Journal of Casting & Materials Engineering
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ISSN 2543-9901
Issue Date
2025
Volume
Vol. 9
Number
No. 2
Description
Journal Volume
Journal of Casting & Materials Engineering
Vol. 9 (2025)
Projects
Pages
Articles
The Occurrence of Chunky Graphite in Ductile Cast Iron Solution Strengthened by Silicon
(AGH University Press, 2025) Zaczyński, Artur; Królikowski, Maciej; Sokolnicki, Marek; Nowak, Adam; Guzik, Edward; Burbelko, Andriy A.
Solution strengthened ferritic cast iron is characterised in EN 1563:2018 (and also in ISO 1083:2018) as grades EN-GJS-450-18, EN-GJS-500-14 and EN-GJS-600-10. Machine and plant builders have been using this material in new designs since 2011. The strength and ductile properties, competitive in comparison with the previous classical ductile cast iron grades, make it pos¬sible to reduce the weight of castings. Particularly preferred is grade EN-GJS-600-10 with Rm min. 600 MPa and A min. 10%. Strengthening of the ferritic matrix is possible due to the content of approximately 4.2% of silicon in the cast iron. In casting practice, this material is difficult to produce in a stable manner due to the frequent occurrence of degenerate chunky graphite in the casting structure, resulting in a loss of ductile properties of the cast iron. In this article, an analysis has been made, based on literature, of the occurrence of strong negative segregation of silicon in classical ductile cast iron. The authors’ own research has confirmed the occurrence of chunky graphite in the cast. Dendritic crystallisation of austenite and strong segregation of silicon favours the formation of chunky graphite. A much stronger proportion of silicon was found in the chunky graphite zone, compared to the adjacent ball graphite zone. The introduction of micro-additives into the liquid melt eliminated the presence of chunky graphite in the casting. The applied modifiers of graphite and metal matrix (hybrid modification) seem to be an effective method to stabilise the technological process of this innovative casting material.
An Analysis of Transient States in the Power Supply System of a Selected Industrial Robot
(AGH University Press, 2025) Nowocień, Sebastian; Ziółkowski, Eugeniusz
Industrial robots are controlled by dedicated controllers powered by a single-phase or three-phase power supply system. The main power parameters characterizing the power supply system of these robots are: nominal supply voltage (1-phase: 100–120 V, 200–240 V or 3-phase 200–575 V AC), frequency of the supply voltage (50 Hz or 60 Hz), the nominal power consumed by industrial robot. The dynamics of power consumption in the power supply system of the controlled robot can be studied by recording instan¬taneous values of voltages and currents in each phase of the power grid. In this article, results are presented for the measurements of mentioned instantaneous values for a chosen single-phase powered robot, taken by specialized recorder. The measurements obtained from the recorder allows the calculation of numerically various energetic values in the power supply system of the robot: peak-peak values, RMS values, coefficients of deformation and values of harmonic amplitudes (FFT), values of active, reactive and apparent power and the power coefficient (tg?). The analysis of the waveforms of the instantaneous values of voltage and current allows the determination of the occurrence of transient states during the work of robot axes and characterizing its duration and the range of value changes. The analyses conducted can be used to properly design the protection systems of the power supply system, the eventual selection of filters for higher harmonics, and to determine the effective power consumption of the studied robot. The analyses of the transient states which occurred during the work of the studied robot in this publication significantly expand the knowledge about the dynamics of power consumption and its possible impact on the quality of electricity in the power supply grid.