Wyniki wyszukiwania - BazTech

1

Wear Resistance of Structural Steels as a Result of Boronising Operations

Kalinowska-Ozgowicz E., Lenik K., Korga S.

Tribologia

|

2018

|

nr 2

37--44

EN

This paper presents the results of investigations on the effect of thermochemical treatment, boronising and chemical composition of selected structural steels on their wear in sliding friction process. The operation of boronising on C45, 37CrNiMo, 42CrMo6, 41Cr4, 50CrSi4-4 steels was performed by powder method at 950°C for 8 h. Following this operation, rod sections of the test steels were subjected to quench hardening from 850°C with isothermal holding at 300°C for 1h. The assessment of the construction, thickness and microhardness of boronised layers depending on the level of carbon and alloying elements in chemical composition of analysed steels was made. The testing for wear resistance of steels after boronising was carried out with the sliding friction method by applying a load of 150 N, counter-sample rotational speed of 1000 rpm and using aqueous solution of potassium chromate as a cooling medium. The metallographic observations of the structure and thickness measurement of the boronised layers were carried out using a light microscope, while the identification of phases was made by the X-ray qualitative analysis method. The hardness and microhardness measurements were taken by the Vickers method.

PL

W publikacji przedstawiono wyniki badań wpływu obróbki cieplno-chemicznej, borowania i składu chemicznego wybranych stali konstrukcyjnych na zużycie w procesie tarcia ślizgowego. Operację borowania stali gatunku C45, 37CrNiMo, 42CrMo6, 41Cr4, 50CrSi4-4, przeprowadzono metodą proszkową w temperaturze 950ºC w czasie 8 godz. Po tej operacji odcinki prętów z badanych stali poddano hartowaniu z 850ºC z wytrzymaniem izotermicznym w temperaturze 300ºC w czasie 1 godz. Przeprowadzono ocenę budowy, grubości i mikrotwardości warstw naborowanych w zależności od stężenia węgla i pierwiastków stopowych w składzie chemicznym analizowanych stali. Badanie odporności na zużycie stali po borowaniu przeprowadzono metodą tarcia ślizgowego, stosując obciążenie 150 N, prędkość obrotową przeciwpróbki wynoszącą 1000 obr./min i roztwór wodny chromianu potasu jako środek chłodzący. Obserwacje metalograficzne struktury i pomiar grubości warstw naborowanych zrealizowano z wykorzystaniem mikroskopu świetlnego, a identyfikacji faz dokonano metodą rentgenowskie analizy jakościowej. Pomiary twardości i mikrotwardości zrealizowano metodą Vickersa.

2

Determination of the frictional resistance in the model forming process by the finite element method

Lenik K., Korga S., Kalinowska-Ozgowicz E.

Tribologia

|

2017

|

nr 5

29--36

EN

This article presents the results of measurements on friction forces carried out in the model forming process (MFP). The description of this process takes into consideration the presence of plastic strain at the interface between the test specimen and tool due to the material flow. The experimental forming process was performer with a laboratory unit constructed and manufactured at the Fundamentals of Technology Faculty of the Lublin University of Technology [L. 1, 2]. This unit was used to carry out the measurements on friction force Turing model forming of shaped test specimens at a pressure of 0 to 100kN acting on a continuous basis during the research process. The results of experimental measurements of friction forces were compared to those of numerical calculations obtained with the finite element method (FEM). Experimental results of friction for ces were compared with the results obtained using the model forming process (MFP). In order to document the effects of plastic strain in the structure of shaped test specimens subjected to experimental model forming, metallographic examinations were carried out using a light microscope. Structure observations were conducted in a bright field and polarised light with a magnification of up to 2000x.

PL

W artykule przedstawiono rezultaty badań sił tarcia w modelowym procesie wytłaczania (MPW). Uwzględniono także występowanie odkształcenia plastycznego zachodzącego wskutek płynięcia materiału przy styku próbki z narzędziem. Modelowy proces wytłaczania przeprowadzono na urządzeniu laboratoryjnym skonstruowanym i wykonanym na Wydziale Podstaw Techniki Politechniki Lubelskiej. Urządzenie pozwalało na prowadzenie badań wytłaczania próbek kształtowych dla siły nacisku (od 0 do 100 N) działającej w sposób ciągły, w trakcie procesu badawczego. Efekty doświadczalne pomiarów sił tarcia porównano z wynikami uzyskanymi metodą obliczeniową przy zastosowaniu MES w modelowym procesie wytłaczania (MPW). Użycie metod numerycznych pozwoliło również na obliczenie rozkładu odkształceń w badanych próbkach. Dla udokumentowania efektów odkształcenia plastycznego w strukturze kształtowników poddanych doświadczalnemu, modelowemu wytłaczaniu przeprowadzono badania metalograficzne przy wykorzystaniu mikroskopu świetlnego. Obserwacje struktury prowadzono w polu jasnym i świetle spolaryzowanym przy powiększeniu do 2000x.

3

Przewody wentylacyjne krytej pływalni – możliwości materiałowe i technologiczne

Ozgowicz W., Kalinowska-Ozgowicz E., Lesz S., Kowalski A.

Rynek Instalacyjny

|

2013

|

Nr 10

71--79

PL

W artykule przedstawiono wyniki badań metalograficznych próbek blach z przewodów wentylacyjnych hali basenowej krytej pływalni, a także alternatywne możliwości materiałowe (stale ferrytyczno-austenityczne) oraz technologiczne (powłoki cynkowe) w celu przeciwdziałania negatywnemu oddziaływaniu środowiska korozyjnego.

EN

The paper presents results of metallographic investigations of steelsheet samples from aspirating ventilation ducts in indoor swimming-pools. It has been found that these samples made of stainless steel type 1.4301 display corrosion on their surface in the form of pin-holes and microcracking and that the corrosive degradation of these steelsheets its the result of pitting corrosion in a chloride medium and a faulty choice of the kind of steel used for the structural elements of the design ventilation installation in an indoor swimming-pool. It also presents alternative possibilities of materials (ferritic-austenitic steels) and technology (zinc coating) in order to counteract the negative impact of corrosive environment.

4

Investigation of the Portevin-Le Chatelier effect by the acoustic emission

Grzegorczyk B., Ozgowicz W., Kalinowska-Ozgowicz E., Kowalski A.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 60, nr 1

7--14

EN

Purpose: The aim of this paper is to determine the relation existing between the behaviour of the signals of acoustic emissions generated in the course of plastic deformation at elevated temperature, and the shape of the work-hardening curves σ-ε and the Portevin - Le Chatelier effect. Design/methodology/approach: Single crystal was investigated applying the method of free compression at a constant strain rate and a temperature within the range from 20°C to 400°C at a strain rate of 10-5 sec-1to 10-1 sec-1, simultaneously recording this phenomenon by means of acoustic emission. Findings: The analysis of the results of these investigations permitted to prove considerable relations between the work-hardening curve σ-ε displaying the PLC effect and the characteristics of the signals of the acoustic emission generated in the uniaxial compression. Practical implications: The AE method applied in the process of plastic deformation of single crystals of the alloy CuZn30 displays also a dependence of the activity of acoustic emissions on the stage of strain-hardening of the investigated alloy. Originality/value: In the range of the occurrence of the PLC effect during the compression test of the investigated single crystals the signal AE displays a cyclic character, distinctly correlated qualitatively with the oscillations of stresses on the curve σ-ε.

5

Segregation of alloying elements in thermomechanically rolled medium-Mn multiphase steels

Grajcar A., Kamińska M., Opiela M., Skrzypczyk P., Grzegorczyk B., Kalinowska-Ozgowicz E.

Journal of Achievements in Materials and Manufacturing Engineering

|

2012

|

Vol. 55, nr 2

256--264

EN

Purpose: The aim of the paper is to assess the tendency of alloying elements to macro- and microsegregation during hot-forging and successive thermomechanical rolling of medium-Mn Al-bearing steel sheets. Design/methodology/approach: The macro- and microsegregation of alloying elements was assessed by EDS and WDS measurements across the thickness of the roughly-forged flats and thermomechanically processed 3.3 mm sheets. The microstructure was revealed using combined methods of optical microscopy (OM) and scanning electron microscopy (SEM). Morphological features of microstructural constituents were discussed with focusing on retained austenite. Findings: It was found that the final multiphase microstructure is mainly dependent on the Mn content and the effect of Nb microaddition is relatively low. The 3Mn steels possess very fine bainite-based microstructures whereas the steels containing 5% Mn are characterized by lath bainitic-martensitic microstructures. All the steels contain retained austenite as fine granules or layers located between bainitic ferrite laths. Some fraction of martensite-austenite (M-A) islands was also identified. The tendency of Mn and Al to macrosegregation was found after the initial hot-forging. It disappears after successive rough and thermomechanical rolling whereas thin martensite and martensite-austenite microbands as a result of Mn microsegregation locally occur. Research limitations/implications: Further investigations are required to quantify the local changes of chemical composition especially in formed microbands and X-ray quantitative phase analysis should be applied to assess a fraction of retained austenite. Practical implications: The knowledge of the macro- and microsegregation of alloying elements in advanced medium-Mn steels containing retained austenite can be useful in designing the thermomechanical rolling procedures of multiphase steel sheets. Originality/value: A problem of macro- and microsegregation of Mn and Al in advanced high strength steels, which belong to the third generation of automotive steels was discussed with concentrating on Mn and Nb microaddition effects.

6

Metallographic aspects of deformed monocrystals of CuZn30 alloys

Grzegorczyk B., Ozgowicz W., Kalinowska-Ozgowicz E., Kowalski A., Pałka P.

Archives of Materials Science and Engineering

|

2012

|

Vol. 54, nr 1

29-36

EN

Purpose: The aim of the paper is to present the technique of production and the analysis of the structures of CuZn30 monocrystals compressed at a temperature of 20°C up to 400°C at a strain rate of 10-5 sec-1 to 10-1 sec-1. Design/methodology/approach: The range of investigations comprised the production of monocrystals for tests, the determination of their crystallographic orientation, the deformation of selected monocrystals by compressing them within the temperature range from 20°C to 400°C at a strain rate of 10-5 sec-1 to 10-1 sec-1, as well as observations of the structures on an optical microscope. Findings: The analysis of the results of these investigations permitted to prove a considerable influence of the temperature, the strain rate and the crystallographic orientation on the metallographic effects of the work hardening of the CuZn30 alloy with the orientation [1 3 9 ]. Practical implications: In the microstructures of the investigated monocrystals typical effects of plastic deformation were observed in the form of parallel cruciform lines and slip zones with locally intensified densities in various ranges of the cross-section of the sample and bands of deflection with weakly visible slip lines in the original system. Originality/value: The analysed microstructures of compressed monocrystals prove that the main mechanism of plastic deformation is the slide. Of essential influence on the structure of plastically deformed monocrystals with the orientation [1 3 9 ] are both the temperature and the strain rate.

7

Thermomechanical treatment of low-alloy copper alloys of the kind CuCo2Be and CuCo1NiBe

Ozgowicz W., Kalinowska-Ozgowicz E., Grzegorczyk B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 46, nr 2

161--168

EN

Purpose: The aim of the investigations is to test the influence of the complex thermomechanical treatment on the structure and mechanical properties of low-alloy copper alloys with cobalt, beryllium and nickel of the kind CuCo2Be (CB4) and CuCo1NiBe (CCNB). Design/methodology/approach: The range of investigations comprises an analysis of the complex technique of thermomechanical treatment of the investigated alloys and the conventional thermal treatment of these alloys, the analysis of their chemical composition, a static tensile test, measurement of their hardness, observations of their structure on a light microscope and a fractographic analysis on an electron scanning microscope. Findings: The analysis of the results of investigations concerning the mechanical effect properties permitted to determine the effect of the combined thermomechanical treatment and the comparatively performed precipitation hardening on the structure and mechanical properties of the investigated low-alloy kinds of copper. The character of cracking in the course of stretching were determined basing on fractographic tests. Practical implications: The investigated copper alloys subjected to a complex thermomechanical treatment display a higher strength and lower plastic properties in comparison with these properties achieved by means of the conventional heat treatment. Originality/value: Complex thermomechanical treatment ensures an optimal strength of the investigated alloys as well as satisfying plastic properties.

8

The structure and mechanical properties of Al-Mg-Mn alloys shaped in the process of thermomechanical treatment

Ozgowicz W., Kalinowska-Ozgowicz E., Kowalski A., Gołombek K.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 45, nr 2

148--156

EN

Purpose: The aim of research was to investigate the effect of heat treatment and low-temperature thermomechanical treatment (LTMT) on the structure and mechanical properties of Al-Mg-Mn alloys. Design/methodology/approach: The range of researches included: performance of heat treatment and low-temperature thermomechanical treatment of AlMg1.5 and AlMg3.5Mn alloys, carry out of static tensile tests, measurements of hardness, metallographic observation (TEM) and fractography (SEM). Findings: Analysis of the results allows to determine the effect of precipitation hardening and low-temperature thermomechanical treatment on the structure and mechanical properties of AlMg1.5 and AlMg3.5Mn alloys and to determine the effect on the topography of the specimens fracture after decohesion in tensile tests. Moreover, SEM researches allow to identity the chemical composition of precipitates in the structure of investigated alloys. Practical implications: The obtained results may serve as a basis for optimization of the process of the material used as components of vessels. Originality/value: The mechanical properties of the investigated aluminium alloys increase with the quantity of Mg, independently of their state and the parameters of heat treatment and low-temperature thermomechanical treatment. More refinement of precipitations, which affect the mechanical properties in ageing, ensured by LTMT compared with conventional heat treatment.

9

Structure and mechanical properties of austenitic steel after cold rolling

Kurc-Lisiecka A., Kalinowska-Ozgowicz E.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 44, nr 2

148--153

EN

Purpose The aim of the paper is to determine the influence of the cold plastic deformation within the range 18-79% and heat treatment in a temperature range of 500 to 700°C on the microstructure and mechanical properties of austenitic stainless steel grade X5CrNi18-8. Design/methodology/approach: The investigations included observations of the microstructure on a light microscope, researches of mechanical properties in a static tensile test and hardness measurements made by Vickers’s method. The analysis of the phase composition was carried out on the basis of X-ray researches. Whereas, X-ray quantitative phase analysis was carried out by the Averbach Cohen method. Finding Heat treatment of X5CrNi18-8 stainless steel in the range 500-700°C causes a significant decrease of the mechanical properties (Rm, Rp02) and increase of elongation (A). Hardness of investigated steel drops with decrease of cold working degree and increase of heat treatment temperature. Research limitations/implications The analysis of the obtained results permits to state that the heat treatment causes an essential changes of the microstructure connected with fading of cold deformation. Heating of cold rolled austenitic stainless steels can cause a reverse transformation a' → y Practical implications: Two-phase structure a’+y of austenitic Cr-Ni steel in deformed state working at elevated temperature undergo a transformation. It significantly influences mechanical properties of steel. Austenite phase undergoes a recrystallization, while martensite a’ phase undergoes reverse transformation. Originality/value: The analytic dependence of the yield point of the investigated steel on the cold working degree in cold rolling process has been confirmed. Revealing this relation is of essential practical importance for the technology of sheetmetal forming of austenitic steel.

10

Metallurgical products of microalloy constructional steels

Ozgowicz W., Opielak M., Grajcar A., Kalinowska-Ozgowicz E., Krukiewicz W.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 44, nr 1

7--34

EN

Purpose: The aim of the paper is a monographic presentation, based on investigations connected with the elaboration of new kinds of microalloy steels and a technique of heat and thermo-mechanical treatment in the production of a selected group of metallurgical products. Design/methodology/approach: The influence of the chemical composition and metallurgical purity on the homogenisation of austenite was analysed, as well as thermally activated processes and phase transformations in the course of deformation and controlled cooling conditions, concerning micradditives Nb, V, Ti, B and metallurgical products. Findings: The chemical composition of the obtained constructional steels with microadditives was quoted, as well as the technological conditions of forging and rolled products required for industrial purposes. Research limitations/implications: The results of investigations concerning the structure and mechanical properties have been presented, as well as the resistance to fracture, mainly of thick plates and hand-forged and drop-forged products and also elements of sheet structures for the automotive industry, made of AHSS steels. Practical implications: The results of the author’s own investigations concerning microalloy steels indicate the actual possibility of their application in practice in many steelworks, particularly in plants producing semi products and final metallurgical products, among others in hot rolling plants and forging shops, first of all in machine building and automotive industry. Originality/value: The application of modern metallurgical technologies and metalforming has been suggested for selected metallurgical products of microalloy steels of the type HSLA with a ferrite-bainite, bainite or tempered martensite structure and also of HSS steels and UHSS steel with a wide range of mechanical properties and technological formability, which is essential in the case of products of the automotive industry.

11

Ocena przyczyn korozji blachy stalowej stosowanej na przewody wentylacyjne krytej pływalni

Ozgowicz W., Kalinowska-Ozgowicz E., Lesz S., Piechurska A.

Instal

|

2011

|

nr 5

5-11

PL

W artykule przedstawiono wyniki badań metalograficznych próbek blach z przewodów wentylacyjnych wywiewających powietrze z hali basenowej krytej pływalni. Stwierdzono, że badane próbki przewodów ze stali nierdzewnej gatunku 1.4301 wykazują powierzchniowe efekty korozji w postaci wżerów i mikropęknięć. Ustalono, że degradacja korozyjna blach stalowych jest wynikiem przebiegu procesu korozji w środowisku chlorków oraz nieprawidłowego doboru gatunku stali na elementy konstrukcji projektowanej instalacji wentylacyjnej budynku krytej pływalni.

EN

The paper presents results of metallographic investigations of steelsheet samples from aspirating ventilation ducts in indoor swimming-pools. It has been found that these samples made of stainless steel type 1.4301 display corrosion on their surface in the form of pinholes and microcracking and that the corrosive degradation of these steelsheets its the result of pitting corrosion in a chloride medium and a faulty choice of the kind of steel used for the structural elements of the design ventilation installation in an indoor swimmingpool.

12

Effects of Mn and Nb on the macro- and microsegregation in high-Mn high-Al TRIP steels

Grajcar A., Kalinowska-Ozgowicz E., Opiela M., Grzegorczyk B., Gołombek K.

Archives of Materials Science and Engineering

|

2011

|

Vol. 49, nr 1

5-14

EN

Purpose: The aim of the paper is to determine the effects of Mn and Nb on the macro- and microsegregation of new-developed (3-5)Mn 1.5Al TRIP steels in the as-cast state and after hot forging. Design/methodology/approach: To assess possible macro- and microsegregation the chemical composition was investigated in the macro scale by OES and by the use of EDS in microregions. To reveal the macrostructure the ingots were etched by Oberhoffer’s reagent. The chemical composition along a diameter of the ingots was tested as well as in different regions of the plastically deformed flats. Metallographic investigations were carried out using optical (OM) and scanning electron microscopy (SEM). Findings: The Mn and Nb contents have significant effects on the obtained bainitic-martensitic structures and the morphology of retained austenite. The tendency to macrosegregation of Mn and Al between middle and external parts of the as-cast ingots and hot forged flats was detected. The Nb micoalloying results in the overall refinement of obtained microstructures and reduces the identified segregation of Al and Mn. A little microsegregation of these alloying elements between structural constituents was also detected. Research limitations/implications: Further investigations to describe in detail the identified structural constituents and the tendency of alloying elements to segregation in the thermomechanically rolled sheets are in progress. Practical implications: The knowledge of the macro- and microsegregation of Mn and Al in the TRIP steels with a high fraction of retained austenite is of primary importance for the manufacturing paths of these multiphase structure steels. Originality/value: A problem of segregation of Al and Mn in advanced high strength steels with and without Nb microaddition was described and interesting types of bainitic structures were identified.

13

The microstructure and mechanical properties of the alloy CuZn30 after recrystallizion annealing

Ozgowicz W., Kalinowska-Ozgowicz E., Grzegorczyk B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2010

|

Vol. 40, nr 1

15-24

EN

Purpose: The aim of the investigations is to determine the influence of the recrystallization temperature on the microstructure and mechanical properties of the brass CuZn30 subjected to cold deformation in the process of rolling at various degrees of strain. Design/methodology/approach: The brass CuZn30 was recrystallization annealed within the temperature range of 300-650°C after cold rolling with the strain of 15.8-70.2%. The tensile test was carried out by the use of universal testing machine. Metallographic observations were performed on an optical microscope and fractographic tests on a scanning electron microscope. The hardness was also measured. Findings: The analysis of the results of investigations concerning the mechanical properties permitted to determine the effect of the temperature of recrystallization annealing on the strength and plastic properties of the investigated brass, subjected to cold deformation with a varying strain in the course of rolling. The character of fracture after decohesion in the tension test was determined basing on fractographic investigations. Practical implications: An increase of the recrystallization temperature within the range of 400-650°C results in a deterioration of the mechanical properties of the brass CuZn30 and an increase of its plastic properties. Originality/value: The results of the investigation revealed the occurrence of the phenomenon of heterogeneous plastic deformation in the recrystallized alloy.

14

Structure and properties of surface layers of selected constructional steels after sulfonitriding

Lesz S., Kalinowska-Ozgowicz E., Gołombek K., Kleczka M.

Archives of Materials Science and Engineering

|

2010

|

Vol. 42, nr 1

21-28

EN

Purpose: The main aim of the paper was to investigate the structure and properties of the surface layers of the C45, 42CrS4, 42CrMoS4 steels after sulfonitriding at a temperature of 540 and 570°C. The thickness of zones occurring in the sulphonitric layer was defined just as their chemical and phase composition and microhardness. Moreover, abrasion resistance in the zones of sulfonitrided layers was investigated. Design/methodology/approach: The following experimental techniques were used: light microscopy (LM), scanning electron microscopy (SEM), X-ray diffraction (XRD) method, Vickers microhardness, abrasion tests. Findings: Changes of microhardness in the zones of sulfonitrided layers have been presented. It has been stated that the surface layers of steels C45, 41CrS4 and 42CrMoS4 after gas sulfonitriding at 570°C are composed of four zones which are: external zone of sulfides with grain-like structure, zone of nitride phases with compound structure and with round sulfides precipitates, zone of nitride phases with diversified structure depending on chemical composition of the steel base of hardness 262 HV for steel 41CrS4 and 330 HV for steel 42CrMoS4, zone of nitride phases in the form of elongated precipitates in matrix of C45 steel or diffusion zone of micro-hardness 500-700 HV at the distance of 100-110 mm from the surface of 41CrS4 and 42CrMoS4 steels. Research limitations/implications: Impossibility of microhardness measurement in the external zone of the sulfonitrided layer. Practical implications: Sulfonitriding is a process of termochemical treatment used for vehicle and device parts on a large scale. Originality/value: Varied morphology of zones of the upper layers revealed by the method of scanning electron microscopy.

15

The influence of the martensite α’ phase occurring in the structure of cold rolled austenitic Cr-Ni steel on its mechanical properties

Kurc A., Kalinowska-Ozgowicz E.

Archives of Materials Science and Engineering

|

2009

|

Vol. 37, nr 1

21-28

EN

Purpose: In this paper the mechanical properties and structure of cold rolled austenitic stainless steel X5CrNi18-8 with a draft of 17%-78% were presented. Design/methodology/approach: The main methods used for these researches were the static tensile test, microhardness and metallographic observations by optical microscopy. The tested samples have also been analyzed fractographically. The amount of martensite α’ in the obtained microstructures was investigated with X-ray diffraction patterns. The scope of this study was to achieve the correlations between the mechanical and structural properties of cold rolled stainless steel. Findings: Results showed increasing the mechanical properties (Rm, Rp0.2, HV) and decreasing the plasticity (A) with the increasing degree of draft during cold rolling of investigated austenitic stainless steel. Research limitations/implications: In future examinations there is a need to broadening the methodology about the magnetic properties investigations which in the more precise way permit to define the quantity of the martensite α’ phase in the structure of steel X5CrNi18-10 and describe its morphology. Practical implications: A wide range of practical applications of austenitic X5CrNi18-8 steel sheets is warranted by both their high corrosion resistance and high plastic properties, especially in the supersaturated state. Originality/value: The analytic dependence of the yield point (Rp0.2) of the investigated steel on the draft degree in cold rolling has been confirmed.

16

The influence of the temperature of tensile test on the structure and plastic properties of copper alloy type CuCr1Zr

Ozgowicz W., Kalinowska-Ozgowicz E., Grzegorczyk B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2008

|

Vol. 29, nr 2

143-146

EN

Purpose: The purpose of this paper is to determine the influence of temperature of plastic deformation on the structure and mechanical properties of copper alloy of the type CuCr1Zr during a tensile test. Design/methodology/approach: The tensile test of the investigated alloy was realized in the temperature range of 20 ÷ 700° C with strain rate of 1.2 • 10 -3 s -1. Metallographic observations of the structure were carried out on a light microscope and the fractographic investigation of fracture on an electron scanning microscope. Findings: The mechanical properties of alloy as well as the range of occurrence of the Portevin - Le Chatelier phenomenon was determined on the basis of σ - ε curves formed by tensile tests; however the character of fracture during the break of the samples was defined on the basis of fractographic investigations. Practical implications: In result of tensile tests of copper alloy it has been found that the PLC effect occurs in temperature range of 250÷400 ° C. However, the ductility minimum temperature of the alloy equals about 550° C. Originality/value: A correlation of temperature of PLC effect was achieved with a qualitative description of the type of "teething" on the σ - ε curves, compatible with the classification quoted in literature.

17

Analiza pękania korozyjnego rur ze stali żaroodpornej ferrytycznej

Kalinowska-Ozgowicz E., Krukiewicz W.

Ochrona przed Korozją

|

2005

|

nr 6

238-243

PL

W pracy przedstawiono wyniki badań korozji rur rekuperatora ze stali ferrytycznej chromowej gatunku H25T eksploatowanej w środowisku spalin gazu ziemnego o temperaturze 850¸1100C°. Badania struktury i własności mechanicznych stali ujawniły, że atmosfera spalin gazu ziemnego i ich wysoka temperatura stanowią dogodne warunki dla przebiegu złożonych procesów korozji wodorowej i naprężeniowej badanych rur. Stwierdzono, że istotnymi czynnikami niszczenia korozyjnego rur są: procesy pełzania, wydzielanie faz międzymetalicznych oraz absorpcja wodoru.

EN

The paper presents the results of investigations on the corrosion of recuperator tubes made of ferritic chromium type H25T steel, used in a medium of natural gas combustion products with a temperature of 850¸1100°C. Investigations concerning the structure and mechanical properties of the steel have shown that the atmosphere of combustion gases and the high temperature provide suitable conditions for the complex processes of hydrogen corrosion and stress corrosion of the tested tubes. Creeping, the precipitation of intermetallic phase and the absorption of hydrogen have been found to be key factors in the corrosion of these tubes.

18

Korozja elementów chromowanych eksploatowanych w warunkach środowiska kopalnianego.

Domagała R., Kalinowska-Ozgowicz E., Krukiewicz W., Ozgowicz W.

Mechanik

|

2002

|

R. 75, nr 1

36-40

PL

Przedstawiono badania galwanicznej powłoki chromowej naniesionej na tłoczyska silników hydraulicznych eksploatowanych w warunkach korozyjnego oddziaływania środowiska wód kopalnianych. Przeanalizowano rodzaj i przyczyny uszkodzeń warstwy chromu z uwzględnieniem mikrostruktury i właściwości stali oraz jakości powierzchni podłoża stalowego, na które naniesiono powłokę, jak również wpływ środowiska korozyjnego.

EN

Testing the galvanig chromium coat deposited on the priston rods of hydraulic servos operated in mining water corrosive medium.

19

Wpływ utwardzania wydzieleniowego na strukturę i własności mechaniczne odlewniczego stopu Al-Si.

Kalinowska-Ozgowicz E., Domagała R., Krukiewicz W.

Rudy i Metale Nieżelazne

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2000

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R. 45, nr 5

292-296

PL

Przeprowadzono badania wpływu obróbki cieplnej na własności mechaniczne i strukturę stopu odlewniczego AlSi9Mg. Badania przeprowadzono na gotowych kołnierzach oraz na próbkach odlewanych. Uzyskane własności mechaniczne stopu Al-Si spełniające wymagania Dansk Standard 3002 pozwoliły na zrealizowanie kontraktu umożliwiającego produkcję eksportową do Danii.

EN

Investigations of influence of heat treatment on mechanical properties and structure of AlSi9Mg casting alloy have been carried out. Investigations have been realized on ready-made flanges and on experimental casted tensile specimens. The obtained mechanical properties of the alloy were complying with requirements of DANSK STANDARD 3002 and let realize the contract export production to Denmark.

20

Właściwości mechaniczne elementów łańcucha pociągowego taśmy montażowej.

Kalinowska-Ozgowicz E., Domagała R.

Mechanik

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2000

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R. 73, nr 1

11-14

PL

Badano właściwości mechaniczne oraz mikrostrukturę ogniw, produkowanych w Polsce, we Włoszech i w Niemczech, stanowiących element łańcucha pociągowego taśmy montażowej samochodów osobowych. Jednocześnie podjęto próbę określenia przyczyny pękania ogniwa produkcji polskiej oraz włoskiej na podstawie przeprowadzonych badań składu chemicznego i właściwości mechanicznych oraz obserwacji metalograficznych makro- i mikroskopowych.

EN

There were examined mechanical properties and the microstructure of the links produced in Poland, Italy and Germany forming a hauling chain of an assembly belt for motor cars. An attempt was made to determine the cause od cracking of Polish-made and Italian-made links on the basis of invetigations of chemical composition nad mechanical properties and also macro- and microskopic metallographic examinations.