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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
|
2021
|
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 Initial Assessment of Graphite Precipitates in Vermicular Cast Iron in the As-Cast State and after Thermal Treatments
Soiński M. S., Jakubus Aneta, Borowiecki B., Mierzwa P.
Archives of Foundry Engineering
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2021
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Vol. 21, iss. 4
131--136
EN
The purpose of the work was to determine the morphology of graphite that occurs in vermicular cast iron, both in the as-cast state and after heat treatment including austenitization (held at a temperature of 890°C or 960°C for 90 or 150 min) and isothermal quenching (i.e. austempering, at a temperature of 290°C or 390°C for 90 or 150 min). In this case, the aim here was to investigate whether the heat treatment performed, in addition to the undisputed influence of the cast iron matrix on the formation of austenite and ferrite, also affects the morphology of the vermicular graphite precipitates and to what extent. The investigations were carried out for the specimens cut from test coupons cast in the shape of an inverted U letter (type IIb according to the applicable standard); they were taken from the 25mm thick walls of their test parts. The morphology of graphite precipitates in cast iron was investigated using a Metaplan 2 metallographic microscope and a Quantimet 570 Color image analyzer. The shape factor F was calculated as the quotient of the area of given graphite precipitation and the square of its perimeter. The degree of vermicularization of graphite was determined as the ratio of the sum of the graphite surface and precipitates with F <0.05 to the total area occupied by all the precipitations of the graphite surface. The examinations performed revealed that all the heat-treated samples made of vermicular graphite exhibited the lower degree of vermicularization of the graphite compared to the corresponding samples in the as-cast state (the structure contains a greater fraction of the nodular or nearly nodular precipitates). Heat treatment also caused a reduction in the average size of graphite precipitates, which was about 225μm2 for the as-cast state, and dropped to approximately 170-200 μm2 after the austenitization and austempering processes.
3
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.
4
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.
5
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.
6
Content available Trends in the Production of Castings in the World and in Poland in the XXI Century
Soiński M. S., Kordas P., Skurka K.
Archives of Foundry Engineering
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2016
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Vol. 16, iss. 2
5--10
EN
The paper presents data concerning the total production of castings over the 2000-2014 period, both on a global scale, and in Poland. The basic types of casting alloys were taken into account. Changes in the production volume and structure over the period of the analysed 15 years were pointed out with respect to countries leading in foundry production. The topmost position in the world foundry industry is held by China for several years (with almost 45% share in the foundry market), the second place is taken by India (with almost 9% share). A distinct reduction in the shares of the once significant producers of castings, such as USA, Japan, Germany, Russia, Italy, or France, was observed over the 2000-2014 period. Poland had a share of 1.16% in 2000, and of 1.02% in 2014. Comparing the detailed data concerning the years 2000 and 2014, one can see that the fractions of castings made of ductile iron, cast steel, aluminium alloys, or magnesium alloys increase on a global scale, while such alloys as grey cast iron or malleable are in decline.
7
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
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2016
|
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%.
8
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).
9
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.
10
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
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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.
11
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
|
2014
|
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.
12
Content available The Initial Assessment of Effectiveness of the Impulse Method of Introducing an Inoculant into Cast Iron
Derda-Ślęzak A., Soiński M. S.
Archives of Foundry Engineering
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2014
|
Vol. 14, iss. 1
29--32
EN
An initial assessment of the effectiveness of cast iron inoculation, performed by the method of impulse introducing the master alloy into cast iron, is presented. The experiment was concerned with the hypoeutectic gray cast iron inoculated with either the Alinoc or the Barinoc master alloy by means of an experimental device for pneumatic transportation. Examinations involved pneumatic injection of the powdered inoculant carried in a stream of gaseous medium (argon) into the metal bath held in the crucible of an induction furnace. It was found that the examined process is characterised by both high effectiveness and stability.
13
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.
14
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.
15
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
|
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.
16
Content available The influence of small amounts of aluminium on the spheroidization of cast iron with cerium mischmetal
Soiński M. S.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 2
117-122
EN
The influence of aluminium (added in quantity from about 0.6% to about 2.8%) on both the alloy matrix and the shape of graphite precipitates in cast iron treated with a fixed amounts of cerium mischmetal (0.11%) and ferrosilicon (1.29%) is discussed in the paper. The metallographic examinations were carried out for specimens cut out of the separately cast rods of 20 mm diameter. It was found that the addition of aluminium in the amounts from about 0.6% to about 1.1% to the cast iron containing about 3% of carbon, about 3.7% of silicon (after graphitizing modification), and 0.1% of manganese leads to the occurrence of the ferrite-pearlite matrix containing cementite precipitates in the case of the treatment of the alloy with cerium mischmetal . The increase in the quantity of aluminium up to about 1.9% or up to about 2.8% results either in purely ferrite matrix in this first case or in ferrite matrix containing small amounts of pearlite in the latter one. Nodular graphite precipitates occurred only in cast iron containing 1.9% or 2.8% of aluminium, and the greater aluminium content resulted in the higher degree of graphite spheroidization. The noticeable amount of vermicular graphite precipitates accompanied the nodular graphite.
17
Content available Inoculation of grey cast iron with master alloys containing strontium and zirconium
Soiński M. S., Jędrecki P., Grzesiak K.
Archives of Foundry Engineering
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2011
|
Vol. 11, iss. 3 spec.
195--198
EN
The effectiveness of cast iron inoculation performed by means of three various inoculants: FeSiSr–SYSTR 75 AV, FeSiZr–SYZR 25 AV and Zircinoc was determined. The inoculants were introduced to the cast iron during the pouring of production moulds. Examination of cast iron structure and mechanical properties were carried out for specimens cut out of the collars of the cast valve bodies. It was found that the quantity of eutectic cells increased to the greatest degree if FeSiZr–SYZR 25 AV inoculant was applied in quantities of 0.20% or 0.25%. This inoculant in the mentioned quantities also increases the tensile strength to the greatest degree, rising it to the level of 250-265 MPa.
18
Content available remote Effectiveness of cast iron vermicularization including 'conditioning' of the alloy
Soiński M. S., Mierzwa P.
Archives of Foundry Engineering
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2011
|
Vol. 11, iss. 2
133-138
EN
The performed investigations have resulted in conclusion that the vermicularizing treatment of 'basic' cast iron, consisting in 'conditioning' the alloy by means of VLCe(2) master alloy, introducing the DENODUL5 master alloy, and graphitizing with SRF75 master alloy, provides for obtaining vermicular graphite precipitates in the structure of material cast within 15 minutes' period from the modifying treatment. The cast iron has been melted in the induction crucible furnace of medium frequency under industrial conditions. The alloy has been subjected to vermicularization in the slender ladle of 1 Mg capacity. Graphitizing has been performed in the course of transferring the cast iron from the slender ladle to the pouring ladle. A series of test coupons in the form of reversed U-blocks of test part walls 25 mm thick have been cast of the produced cast iron. Then specimens both for metallographic examination and for testing the mechanical properties have been taken from the coupons. The analysis of cast iron structure has revealed, among others, that however purely vermicular graphite precipitates occurred in specimens taken out of the lower parts of test coupon walls (which are cooled faster), the nodular graphite precipitates in quantity up to 10% could be observed in specimens from the upper parts of test coupon walls (located close beneath the sinkhead).
19
Content available remote The effect of thermal treatment on the mechanical properties of vermicular cast iron
Mierzwa P., Soiński M. S.
Archives of Foundry Engineering
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2010
|
Vol. 10, iss. 1 spec.
99--102
EN
The work determines the effect of austempering (isothermal quenching) on the basic mechanical properties of cast iron with vermicular graphite. The cast iron has been produced in one of Polish foundries. Copper addition in the amount of about 1% has been introduced to the cast iron in order to obtain the pearlitic matrix. The mechanical properties (Rm, R0,2 , A5, HB) have been determined both for the as-cast state and after austenitizing at 960 °C combined with quenching at 290 °C for 90 minutes, and also after austenitizing at 960 °C followed by isothermal quenching at 290 °C for 150 minutes. It has been found that the thermal treatment, resulting in the cast iron matrix change from the ferritic-pearlitic one to the one composed of acicular precipitates of ferrite and residual austenite, causes a distinct increase in cast iron strength; after the thermal treatment it has reached about 900÷1000 MPa. The examination has been performed using the specimens cut out of the reversed U-block test coupons of walls 25 mm thick and 50 mm high.
20
Content available remote The assessment of hot cracking susceptibility of ferritic-austenitic cast iron
Stradomski Z., Soiński M. S., Stradomski G.
Archives of Foundry Engineering
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2010
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Vol. 10, iss. 2
159--162
EN
An inspiration to the research work has arisen from the problems related to cracking of massive castings made of ferritic-austenitic cast steel. The shape and the character of crack trajectories indicate that they are hot cracks. Investigations have included two cast steel grades, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-3, because some customers had demanded for copper addition which makes possible the ageing treatment; also the alloys with increased carbon content have been investigated and this resulted from difficulties in obtaining sufficiently low carbon content (Cmax 0,03%) in many Polish foundries which are not equipped with argon-oxygen devices for cast steel decarburizing. The method of critical size of a specimen similar in shape to the Hall test specimen has been applied to examine the cast steel susceptibility to hot cracking. The examination results undoubtedly indicate the negative influence of the increased carbon content, especially in the presence of copper. The intercrystalline character of cracks which propagate along the dendritic austenite precipitates suggests that the peritectic reaction occurs in the final stage of solidification, being induced by segregation of the strong austenite-forming alloying elements. The increased hot cracking susceptibility of the ferrite-austenite cast steel containing copper, particularly with simultaneously increased carbon content, indicates that the implementation of production technologies concerning this material should be started with production of castings made of alloy grades without copper addition.
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