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1
Content available The Leading Role of Aluminium in the Growing Production of Castings Made of the Non-Ferrous Alloys
Soiński M. S., Jakubus A.
Archives of Foundry Engineering
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2021
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Vol. 21, iss. 3
33--42
EN
The paper presents changes in the production volume of castings made of non-ferrous alloys on the background of changes in total production of casting over the 2000-2019 period, both on a global scale and in Poland. It was found that the dynamics of increase in the production volume of castings made of non-ferrous alloys was distinctly greater than the dynamics of increase in the total production volume of castings over the considered period of time. Insofar as the share of production of the non-ferrous castings in the total production of castings was less than 16% during the first two years of the considered period, it reached the level of 20% in the last four years analysed. This share, when it comes to Poland, increased even to the greater degree; it grew from about 10% of domestic production of castings to over 33% within the regarded 2000-2019 period. The greatest average annual growth rate of production, both on a global scale and in Poland, was recorded for aluminium alloys as compared with other basic non-ferrous alloys. This growth rate for all the world was 4.08%, and for Poland 10.6% over the 2000-2019 period. The value of the average annual growth rate of the production of aluminium castings in Poland was close to the results achieved by China (12%), India (10.3%) and the South Korea (15.4%) over the same period of time. In 2019, the total production of castings in the world was equal to about 109 million tonnes, including over 21 million tonnes of castings made of non-ferrous alloys. The corresponding data with respect to Poland are about 1 million tonnes and about 350 thousand tonnes, respectively. In the same year, the production of castings made of aluminium alloys was equal to about 17.2 million tonnes in the world, and about 340 thousand tonnes in Poland.
2
Content available Contribution to the Assessment of Thermal Shock Resistance of Metals
Jakubus A., Soiński M. S.
Archives of Foundry Engineering
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2020
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Vol. 20, iss. 4
97--100
EN
The study presents a concept of generation of micro-cracks (or cracks) in metal specimens in order to assess their material with respect to the thermal shock resistance. Both the method of conducting the experiment and the criteria of the assessment of the material resistance to the rapid temperature changes are discussed. The schematic diagram of the research stand used for repeated heating and rapid cooling of specimens, constructed in the Foundry Institute of the Częstochowa University of Technology, is presented. The proposed solution enables to maintain constant conditions of the experiment. The tests were held for flat specimens 70 mm long, 20 mm wide, and 5 mm thick, tapered over a distance of 15 mm towards both ends. The specimens were induction heated up to the specified temperature and then, in response to the signal produced by a pyrometer, dipped in the tank containing the cooling medium. The thermal shock resistance of the material can be assessed on the basis of either the total length of the micro-cracks arisen at the tapered parts of a specimen after a specified number of heating-and-cooling cycles, or the number of such cycles prior to the total damage of a specimen, or else the number of thermal cycles prior to generation of the first crack. The study includes an exemplary view of the metal specimen after the thermal shock resistance tests, as well as the illustrative microstructure of the vermicular cast iron which reveals a crack propagating from the edge towards the core of the material.
3
Content available The Influence of the Shape of Graphite Precipitates on the Cast Iron Abrasion Resistance
Jakubus A., Soiński M. S.
Archives of Foundry Engineering
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2019
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iss. 4
87--90
EN
The paper presents the initial results of investigation concerning the abrasion resistance of cast iron with nodular, vermicular, or flake graphite. The nodular and vermicular cast iron specimens were cut out of test coupons of the IIb type with the wall thickness equal to 25 mm, while the specimens made of grey cast iron containing flake graphite were cut out either of special casts with 20 mm thick walls or of the original brake disk. The abrasion tests were carried out by means of the T-01M tribological unit working in the pin-on-disk configuration. The counterface specimens (i.e. the disks) were made of the JT6500 brand name friction material. Each specimen was abraded over a distance of 4000 m. The mass losses, both of the specimens and of the counterface disks, were determined by weighting. It was found that the least wear among the examined materials was exhibited by the nodular cast iron. In turn, the smallest abrasion resistance was found in vermicular cast iron and in cast iron containing flake graphite coming from the brake disk. However, while the three types of specimens (those taken from the nodular cast iron and from grey cast iron coming either from the special casts or from the brake disk) have almost purely pearlitic matrix (P95/Fe05), the vermicular cast iron matrix was composed of pearlite and ferrite occurring in the amounts of about 50% each (P50/Fe50). Additionally, it was found that the highest temperature at the cast iron/counterface disk contact point was reached during the tests held for the nodular cast iron, while the lowest one occurred for the case of specially cast grey iron.
4
Content available Thermal Shock Resistance of Cast Iron with Various Shapes of Graphite Precipitates
Jakubus A., Soiński M. S.
Archives of Foundry Engineering
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2018
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Vol. 18, iss. 2
121--124
EN
The influence of a shape of graphite precipitates in cast iron on the thermal shock resistance of the alloy was initially determined. Investigations included the nodular cast iron and the vermicular one, as well as the cast iron containing flake graphite. The thermal shock resistance was examined at a special laboratory stand which allowed for multiple heating and cooling of specimens within the presumed temperature range. The specimens were inductively heated and then cooled in water of constant temperature of about 30°C. There were used flat specimens 70 mm long, 5 mm thick in the middle part, and tapering like a wedge over a distance of 15 mm towards both ends. The total length of cracks generated on the test surfaces of the wedge-shaped parts of specimens was measured as a characteristic value inversely proportional to the thermal shock resistance of a material. The specimens heated up to 500°C were subjected to 2000 test cycles of alternate heating and cooling, while the specimens heated up to 600°C underwent 1000 such cycles. It was found that as the heating temperature rose within the 500-600°C range, the thermal shock resistance decreased for all examined types of cast iron. The research study proved that the nodular cast iron exhibited the best thermal shock resistance, the vermicular cast iron got somewhat lower results, while the lowest thermal shock resistance was exhibited by grey cast iron containing flake graphite.
5
Content available The Assessment of Resistance to Thermal Fatigue and Thermal Shock of Cast Iron Used for Glass Moulds
Stradomski G., Gzik S., Jakubus A., Nadolski M.
Archives of Foundry Engineering
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2018
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Vol. 18, iss. 3
173--178
EN
Constantly developing production process and high requirements concerning the quality of glass determine the need for continuous improvement of tools and equipment needed for its production. Such tools like forms, most often made of cast-iron, are characterized by thick wall thickness compared to their overall dimensions and work in difficult conditions such as heating of the surface layer, increase of thermal stresses resulting from the temperature gradient on the wall thickness, occurrence of thermal shock effect, resulting from cyclically changing temperatures during filling and emptying of the mould. There is no best and universal method for assessing how samples subjected to cyclic temperature changes behave. Research on thermal fatigue is a difficult issue, mainly due to the instability of this parameter, which depends on many factors, such as the temperature gradient in which the element works, the type of treatment and the chemical composition of the material. Important parameters for these materials are at high temperature resistance to thermal shock and thermal fatigue what will be presented in this paper.
6
Content available Investigations of Ferritic Nodular Cast Iron Containing About 5-6% Aluminium
Soiński M. S., Kordas P., Skurka K., Jakubus A.
Archives of Foundry Engineering
|
2016
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Vol. 16, iss. 4
141--146
EN
The work presents results of investigations concerning the production of cast iron containing about 5-6% aluminium, with the ferritic matrix in the as-cast state and nodular or vermicular graphite precipitates. The examined cast iron came from six melts produced under the laboratory conditions. It contained aluminium in the amount of 5.15% to 6.02% (carbon in the amount of 2.41% to 2.87%, silicon in the amount of 4.50% to 5.30%, and manganese in the amount of 0.12% to 0.14%). After its treatment with cerium mixture and graphitization with ferrosilicon (75% Si), only nodular and vermicular graphite precipitates were achieved in the examined cast iron. Moreover, it is possible to achieve the alloy of pure ferritic matrix, even after the spheroidizing treatment, when both the aluminium and the silicon occur in cast iron in amounts of about 5.2÷5.3%.
7
Content available Structure of Foundry Production in the World and in Poland over the 1974-2013 Period
Soiński M. S., Skurka K., Jakubus A., Kordas P.
Archives of Foundry Engineering
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2015
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Vol. 15, iss. 2 spec.
69--76
EN
The paper presents data illustrating the total production of castings in the world and in Poland over the 1974-2013 period. The fractions of basic casting alloys in the total amount of material used for the production of metal castings during the considered period of time were found. It was noticed that the fraction of grey cast iron castings in the total amount of the produced castings decreased significantly over the past 40 years, both on a global scale (from about 65-75% to about 45%) and in Poland (from about 75-80% to about 45-55%). The fraction of SG iron increased considerably, up to about 25% in the world, and up to about 12-16% in Poland. The fraction of malleable became almost negligible (about 1%). The fraction of cast steel took different course in Poland and in the world: it stabilised on a global scale at about 10% in recent years, but dropped down to the level of about 4-7% in Poland. The use of aluminium alloys for the production of casting grew dynamically; their fraction in the total production of casting rose from somewhat less than 4% to almost 15% on a global scale. As far as Poland is considered, this growth was ever more intensive: from about 6-8% to about 25-30% in the 1989-2013 period (the detailed data for the previous period of time are lacking).
8
Content available Production of Castings in the World and in Selected Countries from 1999 to 2013
Soiński M. S., Jakubus A., Kordas P., Skurka K.
Archives of Foundry Engineering
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2015
|
Vol. 15, iss. 1 spec.
103--110
EN
The paper compares the foundry production in years 1999-2013 on a world scale, in countries counted among the leading producers of castings, and in Poland. Various types of foundry alloys were taken into account. It was found that the position of China – the leader in the world production of castings – was not changed over many years, however China's share in the total production of casting has stabilised at the level of 42-44% during the recent five years. In the analysed period of time Poland increased the share in the world production of castings from 1.07% to about 1.23%, so that Polish production of castings was almost doubled. There is a tendency on the world scale that the grey cast iron fraction in the total production of castings decreases, while an increase occurs as far as spheroidal graphite cast iron, cast steel, and aluminium alloy castings are concerned.
9
Content available Characteristics of Graphite Precipitates in Aluminium Cast Iron Treated with Cerium Mixture
Soiński M. S., Jakubus A., Kordas P., Skurka K.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 1
93--98
EN
The work determined the influence of aluminium in the amount from about 1% to about 7% on the graphite precipitates in cast iron with relatively high silicon content (3.4% to 3.90%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium mixture and graphitized with ferrosilicon. The performed treatment resulted in occurring of compact graphite precipitates, mainly nodular and vermicular, of various size. The following parameters were determined: the area percentage occupied by graphite, perimeters of graphite precipitates per unit area, and the number of graphite precipitates per unit area. The examinations were performed by means of computer image analyser, taking into account four classes of shape factor. It was found that as the aluminium content in cast iron increases from about 1.1% to about 3.4%, the number of graphite precipitates rises from about 700 to about 1000 per square mm. For higher Al content (4.2% to 6.8%) this number falls within the range of 1300 – 1500 precipitates/mm2. The degree of cast iron spheroidization increases with an increase in aluminium content within the examined range, though when Al content exceeds about 2.8%, the area occupied by graphite decreases. The average size of graphite precipitates is equal to 11-15 μm in cast iron containing aluminium in the quantity from about 1.1% to about 3.4%, and for higher Al content it decreases to about 6 μm.
10
Content available Initial Assessment of Abrasive Wear Resistance of Austempered Cast Iron with Vermicular Graphite
Soiński M. S., Jakubus A.
Archives of Metallurgy and Materials
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2014
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Vol. 59, iss. 3
1073--1076
EN
The work compares the abrasive wear resistance of cast iron containing vermicular graphite, measured in the as-cast state and after austempering carried out at 290°C, 340°C, or 390°C. Theexaminations were performed by means of the T-01M tribological tester using the pin-on-disc configuration. Specimens used for examinations were taken from the end tabs of the tensile specimens, these being cut out of the test walls of the double-leg keel block test castings. Examinations proved that the austempering process increases the abrasive wear resistance of vermicular cast iron by several times as compared with the as-cast material. A tendency for a slight decrease in abrasive wear with an increase in austempering temperature can be stated. The coefficient of friction took a little higher values for cast iron after thermal treatment than for the as-cast material. The work was completed with roughness examination by means of electron scanning microscopy.
PL
W pracy porównano odporność na ścieranie żeliwa z grafitem wermikularnym w stanie lanym oraz po hartowaniu izotermicznym przeprowadzonym w temperaturach 290°C, 340°C i 390°C. Badaniaodporności na ścieranie przeprowadzono przy użyciu zestawu trybologicznego T-01M typu trzpień-tarcza. Próbki do badań pochodziły z próbek wytrzymałościowych wyciętych ze ścianek badawczych wlewków próbnych w kształcie odwróconej litery „U”. Badania wykazały, że poddanie żeliwa wermikularnego hartowaniu izotermicznemu prowadzi do kilkukrotnego wzrostu odporności tworzywa na ścieranie w porównaniu z żeliwem w stanie lanym. Zaobserwowano niewielki spadek zużycia wraz ze wzrostem temperatury hartowania. Współczynnik tarcia dla żeliwa po obróbce cieplej przybrał nieco większe wartości aniżeli w przypadku żeliwa w stanie lanym. W ramach pracy wykonano także badania chropowatości z wykorzystaniem mikroskopii skaningowej.
11
Content available The Effect of Aluminium on Graphitization of Cast Iron Treated with Cerium Mixture
Soiński M. S., Jakubus A., Kordas P., Skurka K.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
95--100
EN
The work determined the influence of aluminium in the amount from about 0.6% to about 8% on graphitization of cast iron with relatively high silicon content (3.4%-3.9%) and low manganese content (about 0.1%). The cast iron was spheroidized with cerium mixture and graphitized with ferrosilicon. It was found that the degree of graphitization increases with an increase in aluminium content in cast iron up to 2.8%, then decreases. Nodular and vermicular graphite precipitates were found after the applied treatment in cast iron containing aluminium in the amount from about 1.9% to about 8%. The Fe3AlCx carbides, increasing brittleness and deteriorating the machinability of cast iron, were not found in cast iron containing up to about 6.8% Al. These carbides were revealed only in cast iron containing about 8% Al.
12
Content available The influence of small amounts of aluminium on the effectiveness of cast iron spheroidization with magnesium
Soiński M. S., Jakubus A.
Archives of Foundry Engineering
|
2013
|
Vol. 13, iss. 3
80--83
EN
The influence of aluminium added in amounts of about 1.6%, 2.1%, or 2.8% on the effectiveness of cast iron spheroidization with magnesium was determined. The cast iron was melted and treated with FeSiMg7 master alloy under industrial conditions. The metallographic examinations were performed for the separately cast rods of 20 mm diameter. They included the assessment of the shape of graphite precipitates and of the matrix structure. The results allowed to state that the despheroidizing influence of aluminium (introduced in the above mentioned quantities) is the stronger, the higher is the aluminium content in the alloy. The results of examinations carried out by means of a computer image analyser enabled the quantitative assessment of the considered aluminium addition influence. It was found that the despheroidizing influence of aluminium (up to about 2.8%) yields the crystallization of either the deformed nodular graphite precipitates or vermicular graphite precipitates. None of the examined specimens, however, contained the flake graphite precipitates. The results of examinations confirmed the already known opinion that aluminium widens the range of ferrite crystallization.
13
Content available The Influence of Aluminium on the Spheroidization of Cast Iron Assessed on the Basis of Wedge Test
Soiński M. S., Jakubus A., Stradomski G.
Archives of Foundry Engineering
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2013
|
Vol. 13, iss. 1 spec.
163--168
EN
The paper discusses the influence of aluminium in quantities from about 1.9% to about 4.7% on both the alloy matrix and the shape of graphite precipitates in cast iron spheroidized with cerium mixture (added in the quantity of 0.11%) and inoculated with ferrosilicon (1.29%). The metallographic examinations were carried out for specimens cut out of the wedge test castings (22 mm base width, 120 mm height, 180 mm length) halfway along their length. It was found that the highest susceptibility to graphitization exhibits the cast iron containing about 2.8% Al. The alloy matrices were classified and the degrees of graphite spheroidization were determined. Microscopic observations were carried out along the wedge test casting height at several places, the first distant by 20 mm from the specimen apex, the next ones every 20 mm farther. Precipitates of nodular and vermicular graphite were found in the cast iron structure. The results of examination allow to state that cast iron spheroidized in the way described here is characterised by the degree of spheroidization which increase with an increase in aluminium content within the examined range.
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