Regional Materials Science and Technology Center

Ostrava, Czech Republic

Regional Materials Science and Technology Center

Ostrava, Czech Republic
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Martinik O.,VSB - Technical University of Ostrava | Smetana B.,VSB - Technical University of Ostrava | Smetana B.,Regional Materials Science and Technology Center | Dobrovska J.,VSB - Technical University of Ostrava | And 12 more authors.
METAL 2016 - 25th Anniversary International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2016

Series of thermal analysis measurements by Differential Thermal Analysis (DTA) and Direct Thermal Analysis (TA) were performed on two real grade medium carbon steel samples in low and high temperature regions. Temperatures of eutectoid transition (TE), end of α-ferrite to γ-austenite transition (Tα→γ), solidus (TS), peritectic transition (TP), liquidus (TL) were determined. The stability and reproducibility of the results were verified by statistic evaluation and discussed with theoretical calculations carried out by Solidification Analysis Package (IDS) and Thermo-Calc™ (2015b, TCFE8; TC) software.


Zla S.,VSB - Technical University of Ostrava | Zla S.,Regional Materials Science and Technology Center | Kawulokova M.,VSB - Technical University of Ostrava | Kawulokova M.,Regional Materials Science and Technology Center | And 13 more authors.
METAL 2016 - 25th Anniversary International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2016

DSC method (Differential Scanning Calorimetry) is one of the thermal analysis methods which is suitable for studying the thermodynamic properties of metallic systems. In this work the heat capacities of real steel grade in the solid phase under strictly defined conditions for controlled heating were studied. The paper deals with the investigation of real steel grade in the solid phase under strictly defined conditions for controlled heating. Heat capacity of steel was obtained using high-temperature calorimeter Setaram MHTC 96 (Multi High Temperature Calorimeter) with 3D DSC sensor. Experimentally acquired heat capacity ("Apparent Heat Capacities") of real steel grade was confronted with the calculated theoretical data (software Thermo-Calc) and with data reported in the available literature.


Smetana B.,VSB - Technical University of Ostrava | Smetana B.,Regional Materials Science and Technology Center | Zla S.,VSB - Technical University of Ostrava | Zla S.,Regional Materials Science and Technology Center | And 15 more authors.
METAL 2015 - 24th International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2015

The paper deals with the study of thermo-physical properties of selected real steel grade. The work is focused mainly on phase transition temperatures and heat capacities, particularly liquidus and solidus temperatures, eutectoid transition, alfa-gamma and magnetic transition. Different thermal analysis methods were used for obtaining of experimental data: "direct" thermal analysis (TA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). Theoretical study of analysed steel grades was performed using IDS SW (Solidification Analysis Package) and thermodynamic SW Thermo-Calc with database TCFE7. Experimental and theoretical data were compared and discussed.


Kawulokova M.,VSB - Technical University of Ostrava | Kawulokova M.,Regional Materials Science and Technology Center | Zla S.,Regional Materials Science and Technology Center | Dobrovska J.,VSB - Technical University of Ostrava | And 11 more authors.
METAL 2015 - 24th International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2015

The paper deals with the study of phase transformations temperatures of real peritectic micro alloyed steel grade. Phase transformations temperatures were obtained using Differential Thermal Analysis (DTA) and Setaram Setsys 18TM laboratory system. There are presented results from the low temperature region (below 1000 °C) and high temperature region (above 1000 °C). Extrapolation of obtained phase transformation temperatures to "zero" mass and "zero" heating rate is performed. The following temperatures of phase transformation were determined: eutectoid transformation (740 C), end of alpha-gamma transformation (845 °C), start of gamma-delta transformation (1472 °C), peritectic transformation (1486 °C) and liquidus temperature (1511 °C).The obtained phase transformations temperatures are discussed. Phase transformations temperatures are calculated using thermodynamic and kinetic software ThermoCalc and IDS also. Experimentally obtained data of phase transformations temperatures are compared with calculated data and discussed. Experimentally obtained data are essential for thermodynamic calculations and they are used also as input data for numerical mathematical and physical models.


Smetana B.,VSB - Technical University of Ostrava | Smetana B.,Regional Materials Science and Technology Center | Zaludova M.,VSB - Technical University of Ostrava | Zaludova M.,Regional Materials Science and Technology Center | And 8 more authors.
METAL 2013 - 22nd International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2013

The paper deals with the study of latent heats of melting and solidifying of Fe based metallic alloys. One real steel grade and "pure" iron were investigated and values of latent heats of melting and solidifying were obtained. Latent heats are very important quantities for thermodynamic and kinetic modelling. Latent heats are valuable data for many SWs used for technological processes modelling. Many SWs for casting of alloys use these quantities. These data are also necessary for proper modelling of processes connected with welding simulation processes. The obtained data can serve for the addition and enhancement of many thermodynamic databases. Continuous thermal analysis (DSC) was performed to obtain the values of latent heats. Latent heats were studied using Setaram MHTC (Multi High Temperature Calorimeter) Line 96 equipped with 3D DSC sensor. Comparison between melting and solidifying latent heats was performed. Advantages of Setaram MHTC equipment are discussed also. Experimental measurements were realised under controlled heating and cooling rate in an inert atmosphere of He. Comparison of experimental, calculated and accessible data in the literature was performed. It follows from the obtained results the necessity of further systematic research of studied quantities. © 2013 TANGER Ltd., Ostrava..


Zaludova M.,Regional Materials Science and Technology Center | Smetana B.,Regional Materials Science and Technology Center | Zla S.,Regional Materials Science and Technology Center | Dobrovska J.,Regional Materials Science and Technology Center | And 5 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2013

The paper deals with the study of phase transformation temperatures of the model Fe-C-O based metallic alloys in the high temperature region (above 1,000 C). Six model alloys with graded carbon and oxygen content were prepared and studied. Temperatures of phase transitions were obtained using DTA method (differential thermal analysis). The Setaram SETSYS 18™ (TG/DTA/DSC/TMA) modular experimental system was used for measurements. Influence of composition change (carbon and oxygen content) on shift of phase transformation temperatures is investigated in this paper. New original data (phase transformation temperatures) were obtained in this study. Controlled heating of the alloys was conducted at the rates of 2, 4, 7, 10, 15 and 20 C min-1. Comparison of the obtained experimental data with the data presented in the literature was also carried out. It follows from comparison of the obtained results with the data accessible in the literature that a lack of experimental data exists, and these available data significantly differ. © 2012 Akadémiai Kiadó, Budapest, Hungary.


Smetana B.,Regional Materials Science and Technology Center | Zaludova M.,Regional Materials Science and Technology Center | Tkadleckova M.,Regional Materials Science and Technology Center | Dobrovska J.,Regional Materials Science and Technology Center | And 6 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2013

Heat capacity of alloys (metals) is one of the crucial thermophysical parameters used for process behaviour prediction in many applications. Heat capacity is an input variable for many thermodynamical (e.g. Thermocalc, Pandat, MTData,.) and kinetic programs (e.g. IDS-Solidification analysis package,.). The dependences of heat capacity on common variables (temperature, pressure,.) are also commonly used as the input data in software packages (e.g. ProCast, Magmasoft, ANSYS Fluent,.) that are applicable in the field of applied research for simulations of technological processes. It follows from the above that the heat capacities of materials, alloys in our case, play a very important role in the field of basic and applied research. Generally speaking, experimental data can be found in the literature, but corresponding (needed) data for the given alloy can very seldom be found or can differ from the tabulated ones. The knowledge of proper values of heat capacities of alloys at the corresponding temperature can be substantially used for addition to and thus towards the precision of the existing database and simulation software. This study presents the values of Cp measured for the hematite ingot mould and comparison of the measured data with the Cp values obtained using the software CompuTherm with respect to simulation of technological casting process. © 2013 Akadémiai Kiadó, Budapest, Hungary.


Kocich R.,VSB - Technical University of Ostrava | Kocich R.,Regional Materials Science and Technology Center | Kunicka L.,VSB - Technical University of Ostrava | Kunicka L.,Regional Materials Science and Technology Center | Machakova A.,Regional Materials Science and Technology Center
IOP Conference Series: Materials Science and Engineering | Year: 2014

The paper proposes a new variation of the application of SPD methods. For the suggested TCMAP (twist channel multi angular pressing) technology a larger strain is imposed more effectively while homogeneity of material is increased. The number of passes needed to obtain the ultra-fine to nano-scale grains in bulk materials can be significantly reduced. Commercially pure Al (99.97%) was used for the experimental verification of the suggested process. The deformation parameters of the process were also described using a numerical simulation based on a FE analysis. The predicted value of imposed strain after a single pass reached approximately 2.7. Deformation homogeneity was confirmed by micro-hardness tests. Due to the designed shape of the channel both ends of the processed sample are defined by a higher imposed strain and vertical faces. © Published under licence by IOP Publishing Ltd.


Zaludova M.,VSB - Technical University of Ostrava | Zaludova M.,Regional Materials Science and Technology Center | Smetana B.,VSB - Technical University of Ostrava | Smetana B.,Regional Materials Science and Technology Center | And 9 more authors.
METAL 2014 - 23rd International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2014

Heat capacity of steels is one of the crucial thermophysical parameters used for process behaviour prediction in many applications. Heat capacity is an input variable for many thermodynamical and kinetic programs. The dependences of heat capacity on common variables (temperature, pressure, etc.) are also commonly used as the input data in software packages that are applicable in the field of applied research for simulations of technological processes. Experimental data of heat capacities can be found in literature, but it is difficult to find data for given steel (with exact chemical composition). The paper deals with the study of heat capacity of real steel grade in the low temperature region. Heat capacity of steel was obtained using DSC continuous method and laboratory system MHTC (Multi High Temperature Calorimeter). Experimentally obtained data of heat capacity were compared with calculated data of heat capacity.


Kawulokova M.,Regional Materials Science and Technology Center | Smetana B.,Regional Materials Science and Technology Center | Zla S.,Regional Materials Science and Technology Center | Kalup A.,Regional Materials Science and Technology Center | And 5 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2016

This work deals with determining temperatures of phase transformations in steel S34MnV in a low-temperature region (below 900 °C). Although S34MnV is a significant tool steel, in the literature, there are only a few works dealing with the study of the thermo-physical properties of this steel. For the study of phase transformation temperatures of steel S34MnV, a differential thermal analysis and dilatometry were used in this study. Both methods are used to determine the phase transformation temperatures of steel. Dilatometry, however, unlike differential thermal analysis, is commonly used to determine the temperature of nonequilibrium phase transformations during cooling. Temperatures of the eutectoid phase transformation (Ac1) and temperatures of the end of the ferrite to austenite transformation (Ac3) were obtained at heating, and temperatures of the start of the ferrite formation (Ar3), the temperature of the start of the pearlite formation (Ar1) and the temperature of the start of the bainite formation (BS) were obtained at cooling using these methods. The temperatures obtained using the both methods were compared and discussed. The original thermo-physical data on steel S34MnV were obtained under precisely defined conditions. For the complexity of the study of the steel, a metallographic analysis of samples was also conducted after thermal analysis, which enables determining the phases occurring in the final structure and their quantity. The experimentally obtained data were compared with data calculated by the software QTSteel. © 2016 Akadémiai Kiadó, Budapest, Hungary

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