Wyniki wyszukiwania - BazTech

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Staliwo stopowe wysokomanganowe w zastosowaniach na odlewane elementy infrastruktury kolejowej

Wróbel Tomasz, Bartocha Dariusz, Jezierski Jan, Sobula Sebastian, Kostrzewa Krzysztof, Feliks Edward

Stal, Metale & Nowe Technologie

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2023

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nr 1-2

30--34

PL

W publikacji przedstawiono charakterystykę staliwa stopowego wysokomanganowego, potocznie określanego mianem staliwa Hadfielda. Staliwa z tej grupy w warunkach wzrostu ciśnienia lub obciążenia, np. w wyniku uderzenia, wykazują dużą skłonność do tzw. umocnienia zgniotem, objawiającego się zwiększeniem powierzchniowej twardości i odporności na zużycie przy zachowaniu ciągliwości rdzenia.

EN

The paper presents the characteristics of a high-manganese alloy cast steel, commonly referred to as Hadfield cast steel. Cast steels of this group demonstrate a high tendency to the so-called strain hardening under the conditions of pressure or load increase, e.g. as a result of an impact, which is manifested by an increase in surface hardness and wear resistance while maintaining the ductility of the core. This is decisive for the applicability of a high-manganese cast steel for the castings of hammers and liners for coal mills and other mills, crusher cones, working elements of construction machines as well as cast elements of turnouts. In particular, the paper presents the chemical composition and usable properties of a high- -manganese cast steel intended for use in railway infrastructure as well as the characteristics of its microstructure finally shaped by heat treatment.

2

Experimental and Numerical Comparison of Lead-Free and Lead-Containing Brasses for Fixture Application

Radzioch Grzegorz, Bartocha Dariusz, Kondracki Marcin

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 3

124--132

EN

A comparative analysis of brasses alloys, namely lead-free CuZn (CB771) and lead containing CuZn (CB770), was conducted in this article. The results of the comparative analysis and experimental investigations aimed to provide comprehensive knowledge about the thermophysical properties and solidification characteristics of these alloys. Thermodynamic simulations using Thermo-Calc software and modifications in the chemical composition of the CB771 alloy were employed to approximate its characteristics to those of the lead containing CuZn alloy. Thermal-derivative analysis of the alloys and a technological trial were carried out to determine their solidification characteristics, fluidity, and reproducibility. The casting trials were conducted under identical conditions, and the results were compared for a comprehensive analysis. Additionally, a solidification process simulation was performed using MagmaSoft software to match the thermophysical properties. The aim of this research was to achieve maximum consistency between the simulation results and experimental investigations.

3

The impact of the melting and pouring process on the quality of the biggest rocking bell called Vox Patris

Bartocha Dariusz, Baron Czesław

Quality Production Improvement - QPI

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2019

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Vol. 1, Iss. 1

230--237

EN

The paper describes the process of melting, metalworking and pouring the form of the world's largest 55-ton rocking bell called Vox Patris. The project was carried out by Pracownia Ludwisarska of Jan Felczyński from Przemyśl in cooperation with Rduch Bells & Clocks from Czernica and Metalodlew SA from Kraków. Comprehensive scientific and technical support of the project was provided by the Department of Foundry of the Silesian University of Technology. The bell is made of bronze, which is an alloy of copper and tin with a content of tin at the level of 20%. The foundry, where the melting and pouring process took place, had two 14 ton electric furnaces, 15 ton transport pouring ladle and a 60 ton collection ladle. Therefore, it was necessary to determine the minimum temperature of the pouring and the conditions for holding the liquid metal so that the metal from the first cast would not solidify before accumulating its total amount (four melts) (Bartocha and Baron, 2015; Bartocha and Baron, 2016). The study presents the tests of alloy properties and a series of computer simulations. Thanks to them the maximum and minimum permissible temperature of metal overheating has been determined (Bartocha, 2017). The final stage of the cast was the mold pouring process. The filling system was responsible for the correct performance of this process. This system comprised a tank (collector) under a doublestopper 60-ton main ladle, an elevenmeter tapping spout, an infusion tank and a downgate. The task of the gating system is uniform and continuous supply of liquid metal to the mold until it is completely filled. The unusual layout, that was used, required checking many factors. Various configurations of the system parameters have been tested based on the series of computer simulations (Czochlarski and Bukowski, 1935; Ignaszak, 1999).