Petr Kawulok

Dr. Petr Kawulok

VSB - Techncical University of Ostrava, Faculty of Materials Science and Engineering
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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22 November 2019 in Metals
Verified
Journal Article
Open access
PDF file
ISIvo Schindler
Ivo Schindler
PKPetr Kawulok
Petr Kawulok
VOVladivoj Očenášek
Vladivoj Očenášek
POPetr Opěla
Petr Opěla
RKRostislav Kawulok
Rostislav Kawulok
SRStanislav Rusz
Stanislav Rusz
Stress-strain curves of the EN AW 6082 aluminium alloy with 1.2 Si-0.51 Mg-0.75 Mn (wt.%) were determined by the uniaxial compression tests at temperatures of 450–550 °C with a strain rate of 0.5–10 s−1. The initial structure state corresponded to three processing types: as-cast structure non-homogenized or homogenized at 500 °C, and the structure after homogenization and hot extrusion. Significantly higher flow stress appeared as a result of low temperature forming of the non-homogenized material. Hot deformation activation energy Q-values varied between 99 and 122 kJ·mol−1 for both homogenized materials and from 200 to 216 kJ·mol−1 for the as-cast state, while the Q-values calculated from the measured steady-state stress were always higher than those calculated from the peak stress values. For the extruded state of the 6082 alloy, the physically-based model was developed to reliably predict the flow stress influenced by dynamic softening, temperature, strain rate, and true strain up to 0.6.

23 August 2016 in Journal of Thermal Analysis and Calorimetry
Verified
Journal Article
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MKMonika Kawuloková
Monika Kawuloková
BSBedřich Smetana
Bedřich Smetana
SZSimona Zlá
Simona Zlá
AKAleš Kalup
Aleš Kalup
EMEva Mazancová
Eva Mazancová
SRSilvie Rosypalová
Silvie Rosypalová

3 August 2012 in Journal of Materials Engineering and Performance
Verified
Journal Article
Closed access
PDF file
ISIvo Schindler
Ivo Schindler
PKPetr Kawulok
Petr Kawulok
EHEugeniusz Hadasik
Eugeniusz Hadasik
DKDariusz Kuc
Dariusz Kuc

1 September 2021 in Journal of Materials Research and Technology
Verified
Journal Article
Open access
POPetr Opěla
Petr Opěla
ISIvo Schindler
Ivo Schindler
PKPetr Kawulok
Petr Kawulok
RKRostislav Kawulok
Rostislav Kawulok
SRStanislav Rusz
Stanislav Rusz
HNHorymír Navrátil
Horymír Navrátil

21 April 2020 in Crystals
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Journal Article
Open access
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RKRostislav Kawulok
Rostislav Kawulok
ISIvo Schindler
Ivo Schindler
JSJaroslav Sojka
Jaroslav Sojka
PKPetr Kawulok
Petr Kawulok
POPetr Opěla
Petr Opěla
VŠVojtěch Ševčák
Vojtěch Ševčák
Based on dilatometric tests, the effect of various values of previous deformation on the kinetics of austenite transformations during the cooling of 100Cr6 steel has been studied. Dilatometric tests have been performed with the use of the optical dilatometric module of the plastometer Gleeble 3800. The obtained results were compared to metallographic analyses and hardness measurements HV30. Uniaxial compression deformations were chosen as follows: 0, 0.35, and 1; note that these are true (logarithmic) deformations. The highly important finding was the absence of bainite. In addition, it has been verified that with the increasing amount of deformation, there is a further shift in the pearlitic region to higher cooling rates. The previous deformation also affected the temperature martensite start, which decreased due to deformation. The deformation value of 1 also shifted the critical cooling rate required for martensite formation from the 12 °C/s to 25 °C/s.

7 August 2020 in Materials
Verified
Journal Article
Open access
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POPetr Opěla
Petr Opěla
ISIvo Schindler
Ivo Schindler
PKPetr Kawulok
Petr Kawulok
RKRostislav Kawulok
Rostislav Kawulok
SRStanislav Rusz
Stanislav Rusz
RJRadek Jurča
Radek Jurča
In the presented research, conventional hot processing maps superimposed over the flow stress maps or activation energy maps are utilized to study a correlation among the efficiency of power dissipation, flow stress, and activation energy evolution in the case of Cr-Mo low-alloyed steel. All maps have been assembled on the basis of two flow curve datasets. The experimental one is the result of series of uniaxial hot compression tests. The predicted one has been calculated on the basis of the subsequent approximation procedure via a well-adapted artificial neural network. It was found that both flow stress and activation energy evolution are capable of expressing changes in the studied steel caused by the hot compression deformation. A direct association with the course of power dissipation efficiency is then evident in the case of both. The connection of the presence of instability districts to the activation energy evolution, flow stress course, and power dissipation efficiency was discussed further. Based on the obtained findings it can be stated that the activation energy processing maps represent another tool for the finding of appropriate forming conditions and can be utilized as a support feature for the conventionally-used processing maps to extend their informative ability.