Wyniki wyszukiwania - Biblioteka Nauki

1

Generator mocy do zgrzewarek ultradźwiękowych

100%

Tupaj M.

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tom Vol. 46, nr 12

73-74

PL

Przedstawiono projekt generatora mocy do zgrzewarek ultradźwiękowych oraz najważniejsze wyniki pomiarów. Opisany generator umożliwia regulację poziomu mocy oraz automatyczną regulację częstotliwości. Pracą generatora steruje mikrokontroler jednoukładowy.

EN

The design and measurements results of power generator for ultrasonic compressor has been presented. The power regulator and the frequency adjustment unit was implemented in this project.

2

Geometry of remeltings and efficiency of the surface remelting process applied to cobalt alloy castings

51%

Mróz M. , Orłowicz W. , Tupaj M.

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tom Vol. 13, iss. 2

95--98

EN

The paper summarises results of measurements of remelting area geometry, thermal efficiency and melting efficiency characterising the surface remelting process applied to castings of MAR-M-509 cobalt alloy. The remelting process was carried out with the use of GTAW (Gas Tungsten Arc Welding) method in protective atmosphere of helium, at the electric current intensity in the range from 100 A to 300 A, and the electric arc scanning velocity vs in the range from 200 mm/min to 800 mm/min. The effect of current intensity and electric arc scanning velocity on geometrical parameters of remeltings, thermal efficiency, and melting efficiency characterising the remelting process has been determined.

3

The Effect of Surface Texture of Steel Disc on Friction and Fretting Wear

51%

Lenart A. , Pawlus P. , Dzierwa A. , Tupaj M.

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tom nr 4

39--48

EN

Fretting tests were performed using an Optimol SRV5 tribotester in a ball-on-flat scheme. Balls from 100Cr6 steel of 60 HRC hardness and diameters of 10 mm co-acted with discs from 42CrMo4 steel of 47 HRC hardness under dry gross fretting conditions. Tests were performed at 30°C and 25–35% relative humidity, and the number of cycles was 18000. During each test, the normal load was kept constant. Six sets of experiments were conducted. Discs had different surface textures as the result of machining. It was found that the lowest coefficients of friction were obtained for anisotropic surfaces when ball movements were perpendicular to main disc texture directions.

PL

W badaniach zastosowano tester tribologiczny Optimol SRV5. Kulka ze stali 100Cr6 o twardości 60 HRC kontaktowała się z tarczą o średnicy 10 mm wykonaną ze stali 42CrMo4 o twardości 47 HRC w warunkach frettingu. Temperatura wynosiła 30°C, wilgotność względna 25–35% przy liczbie cykli równej 18000. Tarcze charakteryzowały się zróżnicowaną strukturą geometryczną powierzchni uzyskaną w wyniku obróbki. Najmniejsze współczynniki tarcia osiągnięto, kiedy ruch kulki odbywał się prostopadle do głównego kierunku ukształtowania powierzchni tarczy.

4

Examination of cast iron material properties by means of the nanoindentation method

51%

Trytek A. , Orłowicz W. , Tupaj M. , Mróz M.

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tom Vol. 12, iss. 4

141-144

EN

The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

5

Stress rupture test of MAR-M509 alloy with structure refined by rapid resolidification

51%

Mróz M. , Orłowicz W. , Tupaj M. , Trytek A.

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tom Vol. 12, iss. 4

117-120

EN

This study presents results of stress rupture test of MAR-M-509 cobalt alloy samples, as-cast and after surface refining with a concentrated stream of heat. Tests were conducted on samples of MAR-M-509 alloy castings, obtained using the lost-wax method. Casting structure refining was performed with the GTAW method in argon atmosphere, using the current I = 200 A and electrical arc scanning velocity vs = 100, 150, 200 and 250 mm/min. The effect of rapid resolidification of the MAR-M-509 alloy on the microstructure was examined and significant improvement in stress rupture test was observed.

6

Współczynniki termiczne procesu GTAW

51%

Mróz M. , Orłowicz A. W. , Tupaj M.

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tom R. 5, nr 17

217-224

PL

W pracy przedstawiono wyniki badań wpływu parametrów technologicznych na sprawność cieplną i sprawność topienia w procesie kształtowania na powierzchni odlewów ze stopu AK 20 nadtopień z zastosowaniem metody Gas Tungsten Arc Welding (GTAW). Do oceny sprawności cieplnej procesu zastosowano kalorymetr przepływowy. Stosowano prędkość skanowania łukiem elektrycznym 200, 400, 600 i 800 mm/min, a natężenie prądu wynosiło 100, 150, 200, 250 i 300 A. Z zastosowaniem metody regresji krokowej ustalono związki pomiędzy parametrami procesu technologicznego, a sprawnością cieplną i sprawnością topienia.

EN

In this work the effect of the Gas Tungsten Arc Welding (GTAW ) process parameters on the arc efficiency and melting efficient was presented. A through-flow calorimeter was employed for thermal measurements. The surface fusion process was performed in argon atmosphere under varied electric arc travel speed (vs =200, 400, 600 and 800mm/min) and current intensity (I = 100, 150, 200, 250 and 300A). Relationships between GTAW process parameters and total heat content of the weld sample, as well as heat input that leads to melting of the weld volume were defined.

7

Wpływ szybkości chłodzenia na strukturę siluminu podeutektycznego modyfikowanego sodem

51%

Orłowicz W. A. , Tupaj M. , Mróz M.

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tom R. 53, nr 7

425-429

PL

Artykuł przedstawia wyniki badań wpływu szybkości chłodzenia podeutektycznego stopu AlSi7Mg na mikrostrukturę i zwartość odlewu. Celem pracy było ustalenie związku pomiędzy szybkością chłodzenia produkcyjnego stopu AlSi7Mg a wskaźnikiem porowatości oraz wartością parametru strukturalnego lambda/E i l/max. Badania wykonano na odlewach klinów wykonanych w masie formierskiej zawierającej u podstawy wnęki ochładzalnik. Stwierdzono, że wzrost szybkości chłodzenia stopu AlSi7Mg wpływa na zmniejszenie wartości analizowanych parametrów. Okazało się, że parametr strukturalny lambda/2D jest bardziej wrażliwy na zmianę szybkości chłodzenia niż parametr strukturalny lambda/E, a parametr strukturalny l/max jest znacznie bardziej wrażliwy na szybkość chłodzenia niż parametr strukturalny lambda/E.

EN

The paper presents the results of a study on the influence of the cooling rate of the AlSi7Mg hypoeutectic silumin microstructure and the cast compactness. The purpose of the study was to determine the relationship between the cooling rate of the AlSi7Mg production alloy void ratio and the value of structural parameters Lambda/2D, Lambda/E and l/MAX. The tests were performed on wedge casts made from moulding sand containing a chill at the cavity base. It was discovered that the cooling rate of the AlSi7Mg alloy influences the decrease in the value of the analyzed parameters. The relationship between the structural parameter Lambda/2D, and the alloy cooling rate is described with the equation [formula], where b and m are equation parameters. The values of [formula] equation parameters obtained in the study are presented against the results of other studies. The obtained results indicate that decreasing the cooling rate from 94.5 degrees of Celsius/min to 12.5 degrees of Celsius/min caused about a three-fold increase in the value of the structural parameter Lambda/2D about 40% increase in the value of the structural parameter Lambda/E and about a four-fold increase in the value of structural parameter l/MAX. The increase in the AlSi7Mg alloy cooling rate results in the decrease in the value of the structural parameter Lambda/2D - the distance between the axes of secondary branches of the alpha(Al) phase dendrites, decrease in the structural parameter Lambda/E - the distance between silicon precipitation in the eutectic and limiting the maximum length of silicon precipitation l/MAX. It occurred that the structural parameter Lambda/2D is more sensitive to the cooling rate change than the structural parameter Lambda/E, and the structural parameter l/MAX is much more sensitive to the cooling rate than the structural parameter Lambda/E. A large difference in the value of alpha(Al) phase dendrites structural parameter Lambda/2D suggests that there were significant differences in the crystallization time in individual cast areas. A small difference in the value of the structural parameter Lambda/E, however, is evidence of low temperature gradients. The increase in the cooling rate in the cast area next to the surface reproduced with a chill caused on increase in the void ratio.

8

Wpływ wydzieleń krzemu na intensywność zużycia ściernego odlewów ze stopu C355 uszlachetnionych powierzchniowo skoncentrowanym strumieniem ciepła

51%

Orłowicz W. , Mróz M. , Tupaj M.

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tom R. 53, nr 8

488-492

PL

Na powierzchni próbek ze stopu C355 wykonano nadtopienia z wykorzystaniem metody GTAW. Proces prowadzono w atmosferze argonu, przy zmiennej w zakresie od 200 do 800 mm/min prędkości skanowania łukiem elektrycznym. Dla materiału z obszaru nadtopień oceniono parametr strukturalny L/MAX, Lambda/E, mikrotwardość oraz zużycie ścierne. Związek pomiędzy prędkością skanowania łukiem elektrycznym, parametrami mikrostruktury, intensywnością zużycia ściernego i twardością opisano z wykorzystaniem metody regresji krokowej.

EN

Surface of the C355 alloy samples was refined by the GTAW method fusions. The process was conducted in an argon atmosphere at variable scanning rate of an electric arc, ranging from 200 to 800 mm per minute. The structural parameter L/MAX, Lambda/E microhardness and frictional wear were assessed for the fused area of the material. Correlation between electric arc scanning rate, microstructure parameters, frictional wear intensity and hardness has been described using stepwise regression method. The results indicate that refining of the top surface of the C355 alloy casts with concentrated heat flux leads both to significant decrease in a scope of silicon precipitation in the eutectic area and to the reduction of a distance between precipitates. Microstructure of the fusion areas, which is crystallization rate dependant, can be controlled by altering the electric arc scanning rate. Refining of the casts surface by means of concentrated heat flux made that both structural parameter L/MAX and structural parameter Lambda/E were three times smaller. It was found that the structural parameter L/MAX is more sensitive to the variation in an electric arc scanning rate (threefold change) than the structural parameter Lambda/E (twofold change). Application of the GTAW method for refining of the C355 alloy casts enabled obtaining the microstructure characterized by high hardness and low value of the coefficient of friction wear intensity. The coefficient of friction wear intensity dropped eightfold. Reduction of friction wear intensity of the concentrated heat flux refined material in comparison to the base material results from the decrease in the scope of silicon precipitation and from the reduction of a distance between precipitates in the eutectic area.

9

Examination of Cast Iron Material Properties by Means of the Scratch Method

51%

Trytek A. , Orłowicz W. , Mróz M. , Tupaj M.

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tom Vol. 12, iss. 2s

75--80

EN

The paper presents results of examination of unalloyed cast iron with diversified structure of the metallic matrix carried out by means of the scratch method. The research work was carried out with cast sample plates and with castings superficially remelted by means of the Gas Tungsten Arc Welding (GTAW) method. The test was carried out with load force of 5 N. Parameters such as the coefficient of friction, penetration depth, and acoustic emission were analysed.

10

The Effect of the Heat Flux Density on Microstructure of Surface Remeltings on C355 Alloy Castings

38%

Orłowicz A. W. , Mróz M. , Tupaj M. , Trytek A. , Jacek M. , Radoń M.

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tom Vol. 18, iss. 2

35--38

EN

The paper presents results of a study on the effect of the flux density of heat carried away for the remelting area to substrate in the course of surface remelting with concentrated heat stream on values of structural parameters λ1D and λ2D of α(Al) phase dendrites in C355 alloy. The remeltings were made with the use of GTAW method, at arc current intensity I = 200 A and concentrated heat stream scanning speed vs = 200, 400, 600, and 800 mm/min. The used protective gas was argon supplied at rate of 20 l/min. It has been found that the increase of the rate of scanning with concentrated heat stream results in a change of the remelting-substrate separation surface shape consisting in reduction of the remelting width and depth. This increases the value of the flux density of heat transmitted from the remelting area to substrate which in turn acts in favor of reduction of structural parameters λ1D and λ2D characterizing α(Al) phase dendrites in C355 alloy.

11

Improvement of Resistance of Cast-iron Heat Exchangers to High-temperature Corrosion

38%

Orłowicz A. W. , Tupaj M. , Trytek A. , Mróz M. , Radoń M. , Jacek M.

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tom Vol. 18, iss. 3

49--52

EN

The paper discusses the possibility of improving resistance of heat exchangers made of gray cast iron with flake graphite to high-temperature corrosion by providing them with metallic coatings. A metallic coating containing 76.9% Ni, 19.8% Cr, 1.7% Si, 0.9% Fe, and 0.9% Mn was applied by means of the plasma spraying method and subjected to cyclically variable thermal loads in the atmosphere of solid fuels combustion products (oxygen, sulfur, chlorine, and sodium). In a 30-day thermal load test held at temperature 500°C it has been found that thickness of the metallic coating decreased from the initial (240 ± 6) μm to (231 ± 6) μm. The depth to which sulfur, chlorine, and sodium penetrated the coating was about 30 μm. Increased oxygen content occurred along the whole coating depth. In the coating area adjacent to the substrate surface, the content was twice as high compared to this observed in the initial coating material. Although presence of oxygen was found within the whole depth of the coating, i.e. (231 ± 6) μm, no signs of susceptibility of the sprayed metallic layer to separation from substrate of gray cast iron with flake graphite were found.

12

The Effect of Structure on Thermal Power of Cast-iron Heat Exchangers

38%

Mróz M. , Orłowicz A. W. , Tupaj M. , Jacek-Burek M. , Radoń M. , Kawiński M.

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tom Vol. 20, iss. 1

27--30

EN

The objective of the study reported in this paper was to determine the effect of structure on thermal power of cast-iron heat exchangers which in this case were furnace chambers constituting the main component of household fireplace-based heating systems and known commonly as fireplace inserts. For the purpose of relevant tests, plate-shaped castings were prepared of gray iron with flake graphite in pearlitic matrix (the material used to date typically for fireplace inserts) as well as similar castings of gray cast iron with vermicular graphite in pearlitic, ferritic-pearlitic, and ferritic matrix. For all the cast iron variants of different structures (graphite precipitate shapes and matrix type), calorimetric measurements were carried out consisting in determining the heat power which is quantity representing the rate of heat transfer to the ambient environment. It has been found that the value of the observed heat power was affected by both the shape of graphite precipitates and the type of alloy matrix. Higher thermal power values characterize plate castings of gray iron with vermicular graphite compared to plates cast of the flake graphite gray iron. In case of plates made of gray cast iron with vermicular graphite, the highest values of thermal power were observed for castings made of iron with ferritic matrix.

13

Morphology and Material Properties of Carbides in High (24%) Chromium Cast Iron

38%

Orłowicz A. W. , Mróz M. , Tupaj M. , Trytek A. , Jacek M. , Radoń M.

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nr 1

14

Improvement of Resistance of Cast-iron Heat Exchangers to High-temperature Corrosion

38%

Radoń M. , Jacek M. , Trytek A. , Tupaj M. , Mróz M. , Orłowicz A. W.

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nr 3

15

Cavitation Erosion of Nodular Cast Iron − Microstructural Effects

38%

Trytek A. , Tupaj M. , Mróz M. , Orłowicz A. W. , Radoń M. , Jacek M.

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16

The Effect of the Heat Flux Density on Microstructure of Surface Remeltings on C355 Alloy Castings

38%

Radoń M. , Jacek M. , Trytek A. , Tupaj M. , Mróz M. , Orłowicz A. W.

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nr 2

17

The Effect of a Thin-Wall Casting Mould Cavity Filling Conditions on the Casting Surface Quality

38%

Trytek A. , Tupaj M. , Mróz M. , Orłowicz A. W. , Markowska O. , Bąk G. , Abram T.

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18

The Effect of Sulphur Content on the Microstructure of Vermicular Graphite Cast Iron

38%

Mróz M. , Orłowicz A. W. , Tupaj M. , Lenik M. , Kawiński M. , Kawiński M.

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tom Vol. 22, iss. 1

18--22

EN

The application of ferritic-matrix vermicular graphite cast iron in the production of fireplace fireboxes improves their thermal output, but the consumer market for these products prioritises their price. Given this consideration, this work concerns a comparison of the quality of vermicular graphite cast iron types produced from 0.025%S pig iron (a less expensive material) and 0.010%S pig iron (a more expensive material) in terms of the number and shape of vermicular graphite precipitates varying with the magnesium level in the alloy. It turned out that the vermicular graphite cast iron made with the 0.025%S pig iron demonstrated a slightly lower number of vermicular graphite precipitates. For both vermicular graphite cast iron melts, 0.028%Mg and 0.020%Mg in the alloys provided a vermicular graphite precipitate share of approx. 50% and 95%, respectively.