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Wyszukujesz frazę "austenite transformation" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Effect of Cr, Mo and Al on Structure and Selected Mechanical Properties of Austenitic Cast Iron
Autorzy:
Medyński, D.
Janus, A.
Powiązania:
https://bibliotekanauki.pl/articles/383202.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
austenitic cast iron
austenite transformation
heat treatment
cast
mechanical properties of cast
nickel equivalent
żeliwo austenityczne
zmiana właściwości
obróbka cieplna
odlew
właściwości mechaniczne odlewu
Opis:
Results of a research on influence of chromium, molybdenum and aluminium on structure and selected mechanical properties of Ni-Mn- Cu cast iron in the as-cast and heat-treated conditions are presented. All raw castings showed austenitic matrix with relatively low hardness, making the material machinable. Additions of chromium and molybdenum resulted in higher inclination to hard spots. However, a small addition of aluminium slightly limited this tendency. Heat treatment consisting in soaking the castings at 500 °C for 4 h resulted in partial transformation of austenite to acicular, carbon-supersaturated ferrite, similar to the bainitic ferrite. A degree of this transformation depended not only on the nickel equivalent value (its lower value resulted in higher transformation degree), but also on concentrations of Cr and Mo (transformation degree increased with increasing total concentration of both elements). The castings with the highest hard spots degree showed the highest hardness, while hardness increase, caused by heat treatment, was the largest in the castings with the highest austenite transformation degree. Addition of Cr and Mo resulted in lower thermodynamic stability of austenite, so it appeared a favourable solution. For this reason, the castings containing the highest total amount of Cr and Mo with an addition of 0.4% Al (to reduce hard spots tendency) showed the highest tensile strength.
Źródło:
Archives of Foundry Engineering; 2019, 4; 39-44
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Model of Bainitic Transformation in Austempered Ductile Iron
Autorzy:
Olejarczyk-Wożeńska, I.
Adrian, H.
Mrzygłód, B.
Głowacki, M.
Powiązania:
https://bibliotekanauki.pl/articles/380252.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phase transformations modelling
austenite ferrite transformation
ADI cast iron
TTT diagram
przemiany fazowe
transformacja austenityczna
żeliwo ADI
diagram TTT
Opis:
A mathematical model of austenite - bainite transformation in austempered ductile cast iron has been presented. The model is based on a model developed by Bhadeshia [1, 2] for modelling the bainitic transformation in high-silicon steels with inhibited carbide precipitation. A computer program has been developed that calculates the incubation time, the transformation time at a preset temperature, the TTT diagram and carbon content in unreacted austenite as a function of temperature. Additionally, the program has been provided with a module calculating the free energy of austenite and ferrite as well as the maximum driving force of transformation. Model validation was based on the experimental research and literature data. Experimental studies included the determination of austenite grain size, plotting the TTT diagram and analysis of the effect of heat treatment parameters on the microstructure of ductile iron. The obtained results show a relatively good compatibility between the theoretical calculations and experimental studies. Using the developed program it was possible to examine the effect of austenite grain size on the rate of transformation.
Źródło:
Archives of Foundry Engineering; 2017, 17, 4; 200-206
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Soaking Parameters on the Segregation and Corrosion Resistance of GJS-X350NiMnCu7-3-2 Ductile Iron
Autorzy:
Medyński, D.
Janus, A.
Stachowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/380330.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat treatment
austenitic ductile iron
transformation of austenite
corrosion resistance
segregation of elements
obróbka cieplna
żeliwo sferoidalne
austenit
odporność na korozję
Opis:
In this paper, the effect of changes the parameters of heat treatment on the structure and the degree of elements segregation was determined, in the context of corrosion resistance of ductile iron Ni-Mn-Cu, containing 7.2% Ni, 2.6% Mn and 2.4% Cu. In the condition after casting, castings of austenitic matrix and 160HBW hardness were obtained. The achieved castings were soaked at 450, 550 and 650°C for 4, 8 and 12 hours, then cooled down at the ambient air. In most cases, the heat treatment resulted in a change in the castings matrix, had the consequence of increasing their hardness in comparison to raw castings. Increasing the temperature and prolonging soaking time resulted in increasing the degree of transformation of austenite, while reducing the degree of elements segregation. This led to the formation of slightly bigger number of pitting due to corrosion, but not so deep and more evenly distributed in comparison to raw castings. Wherein the results of corrosion tests show that heat treatment of castings did not significantly change their corrosion resistance in comparison to raw castings, in contrast to the significant increase in mechanical properties.
Źródło:
Archives of Foundry Engineering; 2017, 17, 2; 69-74
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abrasive-wear Resistance of Austenitic Cast Iron
Autorzy:
Medyński, D.
Janus, A.
Powiązania:
https://bibliotekanauki.pl/articles/380382.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
abrasive wear
austenitic cast iron
heat treatment
nickel equivalent
transformation of austenite
zużycie ścierne
żeliwo austenityczne
obróbka cieplna
nikiel
transformacja austenitu
Opis:
A research of wear resistance of an austenitic cast iron with higher resistance to abrasive-wear and maintained corrosion resistance characteristic for Ni-Resist cast iron is presented. For the examination, structure of raw castings was first formed by proper selection of chemical composition (to make machining possible). Next, a heat treatment was applied (annealing at 550 °C for 4 hours followed by air cooling) in order to increase abrasive-wear resistance. One of the factors deciding intensity of wear appeared to be the chilling degree of castings. However, with respect to unfavourable influence of chilling on machining properties, an important factor increasing abrasive-wear resistance is transformation of austenite to acicular ferrite as a result of annealing non-chilled castings. Heat treatment of non-chilled austenitic cast iron (EquNi > 16%) resulted in much higher abrasive-wear resistance in comparison to the alloy having pearlitic matrix at ambient temperature (EquNi 5.4÷6.8%).
Źródło:
Archives of Foundry Engineering; 2018, 18, 3; 43-48
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Austenitic Stability and Strain-Induced Martensitic Transformation Behavior of Nanocrystalline FeNiCrMoC HSLA Steels
Autorzy:
Park, Jungbin
Jeon, Junhyub
Seo, Namhyuk
Kim, Gwanghun
Son, Seung Bae
Jung, Jae-Gil
Lee, Seok-Jae
Powiązania:
https://bibliotekanauki.pl/articles/2203710.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nanocrystalline
austenite stability
strain induced martensite
transformation induced plasticity
Opis:
The austenitic stability and strain-induced martensitic transformation behavior of a nanocrystalline FeNiCrMoC alloy were investigated. The alloy was fabricated by high-energy ball milling and spark plasma sintering. The phase fraction and grain size were measured using X-ray diffraction. The grain sizes of the milled powder and the sintered alloy were confirmed to be on the order of several nanometers. The variation in the austenite fraction according to compressive deformation was measured, and the austenite stability and strain-induced martensitic transformation behavior were calculated. The hardness was measured to evaluate the mechanical properties according to compression deformation, which confirmed that the hardness increased to 64.03 HRC when compressed up to 30%.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 77--80
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behaviour of steel with the metastable austenite during segmental grinding
Autorzy:
Dąbrowski, L.
Jeleńkowski, J.
Marciniak, M.
Szczęśniak, D.
Powiązania:
https://bibliotekanauki.pl/articles/132144.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
segmental grinding
temperature registration
metastable austenite
deformation martensite
phase transformation
Opis:
The methods of the grinding process efficiency evaluation have been presented in this paper basing upon the temperature in the workpiece tool contact area. The technique of determining this temperature has also been given as a combination of analytical and experimental process. These are especially useful by properties and phase transformation investigations in the metastable austenite steels.
Źródło:
Advanced Technologies in Mechanics; 2014, 1, no. 1 (1); 32-40
2392-0327
Pojawia się w:
Advanced Technologies in Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Carbon Content on Austenite Stability and Strain-induced Transformation of Nanocrystalline FeNiC Alloy by Spark Plasma Sintering
Autorzy:
Oh, Seung-Jin
Kim, Byoung-Cheol
Suh, Man-Chul
Shon, In-Jin
Lee, Seok-Jae
Powiązania:
https://bibliotekanauki.pl/articles/355534.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FeNiC alloy
austenite stability
strain-induced transformation
spark plasma sintering
Opis:
The effects of carbon content on the austenite stability and strain-induced transformation of nanocrystalline Fe-11%Ni alloys were investigated using X-ray analysis and mechanical tests. The nanocrystalline FeNiC alloy samples were rapidly fabricated using spark plasma sintering because of the extremely short densification time, which not only helped attain the theoretical density value but also prevented grain growth. The increased austenite stability resulted from nanosized crystallites in the sintered alloys. Increasing compressive deformation increased the volume fraction of strain-induced martensite from austenite decomposition. The kinetics of the strain-induced martensite formation were evaluated using an empirical equation considering the austenite stability factor. As the carbon content increased, the austenite stability was enhanced, contributing to not only a higher volume fraction of austenite after sintering, but also to the suppression of its strain-induced martensite transformation.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 3; 863-867
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interaction of nitrogen atoms in expanded austenite formed in pure iron by intense nitrogen plasma pulses
Autorzy:
Piekoszewski, J.
Sartowska, B.
Waliś, L.
Werner, Z.
Kopcewicz, M.
Prokert, F.
Stanisławski, J.
Kalinowska, J.
Szymczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/147989.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
alfa-to-gamma phase transformation in iron
expanded austenite
intense nitrogen plasma pulses
Opis:
The paper presents the results of experiments on modification of pure iron by high-intensity nitrogen pulsed-plasma treatment. The duration of nitrogen plasma pulses is approximately 1 mi s, and the energy density amounts to about 5 J/cm2. Such pulses are capable to melt the surface layer of the substrate (1- 2 mi m) and to introduce a significant concentration of nitrogen into the molten layer. Nuclear reaction analysis (NRA), X-ray diffraction (XRD) and conversion electron Mössbauer spectroscopy (CEMS) were used for characterisation of the treated samples. The main results of the data analysis are as follows: it has been stated that such treatment leads to gradual transformation of initial alfa-phase into austenitic gamma structure in which expanded austenite gammaN is present. Treatment with 20 pulses results in almost complete transformation and introduces a retained dose of nitrogen estimated as 5.5 × 1017 N/cm2. The susceptibility for expansion of the lattice transformed to austenite in this way is smaller than in the case when the steel subjected to conventional nitriding is originally of austenite type. The analysis of the ratio of alfa to gammaN as a function of the nitrogen content provides a firm evidence that strong repulsion forces act between the first and the second nearest-neighbour nitrogen atoms in the fcc austenitic structure formed as a result of nitriding of pure iron by intense nitrogen plasma pulses.
Źródło:
Nukleonika; 2004, 49, 2; 57-60
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation of Medium Carbon TRIP Steel Microstructure During Annealing in the Intercritical Temperature Range
Kształtowanie mikrostruktury średniowęglowej stali typu TRIP podczas wyżarzania w zakresie temperatur krytycznych
Autorzy:
Kokosza, A.
Pacyna, J.
Powiązania:
https://bibliotekanauki.pl/articles/354719.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phase transformation
critical temperatures
retained austenite
TRIP steels
przemiany fazowe
temperatury krytyczne
austenit szczątkowy
stale TRIP
Opis:
The paper presents the results of research conducted on austenite formation in the microstructure of 41MnSi6-5 TRIP steel during annealing in the intercritical temperature range. The influence of the annealing temperature on the volume fraction of retained austenite in the microstructure of the investigated steel after water quenching was also determined. Based on the results of a dilatometric analysis and metallographic investigation it was noted that the pearlite-to-austenite transformation does not occur at a constant temperature, which is referred to as Ac1, but rather within some, possible to determine, temperature range which is bounded by the values Ac1s and Ac1f. Moreover, through X-ray analysis, it was stated that the largest amount of retained austenite remained in the samples which were annealed at the lowest temperatures in the Ac1s and Ac1f range prior to quenching. Increasing the annealing temperature to a two-phase a+g (ferrite + austenite) range, resulted in a decrease of the volume fraction of retained austenite. It was also found that during annealing in Ac1s and Ac1f temperature range, austenite is also formed from ferrite simultaneously. This could be the reason for the decrease the carbon content in the formed austenite and consequently the decrease in the volume fraction of retained austenite in the microstructure of the investigated steel, which was quenched after having reached temperatures higher than Ac1s + 30°C.
W pracy przedstawiono wyniki badań nad tworzeniem się austenitu w mikrostrukturze stali 41MnSi6-5 typu TRIP podczas wyżarzania w zakresie temperatur krytycznych. Określono również wpływ temperatury takiego wyżarzania na udział objętościowy austenitu szczątkowego, jaki pozostaje w mikrostrukturze badanej stali po zahartowaniu od takich temperatur. Na podstawie wyników analizy dylatometrycznej oraz badań metalograficznych stwierdzono, że w badanej stali przemiana perlit – austenit nie przebiega w stałej temperaturze określanej jako Ac1s lecz w pewnym, możliwym do określenia jej zakresie, którego granice wyznaczają wartości Ac1s and Ac1f. Ponadto, metodą analizy rentgenowskiej wykazano, że najwięcej austenitu szczątkowego pozostawało w tych próbkach z badanej stali, które przed zahartowaniem były wyżarzane przy najniższej temperaturze z zakresu Ac1s and Ac1f. Podwyższenie temperatury wyżarzania do zakresu dwufazowego a+g (ferryt+ austenit) było przyczyną zmniejszenia udziału austenitu szczątkowego. Stwierdzono, że podczas wyżarzania w zakresie temperatur Ac1s and Ac1f tworzy się również z ferrytu. Mogło to być przyczyną zmniejszenia zawartości węgla w tworzącym się austenicie i spadku udziału austenitu szczątkowego w mikrostrukturze badanej stali po jej zahartowaniu od temperatur wyższych od Ac1s + 30°C.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 1017-1022
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of hot deformation and isothermal holding temperature on retained austenite characteristics in 3-5% Mn multiphase steels
Autorzy:
Opiela, Marek
Grajcar, Adam
Pakieła, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2204525.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hot deformation
bainitic transformation
retained austenite
Mn effect
multiphase structure
manganese effect
austenit szczątkowy
struktura wielofazowa
efekt Mn
odkształacanie wysokotemperaturowe
przemiana bainityczna
Opis:
The paper presents stress-strain characteristics recorded during the four-step compression of axisymmetric samples in the Gleeble thermomechanical simulator. The hot deformability of three steels with Mn concentrations of 3%, 4% and 5% was compared. The analysis of the influence of plastic deformation and Mn content on the microstructure of alloys, and in particular, on a fraction and morphological features of the retained austenite, was performed. The proportion of the retained austenite was determined by the X-ray diffraction method. It was found that the content of Mn in the range from 3% to 5% does not have a significant impact on the high-temperature resistance of the steel during compression tests, but it has a significant influence on the microstructure of the steel and the fraction of retained austenite. The optimal conditions for maximizing the proportion of retained austenite were obtained at the temperature of 400 °C, and it decreased with increasing Mn concentration in the steel. It has been shown that it is related to the redistribution of carbon from the remaining austenite fraction with an increase in the manganese content. The mechanical properties were determined on the basis of hardness measurements.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 2; art. no. e144611
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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