bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Carbides in Turbine Blade Made of IN713C Superalloy After Hot Isostatic Pressing
Authors: Kościelniak B. , Roskosz S. , Cwajna J. 
Published: April 2017

Abstract
The IN713C is nickel-based superalloy, used to produce low pressure turbine blades in a process of investment casting. However, porosity which is formed during the casting, decreases mechanical properties of IN713C. Therefore, to eliminate porosity, a process of hot isostatic pressing was applied. Nonetheless, HIP also least to some changes in the microstructure of tested material. The main aim of this paper is to characterize the morphology of carbides before and after hot isostatic pressing. Microstructural characterization was carried out with the use of a scanning electron microscope equipped with an energy dispersive X-ray spectrometer and an electron backscatter diffraction detector. The size and shape of carbides were evaluated by quantitative metallography methods methods. The results show that the amount, size and heterogeneity of arrangement of the carbides increased after application of HIP treatment.
Forecasting the distribution of precipitate diameters in the presence of changes in the structure of the material
Authors: Zieliński A. , Miczka M. , Golański G. 
Published: April 2017

AbstractThe results of investigations on the microstructure of T23 and T24 low-alloy steels as well as P91 and P92 high-chromium steels in the as-received condition and after 70.000 h annealing at 550-650°C are presented. The quantitative analysis of the existing precipitates was performed for representative images of microstructure. The statistical analysis of collected data allowed the parameters of a selected theoretical statistical distribution to be estimated. A forecast of average precipitate diameter and standard deviation of such a distribution for the time of 100,000 hours at 550 and 600°C for T23 and T24 steels and at 600 and 650°C for P91 and P92 steels was calculated. The obtained results of investigations have made it possible to compare changes in the microstructure of various steel grades due to long-term impact of elevated temperature. They have also confirmed the possibility of using, in evaluating the degradation degree of materials in use, the forecasting methods that derive from mathematical statistics, in particular the theory of stochastic processes and forecast by analogy methods. The presented approach allows the development of a forecast of precipitate diameter probability density under the microstructure instability conditions for selected steel grades. The assessment of material condition that takes into consideration, but is not limited to, the precipitate diameter measurement is useful as an assessment component in estimating the time of safe service of power unit elements working under creep conditions.
Copper droplets agglomeration/coagulation in the conditions similar to industrial ones
Authors: Wołczyński W. , Sypien A. , Tarasek A. , Bydałek A. W. 
Published: April 2017

AbstractThe studied copper droplets suspension in the liquid slag came from the direct-to-blister technology developed in the KGHM - Polska Miedź S.A. plants. A treatment by the stimulators and reagents was performed in the conditions delivered / ensured by the BOLMET S.A., Wiechlice. These conditions were similar to those usually applied to the industrial process. Particularly, this treatment was similar, to some extent, to that known for the electric arc-furnace technology employed in the Smelter and Refinery Plant, Głogów. An effectiveness of the newly developed and patented complex chemical/reagent for the copper removal from slag was tested during the treatment. The effect of the liquid slag stirring on the copper droplets self-cleaning was also analysed. The performed test confirmed the effectiveness of the studied complex reagent in agglomeration, coagulation and sedimentation of the copper droplets.
Determination of pearlite morphology in high-carbon hot rolled steel
Authors: Szala J. , Kuc D. 
Published: April 2017

AbstractThe article presents the results of tests of influence of the thermo-mechanical treatment parameters on the mechanical properties and microstructure of steel C70D for wire rod. The methodology of quantitative description of pearlite morphology in steels with the use of the method on which a new computer program “PILS” - Pearlite Inter-Lamellar Spacing is based was presented. In order to verify the method, some quantitative tests of microstructure in samples after physical simulation of heat-plastic treatment were conducted on a deformation dilatometer device with diverse cooling rate for steel C70D. The process of rolling was conducted in simulation in continuous finishing train arrangement. Elaborated program and conducted tests will be used during preparations of modified technologies of wire rod rolling to prepare products made of steel, the microstructure of which is characterised with smaller interlamellar spacing.
Induction hardening of tool steel for heavily loaded aircraft engine components
Authors: Rokicki P. 
Published: April 2017

Abstract
Induction hardening is an innovative process allowing modification of the materials surface with more effective, cheaper and more reproducible way to compare with conventional hardening methods used in the aerospace industry. Unfortunately, high requirements and strict regulation concerning this branch of the industry force deep research allowing to obtain results that would be used for numerical modelling of the process. Only by this way one is able to start the industrial application of the process. The main scope of presented paper are results concerning investigation of microstructure evolution of tool steel after single-frequency induction hardening process. The specimens that aim in representing final industrial products (as heavily loaded gears), were heat- -treated with induction method and subjected to metallographic preparation, after which complex microstructure investigation was performed. The results obtained within the research will be a basis for numerical modelling of the process of induction hardening with potential to be introduced for the aviation industrial components.
Welding thermal cycle-triggered precipitation processes in steel S700MC subjected to the thermo-mechanical control processing
Authors: Górka J. 
Published: April 2017

Abstract
This study presents tests concerned with welding thermal process-induced precipitation processes taking place in 10 mm thick steel S700MC subjected to the Thermo-Mechanical Control Process (TMCP) with accelerated cooling. The thermomechanical processing of steel S700MC leads to its refinement, structural defects and solutioning with hardening constituents. Tests of thin foils performed using a transmission electron microscope revealed that the hardening of steel S700MC was primarily caused by dispersive (Ti,Nb)(C,N) precipitates (being between several and less than twenty nanometers in size). In arc welding, depending on a welding method and linear energy, an increase in the base material in the weld is accompanied by the increased concentration of hardening microagents in the weld. The longer the time when the base material remains in the liquid state, the greater the amount of microagents dissolved in the matrix. During cooling, such microagents can precipitate again or remain in the solution. An increase in welding linear energy is accompanied by an increase in the content of hardening phases dissolved in the matrix and, during cooling, by their another uncontrolled precipitation in the form of numerous fine-dispersive (Ti,Nb)(C,N) precipitates of several nm in size, leading to a dislocation density increase triggered by type 2 internal stresses.
The influence of manual metal arc multiple repair welding of long operated waterwall on the structure and hardness of the heat affected zone of welded joints
Authors: Pikuła J. , Łomozik M. , Pfeifer T. 
Published: April 2017

Abstract
Welded installations failures of power plants, which are often result from a high degree of wear, requires suitable repairs. In the case of cracks formed in the weld bead of waterwall, weld bead is removed and new welded joint is prepared. However, it is associated with consecutive thermal cycles, which affect properties of heat affected zone of welded joint. This study presents the influence of multiple manual metal arc welding associated with repair activities of long operated waterwall of boiler steel on properties of repair welded joints. The work contains the results of macro and microscopic metallographic examination as well as the results of hardness measurements.
Development of hot tearing evaluation method for Al-based alloys
Authors: Brůna M. 
Published: April 2017

Abstract
This paper focuses on developing an advanced test method and its use to study hot tearing defects in aluminium alloy castings. The paper consists of two parts. The first part introduces the reader to hot tearing in general, and provides theoretical analysis of the hot tearing phenomenon. The second part describes a newly developed method for assessing hot tearing susceptibility, and also gives the results on hot tearing for various aluminium alloys. During the test, the effect of alloy chemical composition on hot tearing susceptibility was analyzed. Three different Al-based alloys with varying Si, Cu and Ti contents were examined. Conclusions deal with the effect of individual elements on hot tearing susceptibility, and confirm that the main objective was achieved and the proposed method proves to be repeatable and reliable.
Influence of the reclamation method of spent moulding sands on the possibility of creating favourable conditions for gases flow in a mould
Authors: Łucarz M. , Drożyński D. 
Published: April 2017

Abstract
The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim) on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles), are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions). It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.
Solid-liquid interface morphology of white carbide eutectic during directional solidification
Authors: Trepczyńska-Łent M. 
Published: April 2017

AbstractIn this paper the analysis of solid-liquid interface morphology in white carbide eutectic was made. In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe - C alloy was produced. The pulling rate was v = 125 μm/s (450 mm/h) and constant temperature gradient G = 33.5 K/mm. The microstructure of the sample was frozen. The microstructure of the sample was examined on the longitudinal section using an light microscope and scanning electron microscope.
Effect of parameters of high-pressure die casting on occurrence of casting nonconformities in sleeves of silumin alloy EN AB 47100
Authors: Pałyga Ł. , Stachowicz M. , Granat K. 
Published: April 2017

Abstract
The paper presents a research on the effect of extreme - for the technology of the considered silumin EN AB 47100 - parameters of high-pressure die casting on occurrence of casting nonconformities. Considered was influence of the way of assembling the mould cooled-down to 140-160°C, non-standard for the selected casting, and pouring temperature in the range of 705 to 720°C (higher than the recommended) of non-refined alloy. The castings were prepared with use of a high-pressure casting machine made by Kirov with mould closing force of 2500 kN. Occurrence of nonconformities was evaluated on properly prepared specimens taken from the castings manufactured with various parameters of the injection piston and various multiplication pressures. The results were subjected to quantitative and qualitative analyses of casting nonconformities and distribution of major alloying elements. It was found that proper selection of working parameters of the casting machine, in spite of disadvantageous pouring conditions, makes it possible to reduce occurrence of some casting defects, like shrinkage cavities and porosity, to improve tightness of castings even when the alloy refining process is omitted.
Influence of sand base preparation on properties of chromite moulding sands with sodium silicate hardened with selected methods
Authors: Stachowicz M. , Granat K. , Pałyga Ł. 
Published: April 2017

Abstract
The paper presents a research on the relation between thermal preparation of chromite sand base of moulding sands containing sodium silicate, hardened with selected physical and chemical methods, and structure of the created bonding bridges. Test specimens were prepared of chromite sand - fresh or baked at 950°C for 10 or 24 hours - mixed with 0.5 wt.% of the selected non-modified inorganic binder and, after forming, were hardened with CO2 or liquid esters, dried traditionally or heated with microwaves at 2.45 GHz. It was shown on the grounds of SEM observations that the time of baking the base sand and the hardening method significantly affect structure of the bonding bridges and are correlated with mechanical properties of the moulding sands. It was found that hardening chromite-based moulding mixtures with physical methods is much more favourable than hardening with chemical methods, guaranteeing also more than ten times higher mechanical properties.
Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating
Authors: Szczęsny A. , Kopyciński D. , Guzik E. 
Published: April 2017

Abstract
Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw) surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite) and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.
Optimization of a thin-walled element geometry using a system integrating neural networks and finite element method
Authors: Golewski P. , Gajewski J. , Sadowski T. 
Published: April 2017

Abstract
Artificial neural networks [ANNs] are an effective method for predicting and classifying variables. This article presents the application of an integrated system based on artificial neural networks and calculations by the finite element method [FEM] for the optimization of geometry of a thin-walled element of an air structure. To ensure optimal structure, the structure’s geometry was modified by creating side holes and ribs, also with holes. The main criterion of optimization was to reduce the structure’s weight at the lowest possible deformation of the tested object. The numerical tests concerned a fragment of an elevator used in the “Bryza” aircraft. The tests were conducted for networks with radial basis functions [RBF] and multilayer perceptrons [MLP]. The calculations described in the paper are an attempt at testing the FEM - ANN system with respect to design optimization.
Selection of basic position in Refill Friction Stir Spot Welding of 2024-T3 and D16UTW aluminum alloy sheets
Authors: Lacki P. , Derlatka A. , Gałaczyński T. 
Published: April 2017

Abstract
One of the important parameters of Refill Friction Stir Spot Welding is the so-called basic position of the tool. This is the arrangement of the pin and sleeve which occurs when the tool is plunged into the material. The basic positions can be divided into two categories. In the first category, the sleeve and the pin are above the sheet surface or below sheet surface and in the second category the pin is retracted within the sleeve or protrudes from it.
The aim of the work was to test four settings of the basic position, and then determine the best setting of the basic position, without changing the other welding parameters. Joints made of an aluminum alloy 2024-T3 sheet having a thickness of 1.0 mm and an aluminum alloy D16UTW sheet having a thickness of 0.6 mm were analysed. The best setting of the basic position was determined based on assessment of the force carried in shear test, macrostructure and weld face of the joints.
Generalized almost paracontact structures
Authors: Blaga Adara M. , Ida Cristian 
Published: April 2017

Abstract
The notion of generalized almost paracontact structure on the generalized tangent bundle TM ⊕ T* M is introduced and its properties are investigated. The case when the manifold M carries an almost paracontact metric structure is also discussed. Conditions for its transformed under a β- or a B-field transformation to be also a generalized almost paracontact structure are given. Finally, the normality of a generalized almost paracontact structure is defined and a characterization of a normal generalized almost paracontact structure induced by an almost paracontact one is given.
Two-channel sampling in wavelet subspaces
Authors: Kim J.M. , Kwon K.H. 
Published: April 2017

Abstract
We develop two-channel sampling theory in the wavelet subspace V
1 from the multi resolution analysis {Vj
}
j

∈𝕫. Extending earlier results by G. G. Walter [11], W. Chen and S. Itoh [2] and Y. M. Hong et al [5] on the sampling theory in the wavelet or shift invariant spaces, we find a necessary and sufficient condition for two-channel sampling expansion formula to hold in V
1.
Effect of the initial stress and rotation on free vibrations in transversely isotropic human long dry bone
Authors: Mahmoud S. R. , Marin M. , Al-Basyouni K.S. 
Published: April 2017

Abstract
The object of the present paper is to study the influence of the initial stress and rotation on wave propagation of harmonic waves in a human long dry bone as transversely isotropic material, subject to the boundary conditions that the outer and inner surfaces are traction free. The equations of elastodynamic are solved in terms of displacements. The natural frequency of the plane vibrations in the case of harmonic vibrations has been obtained. The frequencies and the phase velocity are calculated numerically, the effects of the initial stress and rotation are discussed. Comparisons are made with the result in the absence of rotation and initial stress.
On neighborhoods of functions associated with conic domains
Authors: Yağmur Nihat 
Published: April 2017

Abstract
Let k − ST [A, B], k ≥ 0, −1 ≤ B < A ≤ 1 be the class of normalized analytic functions defined in the open unit disk satisfying

ℜ

(

(
B
−
1
)

z

f
′

(
z
)

f
(
z
)

−
(
A
−
1
)

(
B
+
1
)

z

f
′

(
z
)

f
(
z
)

−
(
A
+
1
)

)

>
k

|

(
B
−
1
)

z

f
′

(
z
)

f
(
z
)

−
(
A
−
1
)

(
B
+
1
)

z

f
′

(
z
)

f
(
z
)

−
(
A
+
1
)

−
1

|

.

$$\Re \left( {{{(B - 1){{zf'(z)} \over {f(z)}} - (A - 1)} \over {(B + 1){{zf'(z)} \over {f(z)}} - (A + 1)}}} \right) > k\left| {{{(B - 1){{zf'(z)} \over {f(z)}} - (A - 1)} \over {(B + 1){{zf'(z)} \over {f(z)}} - (A + 1)}} - 1} \right|.$$

and let k − UCV [A, B], k ≥ 0, −1 ≤ B < A ≤ 1 be the corresponding class satisfying

ℜ

(

(
B
−
1
)

(

z

f
′

(
z
)

)

′

f
′

(
z
)

−
(
A
−
1
)

(
B
+
1
)

(

z

f
′

(
z
)

)

′

f
′

(
z
)

−
(
A
+
1
)

)

>
k

|

(
B
−
1
)

(

z

f
′

(
z
)

)

′

f
′

(
z
)

−
(
A
−
1
)

(
B
+
1
)

(

z

f
′

(
z
)

)

′

f
′

(
z
)

−
(
A
+
1
)

−
1

|

.

$$\Re \left( {{{(B - 1){{\left( {zf'(z)} \right)^{\prime } } \over {f'(z)}} - (A - 1)} \over {(B + 1){{\left( {zf'(z)} \right)^{\prime } } \over {f'(z)}} - (A + 1)}}} \right) > k\left| {{{(B - 1){{\left( {zf'(z)} \right)^{\prime } } \over {f'(z)}} - (A - 1)} \over {(B + 1){{\left( {zf'(z)} \right)^{\prime } } \over {f'(z)}} - (A + 1)}} - 1} \right|.$$

For an appropriate δ > 0, the δ neighborhood of a function f ∈ k − UCV [A, B] is shown to consist of functions in the class k − ST [A, B].
The Transylvanian Party between 1940 and 1944. A Brief History
Authors: Murádin János Kristóf 
Published: April 2017

Abstract
The paper deals with the theme of the Transylvanian Party [Erdélyi Párt], one of the most important Hungarian political formations in Transylvania in the 20th century. After the reintegration of Northern Transylvania in the Hungarian state following the Second Vienna Arbitration, Hungarians became a majority in the region, established their own political party, the Transylvanian Party, with powerful local characteristics. The paper concentrates on the analysis of the Transylvanian Party, it presents its foundation, its representation in the Hungarian Parliament, and its relations with the Hungarian government. The paper tries to give an overview of the successes and failures of the party as well. Finally, the decline of the Transylvanian Party and its political heritage are presented. The source material of the paper consists of archival data, publications of the Transylvanian Party, special books, studies, articles of the contemporary press, and on-line publications.
The Interoperability between the Public and Private Sectors in Light of Adult Education. Supplements to the Planned Downsizing in the Public Sector
Authors: Megyesi Csilla 
Published: April 2017

Abstract
The current study is a result of the Hungarian government’s aspiration to cut bureaucracy and increase public administration’s efficiency, thus impacting personnel and reorganizing the labour market. The public-sector headcount reduction is being justified in terms of Hungary’s inadequate private-/public-sector employment ratio. This reorganization can come to fruition only via the development of intellectual capital and a well-designed system for retraining and further education. In cases of retraining and further education offered by the state, we must be wary of generational differences and possible motivations, while also keeping in mind the influence education can have on the market, society, and the individual. Our research has shown that the demand for a given type of instruction is also influenced by the generational differences among those who wish to learn. Overall, our respondents showed an interest in learning.