Lucia Rozumová

Dr. Lucia Rozumová

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2019 in Journal of Nuclear Engineering and Radiation Science
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Journal Article
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Anna HojnaAnna Hojna
Anna Hojna
FGFosca Di Gabriele
Fosca Di Gabriele
MCMichal Chocholousek
Michal Chocholousek
ZŠZbyněk Špirit
Zbyněk Špirit
LRLucia Rozumová
Lucia Rozumová
The austenitic steel 15-15Ti is being considered as one of the candidate materials for internal structural components of future heavy liquid metal (HLM) nuclear systems. This work studies the steel compatibility with liquid PbBi. Constant extension rate tensile (CERT) tests of tapered specimens were used to study sensitivity to liquid metal embrittlement (LME) and crack initiation. The taper creates a variation of stress along the gauge length which allows the identification of the stress and strain for the crack appearance. Testing was performed in air and in PbBi with 10−6 to 10−12 wt % oxygen content at 300 °C. Post-test observation by scanning electron microscopy (SEM) highlighted the crack morphology. An evaluation of the environmental effect on the crack initiation is presented.

19 February 2021 in Journal of Nuclear Engineering and Radiation Science
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Journal Article
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MPMartina Pazderová
Martina Pazderová
LRLucia Rozumová
Lucia Rozumová
LKLukአKoŠek
LukአKoŠek
Anna HojnaAnna Hojna
Anna Hojna
Heavy liquid metal (HLM) cooled systems are under wide investigation and development. The technology needs to study the materials corrosion, which has a different progress than corrosion caused by aqueous media. Improvement of the corrosion resistance can be achieved by alloying the bare material, but the degradation of steels continues with less or more intensity. Deposition of protective barrier may reduce the metals dissolution and diffusion of liquid lead into the steel substrate. Different types of surface treatment and coatings composition were evaluated to find out the most convenient solution for the steel's protection.

11 December 2018 in Materials
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Anna HojnaAnna Hojna
Anna Hojna
FGFosca Di Gabriele
Fosca Di Gabriele
MCMichal Chocholousek
Michal Chocholousek
LRLucia Rozumová
Lucia Rozumová
JVJan Vít
Jan Vít
The environmental performance of structural materials (e.g., corrosion and environmental assisted cracking) is one of the critical issues being addressed in the development of Generation IV fast reactors. This work aims to support the study of the performance of the ferritic-martensitic steel T91 in liquid lead, under close to operation conditions, in order to assess its suitability for an application in lead fast reactors. T91 steel was tested in air and liquid lead at 400 °C using static and slow loading regimes. Applied stresses were chosen to be slightly above the yield strength in order to evaluate the threshold stress and strain for crack initiation. Three-point bending static exposure and constant extension tests of tapered specimens were performed. Post-test surfaces and cross sections of specimens were observed using scanning electron microscopy techniques in order to detect cracks and to analyze oxide layers. The effect of strain rate of the oxide layer cracking was observed. In conclusion, T91 was not susceptible to liquid metal embrittlement, a special case of environmentally assisted cracking under the testing conditions. The cracking conditions are discussed based on previous experience.

19 February 2021 in Journal of Nuclear Engineering and Radiation Science
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LRLucia Rozumová
Lucia Rozumová
LKLukáš Košek
Lukáš Košek
JVJan Vít
Jan Vít
Anna HojnaAnna Hojna
Anna Hojna
PHPatricie Halodova
Patricie Halodova
Development of liquid lead cooled nuclear systems requires consideration of compatibility issues with the construction materials. In order to understand the corrosion or passivation behavior of the 316 L austenitic stainless steel, the steel specimens were exposed for 1000 h in liquid lead with 1 × 10−7 wt % oxygen level at 480 °C in static and flowing (velocity 1.6 m/s) conditions. Post-test microscopy investigation using scanning electron microscope with focused ion beam (FIB) was performed and it demonstrated significant differences in the formation of thin oxide layers in the two conditions. Maximum oxide thickness was 2 μm in the static lead (Pb) and less than 0.1 μm in the flowing Pb. In the static condition, oxide scale was not continuous and local corrosion attack was indicated; but in flowing condition the oxide layer was continuous without any corrosion attacks.

4 January 2018 in Water
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LRLucia Rozumová
Lucia Rozumová
JPJana Prehradná
Jana Prehradná
The aim of this paper was to study of utilization of converter sludge waste as a sorbent. The sorbent was utilized to reduce the content of manganese, cobalt, and nickel ions from mine water. Sorbent utilized in this work was obtained from the metallurgical industry from a process of gas treatment in an oxygen converter. Converter sludge was characterized by X-ray diffraction, Scanning Electron Microscope, X-ray fluorescence spectroscopy, Specific Surface Area and Particle Size. Sorption experiments were conducted in a batch mode by using the real mine water. The impact of pH and contact time on the pollutant removal efficiency was observed. The sorption kinetics were evaluated with pseudo-first and pseudo-second order kinetic models. For the tested materials, the highest level of mine water purification was achieved; thus, the mine water could be discharged into the watercourse. The results of this study indicate that the application of metallurgical waste as a sorbent is highly effective for the treatment of multicomponent mine water.

10 May 2019 in Journal of Nuclear Engineering and Radiation Science
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Journal Article
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Anna HojnaAnna Hojna
Anna Hojna
MZMariia Zimina
Mariia Zimina
LRLucia Rozumová
Lucia Rozumová
This paper presents results on the effect of a surface treatment on the environmentally assisted corrosion cracking in a pressurized water reactor chemistry. Slow strain rate testing of 316 L austenitic steel with selected rates was performed at pressurized water reactor (PWR) simulated water at 350 °C and in air at 300 °C. Detailed prior and post-testing characterization of two types of surfaces including roughness, hardness, and microstructural analysis was made. Transgranular cleavage-like environmentally assisted cracking (EAC) initiation and growth were observed under PWR conditions. The effect of two surface finishes on the cracking initiation was observed: (i) first crack initiates from the polished surface in a vicinity of the necking area rather than from the ground surface and (ii) then the deeper crack develops in the minimal diameter from the polished surface side than from the ground one.