Wyniki wyszukiwania - Biblioteka Nauki

1

The influence of iron powder and disintegrated steel scrap additives on the solidification of cast iron

100%

Kopyciński D. , Dorula J.

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tom Vol. 36, no. 2

97-104

EN

The study proves that by introducing the iron powder and disintegrated steel scrap to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite gp due to a similar crystallographic behaviour of the regular face centered cubic lattice The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the structure more refined (more eutectic grains) and the mechanical properties higher.

PL

W pracy wykazano, że wprowadzenie do żeliwa o niskiej zawartości siarki, jeszcze przed zabiegiem modyfikowania tradycyjnym modyfikatorem grafityzującym, proszku żelaza i/lub złomu stalowego w postaci rozdrobnionej, prowadzi do otrzymania podobnych właściwości wytrzymałościowych jak przy zabiegu modyfikowania dla żeliwa o zalecanej wyższej zawartości siarki. Zabieg ten zwiększa liczbę zarodków krystalizacji dendrytów austenitu pierwotnego. W tym przypadku cząstki żelaza spełniają rolę podkładek do zarodkowania austenitu pierwotnego ϒp wskutek podobieństwa krystalograficznego sieci regularnej (ściennie centrowanej). Im większa liczba dendrytów austenitu pierwotnego, tym mniej miejsca w przestrzeniach międzydendrytycznych na kształtowanie się ziaren eutektyki grafitowej, a w efekcie nieco drobniejsza struktura (większa liczba ziaren eutektycznych) oraz większe wartości właściwości wytrzymałościowych.

2

Impact of Sprue Base in Gating System on Quality of Filling – the Compromise Between Theory and Practice

80%

Dorula J. , Jezierski J. , Siodmok B. , Romelczyk R.

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3

Impact of Sprue Base in Gating System on Quality of Filling – the Compromise Between Theory and Practice

80%

Siodmok B. , Jezierski J. R. , Dorula J. , Romelczyk R.

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tom Vol. 18, iss. 3

167--172

EN

Foundry technologists use their own style of gating system designing. Most of their patterns are caused by experience. The designs differ from plant to plant and give better or worse results. This shows that the theory of gating systems is not brought into general use sufficiently and therefore not applied in practise very often. Hence, this paper describes the theory and practical development of one part of gating systems - sprue base for automated horizontal moulding lines used for iron castings. Different geometries of sprue bases with gating system and casting were drawn in Solid Edge ST9. The metal flow through the gating systems was then simulated with use of MAGMA Express 5.3.1.0, and the results were achieved. The quality of flow was considered in a few categories: splashes, air entrapment, vortex generation and air contact. The economical aspect (weight of runner) was also taken under consideration. After quantitative evaluation, the best shape was chosen and optimised in other simulations with special attention on its impact on filling velocity and mould erosion. This design (a sprue base with notch placed in drag and cope) is recommended to be used in mass production iron foundries to reduce oxide creation in liquid metal and especially to still metal stream to improve filtration.

4

Zastosowanie analizy termicznej ITACA do minimalizacji zmienności procesu produkcji odlewów żeliwnych

80%

Dorula J. , Sierant Z. , Balicki M. , Wilczyński T.

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2014

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tom Vol. 64, nr 7-8

294--296

PL

Zastosowanie analizy termicznej ITACA pozwala ustalić najbardziej optymalny stan fizykochemiczny żeliwa wyjściowego przeznaczonego do produkcji odlewów z żeliwa.

5

Forming of primary austenite in low-sulphur cast iron

80%

Kopyciński D. , Guzik E. , Dorula J.

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2011

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tom Vol. 11, iss. 1

57-60

EN

The study proves that by introducing the disintegrated steel scrap to low-sulphur cast iron still before the inoculation carried out with a conventional graphitising inoculant, the mechanical properties similar to those obtained during the inoculation treatment carried out on cast iron with the recommended high sulphur content are achieved. The said operation increases the number of crystallisation nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite \ypsilon p due to a similar crystallographic behaviour of the regular face centered cubic lattice. The more numerous are the dendrites of primary austenite, the less free space is available in the interdendritic spaces for the formation of graphite eutectic grains, which makes the structure more refined (more eutectic grains) and the mechanical properties higher.

6

The Influence of Selected Water and Alcohol Based Coatings on Bending Strength of Foundry Moulds and Cores Manufactured in Furan Technology

71%

Romelczyk R. , Przyszlak N. , Siodmok B. , Dorula J. , Studnicki A.

Archives of Foundry Engineering

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2018

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tom Vol. 18, iss. 2

169--172

EN

The subject of this paper was to compare the influence of selected coatings on bending strength of moulds and cores manufactured in a furan technology. In a range of study, there were used three kinds of coatings - water based coating and two kind of alcohol based coating manufactured by FOSECO. Coating were applicated by brush, overpouring/flow and spraying. For each application method, there were realized different kind of drying- at ambient temperature, in a furnace and by burning. Physicochemical properties of coatings were such selected to accommodate them to the application method and type of coating. Based on the conducted studies it was observed that for water based coating application method doesn’t have an important influence on bending strength and it is necessary to optimize the time and temperature of drying to achieve better results of bending strength. For alcohol based coatings, drying by burning causes significant deterioration of bending strength of the mould and core and drying process at ambient allows to obtain high bending strength of mould/cores in regard to time of drying.

7

The Influence of Selected Water and Alcohol Based Coatings on Bending Strength of Foundry Moulds and Cores Manufactured in Furan Technology

71%

Dorula J. , Romelczyk R. , Przyszlak N. , Siodmok B. , Studnicki A.

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8

Inoculation of Austenite Primary Grains in Cast Iron

61%

Kopyciński D. , Guzik E. , Szczęsny J. , Dorula J. , Siekaniec D. , Ronduda M.

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2014

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tom Vol. 14, iss. 4

45--48

EN

The modification is a widespread method of improving the strength properties of cast iron. The impact in terms of increasing amounts of eutectic grains has been thoroughly studied while the issue of the impact on the mechanical properties of primary austenite grains has not been studied in depth yet. The paper presents the study of both aspects. The methodology was to conduct the melting cast iron with flake graphite, then modifying the alloy by two sets of modifiers: the commercial modifier, and a mixture of iron powder with a commercial inoculant. The DAAS test was carried out to identify the primary austenite grains. The degree of supercooling was determined and the UTS test was performed as well. Additionally carried out the metallographic specimen allowing for counting grains. It can be concluded that the introduction of the iron powder significantly improved the number of austenite primary grains which resulted in an increase in tensile strength UTS.