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1
Content available Effect of Regular Shot Peening and Semi-Random Shot Peening Conditions on Selected Properties of the Surface Layer of Gray Cast Iron
Skoczylas Agnieszka, Zaleski Kazimierz
Advances in Science and Technology. Research Journal
|
2024
|
Vol. 18, no 2
284--295
EN
Both dispersed and concentrated shot peening can be an effective method for the finishing of machine components. This work investigates the effect of two different shot peening (SP) processes conducted with the same technological parameters on selected properties of the surface layer of gray cast iron EN-GJL 250. Specifically, regular shot peening (RSP) and semi-random shot peening (SRSP) were investigated in the study. The results demonstrated that the surface quality of EN-GJL 250 samples was higher after RSP than after SRSP. The analyzed surface roughness parameters were lower after RSP than after SRSP, with the exception of the Rvk parameter. As a result of RSP, the analyzed roughness parameters increased from 5% to 62% in relation to their values after pre-treatment. The lowest values of the surface roughness parameters were obtained after RSP conduced with the impact energy E = 100 mJ, the distance between the dimples x = 0.3 mm, and the diameter of the shot peening element d = 14.3 mm. Assessment of the 3D surface topography showed significant differences in the formation of machining traces depending on the employed surface treatment. In RSP, the traces were arranged in a uniform manner, with the assumed step, whereas in SRSP the shot peening traces had no set pattern of orientation. The application of RSP and SRSP caused an increase in surface microhardness. The maximum surface microhardness was 75 HV0.5 for RSP and 98 HV0.5 for SRSP. Residual stresses were higher after SRSP than after RSP. Compressive residual stresses were induced in both types of shot peening process.
2
Content available Influence of Charge Materials on the Metallurgical Quality of Gray Cast Iron
Dwulat Rafał, Janerka Krzysztof, Grzesiak K., Gałuszka M.
Archives of Foundry Engineering
|
2023
|
Vol. 23, iss. 2
66--71
EN
The article presents the influence of the percentage share of pig iron and steel scrap on the chemical composition, physicochemical and mechanical properties. Using an induction furnace, 6 melts were carried out with a variable amount of pig iron in the charge from 0 to 50%. For carburizing, a RANCO 9905 carburizer with a carbon content of 99.2% was used. After melting and introducing FeSi75, temperature measurement was carried out and the metal was superheated to 1500°C. The next step was to pour the samples for chemical analysis, DTA (Derivation Thermal Analysis) and strength and hardness from the melting furnace without inoculation. The last step was to carry out the inoculation by introducing 0.3% barium inoculant into the vat and pouring samplers for DTA analysis. The inoculation was carried out solely to determine changes in DTA parameters, mainly Temin, compared to castings without inoculation.
3
Content available Forecasting the Natural Frequency of the Brake Disccasting
Zyska Andrzej, Bieroński Mariusz
Archives of Foundry Engineering
|
2023
|
Vol. 23, iss. 4
87--92
EN
The paper presents the results of calculations and measurements of the first natural frequency of castings of solid and ventilated brake discs made of gray cast iron of the EN-GJL-200 class. The tests were carried out for three types of chemical composition, taking into account the permissible minimum and maximum content of alloying elements. Numerical simulations of natural vibrations were carried out on the basis of our own production material databases. To determine the elastic properties of cast iron, the ultrasonic method with the measurement of the propagation velocity of longitudinal and transverse waves was used. Measurements were made directly on casts of raw discs of various thicknesses. The values of Young's modulus and Poisson's number calculated from ultrasonic measurements were used to define the stiffness matrix in the equilibrium equation, which is solved by the solver of the MSC Nastran program. A high compatibility between the results of numerical simulations and the results of experimental FRF frequency analysis was obtained. The differences between the calculated and actual values were at the level of several hertz, while the estimated average error of numerical simulations was 0.76%. It was also found out that cast iron melts for brake discs must be subject to strict control in terms of chemical composition. Slight deviations of the eutectic saturation coefficient from the optimal value cause a significant change in the first natural frequency of the brake discs, regardless of their geometry.
4
Content available Case study of accelerated wear of brake discs made of grey cast iron characterized by increased thermal stability
Zemlik Martyna, Dziubek Mateusz, Pyka Dariusz, Konat Łukasz, Grygier Dominika
Combustion Engines
|
2022
|
R. 61, nr 3
45--49
EN
In this paper, the subject of the analysis is Rotinger High Performance brake disc, characterized by increased thermal resistance, which is a result of adequate design and material solutions. However, despite declared performance, the analyzed discs suffered accelerated wear over a period of about 20 months. The aim of this study was to assess the causes of the disc failure. As a result, it was showed that the applied material solution still does not differ from standard ones. According to the authors of this paper, an appropriate procedure to improve resistance to thermal fatigue is, among others, changing the shape of graphite precipitates from flake to spheroidal.
5
Content available A Process of As-Cast Ferritic Gray Cast Iron Production
Hossain Md Sojib
Archives of Foundry Engineering
|
2021
|
Vol. 21, iss. 3
5--10
EN
Though normal air cooling and green sand mold-casted gray iron convey an essentially pearlitic matrix, ferritic gray iron is used in some electro-mechanical applications to have better magnetic properties, ductility, and low hardness. Conventionally, to produce ferritic gray iron, foundryman initially produces pearlitic gray iron, then it is carried through a long annealing cycle process for ferritic transformation. This experiment is conducted to eliminate the long annealing cycle from the conventional process. A process is developed to produce as-cast ferritic gray cast iron by air cooling in the green sand mold. In this experiment, Si content is kept high, but Mn content is kept low based on sulfur content; a unique thermodynamic process is established for decreasing the Mn content from the melt. After a successful preconditioning and optimum foundry return charging, the melt is specially inoculated, and metal is poured into the green sand mold. An extra feeder is added for slowing down the cooling rate where casting thickness is around 15mm. Finally, hardness and metallographic images are observed for final confirmation of the ferritic matrix.
6
Content available The Influence of Selected Melting Parameters on the Physical and Chemical Properties of Cast Iron
Petrus Ł., Bulanowski A., Kołakowski J., Brzeżański M., Urbanowicz M., Sobieraj J., Matuszkiewicz G., Szwalbe L., Janerka K.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 1
105--110
EN
This paper presents the problems related to smelting gray and ductile cast iron. Special attention is paid to the metallurgical quality of cast iron. It depends on the type of furnace, charge materials and the special combination of charge, overheating and holding temperature, melting time, modification and spheroidization method. The evaluation of metallurgical quality has been performed by using derivative-thermal analysis (DTA). During the smelting process and secondary metallurgy, the ITACA system was used allowing to obtain information on alloy characteristic temperatures (Tliquidus, TeMin, TeMax, Tsolidus), VPS value, recalescence value, IGQ coefficient, nucleation gauge, porosity etc. The results of investigations and calculations are displayed in the form of graphs and dependencies. It has been shown that the derivative-thermal analysis (DTA) is an effective complement of chemical analysis and it has been found that both the increase in temperature and metal holding time have a negative impact on the metallurgical quality of liquid metal. The metallurgical quality can be improved by using proper composition of charge materials and modifiers.
7
Content available The Effect of Structure on Thermal Power of Cast-iron Heat Exchangers
Mróz M., Orłowicz A. W., Tupaj M., Jacek-Burek M., Radoń M., Kawiński M.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 1
27--30
EN
The objective of the study reported in this paper was to determine the effect of structure on thermal power of cast-iron heat exchangers which in this case were furnace chambers constituting the main component of household fireplace-based heating systems and known commonly as fireplace inserts. For the purpose of relevant tests, plate-shaped castings were prepared of gray iron with flake graphite in pearlitic matrix (the material used to date typically for fireplace inserts) as well as similar castings of gray cast iron with vermicular graphite in pearlitic, ferritic-pearlitic, and ferritic matrix. For all the cast iron variants of different structures (graphite precipitate shapes and matrix type), calorimetric measurements were carried out consisting in determining the heat power which is quantity representing the rate of heat transfer to the ambient environment. It has been found that the value of the observed heat power was affected by both the shape of graphite precipitates and the type of alloy matrix. Higher thermal power values characterize plate castings of gray iron with vermicular graphite compared to plates cast of the flake graphite gray iron. In case of plates made of gray cast iron with vermicular graphite, the highest values of thermal power were observed for castings made of iron with ferritic matrix.
8
Content available Influence of Cast Iron Modification on Free Vibration Frequency of Casting
Konopka Z., Łągiewka M., Zyska A.
Archives of Foundry Engineering
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2020
|
Vol. 20, iss. 1
23--26
EN
The paper presents the results of investigations concerning the influence of gray cast iron modification on free vibration frequency of the disc casting. Three different chemical composition melts of gray cast iron were prepared in induction furnace. During gravity casting 0.05% and 0.3% mass of the Inolate modifier was added on stream of metal for changing graphite flakes in castings. Sound signal vibration of cast iron sample was registered by means on microphone for free vibration frequency measurements. Decreasing of free vibration frequency of modified cast iron in comparison with non modified castings was observed. Higher contents of modifier causes more decreasing of free vibration frequency. Cast iron with smaller contents of carbon and silicon have higher free vibration frequency in comparison with eutectic composition cast iron. Hardness of examined cast iron is lower when the more modifier is added during modification process. Free frequency is smaller with smaller Brinell hardness of disc casting. It was concluded that control of free vibration frequency of disc castings by means of chemical composition and modification process can improved comfort and safety of working parts.
9
Content available Fabrication of High-Strength Gray Cast Iron Using Permanent Magnet Scrap
Park S.-Y., Kim J. H., Seo S. J., On J. S., Lim K. M.
Archives of Metallurgy and Materials
|
2017
|
Vol. 62, iss. 2B
1113--1117
EN
In this study, we have developed the manufacturing technology for high strength gray cast irons by using the spent permanent magnet scraps. The cast specimen inoculated by using a spent magnet scraps showed the excellent tensile strength up to 306MPa. This tensile strength value is 50MPa higher than that of the specimen cast without inoculation, and is similar to that of the specimen inoculated by using the expensive misch-metal. These superior mechanical properties are attributed to complex sulfides created during solidification that promote the formation and growth of Type-A graphite. It is therefore concluded that spent magnets scrap can provide an efficient and cost-effective inoculation agent for the fabrication of high-performance gray cast iron.
10
Content available Investigation of an Advanced Cellulose Profile Used for the Manufacture of Gating Systems
Zawieja Z., Sawicki J., Gumienny G., Sobczyk-Guzenda A.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 3
123--128
EN
The here in paper contains the results of investigations on a new type of cellulose blend used for the manufacture of profiles applied in the process of making gating systems in the foundry industry. A standard cellulose profile was subjected to an experiment. During the experiment the profile was filled with a liquid cast iron and at the same time the temperatures of the liquid metal crystallizing inside the profile were measured as well as the temperature of the outer layer of the profile was controlled. Further, the microstructure of the cast iron, which crystallized out inside the cellulose profile, was analysed and the cellulose, thermally degraded after the experiment, was verified with the use of the chemical analysis method. Moreover, a quality analysis of the original as well as the degraded cellulose profile was run with the use of the FTIR infrared spectroscopy. The presented results revealed that the cellulose blend is aluminium silicate enriched and contains organic binder additives. The cast iron, which crystallized out, tended to have an equilibrium pearlitic structure with the release of graphite and carbides. The generation of disequilibrium ausferrite phases was also observed in the structure.
11
Content available Właściwości termofizyczne żeliwa przeznaczonego do produkcji tarcz hamulcowych
Rudnik D., Sobczak N., Gazda A., Homa M., Siewiorek A., Pietrzak K., Makowska K.
Prace Instytutu Odlewnictwa
|
2011
|
T. 51, z. 3
23-35
PL
Praca przedstawia wyniki szczegółowych badań podstawowych właściwości termofizycznych tarcz hamulcowych wykonanych z żeliwa szarego. Próbki żeliwa badano przed i po procesie eksploatacji w układzie hamulcowym. Zmierzono współczynniki przewodnictwa temperaturowego w funkcji temperatury za pomocą jednego z najnowocześniejszych zestawów aparaturowych LFA 427 (Laser Flash Apparatus) firmy Netzsch. Wykorzystując różnicową kalorymetrię skaningową DSC i technikę dylatometryczną wyznaczono ciepło właściwe cp(T) i gęstość d(T), co pozwoliło na obliczenie współczynników przewodzenia ciepła λ(T) za pomocą oprogramowania Netzsch LFA Analysis. Badania właściwości termofizycznych pozwoliły na identyfikację przemian fazowych zachodzących wstanie stałym (przemiana eutektoidalna) i ciekłym (topnienie żeliwa, obecność eutektyki fosforowej). Porównanie właściwości termofizycznych dwóch próbek żeliwa oznaczonych ST i NT pozwoliło na stwierdzenie nieznacznego obniżenia parametrów termofizycznych stopu ST, wynikającego z procesu eksploatacji.
EN
This paper presents the results of measurements of thermophysical properties of automotive brake discs made from gray cast iron. The samples were tested before and after operation in the braking system. Thermal conductivity as a function of temperature was measured using one of the most advanced sets of apparatus LFA 427 (Laser Flash Apparatus) produced by Netzsch. Applying differential scanning calorimetry DSC and dilatometric technique the specific heat cp(T) and density d(T) were determined and used for the calculation of coefficients of thermal conductivity λ(T) using Netzsch LFA Analysis software. Investigations of thermophysical property allowed the identification of phase transformations occurring in solid state (eutectoidal reaction) and liquid (melting, the formation of phosphorus eutectic). Comparison of thermophysical properties for the two cast iron alloys (ST and NT) allowed to declare a slight reduction in thermophysical properties of ST, resulting from the exploitation process.
12
Content available Laser hardening of cast iron ways of valves applied in combustion engines
Napadłek W.
Journal of KONES
|
2008
|
Vol. 15, No. 2
347-356
EN
The laser hardening of low-alloyed gray cast iron applied in valve ways production was investigated in our research. 0.8 kW and 2.5 kW technological lasers were applied. In the starting research the parameters of laser hardening were chosen, including beam scanning rate ni and a distance from the lens to the hardened surface Delta f. The main research were focused on metallographic analysis and tribological usage resistance. These experiments were carried on samples and real laser hardened ways, treated at optimal hardening parameters. The proposals of technological laser hardening ways of valves in important areas exhibited on the biggest tribological usage were presented. The experiment and the results of 450 hours long durability test of combustion engine were also described. The metrological measurements and surface topography analysis have proved the advantages of the ways laser hardening. Significant improvement of the tribological damage resistance of the bottom area of the way, exhibited on low lubrication and cyclic heat shocks in high temperatures in combustion chamber of the engine, was obtained. These research are the basis for industrial applications in series production.
PL
W pracy przedstawiono wyniki badań nad utwardzaniem laserowym żeliwa szarego niskostopowego, stosowanego w produkcji prowadnic zaworowych, będących elementami silników spalinowych. W badaniach Zastosowano lasery technologiczne o mocy P = 0,8 i 2,5 kW. W ramach badań wstępnych dokonano doboru parametrów hartowania laserowego z uwzględnieniem mocy wiązki laserowej P, prędkości przemieszczania (skanowania) wiązki laserowej ni oraz odległości ogniska soczewki od powierzchni poddanej utwardzaniu Delta f. Badania zasadnicze obejmowały analizę metalograficzną oraz pomiary odporności na zużycie tribologiczne wykonane na próbkach oraz rzeczywistych prowadnicach utwardzonych laserowo przy najlepszych parametrach obróbki laserowej. Przedstawiono propozycje technologiczne hartowania laserowego prowadnic zaworowych w newralgicznych strefach narażonych na największe zużycia tribologiczne. Opisano także przebieg oraz wyniki 450- godzinnej próby trwałościowej na silniku spalinowym o ZS. Pomiary metrologiczne oraz obserwacje topografii powierzchni przy użyciu boroskopu potwierdziły celowość prowadzenia hartowania laserowego prowadnic. Uzyskano znaczącą poprawę odporności na zużycie tribologiczne, zwłaszcza w dolnej strefie prowadnicy zaworu narażonej na ograniczone smarowanie oraz cykliczne szoki termiczne w wysokich temperaturach, występujących w komorze spalania silnika. Badania te stanowią podstawę do wdrożeń przemysłowych w produkcji seryjnej.
13
Content available remote Eutectic cell and nodule count as the quality factors of cast iron
Fraś E., Górny M.
Archives of Foundry Engineering
|
2008
|
Vol. 8, iss. 3
53-58
EN
In this work the predictions based on a theoretical analysis aimed at elucidating of eutectic cell count or nodule counts N were experimentally verified. The experimental work was focused on processing flake graphite and ductile iron under various inoculation conditions in order to achieve various physicochemical states of the experimental melts. In addition, plates of various wall thicknesses, s were cast and the resultant eutectic cell or nodule counts were established. Moreover, thermal analysis was used to find out the degree of maximum undercooling for the graphite eutectic, [...]. A relationship was found between the eutectic cell or nodule count and the maximum undercooling [...]. In addition it was also found that N can be related to the wall thickness of plate shaped castings. Finally, the present work provides a rational for the effect of technological factors such as the melt chemistry, inoculation practice, and holding temperature and time on the resultant cell count or nodule count of cast iron. In particular, good agreement was found between the predictions of the theoretical analysis and the experimental data.
14
Content available Badania efektów borowania laserowego elementów z żeliwa szarego
Kinal G., Waligóra W.
Journal of Research and Applications in Agricultural Engineering
|
2005
|
Vol. 50, nr 2
54-58
PL
W pracy przedstawiono badania zmierzające do opanowania technologii borowania laserowego elementów wykonanych z żeliwa szarego. Warstwy powierzchniowe wykonane tą technologią cechują się znaczną mikrotwardością i tym samym dużą odpornością na zużycie tribologiczne.
EN
This paper presents the research on establishing a laser boronizing technology of machine elements made of gray cast iron. Significant microhardness and following high tribological resistance are characteristic for surface layers created with the use of this technology.
15
Content available remote Budowa warstwy alfinowanej na żeliwie szarym
Pietrowski S.
Archiwum Odlewnictwa
|
2004
|
R. 4, nr 11/2
95--104
PL
W pracy podano budowę warstwy alfinowanej na żeliwie oraz hipotezę jej wzrostu. Wykazano, że bezpośrednio na żeliwie krystalizuje faza Al12Fe3Si. W dalszej odległości faza Al9Fe2Si. Pomiędzy nimi krystalizuje faza &alpha (Al) i eutektyka &alpha+&beta (Al+Si) podczas usuwania żeliwa z kąpieli Al-Si.
EN
In the paper given structure of alfinizing layer on the gray cast iron and hypothesis of their growth. It exert that the phase Al12Fe3Si crystallizing directty on the cast iron. Among them phase &alpha (Al) crystallizing and eutectic &alpha+&beta (Al+Si) during removal of cast iron from the metal bath Al-Si.
16
Content available remote Zależność właściwości żeliwa od materiałów wsadowych
Bartocha D., Gawroński J., Janerka K.
Archiwum Odlewnictwa
|
2003
|
R. 3, nr 9
22--30
PL
W artykule opisano wstępne badania wpływu rodzaju materiałów wsadowych i sposobu prowadzenia wytopu na właściwości żeliwa szarego.
EN
Preliminaries researches of influent type of charge materials and the way of smelt operating on cast iron’s properties have been described.
17
Content available remote Spektralne ciepło krystalizacji żeliwa szarego
Jura S., Jura Z.
Krzepnięcie Metali i Stopów
|
2000
|
R. 2, nr 44
149--158
PL
Stosując metodę analizy termicznej i derywacyjnej określono kinetykę krystalizacji żeliwa szarego. Opisano sumaryczne ciepło spektralne krystalizacji żeliwa ( q(T) ) jako funkcję temperatury. Przedstawiono przykładowo ciepło krystalizacji dendrytycznej oraz krystalizacji eutektycznej. Pokazano graficznie krzywą kalorymetryczną Tc’(t) oraz strumień ciepła q(t) oddawanego przez komórkę określoną podziałem w metodzie różnic skończonych. Opracowane funkcje ciepła są niezbędne do stosowania w metodach symulacji komputerowej procesu krystalizacji odlewów.
EN
Kinetics of gray cast iron crystallization has been defined thanks to the method of thermal and derivative analysis. Total spectral heat of crystallization of gray cast iron has been described as temperature function. You can find the examples of dendritic crystallization heat as well as eutectic crystallization. Calorimetric curve Tc’(f) and heat flux q(f) which is emitted from finite elements method cell have been presented . Thermal functions are necessary for using them in computer simulation of alloys’ crystallization process.
18
Content available remote Ciepło spektralne krystalizacji żeliwa szarego
Jura Z.
Krzepnięcie Metali i Stopów
|
1999
|
R. 1, nr 40
153--158
PL
Wykorzystując autorską metodę określania ciepła spektralnego krystalizujących faz oraz dane otrzymane w wyniku próby ATD wyznaczono wydzielanie ciepła w funkcji temperatury dla żeliwa. Na podstawie wyznaczonych funkcji określono ilość ciepła krystalizacji wydzielającego się podczas wydzielania fazy gama oraz ciepła przemiany eutektycznej. Znajomość funkcji spektralnego ciepła krystalizacji pozwala na szersze poznanie zjawisk występujących podczas krystalizacji, szczególnie w powiązaniu z innymi metodami badawczymi lub symulacyjnymi.
EN
TDA tests are used for estimation of heat emission in temperature function for cast iron. It was also the base for estimation of crystallisation heat for gamma and eutectic phase. The knowledge of spectral heat allows to investigate crystallisation processes.
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