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.

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 holdingfurnace cause the decreasethe end ofα+Al9Fe3Si2+β and α+Al2Cu+βternary eutectics

crystallizationtemperature in the tested silumin. This is due to the fact an increase in amounts of impurities as a result of reacting theliquid

alloy with the gases contained in the air.It has been shown, however, that examined technological factors ofthe metal preparation do not

cause systematic changes in the cooling rate.

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.

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.

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C per 1% Cu, and the temperature of the this transformation finish

approximately by 8C per 1% Cu. This element decreases the temperature of the austenite transformation start approximately by 5C per

1% Cu, and the finish of this transformation approximately by 6C 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.

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 shrinkag 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.

This paper presents the results of hypoeutectic 226 grade alloy as well as prepared on its basis Al-Si alloy containing Cr, V and Mo. The

additives tested were added as AlCr15, AlV10 and AlMo8 master alloys. Alloys tested were poured into DTA sampler as well as using

pressure die casting. An amount of Cr, V and Mo additives in alloy poured into DTA sampler comprised within the range approximately

0.05-0.35%. Alloys to pressure die casting contained 0.05-0.20% Cr, V and Mo. The crystallization process was examined using the derivative

thermal analysis (DTA). The microstructure of castings made in the DTA sampler as well as castings made with use of pressure die

casting were examined. The basic mechanical properties of castings made using pressure die casting were defined too. It has been shown

in the DTA curves of Al-Si alloy containing approximately 0.30 and 0.35% Cr, Mo, and V there is an additional thermal effect probably

caused by a peritectic crystallization of intermetallic phases containing the aforementioned additives. These phases have a morphology

similar to the walled and a relatively large size. The analogous phases also occur in pressure die casting alloys containing 0.10% or more

additions of Cr, V and Mo. The appearance of these phases in pressure die casting Al-Si alloys coincides with a decrease in the value of

the tensile strength Rm and the elongation A. It has been shown die castings made of Al-Si alloys containing the aforementioned additives

have a higher Rm and A than 226 alloy.

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.

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.

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.

Particles of the Fe-Al type (less than 50 µm 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, A ε , periodically situated FeAl + Fe2Al5 phases, and a non-equilibrium phase, Nε . A hypothesis dealing with the inter-metallic phases formation in such a single particle of the nominal composition 0 N = 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.

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.

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.

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.

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, inner homogeneity and chemical composition.

The paper presents the effect of tin on the crystallization process, microstructure and hardness of cast iron with compacted (vermicular) graphite. The compacted graphite was obtained with the use of magnesium treatment process (Inmold technology). The lack of significant effect of tin on the temperature of the eutectic transformation has been demonstrated. On the other hand, a significant decrease in the eutectoid transformation temperature with increasing tin concentration has been shown. It was demonstrated that tin narrows the temperature range of the austenite transformation. The effect of tin on the microstructure of cast iron with compacted graphite considering casting wall thickness has been investigated and described. The carbide-forming effect of tin in thin-walled (3 mm) castings has been demonstrated. The nomograms describing the microstructure of compacted graphite iron versus tin concentration have been developed. The effect of tin on the hardness of cast iron was given.

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.