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Tytuł:
The Formation of Gaseous Atmosphere in a Molten Cast Iron/MouldingSand Contact System
Autorzy:
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/382409.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
moulding sand
cast iron melt
gas in metal
mould atmosphere
masa formierska
żeliwo
Opis:
Drops of molten cast iron were placed on moulding sand substrates. The composition of the forming gaseous atmosphere was examined. It was found that as a result of the cast iron contact with water vapour released from the sand, a significant amount of hydrogen was evolved. In all the examined moulding sands, including sands without carbon, a large amount of CO was formed. The source of carbon monoxide was carbon present in cast iron. In the case of bentonite moulding sand with sea coal and sand bonded with furan resin, in the composition of the gases, the trace amounts of hydrocarbons, i.e. benzene, toluene, styrene and naphthalene (BTX), appeared. As the formed studies indicate much higher content of BTX at lower temperature it was concluded that the hydrocarbons are unstable in contact with molten iron.
Źródło:
Archives of Foundry Engineering; 2014, 14, 1; 79-84
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiparameter Assessment of the Gas Forming Tendency of Foundry Sands with Alkyd Resins
Autorzy:
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/383265.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gases
moulding sand
casting defects
cast iron
pressure
gazy
masa formierska
żywice alkidowe
wady odlewnicze
żeliwo
Opis:
Gas atmosphere at the sand mould/cast alloy interface determines the quality of the casting obtained. Therefore the aim of this study was to measure and evaluate the gas forming tendency of selected moulding sands with alkyd resins. During direct and indirect gas measurements, the kinetics of gas evolution was recorded as a function of the temperature of the sand mixture undergoing the process of thermal destruction. The content of hydrogen and oxygen was continuously monitored to establish the type of the atmosphere created by the evolved gases (oxidizing/reducing). The existing research methodology [1, 7, 8] has been extended to include pressure-assisted technique of indirect measurement of the gas evolution rate. For this part of the studies, a new concept of the measurement was designed and tested. This article presents the results of measurements and compares gas emissions from two sand mixtures containing alkyd resins known under the trade name SL and SL2002, in which the polymerization process is initiated with isocyanate. Studies of the gas forming tendency were carried out by three methods on three test stands to record the gas evolution kinetics and evaluate the risk of gas formation in a moulding or core sand. Proprietary methods for indirect evaluation of the gas forming tendency have demonstrated a number of beneficial aspects, mainly due to the ability to record the quantity and composition of the evolved gases in real time and under stable and reproducible measurement conditions. Direct measurement of gas evolution rate from the tested sands during cast iron pouring process enables a comparison of the results with the results obtained by indirect methods.
Źródło:
Archives of Foundry Engineering; 2019, 2; 41-48
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gaseous Atmosphere During Gas Forming Tendency Measurements of the Selected Protective Coatings for Sand Moulds
Autorzy:
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/2079824.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas forming
oxygen
hydrogen
carbon monoxide
protective coatings
gaz
tlen
wodór
tlenek węgla
powłoki ochronne
Opis:
Protective coatings have direct contacts with hot and liquid alloys. As the result of such contacts gases are emitted from coatings. Gas forming is a tendency of the tested material to emit gases under a temperature influence. In order to assess the gas forming tendency either direct or indirect methods are applied. In the hereby work, the measurements of the gas forming tendency were performed under laboratory conditions, by means of the developed indirect method. The research material constituted samples of six selected protective coatings dissolved either in alcohol or in water. These coatings are applied in sand moulds and cores for making cast iron castings. The assessment of their gas forming tendency was presented in relation to temperatures and heating times. The occurrence and changes of oxygen and hydrogen contents in gases outflowing from the measuring flask during tests, were measured by means of gas sensors. The process of the carbon monoxide (CO) emission during tests was also assessed. The following gas sensors were installed in flow-through micro chambers: for oxygen - lambda probe, for hydrogen – pellistor, for carbon monoxide - sensor (dedicated for CO) FIGARO TGS 822 TF. The results of direct CO measurements were recalculated according to the algorithm supplied by the producer of this sensor.
Źródło:
Archives of Foundry Engineering; 2021, 21, 3; 11-18
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Destruction of Moulding Sands with Chemical Binders Caused by the Thermal Radiation of Liquid Metal
Autorzy:
Zych, J.
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/382547.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sand mould
thermal destruction
thermal radiation
heating of mould
loss of strength
masa formierska
rozkład termiczny
promieniowanie cieplne
Opis:
The obtained results of heating of sand moulds with binders by means of a thermal radiation of liquid metal are presented in this study. Standard samples for measuring Rg made of the tested moulding sands were suspended at the lower part of the cover which was covering the crucible with liquid metal (cast iron), placed in the induction furnace. The authors own methodology was applied in investigations. The progressing of the samples surface layers heating process was determined as the heating time function. Samples of a few kinds of moulding sands with chemical binders were tested. Samples without protective coatings as well as samples with such coatings were tested. The influence of the thermal radiation on bending resistance of samples after their cooling was estimated. The influence of several parameters such as: time of heating, distance from the metal surface, metal temperature, application of coatings, were tested. A very fast loss of strength of moulding sands with organic binders was found, especially in cases when the distance between metal and sample surfaces was small and equaled to 10÷15 mm. Then, already after app. 15 seconds of the radiation (at Tmet=1400°C), the resistance decreases by nearly 70%. Generally, moulding sands with organic binders are losing their strength very fast, while moulding sands with water glass at first increase their strength and later slightly lose. The deposition of protective coatings increases the strength of the mould surface layers, however does not allow to retain this strength after the metal thermal radiation.
Źródło:
Archives of Foundry Engineering; 2015, 15, 4; 95-100
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics of Gas Emission from Heated Moulding Sands Together with the On-line Assessment of H2 and O2 Fractions - New Investigation Method
Autorzy:
Mocek, J.
Zych, J.
Powiązania:
https://bibliotekanauki.pl/articles/379867.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas emission
evolution rate
hydrogen content
oxygen content
moulding sand
resin
burning
moulding sand destruction
emisja gazu
tempo rozwoju
zawartość wodoru
zawartość tlenu
masa formierska
żywica
spalanie
Opis:
The new investigation method of the kinetics of the gas emission from moulding sands used for moulds and cores is presented in this paper. The gas evolution rate is presented not only as a function of heating time but also as a function of instantaneous temperatures. In relation to the time and heating temperature the oxygen and hydrogen contents in evolving gases was also measured. This method was developed in the Laboratory of Foundry Moulds Technology, Faculty of Foundry Engineering, AGH. Gas amounts which are emitted from the moulding sand at the given temperature recalculated to the time unit (kinetics) are obtained in investigations. Results of investigations of moulding sand with furan resin are presented - as an example - in the paper.
Źródło:
Archives of Foundry Engineering; 2016, 16, 4; 79-84
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of atmosphere in a foundry mould on casting surface quality
Autorzy:
Chojecki, A.
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/382388.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
forma piaskowa
wada powierzchni odlewu
stężenie wodoru
żeliwo sferoidalne
sand mould
defects on casting surface
hydrogen concentration
ductile iron
Opis:
Changes of gas pressure in the moulding sand in the zone adjacent to mould cavity were analysed during pouring of cast iron. No significant effect of pressure on the surface quality of castings was observed. In the second series of tests, the concentration of hydrogen in the gas atmosphere was measured. It has been found that the value of this concentration depends on metal composition and is particularly high in cast iron containing magnesium. This is due to the reduction of water vapour with the element that has high affinity to oxygen. The presence of hydrogen causes the formation of gas-induced defects on the casting surface.
Źródło:
Archives of Foundry Engineering; 2012, 12, 1; 13-18
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of gas atmosphere near the metal-mould interface during casting and solidification of ductile iron
Autorzy:
Mocek, J.
Chojecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/380414.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
żeliwo sferoidalne
emisja gazu
powierzchnia odlewu
ductile iron
metal mould interface
gas evolution
surface of castings
Opis:
In sand moulds, at a distance of 3 mm from the metal-mould interface, the sensors of temperature, and of oxygen and hydrogen content were installed. Temperature and the evolution of partial gas pressure have been analysed in moulds bonded with bentonite with or without the addition of seacoal, water glass or furan resin. Moulds were poured with ductile iron. For comparison, also tests with the grey iron have been executed. It was found that the gas atmosphere near the interface depends mainly on the content of a carbonaceous substance in the mould. In the green sand moulds with 5% of seacoal or bonded with furan resin, after the mould filling, a sudden increase in the hydrogen content and the drop of oxygen is observed. This gas evolution results from the oxidation of carbon and reduction of water vapour in the mould material, and also from the reduction of water vapour and alloy reoxidation. In carbon-free sand, the evolution in the gas composition is slower because water vapour is reduced only at the interface. Changes of oxygen and hydrogen content in the controlled zone are determined by the transport phenomena.
Źródło:
Archives of Foundry Engineering; 2012, 12, 4; 166-170
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas Atmosphere Formed in Casting by Full Mold Process
Atmosfera gazowa występująca podczas wykonywania odlewów w technologii pełnej formy
Autorzy:
Mocek, J.
Chojecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/350844.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
casting
full mold
formation of the gap
odlew
pełna forma
powstawanie szczelin
Opis:
A test mold was designed to investigate the full mold process. Pressure changes in a gap developing between the pattern made of foamed polystyrene and the raising column of liquid alloy were determined. Studies were conducted pouring molds with cast iron and with AK11 silumin. It was found that pressure is significantly higher in the case of cast iron, due to a higher rate of pattern decomposition and more advanced dissociation of hydrocarbons. The increase in pressure was observed to have no significant effect on changes in the pouring rate as it was compensated by higher metallostatic pressure. The increase of pressure occurs immediately after the start of pouring, it reaches a maximum and then stabilizes or decreases smoothly as a result of the drop in metallostatic pressure. The temperature of pouring has a significant effect on the decomposition rate of hydrocarbons evolving from the metal. During pouring of cast iron, the presence of hydrogen was revealed. It was particularly evident across the gas-permeable coating, where the concentration has exceeded 40%. Hydrogen precipitation was accompanied by an evolution on the casting surface of considerable amounts of pyrolytic carbon. It was found that gases forming in the gap were totally free from oxygen.
Zaprojektowano próbną formę do badania procesu full mold. Określono zmiany ciśnienia w szczelinie powstającej pomiędzy styrodurowym modelem a podnoszącym się ciekłym stopem. Badania prowadzono przy zalewaniu form żeliwem oraz siluminem AK11. Stwierdzono, że ciśnienie to jest znacznie wyższe w przypadku żeliwa, co wynika z większej szybkości rozpadu modelu i dalej posuniętej dysocjacji węglowodorów. Wzrost ciśnienia nie powoduje jednak istotnej zmiany szybkości zalewania, ponieważ jest on kompensowany wyższym ciśnieniem metalostatycznym. Wzrost ciśnienia następuje bezpośrednio po rozpoczęciu zalewania, osiąga ono maksimum poczem stabilizuje się lub łagodnie maleje w wyniku zmniejszania ciśnienia metalostatycznego. Temperatura zalewania ma istotny wpływ na stopień rozpadu, wydzielających się z modelu węglowodorów. Przy zalewaniu żeliwa stwierdzono obecność wodoru. Jest ona widoczna zwłaszcza po drugiej stronie powłoki gazoprzepuszczalnej gdzie stężenie sięga powyżej 40%. Wydzielaniu wodoru towarzyszy wydzielanie się na powierzchni odlewu, znacznych ilości pyrolitycznego węgla. Stwierdzono, że gazy tworzące szczelinę są całkowicie wolne od tlenu.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 1045-1049
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gas Generation Properties of Materials Used in the Sand Mould Technology – Modified Research Method
Autorzy:
Zych, J.
Mocek, J.
Snopkiewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/380142.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
moulding mass
materials used
research methodology
generation kinetics
masa formierska
materiały
metodologia badań
kinetyka
Opis:
The paper presents a new methodology for research on gas generation property of materials used for sand forms and cores, models made of foamed polystyrene, protective layers, etc. In the form of an example, full analysis has been presented of gas generation property of a selected furan resin bonded sand, stating the course and kinetics of gas generation, their intensity in the time function, and in the heating temperature function. The description is of quantitative nature. The existence of peaks in gas generation intensity was observed at several temperature values. The results are well-correlated with the inclination to form surface defects of casts made in furnace resin bonded sands. This is the first study on gas generation kinetics in the mass heating temperature function.
Źródło:
Archives of Foundry Engineering; 2014, 14, 3 spec.; 105-109
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Casting of Al-Si alloys in the full-mould technology. Process conditions
Odlewania stopów Al-Si w technologii pełnej formy. Uwarunkowania procesu
Autorzy:
Mocek, J.
Zych, J.
Krubnik, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/264207.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
full-mould
strength
permeability
gas evolution tendency
coatings
pełna forma
powłoki
wytrzymałość
rozpuszczalność
gazotwórczość
Opis:
A review of various technologies using expendable casting patterns made of expanded polystyrene isgiven in the paper.The resultsof our own investigations on implementing this technology at the pilot-plant scale - for the art castings series - were presented. The results of tests of materials and moulds applied in the full-mould technology were shown. Gas evolution tendencies of expanded polystyrenes and protective coatings were estimated. Gas evolutions were described as functions of the polystyrene heating temperature. The tests of protective coatings used in this technology were performed and strength (Rm), permeability (P), and gas evolution tendency of these coatings assessed. New solutions developed by the team of researchers were applied in testing coating strength, permeability, and the gas evolution tendency of expanded polystyrene. A good correlation between the results of coating properties and the obtained casting quality was found. Coatings, which were characterised by higher strengths and better permeability, allowed us to produce castings without surface or inner faults.
Dynamiczny rozwój produkcji odlewów w technologii „pełnej formy" wymaga szybkiej optymalizacji procesu technologicznego dla nowych kształtów odlewów. Wykonanie dobrych odlewów wymaga starannego doboru odpowiednich materiałów formierskich. W tym celu zaproponowano metodykę pomiarową dla wybranych, podstawowych parametrów materiałów formierskich. Określono wytrzymałość powłokochronnych Rm, przepuszczalność powłok i gazotwórczość styropianu, jak również zaproponowano zmodyfikowaną wersję badań gazotwórczości materiałów dla modeli stosowanych w technologii„lost foam". Określono kinetykę wydzielania gazów w funkcji temperatury dla wybranej grupy spienionych polistyrenów. Stwierdzono dobrą korelację pomiędzy wytrzymałością i przepuszczalnością a uzyskiwaniem dobrych („zdrowych") odlewów. Powłoki cechujące się wysoką wytrzymałością i przepuszczalnością pozwalają na produkcję odlewów bez wad. Potwierdzono to, wykonując serię próbnych odlewów ze stopu Al-SI.
Źródło:
Metallurgy and Foundry Engineering; 2014, 40, 3; 161-174
1230-2325
2300-8377
Pojawia się w:
Metallurgy and Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics of Gases Emission from Surface Layers of Sand Moulds
Autorzy:
Zych, J.
Mocek, J.
Kaźnica, N.
Powiązania:
https://bibliotekanauki.pl/articles/382829.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
moulding sand
surface layer
gases
kinetics of gas emission
chemical binders
piasek formierski
warstwa powierzchniowa
gazy
emisja gazów
środki wiążące
Opis:
Gas emission from casting moulds, cores and coatings applied for sand and permanent moulds is one of the fundamental reasons of casting defects occurrence. In the previous studies, gas emission was measured in two ways: normalized, in which the evolving gas volume was measured during heating of the moulding sand sample in a sealed flask, or by measuring the amount of gas from sand core (sample) which is produced during the pouring of liquid metal. After the pouring process the sand mould is heated very unequally, the most heated areas are layers adjacent to the liquid metal. The emission of gas is significantly larger from the surface layer than from the remaining ones. New, original method of measuring kinetics of gas emission from very thin layers of sand moulds heated by liquid metal developed by the authors is presented in the hereby paper. Description of this new method and the investigation results of kinetics of gas emission from moulding sand with furan and alkyd resin are shown. Liquid grey cast iron and Al-Si alloy were used as a heat source in the sand moulds. Comparison of the kinetics of gas emission of these two kinds of moulding sands filled with two different alloys was made. The momentary metal temperature in sand mould was assigned to the kinetics of gas emission, what creates a full view of the possibility of formation of casting defects of the gaseous origin. Moulding sand with alkyd resin is characterized by larger gas emission; however gases are emitted slower than in the case of moulding sands with furan resin. This new investigation method has a high repeatability and is the only one which gives a full view of phenomenon’s in the surface layer which determines quality of the casings. The obtained results are presented on several graphs and analyzed in detail. They have a great application value and can be used in the production of iron as well as light metal alloy castings.
Źródło:
Archives of Foundry Engineering; 2018, 18, 1; 222-226
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gases Emission From Surface Layers of Sand Moulds and Cores Stored Under the Humid Air Conditions
Autorzy:
Kaźnica, N.
Zych, J.
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/381317.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface layer
sand mould
emission of gases
high air humidity
moulding sand
chemical binder
warstwa wierzchnia
forma piaskowa
emisja gazów
wysoka wilgotność powietrza
masa formierska
spoiwo chemiczne
Opis:
A large number of defects of castings made in sand moulds is caused by gases. There are several sources of gases: gases emitted from moulds, cores or protective coatings during pouring and casting solidification; water in moulding sands; moisture adsorbed from surroundings due to atmospheric conditions changes. In investigations of gas volumetric emissions of moulding sands amounts of gases emitted from moulding sand were determined - up to now - in dependence of the applied binders, sand grains, protective coatings or alloys used for moulds pouring. The results of investigating gas volumetric emissions of thin-walled sand cores poured with liquid metal are presented in the hereby paper. They correspond to the surface layer in the mould work part, which is decisive for the surface quality of the obtained castings. In addition, cores were stored under conditions of a high air humidity, where due to large differences in humidity, the moisture - from surroundings - was adsorbed into the surface layer of the sand mould. Due to that, it was possible to asses the influence of the adsorbed moisture on the gas volumetric emission from moulds and cores surface layers by means of the new method of investigating the gas emission kinetics from thin moulding sand layers heated by liquid metal. The results of investigations of kinetics of the gas emission from moulding sands with furan and alkyd resins as well as with hydrated sodium silicate (water glass) are presented. Kinetics of gases emissions from these kinds of moulding sands poured with Al-Si alloy were compared.
Źródło:
Archives of Foundry Engineering; 2017, 17, 4; 79-84
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Conductivity of Moulding Sand with Chemical Binders, Attempts of its Increasing
Przewodność cieplna mas formierskich ze spoiwami chemicznymi, próby jej zwiększenia
Autorzy:
Zych, J.
Mocek, J.
Snopkiewicz, T.
Jamrozowicz, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/351198.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal conductivity
moulding sands
investigation methods
binders
przewodność cieplna
masa formierska
metody badań
spoiwa
Opis:
The investigation results of the thermal conductivity of the selected group of moulding sands with chemical binders, mainly organic, are presented in the hereby paper. Studies encompassed also moulding sands into which additions improving the thermal conductivity were introduced. Two testing methods were applied, i.e. investigations at a steady and unsteady temperature zone. For investigations at a steady temperature zone the new original experimental stand was designed and built, adapted also for testing moulding sands with binders undergoing destruction at relatively low temperatures.
W pracy przedstawiono wyniki badań zdolności do przewodzenia ciepła wybranej grupy mas ze spoiwami, głównie organicznymi. Badaniami objęto również masy, do których wprowadzono dodatki dla zwiększenia przewodności cieplnej. Zastosowano dwie metody badań przewodności cieplnej, tj. badania w ustalonym polu temperatury i badania w nieustalonym polu. Dla badań w stacjonarnym polu zbudowano nowe, oryginalne stanowisko pomiarowe, dostosowane do badań mas ze spoiwami ulegającymi destrukcji w stosunkowo niskiej temperaturze (spoiwa organiczne). Wyniki badań przedstawiono graficznie w układzie: λ = f(T) - współczynnik przewodzenia w funkcji temperatury. Wykazano istnienie minimum funkcji w temperaturze niższej niż w przypadku mas klasycznych. Wprowadzanie do masy dodatku grafitu zwiększa jej przewodność. Wprowadzenie grafitu nie wpływa istotnie na proces wiązania mas furanowych. Masy ze szkłem wodnym charakteryzują się lepszą przewodnością, szczególnie w wyższych (T>400°C) temperaturach.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 1; 351-357
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations of protective coatings for castings of high-manganese cast steels
Autorzy:
Holtzer, M.
Bobrowski, A.
Drożyński, D.
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/382308.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high manganese cast steel
protective coating
silica sand
quality of surface
staliwo wysokomanganowe
powłoka ochronna
piasek kwarcowy
jakość powierzchni
Opis:
When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of the so-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel) sands not containing free silica should be applied (e.g. olivine sand) or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2) originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel) and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.
Źródło:
Archives of Foundry Engineering; 2013, 13, 1; 39-44
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection of protective coatings of moulds for castings of high-manganese cast steel in dependence of the applied moulding sand kind
Dobór powłoki ochronnej na formy dla odlewów ze staliwa wysokomanganowego w zależności od rodzaju stosowanej masy
Autorzy:
Holtzer, M.
Bobrowski, A.
Drożyński, D.
Mocek, J.
Powiązania:
https://bibliotekanauki.pl/articles/353882.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-manganese cast steel
protective coatings
moulding sand
resins
staliwo wysokomanganowe
powłoki ochronne
żywica formierska
masa formierska
Opis:
High-manganese cast steels are characterised by a high abrasion resistance under friction conditions with a simultaneous influence of pressure and impacts. This cast steel is especially suitable for castings of excavator’s scoops, track links, streetcars crossovers, parts of crushers and mills for braking up of hard materials [1-4]. In order to obtain high quality castings of high-manganese cast steels in moulds on the high-silica sand matrices it is necessary to apply protective coatings, which prevent a direct contact between metal and matrix (SiO2). Manganese after being poured into a mould can undergo a partial oxidation forming MnO, which reacts with silica. As a result low-melting manganese silicates are formed, which in a form of a tight layer adhere to the casting surface, significantly increasing a labour input related to cleaning. Three kinds of protective coatings were tested: zirconium, corundum and magnesite. As a base moulding sands on high-silica sand matrices with three kinds of resol resins were applied. The quality of the obtained casting surface was assessed in dependence of the protective coating and resin kind and also in dependence of the metallostatic pressure value.
Staliwo wysokomanganowe odznacza się dużą odpornością na ścieranie w warunkach tarcia z jednoczesnym działaniem nacisku i uderzeń. Staliwo to nadaje się szczególnie na odlewy czerpaków koparek, ogniwa gąsienic traktorów, krzyżownic tramwajowych, części kruszarek i młynów do rozdrabniania twardych materiałów [1-4]. Aby uzyskać wysokiej jakości odlewy ze staliwa wysokomanganowego w masach na osnowie piasku kwarcowego konieczne jest stosowanie powłok ochronnych, które zapobiegają bezpośredniemu kontaktowi metalu z osnową, a konkretnie z SiO2. Mangan, po zalaniu metalu do formy może ulegać częściowemu utlenieniu tworząc m.in. MnO, który reaguje z krzemionką. W wyniku tworzaąsię niskotopliwe krzemiany manganu, które szczelną warstwą przylegają do powierzchni odlewu, znacznie zwiększając nakład pracy na oczyszczanie. Przebadano trzy rodzaje powłok ochronnych: cyrkonowa, korundowa i magnezytowa. Jako podłoże stosowano masy na osnowie piasku kwarcowego z trzema rodzajami żywicy rezolowej. Oceniano jakość uzyskiwanej powierzchni odlewu w zalezności od rodzaju powłoki ochronnej, rodzaju zywicy oraz wielkości ciśnienia metalostatycznego.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 3; 853-857
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 34

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