Wyniki wyszukiwania - BazTech

1

Using thermovision for temperature measurements during turning process

Molenda J., Charchalis A.

Journal of KONES

|

2018

|

Vol. 25, No. 4

293--298

EN

In metal cutting industries, machining processing, especially turning operation is very basic type of machining. For certain processes in manufacturing, it is favourable and necessary to have certain knowledge about heat generation and temperature rise (including average and maximum temperature) during machining process. Increment in maximum temperature at clearance face or at rake face of cutting tool causes the reduction in life of tool. Similarly, the quality of machined surface, a metallurgical structural alteration in tool and workpiece material also depends on the maximum temperature, temperature gradient and cooling rate of both tool and workpiece. Certain physical and chemical reactions that are developed during the cutting process are directly connected with tool wear, power consumption, surface roughness on work piece material and cutting temperature. The natural low of thermal energy gives significant relationship between cutting temperature and cutting parameters in order to improvement of cutting tool’s wok efficiency, quality and accuracy. The heat distribution in cutting tool, in formed chip and in workpiece material strongly depends on (mechanical and chemical) properties of cutting tool and workpiece material, cutting speed, depth of cut, feed rate, nose radius, geometry of tool, type of coolant used and other parameters. This work presents some results of research done during turning steel 235JR realized on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process temperature, realized for different materials.

2

New methods of marine power plant diagnostics

Charchalis A., Szyfelbain M.

Journal of KONES

|

2018

|

Vol. 25, No. 1

33--40

EN

Up-to-date, of high-tech design techniques of machine operation require constant monitoring on some levels. Generally, the monitoring today is limited to failure detection and machinery components check. The Marine Engineering Faculty of Gdynia Maritime University designed the System for Marine Engine Operation Assistance on the basis of Sulzer Diesel AL 25/30 testing station. The engine modernization and wider research and survey capabilities resulted in engine operation quality improvement, marine power plant research enhancement. The project broadens the research range and engine failure expertise as well as takes into consideration innovative marine fuel emissions. The goal has been achieved in the way of the test equipment modernization including: effective pressure sensors, high pressure fuel sensors, monitoring and visualization of the engine systems’ parameters, electronic indictors adopted to continuous operation at all cylinders in the same time, and high class decision aid computer equipment. Engine modernization and data base extension allow for carrying out a wide scope of research. Additionally, the article presents innovative diagnostic solutions together with their applications.

3

Estimating the main dimensions of the ship’s hull

Charchalis A.

Journal of KONES

|

2018

|

Vol. 25, No. 2

75--80

EN

Preliminary ship owner's assumptions for new ship consist of deadweight, speed-shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine to fulfil shipping requirements. Selection of main dimensions of vessel is limited by rules regarding buoyancy, stability, hull strength, manoeuvring capability, and limitations related to seaways or harbours characteristic. In this article is presented the methodology of calculation of principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type, volumetric coefficients, Froude number, and others values affecting ship’s dimensions. It is about midship section coefficient, waterline coefficient, prismatic coefficient. Those values are necessary for calculation of hull resistance. In the article, are presented major constraints for designing of new vessels coming from ship-owner assumptions such as seafaring limitations. In the table is presented comparison of results of calculations above-mentioned values of three type of vessels representing same displacement. There are also presented different calculation methods of transverse midship section coefficient and wet area coefficient, for 3 types of vessels (container vessel, bulk carrier and tanker with displacement of 120000 t.

4

Charchalis A.

Journal of KONES

|

2018

|

Vol. 25, No. 3

85--91

EN

The article presents the methodology of calculation of principal parameters of ship’s hull dimensions, called „significant ships list”, at preliminary stage of design process. Knowledge collected in the database is related to new buildings classified according to type, displacement, or DWT, shipping class, maximum speed etc. Are analysed dimensional constraints due of Froude Number, ships dimensional coefficients block and weigh coefficient, relations of main dimensions such as L/B, B/T, L/H, B/H etc. [7]. Those parameters coming out from ship-owners requirements like type of ship, load capacity, type of cargo, shipping zone, speed and some more. Very helpful tool for such analysis is list of significant ships created for specified types of ships. Mentioned lists are very effective under conditions that cover broad-spectrum new buildings and data included are credible. Uncritical taking values included in significant ships list can lead to critical errors in selection of main dimensions of a ship or its propulsion powering. For that reasons, basing on analysis, as main criteria of similarity of ship’s hull were assumed mass coefficient, block coefficient and Froude Number [2]. That procedure has significant impact at proper estimation of propulsion power. Another reliable parameter of evaluation of power seems to be relation between power and load capacity Ne/D.

5

The effect of burnishing process on the change of the duplex cast steel surface properties

Charchalis A., Dyl T., Rydz D., Stradomski G.

Inżynieria Materiałowa

|

2018

|

Vol. 39, nr 6

223--227

EN

Throughout planning of technological process of manufacturing or regenerating machine components, the method of burnishing, the machining conditions, the shape and number of burners should be selected. The choice of static pressure conditions during burnishing process is dependent on how the pressure components are applied to the workpiece surface, which can be elastic or rigid. The reliability of working machine and equipment is very important in the engineering, power, metallurgical or marine industries. For example, on a ship during a cruise, are made repairs of individual components of the ship’s machinery. Often are regenerated external cylindrical surfaces (e.g. shaft seals of seawater pumps), for this purpose can be proposed burnishing process can be proposed as a finishing, which enables to obtain the technological quality requirements of the products surface layer. The effect of technological conditions of burnishing process on the degree of relative strain hardening and surface roughness reduction ratio were presented. The burnishing process carried out for duplex cast steels series GX2CrNiMoCuN25–6–3–3. The use of duplex cast steel burnishing process is a novelty technology. The experimental investigation were obtained in the surface layer increase in hardness and the material ratio curve a convex shaped, which, taking into account the load capacity of the surface will be directly affected by its resistance to wear and corrosion. The experimental research by application of the burnishing process were made in the Laboratory of Production Engineering of the Department of Marine Maintenance. After the studies it was found that the hardness of the surface layer and the roughness of the shaft necks an important influenced by technological parameters of processing (the recommended parameters: burnishing speed vn = 70 m/min; feed rate fn = 0.2 mm/rev; depth of burnishing an = 1.0 mm; number of machining passes i = 2). The aim of applying burnishing may be, for example, the need to increase surface smoothness and dimensional accuracy of part.

PL

Celem pracy było wyznaczenie wpływu parametrów obróbki plastycznej przez nagniatanie na zmianę współczynnika zmniejszenia chropowatości powierzchni i względnego stopnia umocnienia warstwy wierzchniej staliwa typu dupleks. W artykule przedstawiono wyniki badań doświadczalnych nagniatania staliwa typu dupleks w gatunku GX2CrNiMoCuN25–6–3–3. Nagniatanie czopów wałów przeprowadzono z wykorzystaniem nagniataka krążkowego (NK-01). Po przeprowadzonych badaniach eksperymentalnych określono, że występuje wzrost stopnia umocnienia, następuje zmniejszenie chropowatości, a krzywa udziału materiałowego ma kształt wypukły, co, biorąc pod uwagę nośność powierzchni, wpływa bezpośrednio na jej odporność na zużywanie ścierne i korozyjne. Stwierdzono, że na twardość warstwy wierzchniej oraz chropowatość zewnętrznych powierzchni walcowych mają wpływ parametry technologiczne: posuw nagniatania, dosuw nagniataka, prędkość nagniatania i liczba przejść obróbkowych.

6

Influence of lapping plate temperature on roughness parameters of specimens

Molenda J., Charchalis A.

Journal of KONES

|

2017

|

Vol. 24, No. 2

147--152

EN

Lapping is used in the production of components of the highest quality in terms of form finish accuracy and surface integrity. A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. This article goal was to check the influence of lapping wheel temperature on workpiece roughness after lapping process. In earlier work, authors investigated the dependence between time and the temperature of executory system elements. Tests showed that after five hours of machine working temperature stabilizes and slightly fluctuated around a certain value. Thus, this work concerns lapping results in this elevated temperature. Research was proceed during Al2O3 elements lapping. It was realised with use of ABRALAP 380 lapping machine. The lapping machine executory system consisted of three working conditioning rings. Executory system elements temperature was measured remotely by infrared camera Thermo Gear G100. Elements machining was started after 10, 140, and 270 minutes of machine working time. Studies showed that machine executory system elements temperature affected only the ΔRa parameter, which is higher for surfaces, which were processed starting from 270th minute of machine working time.

7

Estimation of hull’s resistance at preliminary phase of designing

Charchalis A.

Journal of KONES

|

2017

|

Vol. 24, No. 1

77--82

EN

In this paper are presented the methodology of calculation of hull resistance components, principal parameters of a vessel, necessary for calculation of displacement in relation to vessel’s type. That methodology concerns analysis of designing ways at early stage of ship’s power calculation. Ship owners' preliminary assumptions for new ship consist of deadweight (for container vessel load capacity TEU), speed shipping line and others. Taking it as a base, in early stage of design one has to select propulsion type. This goal needs definition of principal dimensions of a vessel, which are the base for further calculations of hull’s resistance and evaluation of necessary power of main engine (engines) to fulfil shipping requirements. In the paper, are presented major constraints for designing of new vessels coming from ship-owner assumptions such as seafaring limitations and safety of shipping regulations due to Classification Societies Rules or coming out from designing experience. In the paper are presented components of ship’s resistance and methods of total resistance calculations what is a basis for power calculation and propulsion designing. Moreover, are presented results of calculations of resistance components of different types of ships, and variety of displacement and sailing velocity. It has to be assumed, that presented method concerns preliminary design stage and can vary from different ships classes and constructions of hulls.

8

Ograniczenie emisji cząstek submikronowych za pomocą aglomeracji elektrostatycznej

Krupa A., Jaworek A., Marchewicz A., Sobczyk A. T., Czech T., Szudyga M., Ottawa A., Antes T., Śliwiński Ł., Charchalis A.

Inżynieria Ekologiczna

|

2017

|

Vol. 18, nr 2

66--74

PL

Celem pracy było opracowanie urządzenia do bardziej skutecznego oczyszczania gazów odlotowych z cząstek submikronowych emitowanych przez energetykę spalającą węgiel kamienny i w ten sposób ograniczenie zanieczyszczenia środowiska. W pracy przyjęto jako najskuteczniejsze rozwiązania wykorzystujące procesy elektrostatyczne. Rozwiązania dotychczas stosowane w elektrofiltracji opracowane zostały dla cząstek dużych, zwykle o rozmiarach >5 mm, które można łatwo usunąć w wyniku działania siły elektrostatycznej na elektrycznie naładowane cząstki. W zakresie cząstek submikronowych (0.1–1 mm) skuteczność odpylania elektrofiltrów jest minimalna, przede wszystkim ze względu na niską wartość ładunku elektrycznego na takich cząstkach. W celu uniknięcia problemów z usuwaniem submikronowych cząstek popiołu lotnego z gazów spalinowych zastosowano aglomerację elektrostatyczną. W procesie tym poprzez zastosowanie przemiennego pola elektrycznego wprowadza się większe cząstki (>1 mm) naładowane elektrycznie w ruch oscylacyjny, w wyniku którego cząstki te „zbierają” mniejsze nienaładowane cząstki. W opracowanym aglomeratorze z przemiennym polem elektrycznym, proces ładowania cząstek oraz ich koagulacji zachodzi w jednym stopniu, co znacznie uprościło konstrukcję urządzenia w porównaniu z innymi rozwiązaniami. Zakres badań obejmował pomiary frakcyjnej skuteczność odpylania cząstek w układzie aglomerator/elektrofiltr dla zakresów PM1 i PM2.5 w urządzeniu wykonanym w skali półtechnicznej. Całkowita skuteczność ilościowa odpylania dla cząstek PM2.5 była większa od 90%, a dla PM1 nieznacznie spadała poniżej 90%. Masowa skuteczność odpylania dla cząstek PM2.5 była większa niż 95%. Stopień aglomeracji powoduje wzrost skuteczności odpylania dla cząstek PM1 na poziomie 5–10%.

EN

The aim of the study was to develop a device for more effective treatment of flue gases from submicron particles emitted by power plants burning bituminous coal and by this way the reduction of environment pollution. Electrostatic processes were employed to this goal, as the most effective solution. The solutions hitherto applied in electrostatic precipitation techniques were designed for large particles, typically with sizes >5 mm, which are easily removed by the action of electrostatic force on the electrically charged particles. In submicron size range (0.1–1 mm) the collection efficiency of an ESP is minimal, because of the low value of electric charge on such particles. In order to avoid problems with the removal of submicron particles of fly ash from the flue gases electrostatic agglomeration has been used. In this process, by applying an alternating electric field, larger charged particles (> 1 mm) oscillate, and the particles “collect” smaller uncharged particles. In the developed agglomerator with alternating electric field, the charging of particles and the coagulation takes place in one stage that greatly simplified the construction of the device, compared to other solutions. The scope of this study included measurements of fractional collection efficiency of particles in the system comprising of agglomerator and ESP for PM1 and PM2.5 ranges, in device made in pilot scale. The collection efficiency for PM2.5 was greater than 90% and PM1 slightly dropped below 90%. The mass collection efficiency for PM2.5 was greater than 95%. The agglomerator stage increases the collection efficiency for PM1 at a level of 5–10%.

9

Using thermovision for machining processes inspection

Molenda J., Charchalis A.

Journal of KONES

|

2016

|

Vol. 23, No. 3

345--350

EN

During metal cutting process, an increase of the tool and workpiece temperatures can be observed. The heat generated has a negative influence on the tool life and performance. It causes rapid tool wear, plastic deformation of the cutting edge, built-up-edge formation and others. Therefore, the control of cutting temperature is required to achieve the desired tool performance. Temperature is the most frequently measured physical quantity, second only to time. Accurate temperature monitoring improves product quality and increases productivity. Downtimes are decreased, since the manufacturing processes can proceed without interruption and under optimal conditions. In this work, authors propose noncontact infrared method for determining temperature of machining processes. This was mainly due to thermography ability to catching moving targets in real time, to measure temperatures over some area not only in point. As a result of measurement, it is obtained a data set that is presented in a form of a colourful map: a thermogram. Getting an accurate temperature of an object using this method is difficult because of numerous errors, which researchers could done during experiments. This work presents some results of research done during turning and drilling realized on conventional lathe CDS 6250 BX-1000. These demonstrate the usefulness of proposed method to study the machining processes temperature.

10

The influence of finishing on the tribological properties of plasma sprayed MMC coatings

Charchalis A., Starosta R.

Journal of KONES

|

2016

|

Vol. 23, No. 1

91--97

EN

During operation of marine pumps, one of the most common disability is tribological wear of shaft neck cooperating with the gland. In the practice, worn shafts are exchanged for new or are regenerated by chromium plating, padding or thermally sprayed of ceramic coatings, mainly Al2O3 In this article, the use of plasma sprayed Ni-5% Al-15%Al2O3 composite coatings were proposed. The surfaces of coatings by turning and burnishing treatments were shaped. Tribological properties of composite materials are dependent on the proportion and size of the reinforcing phase particles contained in a metal matrix. A reinforcement composite with very small dimensions and the amounts may result in increased wear and increase the coefficient of friction. It is therefore important to check whether the advisable of phase composition will not adversely affect the wear of the composite and the cooperating the part. The presence of a 15% volume fraction of the alumina particles on the selected tribological properties of the Ni-5% Al matrix composite coatings were evaluated. In order to assess the effect of the applied tapes of finishing on wear of MMC coatings, the tribological tests were performed on the "T05" machine with head roll- piece type. It has been found that the burnishing favours a lower wear of composite coating and the cooperating element compared to the coatings after turning treatments. At the same time observed more than ten times less wear intensity of MMC coatings in the initial time of friction, which may indicate a shorter time needed to grind of cooperating elements.

11

Statistical evaluation of propriety of measurements of ship’s movement parameters

Charchalis A., Polanowski S.

Journal of KONES

|

2016

|

Vol. 23, No. 1

83--89

EN

The paper presents some problems of carrying out measurements of energetic characteristics and vessel’s performance in the conditions of sea examinations. As the object of propulsion characteristic determination was selected the ship with fixed pitch propeller. In order to formulate models of power characteristics, in first, known physical aspect were taken and subsequently statistic theory was implemented. Models of propulsion performance were built basing on two theoretical methods of determination of required shaft power and torque at a hub, as the function of propeller’s revolutionary speed and sailing condition represented by dimensionless coefficients. Model number one, based on Silukov method presents function with variable power index, of shaft power in domain of revolutionary speed. The second one presents model of torque variations, based on Silovic – Fancev method. For verification of models were taken presented in available bibliography, results of researches of ship’s propulsion systems [6]. We also discuss the manner of reducing the results of measurements to the standard conditions. We present the way of preparing propulsion characteristics and the analysis of examination uncertainty for the measurement of torque. Statistical analysis of deviation of results, using three models, proposed in the paper. As a result of analysis, one point from primary data set was rejected due to its unreliability, what was resulting with higher adequacy of characteristics.

12

Results of lapping process executed in elevated temperature

Molenda J., Charchalis A.

Journal of KONES

|

2016

|

Vol. 23, No. 4

591--596

EN

Lapping is used in the production of components of the highest quality in terms of form finish accuracy and surface integrity. A number of precision manufacturing applications use lapping process as a critical technology to achieve thickness tolerance and surface quality specification. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. This paper goal was to check the influence of temperature of executory system elements on lapping process results. In earlier work, authors investigated the dependence between time and the temperature of executory system elements. Tests showed that after five hours of machine working temperature stabilizes and slightly fluctuated around a certain value. Thus, this work concerns lapping results in this elevated temperature. Research was proceed during Al2O3 elements lapping. It was realised with use of ABRALAP 380 lapping machine. The lapping machine executory system consisted of three working conditioning rings. Executory system elements temperature was measured remotely by infrared camera Thermo Gear G100. Elements machining was started after 10, 140, and 270 minutes of machine working time. Studies showed that machine executory system elements temperature affected only the Ra parameter, which is higher for surfaces, which were processed starting from 270th minute of machine working time.

13

Influence of parameters of grit blasting conducted Dymet® device 412K to obtain roughness

Szyfelbain M., Charchalis A., Starosta M.

Journal of KONES

|

2016

|

Vol. 23, No. 4

521--526

EN

There are several fundamental steps for the technological preparation, which are required to optimize the thermal spray coatings. In order to ensure proper bonding of the coating, important is properly preparation of substrate. The surface of the substrate has to be clean and should have a suitable roughness after previously performed treatment. Knowledge about the effects of process parameters allows designing the coatings obtained with an optimal adherence. Only when all the components of the spraying coating process are used correctly there is possible properly design the technology. The article describes the impact of technological parameters of grit blasting to obtain the roughness of the steel substrate (steel S185) to the process of metallic coatings by cold gas dynamic spraying. Research was carried out by using the Dymet® 412K appliance, designed for applying metal coatings and substrate surface cleaning. Grit blasting is a mechanical method of surface preparation of metal parts. It allows obtaining a high degree of surface cleanliness and a determined roughness. The authors took into account parameters such as operational pressure, spray angle (incidence) of abrasive grit blasting in the axis of the stream and feed rate of used abrasive particles (Al2O3) passed to the nozzle of spray gun. Carried out the multiple regression analysis of the roughness parameters results. It revealed the existence of certain influences and changes of process parameters, which affect on the surface quality. Carried out calculations by using a multiple regression showed that the greatest correlation is between the required roughness and the feed rate of used abrasive particles. The studied roughness was described by the parameters: Ra, Rz, Rt and RSm. Stepped growth (from 0.1 to 0.8 g/s) of abrasive particles feed rate caused a decline of all of the roughness parameters. It has been found that the values of the roughness in the least depend on the operational pressure.

14

Abatement of particulate matter and SO2 emission by ships

Jaworek A., Krupa A., Marchewicz A., Sobczyk A., Czech T., Ottawa A., Śliwiński Ł., Antes T., Kurz M., Szudyga M., Charchalis A.

Journal of KONES

|

2016

|

Vol. 23, No. 4

183--192

EN

Ship engines emit noxious gases (SO2, NOx, and VOC) and particulate matter (PM), mostly black carbon. Since 1990, the International Maritime Organization (IMO) regulations gradually restricted the level of emission of NOx, which since 2016 have to be lower than 2-3.4 g/kWh, depending on engine power. SO2 emission reduction has begun since 2010 and now the content of sulphur in marine fuels is limited to 3.5%. At the same time, the Sulphur Emission Control Areas (SECA) has been established, at which the sulphur content in fuel cannot be higher than 0.1%. Since 2020, only a fuel of 0.5% sulphur can be used at all cruising areas outside SECA. It should be noted that due to lack of efficient technology, IMO still has not issued regulations regarding the PM emission by ships. The paper discusses various electrostatic techniques used for the reduction of PM emission in Diesel engine exhausts. Electrostatic scrubber systems, using seawater, allow removal of PM from exhausts with high efficiency and simultaneously SO2 gas. Electrostatic agglomerators allow increasing submicron and nanoparticles by coagulation of those particles to the larger ones, which could be removed by conventional techniques.

15

Wykorzystanie emisji akustycznej do diagnozowania wtryskiwacza silnika 3Al25/30

Dudzik K., Charchalis A.

Logistyka

|

2015

|

nr 3

1077--1083, CD 1

PL

Metoda emisji akustycznej (AE) może być stosowana do diagnostyki części maszyn takich jak np. wtryskiwacze. W artykule przedstawiono metodykę oraz wyniki badań wtryskiwacza silnika 3Al25/30. Badano wtryskiwacz sprawny i z zasymulowaną awarią polegającą na zakoksowaniu 2 z 9 otworków końcówki wtryskiwacza. Badania przeprowadzono na stanowisku laboratoryjnym za pomocą zestawu do rejestracji i analizy emisji akustycznej Vallen System. W skład zestawu wchodzi: 4 kanałowy rejestrator sygnału typu AMSY 6, dwa moduły pomiarowe ASIP-2/S, przedwzmacniacz o zakresie częstotliwości 20kHz - 1MHz i wzmocnieniu 34dB oraz czujnik pomiaru sygnału AE, typu VS 150M, o zakresie częstotliwości 100 -450kHz. W czasie badań emisji akustycznej (AE) generowanej w trakcie wtrysku rejestrowano między innymi parametry: amplituda sygnału, liczba zdarzeń, całkowity czas wtrysku, wartość skuteczna sygnału (RMS). Analiza wyników badań wykazała wyraźnie dłuższy czas całkowity wtrysku w przypadku wtryskiwacza uszkodzonego w porównaniu do wtryskiwacza sprawnego. Amplituda sygnału była większa jednakże RMS sygnału osiągnęła około 3-krotnie mniejszą wartość dla wtryskiwacza z zakoksowaną końcówką. Oznacza to niższą jakość rozpylania paliwa. Przeprowadzone badania mogą być podstawą, do późniejszej identyfikacji ewentualnych uszkodzeń na pracującym silniku, przy wykorzystaniu emisji akustycznej jako skutecznego narzędzia diagnostycznego.

EN

Acoustic emission method (AE) can be used for the diagnosis of machine parts such as, for example: fuel injectors. This paper presents the methodology and research results of 3Al25/30 engine fuel injector. During research was studied one injector in good condition and second with simulated failure involving the closing 2 of 9 holes of the injector tip. Research was carried out on a laboratory test stand using a set of acoustic emission Vallen System. The kit includes: 4 channel signal recorder AMSY 6, two measurement modules ASIP-2/S, preamplifier with a frequency range 20 kHz - 1 MHz and the strengthening of 34dB and AE signal measurement sensor type VS 150M, with a frequency range 100 - 450kHz. During the study, the acoustic emission (AE) generated during the injection was recorded parameters: amplitude, number of events - hits, the total injection time, the effective value of the signal (RMS). Analysis of the results showed significantly longer total time of the injection in the case of damaged injector compared to the injector in good conditions. Signal amplitude was higher, however, the RMS signal reached approximately 3-times lower value for the injector with damaged tip. This means lower quality fuel atomization. The study can be the basis for subsequent identification of possible damages of the engine equipment while the engine is running, using acoustic emission as an effective diagnostic tool.

16

Wpływ zmiany kąta przystawienia noża tokarskiego typu Wiper na wartość sił skrawania i chropowatość powierzchni czopów wałów pomp okrętowych

Labuda W., Charchalis A.

Logistyka

|

2015

|

nr 3

2781--2788, CD 1

PL

W artykule przedstawiono wyniki badań dotyczące toczenia wykończeniowego czopów wałów pomp okrętowych. Badania przeprowadzono na wałku ze stali nierdzewnej X5CrNi18-10 o średnicy 60 mm. Toczenie wykończeniowe wałów przeprowadzono na tokarce uniwersalnej CDS 6250 BX-1000. Proces skrawania wykonano przy użyciu wymiennych płytek wieloostrzowych firmy Sandvik Coromant. Do badań wykorzystano płytki dogładzające z technologią Wiper (WF). Podczas procesu toczenia zastosowano optymalne parametry skrawania dla płytek: CCMT 09T302 WF, CCMT 09T304 WF, CCMT 09T308 WF. Toczenie czopów wałów przeprowadzono dla kąta przystawienia równego 90° ± 3°. Do procesu toczenia wykorzystano siłomierz DKM 2010. Podczas badań określono wpływ geometrii noża tokarskiego na parametr chropowatości powierzchni Ra stali stosowanej na wały pomp okrętowych. Pomiary chropowatości powierzchni wykonano z wykorzystaniem profilometru T8000.

EN

The article presents the research results of pump shaft pins finish lathing. The research was performed on a roller 60 mm in diameter made of X5CrNi18-10 steel. The finish tooling of pump shaft pins was carry out on a universal CDS 6250 BX-1000 centre lathe. The finish lathing process was carried out by means of Sandvik Coromant cutting tool with replaceable inserts. In the research of lathing process used inserts with Wiper technology (WF). During the lathing the optimal machining parameters were used for inserts: CCMT 09T302 WF,CCMT 09T304 WF, CCMT 09T308 WF. The cutting process was performed at side angle of 90° ± 3°. The process of lathing used cutting tool dynamometer DKM 2010. During the research, the effect of cutting tool geometric on surface roughness parameter Ra of steel applied to marine pumps shaft pins was determined. Measurement of surface roughness parameters was performed by T8000 profilometer.

17

Wpływ twardości materiału obrabianego na jakość powierzchni po docieraniu

Molenda J., Charchalis A.

Logistyka

|

2015

|

nr 3

3363--3370, CD 1

PL

Obecnie, wobec wysokich wymagań co do stanu powierzchni, jakie konstruktorzy stawiają elementom maszyn, szczególne znaczenie ma rozwój metod obróbki bardzo dokładnej. Jedną z takich metod jest docieranie, rozwijane przede wszystkim w zakresie obróbki powierzchni płaskich. Naddatek z powierzchni obrabianej usuwany jest w następstwie wzajemnego oddziaływania pomiędzy powierzchnią obrabianą, powierzchnią docieraka i mikroziarnami ściernymi. Przebieg tego procesu ściśle zależy od twardości materiału obrabianego. Obróbka materiałów ciągliwych odbywa się głównie przez mikroskrawanie oraz odkształcenie plastyczne, naddatek usuwany jest wtedy w dwóch etapach: umocnienie materiału w wyniku odkształcenia i odrywanie cząstek na skutek umocnienia. Kształtowanie powierzchni elementów z materiałów kruchych, jak ceramika, następuje przede wszystkim na skutek propagacji pęknięć. W celu sprawdzenia, jak twardość materiału obrabianego wpływa na efekty docierania, wykonano szereg prób. Do badań wybrano próbki ze stali C45, które obrabiano cieplnie w celu uzyskania trzech wartości twardości: 160 HV, 440 HV i 650 HV. Tak przygotowane próbki szlifowano, następnie docierano stosując te same parametry obróbki. W pracy przedstawiono wyniki badań stereometrii powierzchni prowadzonych przed i po procesie docierania. Potwierdzają one, że twardość ma zasadniczy wpływ na jakość powierzchni obrobionej, którą w tej pracy opisano parametrami chropowatości Ra i poprawy chropowatości KRa. Dodatkowo analizowano fotogramy powierzchni wykonane odwróconym mikroskopem Axiovert 25.

EN

The finishing processes are an important perspective to be considered today to meet the goals like parallelism, tolerances, flatness, and smooth surface of workpieces. These processes are high-precision abrasive processes. A leading importance in this perspective has the lapping process. It leads to a surface with low roughness and high precision. The most extensively used type of lapping process is flat lapping. Stock removal is a result of interactions between abrasive grains, workpiece, and tool surfaces. The mechanism of material removal process strongly depends on workpiece material hardness. At ductile materials (e.g. steel) microcutting and microploughing mainly appear while at brittle materials (e.g. ceramics) microcracking exists. The goal of this paper was to check the influence of workpiece material hardness on workpiece surface quality. For the research steel C45 samples were chosen. Samples were divided to three groups according to planned heat treatment (planned hardnesses). Obtained Vicker’s hardness in each group were 160, 440, and 650 HV. Then speciments were grounded to surface roughness Ra = 0.67 μm. After grinding lapping process was conducted. Experiments were carried out with the same lapping parameters for each group. This paper presents the results of workpiece surfaces measurements conducted before and after lapping. They confirm the influence of material hardness on workpiece surface quality. The surface quality is described by Ra and KRa parameters. Additionally surface photographs were analysed. They were performed with use of inverted microscope Axiovert 25.

18

Wpływ obróbek wykończeniowych na odporność na zmęczenie stykowe powierzchni czopów wałów pomp okrętowych pracujących w wodzie morskiej

Labuda W., Charchalis A.

Logistyka

|

2015

|

nr 3

2772--2780, CD 1

PL

W siłowniach okrętowych odśrodkowe pompy krętne stosowane są w obiegach chłodzenia silników średniej i dużej mocy, do zasilania kotłów oraz w instalacjach zęzowych, balastowych i przeciwpożarowych. Bardzo szerokie zastosowanie pomp krętnych na pokładzie związane jest z ich licznymi zaletami. Podczas eksploatacji wirowych pomp okrętowych dochodzi do zużycia kadłuba, wirnika, uszczelnień i wału. W artykule przedstawiono wyniki badań dotyczące obróbek wykończeniowych czopów wałów pomp okrętowych. Badania przeprowadzono na wałku ze stali nierdzewnej X5CrNi18-10 o średnicy 40 mm. Obróbkę wykończeniową czopów wałów przeprowadzono na tokarce uniwersalnej CDS 6250 BX-1000. Proces toczenia wykonano przy użyciu wymiennych płytek wieloostrzowych firmy Sandvik Coromant. Do badań wykorzystano płytki dogładzające z technologią Wiper (WF). Do procesu szlifowania wykorzystano szlifierkę suportową do tokarek CHRIS MARINE. Do obróbki wykorzystano ściernicę 1–80x10x32–99C 80-N V. Obróbkę nagniataniem przeprowadzono nagniatakiem SRMD firmy Yamato. Dodatkowo określono wpływ liczby przejść narzędzia nagniatającego na odporność na zmęczenie stykowe.

EN

Angular momentum pumps are used in cooling circuits of medium and high power engines, power plant boilers and in bilge, ballast and firefighting installations. Very extensive use of angular momentum pumps on board is connected with their advantages. During operation the wear of marine hull, the rotor and shaft seals takes place. The article presents the research results of pump shaft pins finishing treatments. The research was performed on a roller 40 mm in diameter made of X5CrNi18-10 steel. The finishing treatments of shaft pins was carried out on a universal CDS 6250 BX-1000 centre lathe. The finish lathing process was carried out by means of Sandvik Coromant cutting tool with replaceable inserts. During research of lathing process used inserts with Wiper technology (WF).The grinding process was performed by grinding attachment for lathes by CHRIS MARINE. The 1 - 80x10x32 - 99C 80-N V grinding wheel was used for the process. The process of burnishing was performed by SRMD burnisher by Yamato. In addition, the influence of the burnisher passes number on resistance on fatigue contact was determined.

19

Właściwości korozyjne natryskiwanych cieplnie powłok kompozytowych na osnowie stopu Ni-5%Al przeznaczonych do regeneracji wałów pomp okrętowych

Charchalis A., Starosta R.

Logistyka

|

2015

|

nr 3

667--675, CD 1

PL

W artykule przedstawiono ocenę wpływu zastosowanej technologii natryskiwania cieplnego na właściwości korozyjne (gęstość prądu korozyjnego oraz potencjał korozyjny) powłok stopowych Ni-5%Al oraz powłok kompozytowych Ni-5%Al-Al2O3, zbrojonych dyspersyjnie. Materiały te potencjalnie mogłyby znaleźć zastosowanie w przemyśle okrętowym jako powłoki regeneracyjne służące do naprawy wałów pomp okrętowych. Właściwości korozyjne powłok badano w środowisku zastępczej wody morskiej (3,5% roztwór NaCl) metodą polaryzacyjną. Stwierdzono, że spośród rozpatrywanych zmiennych niezależnych : metoda natryskiwania, udział fazy zbrojącej oraz porowatość, ta ostatnio wymieniona wywiera największy wpływ na właściwości korozyjne natryskiwanych cieplnie powłok na osnowie Ni-5%Al. Zastosowana technologia natryskiwania cieplnego ma znaczący wpływ na wartość potencjału korozyjnego powłok stopowych Ni-5%Al oraz powłok kompozytowych Ni-5%Al-Al2O3. Stwierdzono, że im nowocześniejsza metoda wytwarzania powłok tym większa prędkość materiału powłokowego w strumieniu natryskiwanym co ma istotny pozytywny wpływ na porowatość powłok. Obecność fazy zbrojącej (Al2O3) w powłokach kompozytowych przyczynia się do zmniejszenia wartości gęstości prądu korozyjnego oraz do wzrostu wartości potencjału korozyjnego.

EN

In the paper an assessment of the impact of the thermal spray methods on the corrosion properties (corrosion current density and corrosion potential) of Ni-5%Al alloy coatings and Ni-5%Al-Al2O3 composite coating reinforced by particle dispersion was presented. These materials would potentially be used in the shipbuilding industry as a regenerative coatings for repair of marine pump shaft. Corrosion properties of the coatings were tested in an replacement seawater (3.5% NaCl) by polarization curves method. It has been found that among the independent variables considered: a method of thermal spraying, fraction of reinforcing phase and porosity, the last mentioned has the greatest influence on the corrosion properties of thermally sprayed coatings on the matrix of Ni-5% Al. The value of the corrosion potential of coatings depended on the used thermal spray method. It has been found that the more modern method of producing a coatings of the higher velocity of the coating material in a sprayed stream has a significant positive effect on the porosity of the coatings. The presence of the reinforcing phase (Al2O3) in composite coatings contributes to a reduction of value of the corrosion current density and increase the corrosion potential value.

20

Opory śrub niepracujących w okrętowych napędach wielośrubowych

Charchalis A.

Logistyka

|

2015

|

nr 3

660--666, CD 1

PL

Zapotrzebowanie mocy do napędu okrętów zależy od ich wyporności i prędkości pływania. Na wybór odpowiedniego rodzaju głównych silników napędowych szczególnie istotny dla jednostek szybkich, ma wpływ nie tylko moc silników ale także ograniczona część wyporności , przeznaczona na siłownię. Ma to wpływ na liczbę, rodzaj, moc i gabaryty silników głównych oraz liczbę i średnicę śrub. Jednostki szybkie projektowane są na maksymalne prędkości pływania, natomiast z reguły eksploatowane są prędkościami częściowymi. Powoduje to konieczność wyłączenia z pracy poszczególnych silników czy też śrub napędowych. Śruby niepracujące są holowane przez kadłub okrętu i powodują dodatkowy opór. Opór dodatkowy spowodowany niepracującymi śrubami należy uwzględniać podczas projektowania układu napędowego, szczególnie w zakresie analizy szacowania prędkości pływania. Niepracująca śruba może być zastopowana przy pomocy hamulca lub też w sytuacji gdy moment wytwarzany na śrubie pracującej jak turbina wodna jest mniejszy od momentu tarcia w linii wału oraz swobodnie obracająca się. Momenty i napory występujące na śrubie w tym zakresie pracy można oszacować w oparciu o uniwersalne charakterystyki hydrodynamiczne śrub. Zaprezentowano metodykę oraz przykład obliczania oporów śrub swobodnie obracających się i zastopowanych dla założonego układu napędowego okrętu.

EN

The configuration of a marine propulsion system is selected with regard to the maximum power resulting from its maximum design speed and displacement. The propulsion systems of high speed vessels use three or even four propellers, and each propulsion unit may be multi-engine. High speed vessels are designed for maximum speeds, but their factual exploitation speed parameters are usually considerably lower - partial speed. In such cases particular propulsion propellers and engines need to be shut down. The idle propellers are dragged by the hull and they work in the so-called turbine work mode; they transfer torque to the shaft and generate negative thrust, i.e. additional resistance. Additional resistance contributes to reducing estimated speed of a vessel and increasing fuel consumption. What is more, torque generated on a propeller is transferred to the shaft and when friction resistance torque in shaft stuffing-boxes and bearings, transmission and, possibly, the propulsion engine is exceeded, mobile components rotate as a result, reaching considerable rotational speed values. Torque and thrust on a propeller in this work mode may be estimated on the grounds of universal hydrodynamic characteristics of propellers. Universal hydrodynamic characteristics of propellers are used as reversion characteristics in evaluating the steering properties of a vessel, and may be useful in evaluating resistance of freewheeling and locked propellers in marine multi-shaft propulsion systems. This paper presents charts of universal hydrodynamic characteristics of propellers for the full range of their rotational speed, the methodology and an example of calculating resistance of freewheeling and locked propellers for the given marine propulsion system.