TY  - JOUR
AU  - Dikić, Stefan
AU  - Glišić, Dragomir
AU  - Fadel, Abdunaser
AU  - Jovanović, Gvozden
AU  - Radović, Nenad
PY  - 2022
UR  - https://ritnms.itnms.ac.rs/handle/123456789/625
AB  - The aim of this work was to establish a temperature of finish rolling stage of Nb/Ti microalloyed steel containing 0.06 wt.% C, 0.77 wt.% Mn, 0.039 wt.% Nb and 0.015 wt.% Ti, using physical simulation. Samples were subjected to laboratory simulation at a twist plastometer at high temperatures, i.e. between 825 and 950 degrees C. Five pass deformation and interpass times were selected in accordance with a processing parameters at five stand finishing hot strip mill. Restoration (recovery and/or recrystallization) behavior was evaluated by calculation of Fraction Softening (FS) and Area Softening Parameter (ASP) values. At 950 degrees C all individual pass stress-strain curves, FS and ASP show full recrystallization in all interpass intervals. On the other hand, with a decrease in temperature to the interval of 875-825 degrees C, the extent of restoration is decreasing, leading to recovery as a sole softening mechanism at 825 degrees C, which was confirmed by the stress-strain curve shape, and values of FS and ASP. It is assumed that, due to high supersaturation, strain-induced precipitation promoted pinning of grain and subgrain boundaries and suppressed recrystallization. Therefore, the critical temperature for finish rolling was estimated to be 825 degrees C.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Physical simulation of finish rolling of microalloyed steels in isothermal conditions
EP  - 236
IS  - 4
SP  - 227
VL  - 76
DO  - 10.2298/HEMIND220816018D
UR  - conv_962
ER  - 

@article{
author = "Dikić, Stefan and Glišić, Dragomir and Fadel, Abdunaser and Jovanović, Gvozden and Radović, Nenad",
year = "2022",
abstract = "The aim of this work was to establish a temperature of finish rolling stage of Nb/Ti microalloyed steel containing 0.06 wt.% C, 0.77 wt.% Mn, 0.039 wt.% Nb and 0.015 wt.% Ti, using physical simulation. Samples were subjected to laboratory simulation at a twist plastometer at high temperatures, i.e. between 825 and 950 degrees C. Five pass deformation and interpass times were selected in accordance with a processing parameters at five stand finishing hot strip mill. Restoration (recovery and/or recrystallization) behavior was evaluated by calculation of Fraction Softening (FS) and Area Softening Parameter (ASP) values. At 950 degrees C all individual pass stress-strain curves, FS and ASP show full recrystallization in all interpass intervals. On the other hand, with a decrease in temperature to the interval of 875-825 degrees C, the extent of restoration is decreasing, leading to recovery as a sole softening mechanism at 825 degrees C, which was confirmed by the stress-strain curve shape, and values of FS and ASP. It is assumed that, due to high supersaturation, strain-induced precipitation promoted pinning of grain and subgrain boundaries and suppressed recrystallization. Therefore, the critical temperature for finish rolling was estimated to be 825 degrees C.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Physical simulation of finish rolling of microalloyed steels in isothermal conditions",
pages = "236-227",
number = "4",
volume = "76",
doi = "10.2298/HEMIND220816018D",
url = "conv_962"
}

Dikić, S., Glišić, D., Fadel, A., Jovanović, G.,& Radović, N.. (2022). Physical simulation of finish rolling of microalloyed steels in isothermal conditions. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 76(4), 227-236.
https://doi.org/10.2298/HEMIND220816018D
conv_962

Dikić S, Glišić D, Fadel A, Jovanović G, Radović N. Physical simulation of finish rolling of microalloyed steels in isothermal conditions. in Hemijska industrija. 2022;76(4):227-236.
doi:10.2298/HEMIND220816018D
conv_962 .

Dikić, Stefan, Glišić, Dragomir, Fadel, Abdunaser, Jovanović, Gvozden, Radović, Nenad, "Physical simulation of finish rolling of microalloyed steels in isothermal conditions" in Hemijska industrija, 76, no. 4 (2022):227-236,
https://doi.org/10.2298/HEMIND220816018D .,
conv_962 .

TY  - JOUR
AU  - Jovanović, Gvozden
AU  - Glišić, Dragomir
AU  - Dikić, Stefan
AU  - Radović, Nenad
AU  - Patarić, Aleksandra
PY  - 2022
UR  - https://ritnms.itnms.ac.rs/handle/123456789/634
AB  - Cleavage fracture of the V and Ti-V microalloyed forging steels was investigated by the four-point bending testing of the notched specimens of Griffith-Owen's type at -196 degrees C, in conjunction with the finite element analysis and the fractographic examination by scanning electron microscopy. To assess the mixed microstructure consisting mostly of the acicular ferrite, alongside proeutectoid ferrite grains and pearlite, the samples were held at 1250 degrees C for 30 min and subsequently cooled instill air. Cleavage fracture was initiated in the matrix under the high plastic strains near the notch root of the four-point bending specimens without the participation of the second phase particles in the process. Estimated values of the effective surface energy for the V and the Ti-V microalloyed steel of 37 Jm(-2) and 74 Jm(-2), respectively, and the related increase of local critical fracture stress were attributed to the increased content of the acicular ferrite. It was concluded that the observed increase of the local stress for cleavage crack propagation through the matrix was due to the increased number of the high angle boundaries, but also that the acicular ferrite affects the cleavage fracture mechanism by its characteristic stress-strain response with relatively low yield strength and considerable ductility at -196 degrees C.
PB  - MDPI, Basel
T2  - Materials
T1  - Cleavage Fracture of the Air Cooled Medium Carbon Microalloyed Forging Steels with Heterogeneous Microstructures
IS  - 5
VL  - 15
DO  - 10.3390/ma15051760
UR  - conv_938
ER  - 

@article{
author = "Jovanović, Gvozden and Glišić, Dragomir and Dikić, Stefan and Radović, Nenad and Patarić, Aleksandra",
year = "2022",
abstract = "Cleavage fracture of the V and Ti-V microalloyed forging steels was investigated by the four-point bending testing of the notched specimens of Griffith-Owen's type at -196 degrees C, in conjunction with the finite element analysis and the fractographic examination by scanning electron microscopy. To assess the mixed microstructure consisting mostly of the acicular ferrite, alongside proeutectoid ferrite grains and pearlite, the samples were held at 1250 degrees C for 30 min and subsequently cooled instill air. Cleavage fracture was initiated in the matrix under the high plastic strains near the notch root of the four-point bending specimens without the participation of the second phase particles in the process. Estimated values of the effective surface energy for the V and the Ti-V microalloyed steel of 37 Jm(-2) and 74 Jm(-2), respectively, and the related increase of local critical fracture stress were attributed to the increased content of the acicular ferrite. It was concluded that the observed increase of the local stress for cleavage crack propagation through the matrix was due to the increased number of the high angle boundaries, but also that the acicular ferrite affects the cleavage fracture mechanism by its characteristic stress-strain response with relatively low yield strength and considerable ductility at -196 degrees C.",
publisher = "MDPI, Basel",
journal = "Materials",
title = "Cleavage Fracture of the Air Cooled Medium Carbon Microalloyed Forging Steels with Heterogeneous Microstructures",
number = "5",
volume = "15",
doi = "10.3390/ma15051760",
url = "conv_938"
}

Jovanović, G., Glišić, D., Dikić, S., Radović, N.,& Patarić, A.. (2022). Cleavage Fracture of the Air Cooled Medium Carbon Microalloyed Forging Steels with Heterogeneous Microstructures. in Materials
MDPI, Basel., 15(5).
https://doi.org/10.3390/ma15051760
conv_938

Jovanović G, Glišić D, Dikić S, Radović N, Patarić A. Cleavage Fracture of the Air Cooled Medium Carbon Microalloyed Forging Steels with Heterogeneous Microstructures. in Materials. 2022;15(5).
doi:10.3390/ma15051760
conv_938 .

Jovanović, Gvozden, Glišić, Dragomir, Dikić, Stefan, Radović, Nenad, Patarić, Aleksandra, "Cleavage Fracture of the Air Cooled Medium Carbon Microalloyed Forging Steels with Heterogeneous Microstructures" in Materials, 15, no. 5 (2022),
https://doi.org/10.3390/ma15051760 .,
conv_938 .

TY  - JOUR
AU  - Dikić, Stefan
AU  - Glišić, Dragomir
AU  - Fadel, Abdunaser
AU  - Jovanović, Gvozden
AU  - Radović, Nenad
PY  - 2021
UR  - https://ritnms.itnms.ac.rs/handle/123456789/590
AB  - Isothermal transformation characteristics of a medium carbon Ti-V microalloyed steel were investigated using light microscopy, scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and by uniaxial compressive testing. Samples austenitized on 1100 degrees C were isothermally treated in the range from 350 to 600 degrees C and subsequently water quenched. The final microstructure of the samples held at 350 degrees C consisted of bainitic sheaves and had compressive yield strength, approximately from 1000 MPa, which is attributed to high dislocation density of low bainite. At 400 and 450 degrees C, acicular ferrite became prevalent in the microstructure. It was also formed by a displacive mechanism, but the dislocation density was lower, leading to a decrease of compressive yield strength to approximately 700 MPa. The microstructure after the heat treatment at 500 degrees C consisted of coarse non-polygonal ferrite grains separated by pearlite colonies, principally dislocation free grains, so that the compressive YS reached a minimum value of about 700 MPa. The microstructure of the samples heat-treated at 550 and 600 degrees C consisted of pearlite and both grain boundary and intragranular ferrite, alongside with some martensite. After 600 s, austenite became stable and transformed to martensite after water quenching. Therefore, the presence of martensite increased the compressive YS to approx. 800 MPa.
PB  - MDPI, Basel
T2  - Metals
T1  - Structure and Strength of Isothermally Heat-Treated Medium Carbon Ti-V Microalloyed Steel
IS  - 7
VL  - 11
DO  - 10.3390/met11071011
UR  - conv_911
ER  - 

@article{
author = "Dikić, Stefan and Glišić, Dragomir and Fadel, Abdunaser and Jovanović, Gvozden and Radović, Nenad",
year = "2021",
abstract = "Isothermal transformation characteristics of a medium carbon Ti-V microalloyed steel were investigated using light microscopy, scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and by uniaxial compressive testing. Samples austenitized on 1100 degrees C were isothermally treated in the range from 350 to 600 degrees C and subsequently water quenched. The final microstructure of the samples held at 350 degrees C consisted of bainitic sheaves and had compressive yield strength, approximately from 1000 MPa, which is attributed to high dislocation density of low bainite. At 400 and 450 degrees C, acicular ferrite became prevalent in the microstructure. It was also formed by a displacive mechanism, but the dislocation density was lower, leading to a decrease of compressive yield strength to approximately 700 MPa. The microstructure after the heat treatment at 500 degrees C consisted of coarse non-polygonal ferrite grains separated by pearlite colonies, principally dislocation free grains, so that the compressive YS reached a minimum value of about 700 MPa. The microstructure of the samples heat-treated at 550 and 600 degrees C consisted of pearlite and both grain boundary and intragranular ferrite, alongside with some martensite. After 600 s, austenite became stable and transformed to martensite after water quenching. Therefore, the presence of martensite increased the compressive YS to approx. 800 MPa.",
publisher = "MDPI, Basel",
journal = "Metals",
title = "Structure and Strength of Isothermally Heat-Treated Medium Carbon Ti-V Microalloyed Steel",
number = "7",
volume = "11",
doi = "10.3390/met11071011",
url = "conv_911"
}

Dikić, S., Glišić, D., Fadel, A., Jovanović, G.,& Radović, N.. (2021). Structure and Strength of Isothermally Heat-Treated Medium Carbon Ti-V Microalloyed Steel. in Metals
MDPI, Basel., 11(7).
https://doi.org/10.3390/met11071011
conv_911

Dikić S, Glišić D, Fadel A, Jovanović G, Radović N. Structure and Strength of Isothermally Heat-Treated Medium Carbon Ti-V Microalloyed Steel. in Metals. 2021;11(7).
doi:10.3390/met11071011
conv_911 .

Dikić, Stefan, Glišić, Dragomir, Fadel, Abdunaser, Jovanović, Gvozden, Radović, Nenad, "Structure and Strength of Isothermally Heat-Treated Medium Carbon Ti-V Microalloyed Steel" in Metals, 11, no. 7 (2021),
https://doi.org/10.3390/met11071011 .,
conv_911 .

TY  - JOUR
AU  - Gligorijević, Bojan R.
AU  - Vilotijević, Miroljub
AU  - Scepanović, Maja
AU  - Vuković, Nikola
AU  - Radović, Nenad
PY  - 2016
UR  - https://ritnms.itnms.ac.rs/handle/123456789/376
AB  - The aim of the present study was to investigate the influence of substrate preheating on the structural properties of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. The deposition experiments were performed within the 20-200 degrees C temperature range at different stand-off distances. The structural properties in the thickness direction and at the surface of the HACs were investigated by using the micro-Raman spectroscopy, scanning electron microscopy coupled with energy dispersive spectrometry, and X-ray powder diffractometry. The deposition without the preheating of the substrate produced HACs with crystallinity gradient in the thickness direction. At the stand-off distance of 80 mm, the preheating of the substrate at 200 degrees C practically eliminated the crystallinity gradient. At distances from the coating/substrate interface shorter than similar to 100 mu m, the increase of crystallinity with the preheating of the substrate was dominantly attributed to the recrystallization of hydroxyl-rich ACP into HA. At longer distances and higher initial substrate temperatures ( > 100 degrees C), the crystallinity changes were negligible, whereas the recrystallization of hydroxyl-deficient ACP into oxyapatite (OA) was also possible. The X-ray diffractometry indicated the deposition conditions under which a minimum residual stress was achieved. The results of the present study strongly suggested the relation between the ACP -> HA remystallization process and the bonding strength of the HACs.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings
EP  - 420
IS  - 1
SP  - 411
VL  - 42
DO  - 10.1016/j.ceramint.2015.08.125
UR  - conv_743
ER  - 

@article{
author = "Gligorijević, Bojan R. and Vilotijević, Miroljub and Scepanović, Maja and Vuković, Nikola and Radović, Nenad",
year = "2016",
abstract = "The aim of the present study was to investigate the influence of substrate preheating on the structural properties of hydroxyapatite coatings (HACs) deposited by using the high power (52 kW) laminar plasma jet. The deposition experiments were performed within the 20-200 degrees C temperature range at different stand-off distances. The structural properties in the thickness direction and at the surface of the HACs were investigated by using the micro-Raman spectroscopy, scanning electron microscopy coupled with energy dispersive spectrometry, and X-ray powder diffractometry. The deposition without the preheating of the substrate produced HACs with crystallinity gradient in the thickness direction. At the stand-off distance of 80 mm, the preheating of the substrate at 200 degrees C practically eliminated the crystallinity gradient. At distances from the coating/substrate interface shorter than similar to 100 mu m, the increase of crystallinity with the preheating of the substrate was dominantly attributed to the recrystallization of hydroxyl-rich ACP into HA. At longer distances and higher initial substrate temperatures ( > 100 degrees C), the crystallinity changes were negligible, whereas the recrystallization of hydroxyl-deficient ACP into oxyapatite (OA) was also possible. The X-ray diffractometry indicated the deposition conditions under which a minimum residual stress was achieved. The results of the present study strongly suggested the relation between the ACP -> HA remystallization process and the bonding strength of the HACs.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings",
pages = "420-411",
number = "1",
volume = "42",
doi = "10.1016/j.ceramint.2015.08.125",
url = "conv_743"
}

Gligorijević, B. R., Vilotijević, M., Scepanović, M., Vuković, N.,& Radović, N.. (2016). Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings. in Ceramics International
Elsevier Sci Ltd, Oxford., 42(1), 411-420.
https://doi.org/10.1016/j.ceramint.2015.08.125
conv_743

Gligorijević BR, Vilotijević M, Scepanović M, Vuković N, Radović N. Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings. in Ceramics International. 2016;42(1):411-420.
doi:10.1016/j.ceramint.2015.08.125
conv_743 .

Gligorijević, Bojan R., Vilotijević, Miroljub, Scepanović, Maja, Vuković, Nikola, Radović, Nenad, "Substrate preheating and structural properties of power plasma sprayed hydroxyapatite coatings" in Ceramics International, 42, no. 1 (2016):411-420,
https://doi.org/10.1016/j.ceramint.2015.08.125 .,
conv_743 .