Ladislav Válek

Automated Region of Interest Retrieval of Metallographic Images for Quality Scoring Estimation

The aim of the research is development and testing of new methods to assess the quality of digital metallographic images introduced in the quality of steel with high added value. In this paper, we will address the development of methods to assess the quality of metallographic samples, including slabs with the main emphasis on the quality of the image center. For this reason, we introduce an alternative method for automated region of interest retrieval. In the first step, the metallographic image is segmented using both spectral method and thresholding. Then, the extracted macrostructure of the metallographic image is automatically analyzed by statistical methods. Finally, automatically extracted region of interests are compared with results of human experts.

Study of macro-segregations in a continuously cast billet

Ta clanek obravnava studij makro-izcej na vzdolžnem prerezu kontinuirno ulite gredice O 160 mm namenjene za proizvodnjo brezsivnih cevi. Ocena je sestavljena iz vizuelnega pregleda po makrojedkanju, iz ocene in kvantitativne rentgenske mikroanalize s pomocjo energijsko disperzijske rentgenske analize (EDX) izbranih podrocij. Izracunani so bili tudi parametri izcejanja s pomocjo podatkov zgorevne analize. Rezultati, prikazani v tem clanku, predstavljajo osnovno informacijo o notranji strukturi v kontinuirno uliti gredici. Rezultati bodo uporabljeni, poleg drugega, tudi za preverjanje rezultatov numericnega modeliranja kontinuirno ulitih gredic.

Thermal Analysis Results and the Theoretical Determination of Solidus and Liquidus Temperatures for the Grain Oriented Electrical Steel

This paper is devoted to the comparison of theoretically defined solidus and liquidus temperatures based on above mentioned theoretical methods with the results of high-temperature thermal analysis carried out on two devices (Netzsch STA 449 F3 Jupiter; Setaram SETSYS 18TM). On large samples (23 g), the method of direct thermal analysis was applied. On small samples (200 mg), the experiments using differential thermal analysis were realized. It was found out that the solidus and liquidus temperatures for the studied steel grade can vary in dependence on the used determination method. The used methodology of thermal analysis is fully reproducible, and the these thermo-analytical results can be considered as necessary for the correct setting of critical parameters in applied research on the process of steel casting.