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1
Content available Influence of Type and Shape of the Chill on Solidification Process of Steel Casting
Jaromin M., Dojka R., Jezierski J. R., Dojka M.
Archives of Foundry Engineering
|
2019
|
iss. 1
35--40
EN
The article is a case study of the steel milling ring casting of about 6 tonnes net weight. The casting has been cast in the steel foundry the authors have been cooperating with. The aim was to analyse the influence of the shape of the chills and the material which was used to make them on the casting crystallization process. To optimally design the chills the set of the computer simulation has been carried out with 3 chills’ shape versions and 3 material’s versions and the results have been compared with the technology being in use (no chills). The proposed chills were of different thermal conductivity from low to high. Their shapes were obviously dependant on the adjacent casting surface geometry but were the result of the attempt to optimise their effect with the minimum weight, too. The chills working efficiency was analysed jointly with the previously designed top feeders system. The following parameters have been chosen to compare their effectiveness and the crystallization process: time to complete solidification and so-called fed volume describing the casting feeding efficiency. The computer simulations have been carried out with use of MagmaSoft v. 5.2 software. Finally, the optimisation has led to 15% better steel yield thanks to 60% top feeders weight reduction and 40% shorter solidification time. The steel ring cast with use of such technology fulfil all quality criteria.
2
Content available Crystallization Process of High Chromium Cast Iron with the Addition of Ti and Sr
Dojka M., Kondracki M., Studnicki A., Dojka R.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 2
57--64
EN
The paper concerns the processes connected with the formation of chromium white cast iron microstructure. The influence of titanium and strontium on the alloy crystallization has been described using TDA method and EDS analysis. Conducted experiments allowed the determination of the selected additions influence on the microstructure of examined alloys. TDA analysis enabled indication of the characteristic temperatures of thermal effects for samples with strontium and titanium and the comparison of results for the reference sample without additions. The results of TDA test also included the analysis of the temperature first derivative values, which presented interesting differences as well. The scanning microscopy observation clearly indicated the difference between the effect of strontium and titanium on the alloy microstructure. The EDS analysis helped to identify the chemical composition of the evolving phases and confirmed the strontium presence in the eutectic. Experimental results allowed to draw reliable conclusions about the effect of applied additions on the crystallization and microstructure of chromium cast iron.
3
Content available The Effect of Heat Removal from the Casting Mould on the Crystallization High Silicon Cast Iron
Stawarz M., Gromczyk M., Szajnar J.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 2 spec.
83--86
EN
Silicon cast iron with high chemical resistance, which is the biggest advantage of this material, did not have any competition for a long time. It was popular on the market of metal materials because of its low price. However, the production of this material requires special attention and precautions, which is a barrier for foundry. The article presents the results of research of high silicon cast iron crystallization based on thermal derivative analysis (which has identified characteristic temperatures of the investigated alloy crystallization process basis on the part of Fe–Si phase diagram and process analysis using calculations made in Thermo–Calc software) and metallographic analysis of the structure.
4
Content available Effect of Chromium on the Solidification Process and Microstructure of Vermicular Graphite Cast Iron
Gumienny G., Dondzbach M., Kacprzyk B.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3
29--34
EN
The paper presents the results of studies of the effect of chromium concentration on the solidification process, microstructure and selected properties of cast iron with vermicular graphite. The vermicular graphite cast iron was obtained by an Inmold process. Studies covered the cast iron containing chromium in a concentration at which graphite is still able to preserve its vermicular form. The effect of chromium on the temperature of eutectic crystallization and on the temperature of the start and end of austenite transformation was discussed. The conditions under which, at a predetermined chromium concentration, the vermicular graphite cast iron of a pearlitic matrix is obtained were presented, and the limit concentration of chromium was calculated starting from which partial solidification of the cast iron in a metastable system takes place. The effect of chromium on the hardness of cast iron, microhardness of individual phases and surface fraction of carbides was disclosed.
5
Content available Crystallization of AlSi17Cu5Mg Alloy after Time-thermal Treatment
Piątkowski J., Kamiński P.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1
83--86
EN
In the dissertation it has been shown, that so called “time-thermal treatment” (TTT) of the alloy in liquid state as overheating the metal with around 250°C above Tliq. and detailing it in temperature for 30 to 40 minutes has the influence on changing the crystallization parameters (Tliq., TEmin., TEmax., TE(Me), TSol.). It was ascertained, that overheating the AlSi17Cu5Mg alloy substantially above Tliq. results with microcrystalline structure. Evenly distributed in the eutectic warp primeval silicon crystals and supersaturated with alloying additives of base content (Cu, Mg, Fe) of α(Al) solution, ensures not only increase durability in ambient temperature, but also at elevated temperature (250°C), what due to it’s use in car industry is an advantage.
6
Content available Badania mikroskopowe krystalizacji paliw konwencjonalnych i biopaliw podczas chłodzenia
Baczewski K., Szczawiński P.
Aparatura Badawcza i Dydaktyczna
|
2014
|
T. 19, nr 3
227-235
PL
Przedstawiono wyniki badań mikroskopowych procesu krystalizacji bazowego oleju napędowego (HON) oraz estru metylowego oleju rzepakowego (RME), obu czystych i z dodatkiem depresatora podczas chłodzenia. Opisano proces krystalizacji i morfologię kryształów. Wykazano, że krystalizacja HON i RME, zarówno czystych, jak i z dodatkiem depresatora, przebiega odmiennie. Podczas krystalizacji HON powstaje więcej kryształów w kształcie płytek, a RME - więcej kryształów w kształcie igieł. Proces krystalizacji determinuje zmianę właściwości reologicznych badanych paliw. Depresator modyfikuje przebieg procesu krystalizacji odmiennie dla HON i RME.
EN
Document contains the microscopic investigations results of crystallization process of base diesel oil (HON), rapeseed oil methyl ester (RME) both pure and with the addition of depressant during cooling. In addition a process of the crystallization and the crystals morphology were described. It has been shown that crystallization HON and RME, either pure or with the depressant addition proceeds differently. HON formed during the crystallization more platelet-shaped crystals and RME - more needle- shaped crystals. The crystallization process determines change in rheological properties of tested fuels. Depressant modifies the crystallization process differently for HON and RME.
7
Content available remote Influence of vibrations during crystallization on mechanical properties and porosity of AlSi13Cu2 alloy
Ciućka T.
Archives of Foundry Engineering
|
2010
|
Vol. 10, iss. 1 spec.
127--130
EN
Today’s industry aims at such situation, where number of defective products, so called defects shall approach to zero. Therefore, one introduces a various changes in technology of production, introduces improvements which would help in accomplishment of this objective. Another important factor is introduction of different type of testing, which shall help in assessment which factor has significant effect on quantity of rejects, and which one could be neglected. Existence of casting rejects is unavoidable; therefore a new ideas, technologies and innovations are necessary in the entire widely understood foundry branch, in order to minimize such adverse effect. Performance of tests aimed at unequivocal determination of an effect of vibrations during crystallization on mechanical properties and porosity of the AlSi13Cu2 alloy was the objective of the present work. To do this, there were produced 36 castings from AlSi13Cu2 alloy. All the castings underwent machining operations. Half of the casting was destined to strength tests, the other half served to determination of an effect of vibrations on porosity of the alloy. The specimens were divided into 12 groups, depending on amplitude of vibrations and tilt angle of metal mould during pouring operation.
8
Content available remote Proeutectic crystallisation in hypereutectic silumins modified with Al-CuP-Me master alloys
Piątkowski J.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 4
195-198
EN
Using thermal analyses TA and ATD, within a narrow range of the crystallisation period, i.e. until reaching an equilibrium temperature, the occurrence of exothermic effect was stated. Most probably, the said effect is due to a proeutectic crystallisation of \alfa phase or of \beta phase crystals. The said effect was observed to occur only in alloys after the process of modification with an addition of high-melting point elements. Complex inoculants of Al-CuP-Me (Me = Mo, Co, Cr, Nb, TiB, W) type cause hardening of silumins, due to the formation of new phases of the AlxMey type, which can act as substrates for the nucleation of \alfa dendrites and crystals of \beta phase. The experiments carried out on castings solidifying with different rates of heat transfer have proved that proeutectic crystallisation does not occur when free solidification conditions (microspheres) are provided. This fact can be related to the heat transfer rate.
9
Content available remote Coefficient of crystal lattice matching as a parameter of substrate - crystal structure compatibility in silumins
Piątkowski J.
Archives of Foundry Engineering
|
2009
|
Vol. 9, iss. 4
191-194
EN
Adding high-melting point elements (Mo, Nb, Ni, Ti, W) to complex silumins results in hardening of the latter ones, owing to the formation of new intermetallic phases of the AlxMey type, with refinement of dendrites in \alfa solution and crystals in \beta phase. The hardening is also due to the effect of various inoculants. An addition of the inoculant is expected to form substrates, the crystal lattice of which, or some (privileged) lattice planes and interatomic spaces should bear a strong resemblance to the crystal nucleus. To verify this statement, using binary phase equilibria systems, the coefficient of crystal lattice matching, being one of the measures of the crystallographic similarity, was calculated. A compatibility of this parameter (up to 20%) may decide about the structure compatibility between the substrate and crystal which, in turn, is responsible for the effectiveness of alloy modification. Investigations have proved that, given the temperature range of their formation, the density, the lattice type, and the lattice parameter, some intermetallic phases of the AlxMey type can act as substrates for the crystallisation of aluminium and silicon, and some of the silumin hardening phases.
10
Content available remote The structure of liquid eutectic as a gowerning factor in crystallization processes
Prokhorenko W., Mudry S., Prokhorenko S., Bylica A., Navotska J.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 18/2
527--530
EN
The structure of Ga-In-Sn eutectic melt has been studied by means of x-ray diffraction method. The structure factors and pair correlation functions are analyzed. It is shown that inhomogeneous structure exists within some temperature range and can be changed by outside energetic influence.
PL
W pracy przedstawiono wyniki porównawczych badań stukturalnych eutektycznego stopu Ga-In-Sn. Uzyskane wyniki potwierdziły występowanie w tym stopie struktur niehomogenicznych w szerokim zakresie temperatury oraz możliwość zmiany takich struktur przez zewnętrzne oddziaływanie energetyczne.
11
Content available remote Diagnozowanie procesów krystalizacji metali nieżelaznych stosowanych w budowie maszyn
Dudyk M.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 18/1
77--84
PL
W artykule przedstawiono wyniki badań procesów krystalizacji stopów: aluminium – (AK9, AK65, AK132), miedzi – (MO5, B555) i cynku – Z41. Przebieg procesów krystalizacji zarejestrowano w postaci zapisu graficznego krzywych termicznych t = f(τ) i przewodności elektrycznej σ = f(τ) oraz ich pierwszych pochodnych. Opracowane programy komputerowe pozwalają określić – w charakterystycznych punktach (pikach) – na krzywych krystalizacji powstające fazy tworzące strukturę odlewu. Przeprowadzona analiza wartości liczbowych – zaznaczonych kursorami – umożliwia określenie stopnia uszlachetnienia badanych stopów.
EN
The paper presents the result of research on processes of crystallisation of alloys: aluminium – AK9, AK64, AK132; copper – MO59, B555 and zinc – Z41. The processes of crystallisation ware registered in graphical notation of thermal curves – t=f(τ) and electrical conductivity - σ = f(τ) as well as their first derivatives. Developed computer programs enable to determine – in characteristic points (peaks) of crystallisation curves – the phases building the structure of the cast. The carried out analysis of numerical values – marked with cursors – enables to determine the degree of purification of alloys.
12
Content available remote Komputerowo wspomagane stanowisko do „zamrażania” próbek w badaniach procesu krzepnięcia i krystalizacji
Soiński M. S., Wilk M.
Archiwum Odlewnictwa
|
2003
|
R. 3, nr 10
181--186
PL
W pracy przedstawiono zmiany w konstrukcji wcześniej zbudowanego stanowiska do „zamrażania” próbek w trakcie stygnięcia i krzepnięcia. Obejmowały one zmiany w izolacji cieplnej tygielka z próbką, użycie odpowiednio nawiniętej cewki indukcyjnej oraz zastosowanie sterowanego komputerowo elektromagnetycznego mechanizmu do uwalniania próbek kierowanych do „zamrożenia”.
EN
Changes in the construction of earlier built equipment for the so-called “freezing” of specimens were presented in this work. They include changes in the thermal insulation of the malting crucible containing a specimen, as well as employing of a new high frequency coil and the computer-controlled electromagnetic mechanism for “freezing” of specimens.
13
Content available remote Modelling of pure metal crystallization process with regard to sensitivity analysis
Majchrzak E., Mendakiewicz J., Piasecka-Belkhayat A.
Archiwum Odlewnictwa
|
2002
|
R. 2, nr 4
141--146
EN
In the paper the sensitivity analysis of pure metal crystallization process with respect to the number of nuclei N and growth coefficient μ is presented. The basic problem and additional problems connected with the sensitivity analysis are solved using the boundary element method. In the final part the results of computations are shown.
PL
W pracy przedstawiono analizę wrażliwości procesu krystalizacji czystego metalu ze względu na liczbę ziaren N i współczynnik wzrostu μ. Zadanie podstawowe i problemy dodatkowe wynikające z analizy wrażliwości rozwiązano stosując metodę elementów brzegowych. W końcowej części artykułu przedstawiono wyniki obliczeń.
14
Content available remote Zastosowanie metody ATD do kontroli żeliwa wermikularnego
Władysiak R.
Krzepnięcie Metali i Stopów
|
2000
|
R. 2, nr 44
355--364
PL
W pracy przedstawiono wyniki badań procesu krystalizacji metodą ATD żeliwa wermikularnego. Stwierdzono występowanie charakterystycznych różnic między krzywymi ATD żeliwa wyjściowego i wermikularnego oraz istnienie korelacji pomiędzy charakterystycznymi parametrami krzywych ATD a właściwościami Rm, Rp0,2, A5 i HB. Otrzymane wyniki potwierdzają możliwość zastosowania metody ATD do kontroli procesu otrzymywania żeliwa wermikularnego.
EN
The test results of crystallization of cast iron with vermicular graphite, which were made with the thermal-derivative analysis method, have been presented here. The characteristic differences between cast iron before and after the vermicularization have been stated on the derivative curve. It has been proved, that there is a statistic dependence between the characteristic parameters of ATD curves and mechanical properties: Rm, Rp0,2, A5 and HB of this cast iron. The results verify the possibility to use the ATD method to control of production of cast iron with vermicular graphite.
15
Content available remote Rejestracja procesów krystalizacji metodą ATND
Ciućka T.
Krzepnięcie Metali i Stopów
|
2000
|
R. 2, nr 44
81--86
PL
W artykule przedstawiono próbę zastosowania jednoczesnej metody Analizy Termiczno-Napięciowo Derywacyjnej do badań metalograficznych stopów metali nieżelaznych. Badania były prowadzone na stopie AK132 i AL99,75 poddanego typowym zabiegom rafinacji i modyfikacji.
EN
The evaluation test of structure properties of the AK132 silumin and AL99,75 have been described in this paper. The characteristics points obtained from the solidification curves and from the electrical curves, as well from their derivatives have been determined on the state of the solidification and crystallization curves using the method simultaneous recording ATND.
16
Content available remote Stabilność wzrostu kryształów kolumnowych w odlewach tradycyjnych i wykonywanych pod wpływem pola magnetycznego
Szajnar J.
Krzepnięcie Metali i Stopów
|
1999
|
R. 1, nr 40
213--224
PL
W pracy przeprowadzono analizę wzrostu kryształów kolumnowych w odlewach ze stopu ZnAl0,2 krzepnących pod działaniem wirującego pola magnetycznego. Analizy dokonano w oparciu o metodę perturbacyjną Mullinsa i Sekerki [1] oraz kryterium stabilności marginalnej Langera i Mullera-Krumbhaara [2]. Stwierdzono dużą zgodność otrzymanych obliczeń z wynikami pomiarów szerokości strefy kryształów kolumnowych.
17
Content available remote Modelowe badania przemiany perytektycznej
Fraś E., Kapturkiewicz W., Burbelko A., Lopez H.
Krzepnięcie Metali i Stopów
|
1998
|
nr 36
9--17
PL
Przemiana perytektyczna jest jedną z kilku przemian fazowych zachodzących przy krzepnięciu stopów, która prowadzi do utworzenia struktury wielofazowej. Liczba publikacji z zakresu krystalizacji perytektycznej jest niewielka [1-10] i podstawowe pojęcia z tego zakresu są różnie interpretowane przez poszczególnych autorów. [...]
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