Iron nanoparticle influence on the structure of improved structural steel and its properties
The results of the study of the effect of nanoparticles in the shell of iron oxide Fe2O3, which when injected into the melt and heated up to melt temperature is converted into oxide Fe3O4, on the microstructure of hardened and tempered steel 25GSL and its properties. It is shown that in modified ste...
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National Academy of Sciences of Ukraine. Physico- Technological Institute of Metals and Alloys
2020-12-01
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Series: | Металознавство та обробка металів |
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Online Access: | https://momjournal.com.ua/sites/default/files/МОМ4_20-10-16_0.pdf#overlay-context=en/2020-4-2 |
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doaj-02273a8e20c84908ab54e1e24ea4d0e12021-06-07T11:52:00ZengNational Academy of Sciences of Ukraine. Physico- Technological Institute of Metals and Alloys Металознавство та обробка металів2073-95832664-24412020-12-01264101610.15407/mom2020.04.010Iron nanoparticle influence on the structure of improved structural steel and its propertiesY. G. Aftandiliants0https://orcid.org/0000-0001-5864-9855К.G. Lopatko 1National University of Life and Environmental Sciences of Ukraine, Kyiv, UkraineNational University of Life and Environmental Sciences of Ukraine, Kyiv, UkraineThe results of the study of the effect of nanoparticles in the shell of iron oxide Fe2O3, which when injected into the melt and heated up to melt temperature is converted into oxide Fe3O4, on the microstructure of hardened and tempered steel 25GSL and its properties. It is shown that in modified steel martensite crystals thickness is reduced compared to the original steel in average 1.9 times after the quenching, tempered martensite crystal length after tempering hardened steel at 200oC - 3 times, the plate cementite length in troostite after tempering hardened steel at 450 оС – 1,4 times, the carbide length of after tempering of steel at 550 оС – 1,6 times. It has been found that modification of iron nanoparticles in a shell of Fe3O4 oxide leads to dispersion of the subgrain structure (regions of coherent scattering) and to the decrease of the crystal lattice parameters of solid solutions. The mechanism of nanoparticle influence on the reduction of the crystal lattice parameters of solid solutions, which is to accelerate the diffusion of interstitial atoms of the elements into the zones of high stress on the nanoparticles surface, is proposed. It is determined that the optimal improvement mode of the modified steel is quenching at 900 °C and tempering at 550 °C. The yield, tensile strengths and toughness of the modified steel are 894 MPa, 993 MPa and 92 J/mm2, respectively, on 62, 41 and 14% higher than the original steel. The injection of iron nanoparticles in a refractory shell into the steel melt before crystallization predetermines the effective modification and enhancement of mechanical properties.https://momjournal.com.ua/sites/default/files/МОМ4_20-10-16_0.pdf#overlay-context=en/2020-4-2iron nanoparticlesstructuremartensitetroostitesorbitecarbidesstressesphase transformations. |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Y. G. Aftandiliants К.G. Lopatko |
spellingShingle |
Y. G. Aftandiliants К.G. Lopatko Iron nanoparticle influence on the structure of improved structural steel and its properties Металознавство та обробка металів iron nanoparticles structure martensite troostite sorbite carbides stresses phase transformations. |
author_facet |
Y. G. Aftandiliants К.G. Lopatko |
author_sort |
Y. G. Aftandiliants |
title |
Iron nanoparticle influence on the structure of improved structural steel and its properties |
title_short |
Iron nanoparticle influence on the structure of improved structural steel and its properties |
title_full |
Iron nanoparticle influence on the structure of improved structural steel and its properties |
title_fullStr |
Iron nanoparticle influence on the structure of improved structural steel and its properties |
title_full_unstemmed |
Iron nanoparticle influence on the structure of improved structural steel and its properties |
title_sort |
iron nanoparticle influence on the structure of improved structural steel and its properties |
publisher |
National Academy of Sciences of Ukraine. Physico- Technological Institute of Metals and Alloys |
series |
Металознавство та обробка металів |
issn |
2073-9583 2664-2441 |
publishDate |
2020-12-01 |
description |
The results of the study of the effect of nanoparticles in the shell of iron oxide Fe2O3, which when injected into the melt and heated up to melt temperature is converted into oxide Fe3O4, on the microstructure of hardened and tempered steel 25GSL and its properties. It is shown that in modified steel martensite crystals thickness is reduced compared to the original steel in average 1.9 times after the quenching, tempered martensite crystal length after tempering hardened steel at 200oC - 3 times, the plate cementite length in troostite after tempering hardened steel at 450 оС – 1,4 times, the carbide length of after tempering of steel at 550 оС – 1,6 times. It has been found that modification of iron nanoparticles in a shell of Fe3O4 oxide leads to dispersion of the subgrain structure (regions of coherent scattering) and to the decrease of the crystal lattice parameters of solid solutions. The mechanism of nanoparticle influence on the reduction of the crystal lattice parameters of solid solutions, which is to accelerate the diffusion of interstitial atoms of the elements into the zones of high stress on the nanoparticles surface, is proposed. It is determined that the optimal improvement mode of the modified steel is quenching at 900 °C and tempering at 550 °C. The yield, tensile strengths and toughness of the modified steel are 894 MPa, 993 MPa and 92 J/mm2, respectively, on 62, 41 and 14% higher than the original steel. The injection of iron nanoparticles in a refractory shell into the steel melt before crystallization predetermines the effective modification and enhancement of mechanical properties. |
topic |
iron nanoparticles structure martensite troostite sorbite carbides stresses phase transformations. |
url |
https://momjournal.com.ua/sites/default/files/МОМ4_20-10-16_0.pdf#overlay-context=en/2020-4-2 |
work_keys_str_mv |
AT ygaftandiliants ironnanoparticleinfluenceonthestructureofimprovedstructuralsteelanditsproperties AT kglopatko ironnanoparticleinfluenceonthestructureofimprovedstructuralsteelanditsproperties |
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