Nauki Techniczne

Archives of Foundry Engineering

Zawartość

Archives of Foundry Engineering | 2017 | vol. 17 | No 2 |

Abstrakt

The rebuilding technologies are used to develop surface of ladle. Among many welding methods currently used to obtain surface layer

without defects one of the most effective way of rebuilding is using metal arc welding. This additional material gives more possibilities to

make expected quality of rebuild surface.

Chemical composition, property and economic factors allow to use metal wire. Because of these reasons, solid wire gives opportunity to be

wildly used as material to rebuild or repair the surface in different sectors of industry.

The paper shows a few ways to rebuild the surface in the massive cast with the use of metal active gas welding for repair. The work

presents studies of defect in the massive cast. It contains the pictures of microstructures and defects. The method of removing defects and

the results of checking by visual and penetrant testing methods are shown. The paper describes the methodology of repair the ladle with

metal active gas welding, preheating process and standards nondestructive testing method.

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There are presents the internal recycling in anode furnace, in addition to mainly blister copper and converter copper. During the process

there arise the two types of semi-finished products intended for further pyro metallurgical processing: anode copper and anode slag. The

stream of liquid blister copper enters into the anode furnace treatment, in which the losses are recovered, e.g. copper, resulting from

oxidation and reduction of sulfides, oxides and the oxidation of metallic compounds of lead, zinc and iron. In the liquid phase there are

still gaseous states, which gives the inverse relationship relating to the solid phase, wherein the gases found an outlet in waste gas or

steam. The results of chemical analysis apparently differ from each other, because crystallite placement, the matrix structure and the

presence of other phases and earth elements are not compared, which can be regained in the process of electrorefining. One should not

interpret negatively smaller proportion of copper in the alloy, since during the later part of the production more elements can be obtained,

for example from sludge, such as platinum group metals and lanthanides. According to the research the quality of blister copper, to a large

extent, present in the alloy phase to many other elements, which can be recovered.

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The objective of the research was to determine the influence of boron on the crystallization process and microstructure of ductile cast iron.

In the case of ductile cast iron it is a vital issue because even as little as trace presence of boron changes the properties of ductile cast iron

in a significant way. With the use of a new ATD-4 (TDA) tester and CRYSTALDIGRPAH converter it was possible to measure the

crystallization process parameters of the same alloy with four different contents of boron in one mould. Four samples with different boron

contents were extracted, their microhardness was measured and quantitative analysis of microstructure was conducted. Obtained results

allowed to state that with increasing content of boron the amount of graphite precipitates decreases, the amount of pearlite precipitates

increases, the shape of graphite precipitates deteriorates and hardness increases. It is also planned to perform additional testings with boron

contents between previously tested values.

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Within the research, selected multilayer technological systems created as combinations of water-glass containing moulding sand with

foundry tooling, were characterised on the grounds of their electrical properties. By measuring resonance frequency and quality factor of a

waveguide resonance cavity, real component of permittivity εr′ and loss tangent tgδ were determined for multilayer foundry systems with

various qualitative and quantitative compositions. It was demonstrated that combination of a sandmix and foundry tooling with known

dielectric properties results in a system with different physico-chemical properties, whose relation to the parameters of individual

components of the system is undefined at this research stage. On the grounds of measurement results, theoretical value of microwave

heating power, dissipated in unit volume of the selected multilayer foundry system, was determined. Knowledge of theoretical heating

power and evaluation of physical, chemical and structural changes occurring in moulding sands exposed to microwaves in such a

technological system makes a ground for empirical modelling of the process of microwave heating of foundry moulds and cores.

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The research focuses on assessing the metal content, mainly copper, lead, iron and also silver in metallurgical slag samples from the area

where historical metallurgical industry functioned. In the smelter located in Mogiła, near Krakow (southern Poland), whose operation is

confirmed in sources from 1469, copper was probably refined as well as silver was separated from copper. Based on the change of

chemical and soil phase content and also taking cartographic and historical data into account, considering the restrictions resulting from

the modern land use the area was determined whose geochemical mapping can point to the location of the 15th century Jan Thurzo’s

smelter in Mogiła near Krakow. Moreover, using the same approach with the samples of this kind here as with hazardous waste, an

attempt has been made to assess their impact on the environment. Thereby, taking the geoenvironmental conditions into account, potential

impact of the industrial activity has been assessed, which probably left large scale changes in the substratum, manifested in the structure,

chemical content and soil phase changes. Discovering areas which are contaminated above the standard value can help to identify

historical human activities, and finding the context in artefacts allows to treat geochemical anomalies as a geochronological marker. For

this purpose the best are bed sediments, at present buried in the ground, of historical ditches draining the area of the supposed smelter.

Correlating their qualities with analogical research of archeologically identified slags and other waste material allows for reconstructing

the anthropopressure stages and the evaluation of their effects. The operation of Jan Thurzo’s smelter is significant for the history of

mining and metallurgy of Poland and Central and Eastern Europe.

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The aim of the study was to determine the applicability of a new product added to water glass-containing foundry sands hardened with

ethylene glycol diacetate. The new additive designated by the symbol "B" is a composition of aqueous solutions of modified polyalcohols,

improving the sand knocking out properties. The scope of studies included testing various mechanical and technological properties

of foundry sand mixtures, such as permeability, friability, life cycle of cores and knocking out properties.

In the technological studies, two types of water glass with different values of the silica modulus and density, designated as R145 and R150,

were used. Moulding sands were prepared with the additive "B". For comparison, reference sands with water glass but without the additive

"B" were also made. In Part I of the article, the results of studies of the effect of additive "B" on the properties of foundry sands with water

glass hardened by CO2 blowing were discussed.

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The article deals with ultrasonic testing possibilities of the copper alloy centrifugal casts. It focused on the problems that arise when testing

of castings is made of non-ferrous materials. Most common types of casting defects is dedicated in theoretical introduction of article.

Ultrasonic testing technique by conventional ultrasound system is described in the theoretical part too. Practical ultrasonic testing of

centrifugal copper alloy cast - brass is in experimental part. The experimental sample was part of centrifugally cast brass ring with

dimensions of Ø1200x34 mm. The influence of microstructure on ultrasonic attenuation and limitations in testing due to attenuation is

describes in experimental part. Conventional direct single element contact ultrasound probe with frequencies of 5 MHz, 3.5 MHz and 2

MHz were used for all experimental measurements. The results of experimental part of article are recommendations for selecting

equipment and accessories for casting testing made of non-ferrous metals.

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The work presents the results of examinations concerning the influence of various amounts of home scrap additions on the properties of

castings made of MgAl9Zn1 alloy. The fraction of home scrap in the metal charge ranged from 0 to 100%. Castings were pressure cast by

means of the hot-chamber pressure die casting machine under the industrial conditions in one of the domestic foundries. The examinations

consisted in the determination of the following properties: tensile strength Rm, yield strength Rp0.2, and the unit elongation A5, all being

measured during the static tensile test. Also, the hardness measurements were taken by the Brinell method. It was found that the

mechanical properties (mainly the strength properties) are being improved up to the home scrap fraction of 50%. Their values were

increased by about 30% over this range. Further rise in the home scrap content, however, brought a definite decrease in these properties.

The unit elongation A5 exhibited continual decrease with an increase in the home scrap fraction in the metal charge. A large growth of

hardness was noticed for the home scrap fraction increasing up to the value of 50%. Further increasing the home scrap percentage,

however, did not result in a significant rise of the hardness value any more.

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The paper presents results of compressive strength investigations of EN AC-44200 based aluminum alloy composite materials reinforced

with aluminum oxide particles at ambient and at temperatures of 100, 200 and 250C. They were manufactured by squeeze casting of the

porous preforms made of α-Al2O3 particles with liquid aluminum alloy EN AC-44200. The composite materials were reinforced with

preforms characterized by the porosities of 90, 80, 70 and 60 vol. %, thus the alumina content in the composite materials was 10, 20, 30

and 40 vol.%. The results of the compressive strength of manufactured materials were presented and basing on the microscopic

observations the effect of the volume content of strengthening alumina particles on the cracking mechanisms during compression at

indicated temperatures were shown and discussed. The highest compressive strength of 470 MPa at ambient temperature showed

composite materials strengthened with 40 vol.% of α-Al2O3 particles.

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The Structural Peclet Number has been estimated experimentally by analyzing the morphology of the continuously cast brass ingots. It

allowed to adapt a proper development of the Ivantsov’s series in order to formulate the Growth Law for the columnar structure formation

in the brass ingots solidified in stationary condition. Simultaneously, the Thermal Peclet Number together with the Biot, Stefan, and

Fourier Numbers is used in the model describing the heat transfer connected with the so-called contact layer (air gap between an ingot and

crystallizer). It lead to define the shape and position of the s/l interface in the brass ingot subjected to the vertical continuous displacement

within the crystallizer (in gravity). Particularly, a comparison of the shape of the simulated s/l interface at the axis of the continuously cast

brass ingot with the real shape revealed at the ingot axis is delivered. Structural zones in the continuously cast brass ingot are revealed: FC

– fine columnar grains, C – columnar grains, E – equiaxed grains, SC – single crystal situated axially.

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The friction and wear properties of 201HT aluminum alloys and the corresponding competitive coupons were tested on an electrohydraulic

servo face friction and wear testing machine (MM-U10G). The microstructures of the competitive coupons were investigated by

scanning electron microscopy (SEM) and consequently the corresponding friction and wear mechanisms were studied. The results

demonstrated that: (1) the best competitive material of friction and wear performance of the 201HT was the 201HTC. (2) the 201HTC

modified by carbon following the initial mill for oil storage of the micro-groove to be produced, increased the corresponding lubrication

performance reduced the friction coefficient and wear rate effectively. (3) the 201HT-201HTC could obtain both better friction and wear

mainly due to the initial process of grinding following the 201HT plastic deformation occurred in the surface and the formation of a series

of re-melting welding points, whereas the 201HT material hardness would be similar to the 201HTC material hardness, which led into the

competitive material friction and wear performance improvement.

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The work presents the results of the studies of Co-Cr-Mo casting alloys used in the production of frame casts of removable dentures,

crowns and bridges in dental prosthetics. The studies were performed on four Co-Cr-Mo alloys of different contents of Mo, W and other

additives. Electrochemical tests were performed, which aimed at examining the corrosion resistance of the alloys and observing the alloy

structure after chronoamperometric tests with the potential in the area of the occurrence of the passive layer breakpoint. The alloy

microstructure images after chronoamperometric tests show the presence of non-uniformly distributed general corrosion. Moreover, a

project of cobalt alloy casting was elaborated using a ceramic mold casting. Additionally, analysis of the obtained microstructure was

performed. The microstructure of the examined alloys was of the dendrite type. This microstructure was chemically inhomogeneous and

consisted of an austenitic matrix formed by a solid cobalt solution and chromium in the core dendritic structure.

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In this paper, the effect of changes the parameters of heat treatment on the structure and the degree of elements segregation was

determined, in the context of corrosion resistance of ductile iron Ni-Mn-Cu, containing 7.2% Ni, 2.6% Mn and 2.4% Cu. In the condition

after casting, castings of austenitic matrix and 160HBW hardness were obtained. The achieved castings were soaked at 450, 550 and

650°C for 4, 8 and 12 hours, then cooled down at the ambient air. In most cases, the heat treatment resulted in a change in the castings

matrix, had the consequence of increasing their hardness in comparison to raw castings. Increasing the temperature and prolonging soaking

time resulted in increasing the degree of transformation of austenite, while reducing the degree of elements segregation. This led to the

formation of slightly bigger number of pitting due to corrosion, but not so deep and more evenly distributed in comparison to raw castings.

Wherein the results of corrosion tests show that heat treatment of castings did not significantly change their corrosion resistance in

comparison to raw castings, in contrast to the significant increase in mechanical properties.

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The paper deals with the impact of technological parameters on the heat transfer coefficient and microstructure in AlSi12 alloy using

squeeze casting technology. The casting with crystallization under pressure was used, specifically direct squeeze casting method. The goal

was to affect crystallization by pressure with a value 100 and 150 MPa. The pressure applied to the melt causes a significant increase of

the coefficient of heat transfer between the melt and the mold. There is an increase in heat flow by approximately 50% and the heat

transfer coefficient of up to 100-fold, depending on the casting conditions. The change in cooling rate influences the morphology of the

silicon particles and intermetallic phases. A change of excluded needles to a rod-shaped geometry with significantly shorter length occurs

when used gravity casting method. By using the pressure of 150 MPa during the crystallization process, in the structure can be observed an

irregular silica particles, but the size does not exceed 25 microns.

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The aim of this study is to design and implement a computer system, which will allow the semantic cataloging and data retrieval in the

field of cast iron processing. The intention is to let the system architecture allow for consideration of data on various processing techniques

based on the information available or searched by a potential user. This is achieved by separating the system code from the knowledge of

the processing operations or from the chemical composition of the material being processed. This is made possible by the creation and

subsequent use of formal knowledge representation in the form of ontology. So, any use of the system is associated with the use of

ontologies, either as an aid for the cataloging of new data, or as an indication of restrictions imposed on the data which draw user attention.

The use of formal knowledge representation also allows consideration of semantic meaning, a consequence of which may be, for example,

returning all elements in subclasses of the searched process class or material grade.

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The present work, presented the study of effect of different inoculants on impact toughness in High Chromium Cast Iron. The molds were

pouring in industrial conditions and samples were tested in laboratory in Faculty of Foundry Engineering at AGH. Seven samples were tested

- one reference sample, three with different addition of Fe-Ti, and three with different addition of Al. The samples were subjected to impact

toughness on Charpy hammer and the hardness test. The presented investigations indicate that for the each inoculant there is an optimal

addition at which the sample obtained the highest value of impact toughness. For the Fe-Ti it is 0.66% and for Al is 0.17%. Of all the

examined inoculants best results were obtained at a dose of 0.66% Fe-Ti. Titanium is a well-known as a good modifier but very interesting

results gives the aluminum. Comparing the results obtained for the Fe-Ti and Al can be seen that in the case of aluminum hardness is more

stable. The hardness of all samples is around 40-45 HRC, which is not high for this type of cast iron. Therefore, in future studies it is

planned to carry out the heat treatment procedure that may improves hardness.

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Railway buffers during the operation are staying in almost permanent contact with each other, creating friction node in the point of contact

of two railway buffer heads. In consequence of overcoming track curves, turnouts and unevenness of track, the railway buffer heads moves

relative to each other causing friction, which results in its wear. When the wear is excessive, it might be a reason to withdrawn vehicle

from service, it causes flattening of buffer head, and in consequence its abnormal cooperation. To avoid this phenomenon the buffer heads

should be covered with graphitized grease, but this method has many disadvantages. Accordingly, it was found that it would be beneficial

to cover the buffer head with bronze using laser cladding. In this article the metallographic and mechanical analysis of the newly created

top layer of railway buffer head are presented. In article the results from tribological tests conducted on Amsler test bench are also

presented. Based on test results described in article concluded that the layer of bronze coat on working surface of railway buffer head can

be beneficial from operational point of view.

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In the paper, a research on effects of baking temperature on chromite sand base of moulding sands bonded with sodium silicate is

presented. Pure chromite sand and its chromite-based moulding sand prepared with use of sodium silicate were subjected to heating within

100 to 1200 °C. After cooling-down, changes of base grains under thermal action were determined. Chromite moulding sand was prepared

with use of 0.5 wt% of domestic made, unmodified sodium silicate (water-glass) grade 145. After baking at elevated temperatures, creation

of rough layer was observed on grain surfaces, of both pure chromite sand and that used as base of a moulding sand. Changes of sand

grains were evaluated by scanning microscopy and EDS analyses. It was found that changes on grain surfaces are of laminar nature. The

observed layer is composed of iron oxide (II) that is one of main structural components of chromite sand. In order to identify changes in

internal structure of chromite sand grains, polished sections were prepared of moulding sand hardened with microwaves and baked at

elevated temperatures. Microscopic observations revealed changes in grains structure in form of characteristically crystallised acicular

particles with limited magnesium content, intersecting at various angles. EDS analysis showed that these particles are composed mostly of

chromium oxide (III) and iron oxide (II). The temperature above that the a.m. changes are observed in both chromite-based moulding sand

and in pure chromite sand. The observed phenomena were linked with hardness values and mass of this sand.

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The article presents results of pitting corrosion studies of selected silicon cast irons. The range of studies included low, medium and high

silicon cast iron. The amount of alloying addition (Si) in examined cast irons was between 5 to 25 %. Experimental melts of silicon cast

irons [1-3] were conducted in Department of Foundry of Silesian University of Technology in Gliwice and pitting corrosion resistance

tests were performed in Faculty of Biomedical Engineering in Department of Biomaterials and Medical Devices Engineering of Silesian

University of Technology in Zabrze. In tests of corrosion resistance the potentiostat VoltaLab PGP201 was used. Results obtained in those

research complement the knowledge about the corrosion resistance of iron alloys with carbon containing Si alloying addition above 17 %

[4-6]. Obtained results were supplemented with metallographic examinations using scanning electron microscopy. The analysis of

chemical composition for cast irons using Leco spectrometer was done and the content of alloying element (silicon) was also determined

using the gravimetric method in the laboratory of the Institute of Welding in Gliwice. The compounds of microstructure were identify by

X-ray diffraction.

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Using the available analytical methods, including the determination of chemical composition using wavelength-dispersive X-ray

fluorescent spectroscopy technique and phase composition determined using X-ray diffraction, microstructural observations in a highresolution

scanning microscope equipped with an X-ray microanalysis system as well as determination of characteristic softening and

sintering temperatures using high-temperature microscope, the properties of particular chromite sands were defined. For the study has been

typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the

grinding process. Using these kinds of sand in foundries resulted in the occurrence of the phenomenon of the molding mass sintering.

Impurities were identified and causes of sintering of a moulding sand based on chromite sand were characterized. Next, research methods

enabling a quick evaluation of chromite sand suitability for use in the preparation of moulding sands were selected.

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The analysis of influence of mould withdrawal rate on the solidification process of CMSX-4 single crystal castings produced by Bridgman

method was presented in this paper. The predicted values of temperature gradient, solidification and cooling rate, were determined at the

longitudinal section of casting blade withdrawn at rate from 1 to 6mm/min using ProCAST software. It was found that the increase of

withdrawal rate of ceramic mould results in the decrease of temperature gradient and the growth of cooling rate, along blade height. Based

on results of solidification parameter G/R (temperature gradient/solidification rate), maximum withdrawal rate of ceramic mould

(3.5 mm/min), which ensures lower susceptibility to formation process of new grain defects in single crystal, was established. It was

proved that these defects can be formed in the bottom part of casting at withdrawal rate of 4 mm/min. The increase of withdrawal rate to 5

and 6 mm/min results in additional growth of susceptibility of defects formation along the whole height of airfoil.

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This work presents the qualitative and quantitative changes in the products of isothermal transformation (reaction) in a ductile cast iron

austenite after supercooling to the temperature range Ar1. The austenitizing temperature considered in this work was 900, 960 or 1020°C.

The eutectoid reaction was investigated by metallographic examination at a holding temperature right below Ar11 (820°C) or right below

Ar12 (760°C). The quantitative metallographic examination was carried out with a light microscope (LM). The initial transformation stage

products were identified with a transmission electron microscope (TEM). The selected samples were studied for chemical

microsegregation of manganese, silicon, phosphorus, and carbon with an X-ray microanalyser (MAR). The tested cast iron material was

found to predominantly feature a eutectoid reaction in the metastable system the ratio of which was increasing with the austenitizing

temperature. The austenitizing temperature was found to be conducive to the evolution kinetics of individual phases and to the

graphitization kinetics of the eutectoid cementite that was formed during the contemplated reaction.

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In the present study, the corrosion behaviour of A356 (Al-7Si-0.3Mg) alloy in 3.5% NaCl solution has been evaluated using

cyclic/potentiodynamic polarization tests. The alloy was provided in the unmodified form and it was then modified with AlTi5B1 for grain

refinement and with AlSr15 for Si modifications. These modifications yield to better mechanical properties. Tensile tests were performed.

In addition, bifilm index and SDAS values were calculated and microstructure of the samples was investigated. As a result of the corrosion

test, the Ecorr values for all conditions were determined approximately equal, and the samples were pitted rapidly. The degassing of the

melt decreased the bifilm index (i.e. higher melt quality) and thereby the corrosion resistance was increased. The lowest corrosion rate was

founded at degassing and as-received condition (3.9x10-3 mm/year). However, additive elements do not show the effect which degassing

process shows.

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In modern times, there are increasing requirements for products quality in every part of manufacturing industry and in foundry industry it

is not different. That is why a lot of foundries are researching, how to effectively produce castings with high quality. This article is dealing

with search of the influence of using different types of risers or chills on shrinkage cavity production in ductile iron castings. Differently

shaped risers were designed using the Wlodawer´s modulus method and test castings were poured with and without combination of chills.

Efficiency of used risers and chills was established by the area of created shrinkage cavity using the ultrasound nondestructive method.

There are introduced the production process of test castings and results of ultrasound nondestructive reflective method. The object of this

work is to determine an optimal type of riser or chill for given test casting in order to not use overrated risers and thus increase the cost

effectiveness of the ductile iron castings production.

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The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting

efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization

process and microstructure of multicomponent synthetic hypereutectic alloy AlSi20CuNiCoMg. The study was conducted for unmodified

silumin on the research station allowing the cooling of the special permanent sampler using a program of computer control. Furthermore,

the study used a thermal imaging camera to analyze the solidification process of multicomponent alloy. The study demonstrated that the

use of mold cooled with water mist stream allows in wide range to form the microstructure of hypereutectic multicomponent silumin. It

leads to higher homogeneity of microstructure and refinement of crystallizing phases of casting.

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The paper presents the research results of horizontal continuous casting of ingots of aluminium alloy containing 2% wt. silicon (AlSi2).

Together with the casting velocity (velocity of ingot movement) we considered the influence of electromagnetic stirring in the area of the

continuous casting mould on refinement of the ingot’s primary structure and their selected mechanical properties, i.e. tensile strength, yield

strength, hardness and elongation. The effect of primary structure refinement and mechanical properties obtained by electromagnetic

stirring was compared with refinement obtained by using traditional inoculation, which consists in introducing additives, i.e. Ti, B and Sr,

to the metal bath. On the basis of the obtained results we confirmed that inoculation done by electromagnetic stirring in the range of the

continuous casting mould guarantees improved mechanical properties and also decreases the negative influence of casting velocity, thus

increasing the structure of AlSi2 continuous ingots.

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A possibility to control the strength, hardness and ductility of the L35HM low-alloy structural cast steel by the applied tempering

temperature is discussed in the paper. Tests were carried out on samples taken from the two randomly selected industrial melts. Heat

treatment of the cast samples included quenching at 900 °C, cooling in an aqueous solution of polymer, and tempering at 600 and 650 °C.

The obtained results showed that the difference in the tempering temperature equal to 50 °C can cause the difference of 121 MPa in the

values of UTS and of 153 MPa in the values of 0.2%YS. For both melts tempered at 600 °C, the average values of UTS and 0.2%YS were

equal to 995 MPa and 933 MPa, respectively. The values of EL and RA did not show any significant differences. Attention was drawn to

large differences in strength and hardness observed between the melts tempered at 600 and 650 °C. Despite differences in the mechanical

properties of the examined cast steel, the obtained results were superior to those specified by the standard.

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This paper shows the results of studying the technology of manufacturing cortical electrode-instruments (EI) with the use of indirect

methods of the Rapid Prototyping technology. Functional EI prototypes were made by layered synthesis of the photopolymer material with

the use of the stereolithography technology (SLA - Stereo Lithography Apparatus). The article is focused on two methods of indirect EI

manufacturing. One of the EI prototypes was used for making a molded wax model for hot investment casting, followed by applying

copper coating. The second prototype was used for applying copper plating to a prepared current-conductive layer. As a result of EDMing

a steel workpiece, both EIs reached the desired depth, which is 1 mm. The copper plating applied to the EI preserves its integrity. Through

the use of the casting technology, there is a possibility to cut the economic costs by 35%. Using a prototype with preliminarily applied

conductive coating makes it possible to make geometrically-complex EIs.

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Chemical bonded resin sand mould system has high dimensional accuracy, surface finish and sand mould properties compared to green

sand mould system. The mould cavity prepared under chemical bonded sand mould system must produce sufficient permeability and

hardness to withstand sand drop while pouring molten metal through ladle. The demand for improved values of permeability and mould

hardness depends on systematic study and analysis of influencing variables namely grain fineness number, setting time, percent of resin

and hardener. Try-error experiment methods and analysis were considered impractical in actual foundry practice due to the associated cost.

Experimental matrices of central composite design allow conducting minimum experiments that provide complete insight of the process.

Statistical significance of influencing variables and their interaction were determined to control the process. Analysis of variance

(ANOVA) test was conducted to validate the model statistically. Mathematical equation was derived separately for mould hardness and

permeability, which are expressed as a non-linear function of input variables based on the collected experimental input-output data. The

developed model prediction accuracy for practical usefulness was tested with 10 random experimental conditions. The decision variables

for higher mould hardness and permeability were determined using desirability function approach. The prediction results were found to be

consistent with experimental values.

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In this study, Taguchi method is used to find out the effect of micro alloying elements like vanadium, niobium and titanium on the

hardness and tensile strength of the normalized cast steel. Based on this method, plan of experiments were made by using orthogonal

arrays to acquire the data on hardness and tensile strength. The signal to noise ratio and analysis of variance (ANOVA) are used to

investigate the effect of these micro alloying elements on these two mechanical properties of the micro alloyed normalized cast steel. The

results indicated that in the micro alloyed normalized cast steel both these properties increases when compared to non-micro-alloyed

normalized cast steel. The effect of niobium addition was found to be significantly higher to obtain higher hardness and tensile strength

when compared to other micro alloying elements. The maximum hardness of 200HV and the maximum tensile strength of 780 N/mm2

were obtained in 0.05%Nb addition micro alloyed normalized cast steel. Micro-alloyed with niobium normalized cast steel have the finest

and uniform microstructure and fine pearlite colonies distributed uniformly in the ferrite. The optimum condition to obtain higher hardness

and tensile strength were determined. The results were verified with experiments.

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The paper presents the results of analyzes of gases emitted during exposure to high temperature foundry molding sands, where binders are

organic resins. As a research tool has been used special gas chromatograph designed to identify odorous compounds including the group of

alkanes.

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The aim of research was creation of a furnace for aluminum alloys smelting “in a liquid bath” in order to reduce metal loss. In the paper,

the author demonstrates the results of research on smelting of aluminum alloys in a shaft-reverberatory furnace designed by the author. It

has been shown that smelting aluminum alloy in a liquid bath was able to significantly reduce aluminum loss and that shaft-reverberatory

design provided high efficiency and productivity along with lower energy costs. Ensuring continuous operation of the liquid bath and

superheating chamber, which tapped alloy with the required texture, was achieved by means of the optimal design of partition between

them. The optimum section of the connecting channels between the liquid bath of smelting and the superheating chamber has been

theoretically substantiated and experimentally confirmed. The author proposed a workable shaft-reverberatory furnace for aluminum

alloys smelting, providing solid charge melting in a liquid bath.

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In Poland, researchers have a very strong interest in archaeometallurgy, which, as presented in classical works, focuses on dating artefacts

from the prehistoric and early medieval periods in the form of cast iron and copper castings. This study, extending the current knowledge,

presents the results of a microstructure investigation into the findings from the Modern era dating back to the late Middle Ages. The

investigated material was an object in the form of a heavy solid copper block weighing several kilograms that was excavated by a team of

Polish archaeologists working under the direction of Ms Iwona Młodkowska-Przepiórowska during works on the marketplace in the city of

Czestochowa during the summer of 2009. Pre-dating of the material indicates the period of the seventeenth century AD.

The solid copper block was delivered in the form of a part shaped like a bell, named later in this work as a “kettlebell”. To determine the

microstructure, the structural components, chemical composition, and homogeneity, as well as additives and impurities, investigations

were carried out using light microscopy, scanning electron microscopy including analysis of the chemical composition performed in

micro-areas, and qualitative X-ray phase analysis in order to investigate the phase composition.

Interpretation of the analytical results of the material’s microstructure will also help modify and/or develop new methodological

assumptions to investigate further archaeometallurgical exhibits, throwing new light on and expanding the area of knowledge of the use

and processing of seventeenth-century metallic materials.

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The results of investigations of thermal reclamation of spent moulding sands originating from an aluminum alloy foundry plant are

presented in this paper. Spent sands were crushed by using two methods. Mechanical fragmentation of spent sand chunks was realized in

the vibratory reclaimer REGMAS. The crushing process in the mechanical device was performed either with or without additional

crushing-grinding elements. The reclaimed material obtained in this way was subjected to thermal reclamations at two different

temperatures. It was found that a significant binder gathering on grain surfaces favors its spontaneous burning, even in the case when

a temperature lower than required for the efficient thermal reclamation of furan binders is applied in the thermal reclaimer. The burning

process, initiated by gas burners in the reclaimer chamber, generates favorable conditions for self-burning (at a determined amount of

organic binders on grain surfaces). This process is spontaneously sustained and decreases the demand for gas. However, due to the

significant amount of binder, this process is longer than in the case of reclaiming moulding sand prepared with fresh components.

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Theory and practice of environmental protection in the case of foundries in Europe and Asia

• Experience resulting from the cooperation with the foundries in a few European countries, China and India

• Phenomena and factors affecting the pollution of the natural environment and the implementation of measures aiming at the

environmental protection

Every specialist dealing with foundry processes and their impact on environmental pollution must have encountered in their professional

careers numerous situations in which the theory of environmental protection confronts the stark reality. The discrepancy between theory

and practice can particularly be noticed in foundry engineering in developing countries where the contrasts between different countries and

casting plants are extremely striking. The comparison of working conditions in European and Asian foundries provides a vast scope for

further observations and analyses. Environmental protection seems not only a concern of manufacturers of castings, but also of their

customers whose opinion exerts a significant influence on both the acceptability of working conditions and on the approach to

environmental pollution adopted in metal casting industry.

The article presents a number of examples of various outlooks on environmental issues in foundries manufacturing a wide range of cast

steel and cast iron castings, where different technologies and production processes are applied.

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Tests concerning EN AC 48000 (AlSi12CuNiMg) alloy phase transition covered (ATD) thermal analysis and (DSC) differential scanning

calorimetry specifying characteristic temperatures and enthalpy of transformations. ATD thermal analysis shows that during cooling there

exist: pre-eutectic crystallization effect of Al9Fe2Si phase, double eutectic and crystallization α(Al)+β(Si) and multi-component eutectic

crystallization. During heating, DSC curve showed endothermic effect connected with melting of the eutectic α(Al)+β(Si) and phases:

Al2Cu, Al3Ni, Mg2Si and Al9Fe2Si being its components. The enthalpy of this transformation constitutes approx. +392 J g-1

. During

freezing of the alloy, DSC curve showed two exothermal reactions. One is most likely connected with crystallization of Al9Fe2Si phase

and the second one comes from freezing of the eutectic α(Al)+β(Si). The enthalpy of this transformation constitutes approx. –340 J g-1

.

Calorimetric test was accompanied by structural test (SEM) conducted with the use of optical microscope Reichert and scanning

microscope Hitachi S-4200. There occurred solution's dendrites α(Al), eutectic silicon crystal (β) and two types of eutectic solution: double

eutectic α(Al)+β(Si) and multi-component eutectic α+AlSiCuNiMg+β.

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In Al-Si alloy the iron is the most common impurity and with presence of other elements in alloy creates the intermetallic compounds,

which decreases mechanical properties and increases of porosity. The cause of the negative effect of intermetallic particles on the

mechanical properties is that it is more easily break off the tension load as the aluminium matrix or small particles of silicon. By adding

suitable alloying elements, also known as iron correctors, is possible to reduce this harmful effect.

In the article is evaluated influence of manganese on microstructure with performed EDX analysis selected intermetallic phases and tensile

test and measurement of length of Al5FeSi phase. For realization experiments was used AlSi7Mg0.3 alloy with increased iron content.

Manganese was added in the amount 0.3 wt. %, 0.6 wt. %, 0.8 wt.% and 1,2 wt. %. From performed measurements it has been concluded,

that increased amount of manganese, i.e. Mn/Fe ratio, does not have significant influence on mechanical properties AlSi7Mg0.3 alloy in

the melted state.

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In spite of the fact that in most applications, magnesium alloys are intended for operation in environments with room temperature, these

alloys are subject to elevated temperature and oxidizing atmosphere in various stages of preparation (casting, welding, thermal treatment).

At present, the studies focus on development of alloys with magnesium matrix, intended for plastic forming. The paper presents results of

studies on oxidation rate of WE43 and ZRE1 magnesium foundry alloys in dry and humidified atmosphere of N2+1%O2. Measurements of

the oxidation rate were carried out using a Setaram thermobalance in the temperature range of 350-480°C. Corrosion products were

analyzed by SEM-SEI, BSE and EDS. It was found that the oxide layer on the WE43 alloy has a very good resistance to oxidation. The

high protective properties of the layer should be attributed to the presence of yttrium in this alloy. On the other hand, a porous, two-layer

scale with a low adhesion to the substrate forms on the ZRE1 alloy. The increase in the sample mass in dry gas is lower than that in

humidified gas.

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In highly developed countries, a significant progress in the use of alternative and clean energy sources has recently been observed. The

European Union has implemented a programme to build wind turbines. It is estimated that in the coming years, thanks to the support in tax

and credit, the global energy will develop very intensively.

Many components of the wind turbines are castings. The basic material used for these castings is ductile iron, which in this particular case

must meet high requirements imposed by the operating conditions of wind turbines. Anticipating an increase in customer demand for this

type of castings, Krakodlew SA has decided to modernize its foundry using the ability to obtain external financing.

The ductile iron manufacturing technology is now being developed and adapted to the specific conditions of the foundry plant, including

the melting process yielding cast material with the required chemical composition, the technology of moulding, and the conditions for

possible secondary metallurgy, spheroidizing treatment and graphitizing inoculation. The fulfilment of the imposed conditions for the

casting production demands the use of advanced casting technologies introduced to the manufacturing process.

The development of technology to launch the production of ductile iron castings for the wind power industry was supported by The

National Centre for Research and Development (NCBiR). This article presents part of research on the binding kinetics of furan resin sands

and choice of their composition for moulds and cores to make heavy castings used as components of equipment for the wind power

industry.

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The gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been

studied. During smelting of aluminum, the intermetallic compound (IMC) may be formed at the interface between molten aluminum and

solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The

rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the

range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to

investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The

thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate

specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was

more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed

dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

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Redakcja

CHIEF EDITORS
Editor
J. Szajnar
Deputy Editor
J. Jezierski

SUBJECT EDITORS
Theoretical Aspects of Casting Processes
K. Eigenfeld – Freiberg, Germany
E. Guzik – Kraków, Poland
T. G. Mathia - Lyon, France
W. Wołczyński – Kraków, Poland
Innovative Foundry Technologies and Materials
T. Elbel – Ostrava, Czech Republic
Z. Ignaszak – Poznań, Poland
O. P. Pandey – Punjab, India
A. Pereira - Vigo, Spain
Foundry Processes Computer Aiding
B. Mochnacki – Częstochowa, Poland
J. Roučka – Brno, Czech Republic
J.S. Suchy – Kraków, Poland
Mechanization, Automation and Robotics in Foundry
J. Bast – Freiberg, Germany
R. Wrona – Kraków, Poland
Transport Systems in Foundry
J. Dańko – Kraków, Poland
Z. Li – Shijiazhuang, China
Castings Quality Management
D. Bolibruchova– Żilina, Slovak Republic
J. D. B. de Mello - Santa Monica, Brazil
M. Perzyk – Warszawa, Poland
Environment Protection
M. Holtzer – Kraków, Poland
H. Polzin – Freiberg, Germany
J. Sobczak – Kraków, Poland
I. Volchok – Zaporizhzhya, Ukraine

EDITORIAL ADVISORY BOARD
J. Braszczyński – Częstochowa, Poland
B. K. Dhindaw – Rupnagar, India
L. A. Dobrzański – Gliwice, Poland
W. A. Hufenbach – Dresden, Germany
P. Jelínek – Ostrava, Czech Republic
L. Jeziorski – Częstochowa, Poland
J. Lacaze – Toulouse, France
V. L. Naydek – Kiev, Ukraine
A. Passerone – Genova, Italy
I. Riposan – Bucharest, Romania
F. Romankiewicz – Zielona Góra, Poland
A. Sládek – Żilina, Slovak Republic

INTERNATIONAL SCIENTIFIC REVIEW COMMITTEE
S. A. Argyropoulos – Toronto, Canada
M. Azadi – Tehran, Iran
Y. Babaskin – Kiev, Ukraine
K. Bako – Miskolc, Hungary
E. Bayraktar – Paris, France
L. Bechný – Zilina, Slovak Republic
V. Bednarova - Ostrava, Czech Republic
F. Bińczyk – Katowice, Poland
A. Bokota – Częstochowa, Poland
G.P. Borisov – Kiev, Ukraine
A. Bydałek – Kraków, Poland
C. H. Cáceres – Brisbane, Australia
J. Čech – Brno, Czech Republic
L. Q. Chen – Shenyang, China
A. Chojecki – Kraków, Poland
M. Cholewa – Gliwice, Poland
I. A. Dibrov – Moscow, Russia
D. Dispinar – Istanbul, Turkey
S. M. Dobosz – Kraków, Poland
V. I. Dubodelov – Kiev, Ukraine
A. Fedoryszyn – Krakow, Poland
J. Głownia – Kraków, Poland
K. Granat – Wrocław, Poland
J. Hampl – Ostrava, Czech Republic
J. Helber – Düsseldorf, Germany
M. Hetmańczyk – Katowice, Poland
M. Horáček – Brno, Czech Republic
M. Kaczorowski – Warszawa, Poland
W. Kapturkiewicz – Kraków, Poland
R. Kawalla – Freiberg, Germany
Z. Konopka – Czestochowa, Poland
D. Kopyciński – Kraków, Poland
W. K. Krajewski – Kraków, Poland
Z. Libo – Beijing, China
P. Lichy – Ostrava, Czech Republic
Y. P. Lim – Setapak, Malaysia
T. Lipiński – Olsztyn, Poland
E. Majchrzak – Gliwice, Poland
A. Mityayev - Zaporizhzhya, Ukraine
M. Murgaš – Trnava, Slovak Republic
I. Nová – Liberec, Czech Republic
W. Orłowicz – Rzeszów, Poland
T. Pacyniak – Łódź, Poland
B. Piekarski – Szczecin, Poland
A. Rimmer – West Bromwich, United Kingdom
S. Samavedam – Hyderabad, India
P. Schumacher – Leoben, Austria
N. Sczygiol – Częstochowa, Poland
P. Skočovský – Żilina, Slovak Republic
M.S. Soiński – Częstochowa, Poland
J. Sokolowski – Ottawa, Kanada
K. V. Sudhakar – Butte, USA
B. G. Thomas - Champaign, USA
M. Trbižan – Ljubljana, Slovenia
J. Vuorinen – Tampere, Finland
E. Ziółkowski – Kraków, Poland
J. Zych – Kraków, Poland

ASSOCIATE EDITORS
D. Bartocha – Gliwice, Poland, - editorial secretary
J. Suchoń – Gliwice, Poland - editorial secretary
J. Szymszal – Katowice, Poland, Statistic Editor
A. Dulska – Gliwice, Poland
M. Kondracki – Gliwice, Poland
C. Borek –Chicago, USA, Language Editor

 

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