transportation means. Pipe integrity is essential for a reliable work of the entire plant, as well as for safety assurance. Also, serious ecological consequences may follow the pipeline failure in some cases, i.e. due to the leak of toxic, flammable or otherwise dangerous fluids in a chemical or some other plant. Therefore, it is very important to examine the fracture behaviour of pipelines, which is done here by testing the recently proposed ring-shaped specimens exposed to bending. The specimens were fabricated from a seam pipe for pressure applications (allowed for usage on temperatures up to 300 degrees C). Initial defects, very narrow notches, were machined either in the base metal and weld metal (seam) or in the base metal only. Regardless of the defect position, ductile fracture mechanism is observed in all specimens. The results show that the ring-shaped specimen can be successfully used for fracture characterisation of pipeline material, especially for thin-walled pipes which are not suitable for production of standard fracture mechanics specimens due to the insufficient wall thickness.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Seam pipes for process industry - Fracture analysis by using ring-shaped specimens",
pages = "46-39",
number = "1",
volume = "72",
doi = "10.2298/HEMIND170530014M"
}

Musraty, W., Međo, B., Gubeljak, N., Stefane, P., Radosavljević, Z., Burzić, Z.,& Rakin, M.. (2018). Seam pipes for process industry - Fracture analysis by using ring-shaped specimens. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 72(1), 39-46.
https://doi.org/10.2298/HEMIND170530014M

Musraty W, Međo B, Gubeljak N, Stefane P, Radosavljević Z, Burzić Z, Rakin M. Seam pipes for process industry - Fracture analysis by using ring-shaped specimens. in Hemijska industrija. 2018;72(1):39-46.
doi:10.2298/HEMIND170530014M .

Musraty, Walid, Međo, Bojan, Gubeljak, Nenad, Stefane, Primoz, Radosavljević, Zoran, Burzić, Zijah, Rakin, Marko, "Seam pipes for process industry - Fracture analysis by using ring-shaped specimens" in Hemijska industrija, 72, no. 1 (2018):39-46,
https://doi.org/10.2298/HEMIND170530014M . .

TY  - JOUR
AU  - Veljić, Darko
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Radosavljević, Zoran M.
AU  - Bajić, Nikola
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3439
AB  - Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding of high-strength aluminum alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A 3-D finite element model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly dfferent for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.
PB  - Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd
T2  - Thermal Science
T1  - Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351
EP  - 254
IS  - 1
SP  - 247
VL  - 20
DO  - 10.2298/TSCI150313059V
ER  - 

@article{
author = "Veljić, Darko and Međo, Bojan and Rakin, Marko and Radosavljević, Zoran M. and Bajić, Nikola",
year = "2016",
abstract = "Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding of high-strength aluminum alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A 3-D finite element model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly dfferent for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.",
publisher = "Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd",
journal = "Thermal Science",
title = "Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351",
pages = "254-247",
number = "1",
volume = "20",
doi = "10.2298/TSCI150313059V"
}

Veljić, D., Međo, B., Rakin, M., Radosavljević, Z. M.,& Bajić, N.. (2016). Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351. in Thermal Science
Univerzitet u Beogradu - Institut za nuklearne nauke Vinča, Beograd., 20(1), 247-254.
https://doi.org/10.2298/TSCI150313059V

Veljić D, Međo B, Rakin M, Radosavljević ZM, Bajić N. Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351. in Thermal Science. 2016;20(1):247-254.
doi:10.2298/TSCI150313059V .

Veljić, Darko, Međo, Bojan, Rakin, Marko, Radosavljević, Zoran M., Bajić, Nikola, "Analysis of the tool plunge in friction stir welding comparison of aluminum alloys 2024 t3 and 2024 t351" in Thermal Science, 20, no. 1 (2016):247-254,
https://doi.org/10.2298/TSCI150313059V . .