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1
Content available Intermetallic Phases in Alloyed Cast Iron with 18%Si Addition
Stawarz M.
Archives of Foundry Engineering
|
2020
|
Vol. 20, iss. 2
37--42
EN
The paper presents an analysis of a selected grade of high silicon cast iron intended for work in corrosive and abrasive conditions. The text describes its microstructure taking into account the process of crystallization, TDA analysis, EDS, XRD and the chemical composition analysis. In order to determine the phase composition, X-ray diffraction tests were carried out. The tests were executed on a Panalytical X'Pert PRO X-ray diffractometer with filtration of radiation from a lamp with copper anode and PIXcel 3D detector on the deflected beam axis. Completed tests allowed to describe the microstructure with detailed consideration of intermetallic phases present in the alloy. Results of the analysis of the examined alloy clearly show that we deal with intermetallic phases of Fe3Si, Fe5Si3 types, as well as silicon ferrite and crystals of silicon. In the examined alloy, we observed the phenomenon of segregation of carbon, which, as a result of this process, enriches the surface of silicon crystals, not creating a compound with it. Moreover, the paper demonstrates capability for crystallization of spheroidal graphite in the examined alloy despite lack of elements that contribute to balling in the charge materials.
2
Content available Grain Refinement of AlSi7Mg0,3 Alloy Cast by Rheocasting SEED
Bryksí Stunová B., Bryksí V., Vitkova J.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 3
161--166
EN
The paper concerns experimental work studying chemical composition, structures and selected mechanical properties of castings produced by rheocasting method SEED. After previous experiments, which showed inclusions in the primary phase α(Al) when observing structures, hypothesis of external nuclei was taken. The main goal of the work was to determine the influence of inoculation by various additions of titanium/boron based inoculant on the structure and properties of AlSi7Mg0,3 alloy. The master alloy AlTi5B1 was added in amounts of 0,05, 0,1, 0,15, 0,2 wt %. Metallographic observation by light and SEM microscopy was used for analysing the structures. Measurements of grain size were realised and evaluated. Brinell hardness measurements were performed. Chemical composition was measured by GDS analysis. Undertaken experiments did not prove the effect of inoculation of combined AlTi5B1 master alloy on castings made of AlSi7Mg0,3 alloy made by rheocasting SEED at given amounts and conditions.
3
Content available Crystallization Process of Silicon Molybdenum Cast Iron
Stawarz M.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 2
100--104
EN
The article presents results of studies of silicon – molybdenum cast iron (4.42% Si, 2.59% Mo and 2.48% C wt.-%) crystallization process. Metallographic analysis was carried out using SEM-scanning electron microscopy with the EDS system. In order to determine the phase composition, X-ray diffraction studies were performed. Thermo-Calc, a computer simulation program, was used to simulate the crystallization process. . The obtained data allowed to describe the effect of some elements on the crystallization process. The silicon phase of MnSi could not be identified during metallographic studies. Also, computer simulation of the crystallization process did not answer the question at which point the silicon phase of MnSi crystallizes in the tested alloy. Therefore, not all results obtained were linked to the registered crystallization process (TDA process). The EDS analysis revealed an unusual distribution of molybdenum in the microstructure of the sample, where it is clearly visible that the area enriched with this element is also the separation of spheroidal graphite. The possibility of occurrence of Mo-rich micro-areas found in graphite is considered. The case is debatable and difficult to resolve at this stage. Perhaps, at such a high concentration of molybdenum (2.59% Mo) in the alloy, conditions are created for simultaneously crystallization of graphite and molybdenum phases.
4
Content available Copper in Ausferritic Compacted Graphite Iron
Gumienny G., Kacprzyk B.
Archives of Foundry Engineering
|
2018
|
Vol. 18, iss. 1
162--166
EN
This paper shows how it is possible to obtain an ausferrite in compacted graphite iron (CGI) without heat treatment of castings. Vermicular graphite in cast iron was obtained using Inmold technology. Molybdenum was used as alloying additive at a concentration from 1.6 to 1.7% and copper at a concentration from 1 to 3%. It was shown that ausferrite could be obtained in CGI through the addition of molybdenum and copper in castings with a wall thickness of 3, 6, 12 and 24 mm. Thereby the expensive heat treatment of castings was eliminated. The investigation focuses on the influence of copper on the crystallization temperature of the graphite eutectic mixture in cast iron with the compacted graphite. It has been shown that copper increases the eutectic crystallization temperature in CGI. It presents how this element influences ausferrite microhardness as well as the hardness of the tested iron alloy. It has been shown that above-mentioned properties increases with increasing the copper concentration.
5
Content available Microstructural and Mechanical Characterization of Solidified Austenitic Stainless Steels
Celik A. G., Polat S., Atapek S. H., Haidemenopoulos G. N.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 3
163--167
EN
Among the family of stainless steels, cast austenitic stainless steels (CASSs) are preferably used due to their high mechanical properties and corrosion resistance. These steels owe their properties to their microstructural features consisting of an austenitic matrix and skeletal or lathy type δ-ferrite depending on the cooling rate. In this study, the solidification behavior of CASSs (304L and 316L grades) was studied using ThermoCalc software in order to determine the solidification sequence and final microstructure during cooling. Theoretical findings were supported by the microstructural examinations. For the mechanical characterization, not only hardness measurements but also tribological studies were carried out under dry sliding conditions and worn surfaces were examined by microscopy and 3D profilometric analysis. Results were discussed according to the type and amount of microstructural features.
6
Content available Effect of Copper on the Crystallization Process, Microstructure and Selected Properties of CGI
Gumienny G., Kacprzyk B., Gawroński J.
Archives of Foundry Engineering
|
2017
|
Vol. 17, iss. 1
51--56
EN
The paper presents the results of the research on the effect of copper on the crystallization process, microstructure and selected properties of the compacted graphite iron. Compacted graphite in cast iron was obtained using Inmold process. The study involved the cast iron containing copper at a concentration up to approximately 4%. The effect of copper on the temperature of the eutectic crystallization as well as the temperature of start and finish of the austenite transformation was given. It has been shown that copper increases the maximum temperature of the eutectic transformation approximately by 5 oC per 1% Cu, and the temperature of the this transformation finish approximately by 8 o C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5 oC per 1% Cu, and the finish of this transformation approximately by 6oC per 1% Cu. It was found that in the microstructure of the compacted graphite iron containing about 3.8% Cu, there are still ferrite precipitations near the compacted graphite. The effect of copper on the hardness of cast iron and the pearlite microhardness was given. This stems from the high propensity to direct ferritization of this type of cast iron. It has been shown copper increases the hardness of compacted graphite iron both due to its pearlite forming action as well as because of the increase in the pearlite microhardness (up to approx. 3% Cu). The conducted studies have shown copper increases the hardness of the compacted graphite iron approximately by 35 HB per 1% Cu.
7
Content available Structural Zones in Large Static Ingot. Forecasts for Continuously Cast Brass Ingot
Wołczyński W., Lipnicki Z., Bydałek A. W., Ivanova A. A.
Archives of Foundry Engineering
|
2016
|
Vol. 16, iss. 3
141--146
EN
Some metallographic studies performed on the basis of the massive forging steel static ingot, on its cross-section, allowed to reveal the following morphological zones: a/ columnar grains (treated as the austenite single crystals), b/ columnar into equiaxed grains transformation, c/ equiaxed grains at the ingot axis. These zones are reproduced theoretically by the numerical simulation. The simulation was based on the calculation of both temperature field in the solidifying large steel ingot and thermal gradient field obtained for the same boundary conditions. The detailed analysis of the velocity of the liquidus isotherm movement shows that the zone of columnar grains begins to disappear at the first point of inflection and the equiaxed grains are formed exclusively at the second point of inflection of the analyzed curve. In the case of the continuously cast brass ingots three different morphologies are revealed: a/ columnar structure, b/ columnar and equiaxed structure with the CET, and c/ columnar structure with the single crystal formation at the ingot axis. Some forecasts of the temperature field are proposed for these three revealed morphologies. An analysis / forecast of the behavior of the operating point in the mold is delivered for the continuously cast ingot. A characteristic delay between some points of breakage of the temperature profile recorded at the operating point and analogous phenomena in the solidifying alloy is postulated.
8
Content available Effect of Cr and W on the Crystallization Process, the Microstructure and Properties of Hypoeutectic Silumin to Pressure Die Casting
Szymczak T., Gumienny G., Pacyniak T.
Archives of Foundry Engineering
|
2016
|
Vol. 16, iss. 3
109--114
EN
This article presents the results of studies in the hypoeutectic silumin destined for pressure die casting with the simultaneous addition of chromium and tungsten. The study involved the derivative and thermal analysis of the crystallization process, metallographic analysis and mechanical properties testing. Silumin 226 grade was destined for studies. It is a typical silumin to pressure die casting. AlCr15 and AlW8 preliminary alloys were added to silumin. Its quantity allowed to obtain 0.1, 0.2, 0.3 and 0.4% of Cr and W in the tested alloy. Studies of the crystallization process as well as the microstructure of the silumin poured into DTA sampler allowed to state the presence of additional phase containing 0.2% or more Cr and W. It has not occurred in silumin without the addition of above mentioned elements. It is probably the intermetallic phase containing Cr and W. DTA studies have shown this phase crystallizes at a higher temperature range than α (Al) solid solution. In the microstructure of each pressure die casting containing Cr and W the new phases formed. Mechanical properties tests have shown Cr and W additives in silumin in an appropriate amount may increase its tensile strength Rm (about 11%), the yield strength Rp0.2 (about 21%) and to a small extent elongation A.
9
Content available Numerical Model for Solidification Zones Selection in the Large Ingots
Wołczyński W., Kwapisiński P., Kania B., Wajda W., Skuza W., Bydałek A. W.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 4
87--90
EN
A vertical cut at the mid-depth of the 15-ton forging steel ingot has been performed by curtesy of the CELSA – Huta Ostrowiec plant. Some metallographic studies were able to reveal not only the chilled undersized grains under the ingot surface but columnar grains and large equiaxed grains as well. Additionally, the structural zone within which the competition between columnar and equiaxed structure formation was confirmed by metallography study, was also revealed. Therefore, it seemed justified to reproduce some of the observed structural zones by means of numerical calculation of the temperature field. The formation of the chilled grains zone is the result of unconstrained rapid solidification and was not subject of simulation. Contrary to the equiaxed structure formation, the columnar structure or columnar branched structure formation occurs under steep thermal gradient. Thus, the performed simulation is able to separate both discussed structural zones and indicate their localization along the ingot radius as well as their appearance in term of solidification time.
10
Content available Effect of Vanadium and Molybdenum on the Crystallization, Microstructure and Properties of Hypoeutectic Silumin
Szymczak T., Gumienny G., Pacyniak T.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 4
81--86
EN
The paper presents the results of hypoeutectic silumin 226 grade and silumin produced on its basis through the addition of V and Mo. Vanadium and molybdenum were added as the preliminary alloy AlV10 and AlMo8 in an amount providing the concentration of 0.1; 0.2; 0.3 and 0.4% V and Mo. TDA curves of tested silumins were presented; regardless of the chemical composition there were similar thermal effects. Pressure castings microstructure research revealed the presence in silumins with the addition of V and Mo phases do not occur in silumin without these additives. These phases have a morphology similar to the walled, and their size increases with increasing concentration of V and Mo. The size of the precipitates of these phases silumin containing 0.1% V and Mo does not exceed 10 microns, while 0.4% of the content of these elements increases to about 80 microns. Tests of basic mechanical properties of silumins were carried out. It has been shown that the highest values of tensile strength Rm = 295 MPa and elongation A = 4.2% have silumin containing approximately 0.1% V and Mo. Increasing concentrations of these elements causes a gradual lowering of the Rm and A values.
11
Content available Effect of Chromium on the Solidification Process and Microstructure of Vermicular Graphite Cast Iron
Gumienny G., Dondzbach M., Kacprzyk B.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3
29--34
EN
The paper presents the results of studies of the effect of chromium concentration on the solidification process, microstructure and selected properties of cast iron with vermicular graphite. The vermicular graphite cast iron was obtained by an Inmold process. Studies covered the cast iron containing chromium in a concentration at which graphite is still able to preserve its vermicular form. The effect of chromium on the temperature of eutectic crystallization and on the temperature of the start and end of austenite transformation was discussed. The conditions under which, at a predetermined chromium concentration, the vermicular graphite cast iron of a pearlitic matrix is obtained were presented, and the limit concentration of chromium was calculated starting from which partial solidification of the cast iron in a metastable system takes place. The effect of chromium on the hardness of cast iron, microhardness of individual phases and surface fraction of carbides was disclosed.
12
Content available Analysis of the Graphite Shape in Cast Iron Obtaining by Inmold Process
Gumienny G., Kurowska B.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 3 spec.
15--20
EN
The paper presents results of research on the effect of magnesium on the graphite shape in cast iron obtained by Inmold process. For testing Lamet® 5504 master alloy was used. The crystallization process of cast iron with various Mg concentrations was evaluated with use of the thermal and derivative analysis (TDA) method. The conditions were demonstrated for which a flake, vermicular and nodular graphite were obtained. Values of graphite “c” coefficient were analyzed. Results from it the significant differences between the assessment of the graphite on metallographic specimen and by the "c" coefficient. An effect of wall thickness of the casting on the graphite coefficient was indicated.
13
Content available The Crystal Segregation During Casting of the Alloy AlZn5.5Mg2.5Cu1.5
Weiss V., Svobodova J., Cais J.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 2
63--68
EN
In the course of homogenizing annealing of aluminium alloys being cast continually or semi-continually it appears that chemical inhomogenity takes off within separate dendritic cells (crystal segregation). It is about a diffusion process that takes place at the temperature which approaches the liquid temperature of the material. In that process the transition of soluble intermetallic compounds and eutectic to solid solution occurs and it suppresses crystal segregation significantly [1]. The temperature, homogenization time, the size of dendritic cells and diffusion length influences homogenizing process. The article explores the optimization of homogenizing process in terms of its time and homogenizing annealing temperature which influence mechanical properties of AlZn5,5Mg2,5Cu1,5 alloy.
14
Content available Effect of the Hold Time and Temperature on Characteristic Quantities of TDA Curves
Szymczak T., Gumienny G., Pacyniak T.
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 1
113--116
EN
This paper presents the effect of the temperature and hold time in the holding furnace of 226 silumin on the characteristic quantities of TDA curves. The temperature of phase transformations and the cooling rate were tested. It has been shown that increasing both the hold time and the temperature in the holding furnace cause the decreasethe end ofα+Al9Fe3Si2+β and α+Al2Cu+β ternary eutectics crystallization temperature in the tested silumin. This is due to the fact an increase in amounts of impurities as a result of reacting the liquid alloy with the gases contained in the air. It has been shown, however, that examined technological factors of the metal preparation do not cause systematic changes in the cooling rate.
15
Content available Crystallization of Eutectics in Fe-C-V-Si Alloys
Kawalec M
Archives of Foundry Engineering
|
2014
|
Vol. 14, iss. 1 spec.
143--146
EN
This article addresses the results of microstructural examinations of the volume solidifying Fe–C–V–Si alloys containing carbon in the range of 1.39÷1.76%, vanadium in the range of 6.77÷7.77% and silicon in the range of 0.02÷3.10. The melting charge was Armco iron, ferro-vanadium with 81.7 wt.%V, spectrally pure graphite and technically pure silica. It was shown that with increasing the silicon content, the microstructure of the resulting alloy changing. These changes include both a matrix the shape of the primary carbides and type of crystallizing eutectic. In the studied alloys was observed following eutectic: fibrous (crystallize as non-faceted/ non-faceted eutectic), complex regular (crystallize as faceted/ non-faceted eutectic), spiral (crystallize as faceted/ faceted eutectic). The results illustrated by the images of the microstructures made with an optical microscope and a scanning electron microscope.
16
Content available Effect of the remelting on transformations in Co-Cr-Mo prosthetics alloy
Kacprzyk B., Szymczak T., Gumienny G., Klimek L.
Archives of Foundry Engineering
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2013
|
Vol. 13, iss. 3
47--50
EN
In the article we were studing the impact of the remelting on transformations in Co-Cr-Mo prosthetics alloy. The TDA curves were analyzed, the microstructure was examined, the analysis of the chemical composition and hardness using the Brinell method was made. It was found that the obtained microstructure of the alloys that we studied do not differ significantly. In all four samples, microscopic images were similar to each other. The volume, size and distribution of the phases remain similar. Analysis of the chemical composition showed that all the samples fall within the compositions provided for the test alloy. Further to this the hardness of the samples, regardless of the number of remeltings did not show any significant fluctuations and remained within the error limit. After analyzing all the results, it can be concluded that the remeltings of the alloys should not have a significant impact on their properties. Secondarily melted alloys can be used for prosthetics works.
17
Content available Meta-stable solidification created by the detonation method of coating formation
Wołczyński W., Garzeł G., Morgiel J., Senderowski C., Pawłowski A.
Archives of Foundry Engineering
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2012
|
Vol. 12, iss. 2
93-96
EN
Particles of the Fe-Al type (less than 50 m in diameter) were sprayed onto the 045 steel substrate by means of the detonation method. The TEM, SAED and EDX analyses revealed that the Fe-Al particles have been partially melted in the experiment of coating formation. Particle undergone melting even within about 80% of its volume. Therefore, solidification of the melted part of particles was expected. Solidification differed significantly due to a large range of chemical composition of applied particles (from 15 at.% Al up to 63 at.% Al). A single particle containing 63 at.% Al was subjected to the detailed analysis, only. The TEM / SAED techniques revealed in the solidified part of particle three sub-layers: an amorphous phase, [...] , periodically situated FeAl + Fe2Al5 phases, and a non-equilibrium phase, [...]. A hypothesis dealing with the inter-metallic phases formation in such a single particle of the nominal composition No = 0.63 is presented. At first, the solid / liquid system is treated as an interconnection: substrate / liquid / nonmelted particle part . Therefore, it is suggested that the solidification occurs simultaneously in two directions: towards a substrate and towards a non-melted part of particle. The solidification mechanism is referred to the Fe-Al meta-stable phase diagram. It is shown that the melted part of particle solidifies rapidly according to the phase diagram of meta-stable equilibrium and at a significant deviation from the thermodynamic equilibrium.
18
Content available Mechanical properties of two manganese steels
Cagala M., Mazancová E., Lichý P., Beňo J., Břuska M., Špirutová N.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1
9-12
EN
The article is focused on thermomechanical and plastic properties of two high-manganese TRIPLEX type steels with an internal marking 1043 and 1045. Tensile tests at ambient temperature and at a temperature interval 600 C to 1100 C were performed for these heats with a different chemical composition. After the samples having been ruptured, ductility was observed which was expressed by reduction of material after the tensile test. Then the stacking fault energy was calculated and dilatation of both high-manganese steels was measured. At ambient temperature (20 C), 1043 heat featured higher tensile strength by 66MPa than 1045 heat. Microhardness was higher by 8HV0,2 for 1045 steel than for 1043 steel (203HV0,2). At 20 C, ductility only differed by 3% for the both heats. Decrease of tensile properties occurred at higher temperatures of 600 up to 1100 C. This tensile properties decrease at high temperatures is evident for most of metals. The strength level difference of the both heats in the temperature range 20 C up to 1100 C corresponded to 83 MPa, while between 600 C and 1100 C the difference was only 18 MPa. In the temperature range 600 C to 800 C, a decrease in ductility values down to 14 % (1045 heat), or 22 % (1043 heat), was noticed. This decrease was accompanied with occurrence of complex Aluminium oxides in a superposition with detected AlN particles. Further ductility decrease was only noted for 1043 heat where higher occurrence of shrinkage porosity was observed which might have contributed to a slight decrease in reduction of area values in the temperature range 900 C to 1100 C, in contrast to 1045 heat matrix.
19
Content available Homogenity of die casting and returning material
Malik J., Vasková I., Fecko D., Futáš P.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 2
61-64
EN
Homogeneity of die castings is influenced by wide range of technological parameters as piston velocity in filling chamber of die casting machine, filling time of mould cavity, temperature of cast alloy, temperature of the mould, temperature of filling chamber, surface pressure on alloy during mould filling, final pressure and others. Based on stated parameters it is clear, that main parameters of die casting are filling time of die mould cavity and velocity of the melt in the ingates. Filling time must ensure the complete filling of the mould cavity before solidification process can negatively influence it. Among technological parameters also belong the returning material, which ratio in charge must be constrained according to requirement on final homogeneity of die castings. With the ratio of returning material influenced are the mechanical properties of castings, innerhomogeneity and chemical composition.
20
Content available remote The solidification during flow of composite suspension in the permanent mould
Łągiewka M., Konopka Z., Zyska A., Nadolski M.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 2
75-78
EN
The presented work presents the influence of graphite particles on the solidification kinetics of metal suspension based on AlSi10Mg alloy during the die cavity filling. In order to examine this problem, the measurements concerning temperature changes in the selected points of the metal mould have been taken for two materials poured into the die: the pure AlSi10Mg alloy and the alloy reinforced with graphite particles. Thus the solidification and cooling curves of the examined material have been achieved. The recorded temperature changes have served as a basis for preparing graphs representing the velocity of the metal stream and the distance travelled by the front of the stream against the time. The introduction of graphite particles into the matrix alloy has caused the shortening of the distance flown by the material by 50% as compared with the non-reinforced alloy. The recorded temperature changes have allowed also for determining the temperature changes for the front of the metal stream during the die filling. Taking into account these results it has been found that the AlSi10Mg+10%Cgr composite begins its solidification after having covered the distance seven times shorter than the corresponding distance measured for the non-reinforced AlSi10Mg alloy.
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