In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast proces so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer). The bearing part of bimetallic layered casting is typical foundry material i.e. ferritic-pearlitic unalloyed cast steel, whereas working part (layer) is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.
The paper presents the technology of manufacturing layered castings, consisting of grey cast iron (base part) and high-chromium stainless steel (working part/layer). The aim of researches was an attempt of integration of heat treatment of steel X46Cr13 grade with founding of grey cast iron in bimetallic system and determination of the influence of cooling rate of bimetallic system in classical sand mould with bentonite on microstructure and hardness of the working layer. The castings were manufactured using mould cavity preparation method, where steel plate was poured by grey cast iron using different pouring temperature and thickness of base part. Then, the quality of joint between cast iron and steel plate was estimated by using ultrasonic non-destructive testing. The efficiency of heat treatment process was analysed by measurement of hardness and in metallographic examination. Conducted studies showed, that self-hardening’s ability of steel X46Cr13 let obtain technologically usable layered casting characterized by hardness of working surface up to 35 HRC.
In paper is presented technology of bimetallic layered castings based on founding method of layer coating directly in cast process so-called method of mould cavity preparation. Prepared castings consist two fundamental parts i.e. bearing part and working part (layer). The bearing part of bimetallic layered casting is typical foundry material i.e. unalloyed cast steel, whereas working part is plate of austenitic alloy steel sort X2CrNi 18-9. The ratio of thickness between bearing and working part is 8:1. The aim of paper was assessed the quality of the joint between bearing and working part in dependence of pouring temperature and carbon concentration in cast steel. The quality of the joint in bimetallic layered castings was evaluated on the basis of ultrasonic non-destructive testing, structure and microhardness researches.
The article presents the results of research concerning AlCu4MgSi alloy ingots produced using horizontal continuous casting process under variable conditions of casting speed and cooling liquid flow through the crystallizer. The mechanical properties and structure of the obtained ingots were correlated with the process parameters. On the basis of the obtained results, it has been shown that depending on the cooling rate and the intensity of convection during solidification, significant differences in the mechanical properties and structure and of the ingots can occur. The research has shown that, as the casting speed and the flow rate of the cooling liquid increase, the hardness of the test samples decreases, while their elongation increases, which is related to the increase of the average grain size. Also, the morphology of the intermetallic phases precipitations lattice, as well as the centerline porosity and dendrite expansion, significantly affect the tensile strength and fracture mechanism of the tested ingots.
The article presents results of research on the influence of variable parameters of horizontal continuous casting on the structure of AlCu4MgSi (EN AW-2017A) alloy ingots. The special character of the process allows for a continuous change of some of its parameters, namely, of the casting speed and of the rate of the cooling fluid flow thorough the crystallizer. These parameters have a significant impact on the crystallization process of the liquid metal. Depending on the cooling rate, intensity of the convection inside the solidifying alloy, and its chemical composition, there may arise some differences in the structure of the cast. In this study, ingots obtained at different casting speeds have been analyzed. The research methodology, based on light microscopy and electron microscopy (SEM), as well as energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), allowed for a thorough examination of the structure of the studied materials. The results were shown that an increase in the ingot casting speed leads to an increase in the average grain surface area.
In this paper crystallization studies of low-alloyed construction cast steel were presented for different additions of chromium, nickel and
molybdenum modified with vanadium and titanium. Studies were conducted using developed TDA stand, which additionally enabled
evaluation of cooling rate influence on crystallization process of investigated alloys.
The paper presents an innovative method of creating the layered castings. The innovation relies on application the 3D printing insert obtaining in SLM (selective laser melting) method. This type of scaffold insert made from pure Ti powder, was placed into mould cavity directly before pouring by grey cast iron. In result of used method was obtained grey cast iron casting with surface layer reinforced by titanium carbides. In range of studies were carried out metallographic researches using light microscope and scanning electron microscope, microhardness measurements and abrasive wear resistance. On the basis of obtaining results was stated that there is a possibility of reinforcing surface layer of the grey cast iron casting by using 3D printing scaffold insert in the method of mould cavity preparation. Moreover there was a local increase in hardness and abrasive wear resistance in spite of the precipitation of titanium carbides in surface layer of grey cast iron. While the usable properties of composite surface layer obtained in result of use of the method presented in the paper, strongly depend of dimensions of scaffold insert, mainly parameters Re and Ri.
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.
In paper is presented results of studies concerning ingot of Al with a purity of 99.5% cast with use of stand of horizontal continuous
casting. Mainly together with casting velocity was considered influence of electromagnetic stirrer, which was placed in continuous casting
mould on refinement of ingots structure and theirs usability to plastic deformation. Effect of structure refinement and usability to plastic
deformation obtained by influence of electromagnetic stirring was compared with refinement obtained by use of traditional inoculation,
which consists in introducing of additives i.e. Ti and B to metal bath. On the basis of obtained results was affirmed that inoculation
realized by electromagnetic stirring in range of continuous casting mould guarantees improvement in structure refinement and usability to
rolling of pure Al continuous ingots.
In paper is presented idea of construction and influence of selected parts of stand of horizontal continuous casting on quality of pure Al and AlSi2
alloy ingots. The main parts of the made stand belong to induction furnace, which is also tundish, water cooled continuous casting mould, system
of recooling, system of continuous ingot drawing and cutting. Mainly was considered influence of electromagnetic stirrer, which was placed
in continuous casting mould on refinement of ingots structure. Effect of structure refinement obtained by influence of electromagnetic stirring was
compared with refinement obtained by use of traditional inoculation, which consists in introducing of additives i.e. Ti and B to metal bath. The
results of studies show possibility of effective refinement of Al and AlSi2 alloy primary structure, only with use of horizontal electromagnetic field
and without necessity of application of inoculants. This method of inoculation is important, because inoculants decrease the degree of purity
and electrical conductivity of pure aluminum and moreover are reason of point cracks formation during rolling of ingots.
In the paper the results and analysis of abrasive wear studies were shown for two grades of cast steels: low-alloyed cast steel applied for
heavy machinery parts such as housing, covers etc. and chromium cast steels applied for kinetic nodes of pin-sleeve type. Studies were
performed using the modified in Department of Foundry pin-on-disc method.
The article presents the results of research concerning to AlCu4MgSi alloy ingots produced using horizontal continuous casting process. The presented research was focused on the precise determination of phase composition of the precipitates formed during the solidification of ingots and the analysis of their thermal stability. In order to assess the morphology of precipitates in the AlCu4MgSi alloy, data obtained by using a computer simulation of thermodynamic phenomena were compiled with results obtained using advanced research techniques, i.e. High-temperature X-ray diffraction (HT-XRD), SEM-EDS, Thermal and derivative analysis (TDA) and Glow discharge optical emission spectroscopy (GD OES). SEM observations and analysis of chemical composition in micro-areas showed that the precipitates are mainly intermetallic θ-Al2Cu and β-Mg2Si phases, and also presence of Al19Fe4MnSi2 intermetallic phase was confirmed by X-ray diffraction studies. Based on the prepared Thermo-Calc simulation data, high-temperature X-ray diffraction measurements were conducted.
The paper presents the research results concerning the chromium-nickel-molybdenum duplex cast steel GX2CrNiMoCuN 25-6-3-3 grade. The aim of studies was the description of the influence of hyperquenching temperature Tp i.e. 1100, 1125 and 1150℃ on microstructure and mainly mechanical properties i.e. tensile strength UTS, yield strength YS, hardness HB, elongation EL and impact energy KV of duplex cast steel GX2CrNiMoCuN 25-6-3-3 grade. The range of studies included ten melts which were conducted in foundry GZUT S.A. Based on the obtained results was confirmed that application of hyperquenching process guarantees the elimination of brittle s phase in the microstructure of studied duplex cast steel. Moreover on the basis of conducted statistical analysis of the researches results is concluded that with the decrease in hyperquenching temperature increases ductility and amount of austenite, while decreases strength and amount of ferrite in studied duplex cast steel GX2CrNiMoCuN 25-6-3-3 grade.
The paper presents the problem which concerning the technology of bimetallic castings in materials configuration: high-chromium steel as the working layer and grey cast iron as the base part. The aim of the studies was integrate the process of manufacturing of bimetallic casting with the heat treatment of hardening type of X46Cr13 steel insert by applying the mould with sandmix on a matrix of chromite sand. Range of studies included the chemical composition analysis, non-destructive ultrasonic tests to examine the quality of the permanent bond between the working layer (steel insert) and the base part (grey cast iron) of the bimetallic castings, hardness measurements as well as metallographic examinations performed on the optical and scanning electron microscopes. On the basis of obtained results was concluded that the self-hardening process occurred in the X46Cr 13 steel working layer and in result of this the hardness on its surface equalled approx. 45HRC in case of the bimetallic castings with full permanent bond between both parts.
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