Wyniki wyszukiwania - Biblioteka Nauki

1

Weld defects and precipitates of deposited metal in 9Ni steel welded joint

100%

Ma C. , Qi Y. , Zhang Y. , Wu Z. , Zhang X.

Materials Science Poland

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2022

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tom Vol. 40, No. 1

25--48

EN

Three kinds of electrode with different niobium contents were developed and compared, and the influence of alloying elements on microstructure and mechanical properties was summarized. Strong carbide elements such as Nb, Ti, and V were added to form stable precipitates. The existence of intercrystalline precipitates leads to pinning and zigzag of grain boundaries, hinders the propagation of cracks, and enhances the low temperature strength and impact toughness of the materials. The No. 1 and No. 2 ENiCrMo-6 electrodes meet the requirements of LNG (liquified natural gas) equipment. The tensile strength of the deposited metal reaches 687 MPa, while the average impact energy at −196°C is 131 J. Owing to fluctuations in the stress concentration at the junction of grain boundaries, cracks may easily form. MC carbide can retard the crack propagation. With the increase of Nb and other alloys, the strength and hardness increase gradually, but the plasticity and toughness are retarded to a certain extent.

2

Prognostic Models of Panicum virgatum L. Using Artificial Neural Networks

75%

Lopushniak V. I. , Hrytsuliak H. M. , Bykin A. V. , Bordyuzha N. P. , Semenko L. O. , Polutrenko M. S. , Kotsyubynska Y. Z.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 11

62--71

EN

The article shows the possibility of using modern methods of artificial intelligence to calculate the yield of biomass of crops according to the given set input data (fertilizer doses, agrochemical parameters of the soil, productivity). The study reflects the results of testing a model of a computer program of an artificial neural network, which allowed forecasting the yield of Panicum virgatum L. (Switchgrass) depending on the joint application of fertilizers mineral and precipitate. On the basis of the calculations, the obtained model of productivity of vegetative mass of switchgrass shows a high level of forecasting efficiency (up to 97%). According to the results of experimental studies, the use of sewage sludge at a doses of 20–40 t/ha provides a dry biomass yield of Panicum virgatum L. (Switchgrass) in the range of 13.1–20.3 t/ha, which is 3.4–7.2 t/ha more than in the option without fertilizer.

3

Effect of Sulfur and Acid Soluble Aluminum Content on Precipitate and Microstructure of Grain-Oriented Silicon Steel

75%

Zhou B. , Zhu C. , Li G. , Luo Z. , Gao Y. , Bao S. , Schneider J.

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tom 63

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nr 4

4

Formowanie przeciwzużyciowych heterogenicznych warstw powierzchniowych na elementy ślizgowych węzłów tarcia

75%

Madej M. , Ozimina D.

Problemy Eksploatacji

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2005

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tom nr 1

35--42

PL

W artykule przedstawiono metodykę wytwarzania kompozytowych warstw powierzchniowych o osnowie metalowej z wtrąceniami drobnodyspersyjnej fazy ceramicznej. Warstwy kompozytowe Ni-P-Al2O3 osadzano sposobem bezprądowym na stali 45. Analiza właściwości otrzymanych warstw wskazuje, że obecność drobnodyspersyjnego Al2O3 wpływa na właściwości wytwarzanych warstw powierzchniowych.

EN

The article presents methods of composite surface layers formation with metal matrix and microdispersion ceramic phase inclusions. Composite layers were deposited current less on the steel 45. The layers analysis presents that the presence of microdispersion Al2O3 has influenced on the characteristics of formed surface layers.

5

Effect of Sulfur and Acid Soluble Aluminum Content on Precipitate and Microstructure of Grain-Oriented Silicon Steel

75%

Zhou B. , Zhu C. , Li G. , Luo Z. , Gao Y. , Bao S. , Schneider J.

Archives of Metallurgy and Materials

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2018

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tom Vol. 63, iss. 4

1701--1708

EN

The combined effect of sulfur (S) and acid soluble aluminum (Als ) content on precipitates and microstructures in grain-oriented silicon steel were investigated. The results show that there are dominant AlN and a little amount of MnS-AlN composite in annealed hot-rolled band, and the amount of precipitates increases distinctly with increasing Als content, while S content plays a negligible role. The inhibitors that precipitate during hot band annealing can restrain the grain growth during hot band annealing and primary annealing, and the smaller grains of annealed hot-rolled band can contribute to the formation of {111} <112> texture during primary annealing. Lower S content is conducive to the formation of {111} <112> texture during primary annealing by promoting the formation of Goss texture during hot rolling.

6

Osady na powierzchniach grzewczych kotłów opalanych węglem

63%

Tomeczek J. , Palugniok H. , Ochman J.

Gospodarka Paliwami i Energią

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2004

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tom nr 9-10

28-33

PL

Przedstawiono mechanizm tworzenia osadów na powierzchniach grzewczych pyłowych kotłów węglowych uzależniający szybkość wzrostu osadów od rodzaju spalanego węgla, pozwalający prognozować kształt i wielkość osadów w kotle. Wykazano, że osady nie są tworzone równomiernie, lecz w wyraźnie identyfikowanych obszarach przemieszczających się wzdłuż kotła w trakcie jego eksploatacji.

EN

A mechanism of deposits formation on heating surfaces of pulverised coal boilers is presented which relates the rate of deposits growth to the burned coal type, enabling the prediction of the deposits shape and size. It has been shown that deposits are not formed uniformly on the heating surfaces but on clearly identified regions shifting along the boiler with its operational time.

7

Analiza morfologii wydzieleń rdzeniowych otrzymywanych w stopie 2024 po nowoczesnych obróbkach cieplno-plastycznych

63%

Radziszewska H. , Kaczmarek Ł. , Adamczyk-Cieślak B. , Mizera J. , Brodova I. G. , Petrova A. N.

Inżynieria Materiałowa

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2013

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tom Vol. 34, nr 6

806--809

PL

W pracy przedstawiono przegląd literatury i wyniki badań własnych dotyczące mikrostruktury stopu aluminium 2024, składu chemicznego, morfologii wydzieleń faz umacniających otrzymywanych po obróbce cieplnej T6I6 oraz plastycznej HPT. Zaprezentowano wyniki badań potwierdzające możliwość otrzymania wśród innych faz umacniających także wydzieleń o budowie rdzeniowej. Zastosowanie obróbki T6I6 – zabiegu przerwania procesu wydzieleniowego w czasie pierwotnego starzenia przez schłodzenie do temperatury pokojowej oraz zoptymalizowanie parametrów wtórnego wysokotemperaturowego starzenia dało warunki do powstania wydzieleń rdzeniowych. Wydzielenia te wpływają na uzyskanie relatywnie wysokich własności wytrzymałościowych bez pogorszenia plastyczności materiału, co wpływa na zmniejszenie zagrożenia powstawania kruchych pęknięć podczas procesu produkcyjnego. Mikroanaliza chemiczna EDS wydzieleń rdzeniowych wykazała, że są to fazy o ściśle nieokreślonym składzie stechiometrycznym (powłoka i rdzeń) oraz znacząco różnym stężeniu atomów Cu, Mn i Fe, które można zapisać Alx(CuyFev) i Alx(CuzMnw) odpowiednio dla fazy zewnętrznej i rdzenia. Ponadto zaobserwowano znacząco różne stężenie atomów Cu, Mn i Fe odpowiednio w fazie zewnętrznej i w rdzeniu, natomiast stabilne stężenie atomów Si i Mg. Wyniki pozwalają domniemać, że fazy są pochodnymi związków typu Al6X lub Al4X. Przedstawiono także zależność zmian morfologii wydzieleń podczas obróbki plastycznej HPT dla stopu po obróbce T6I6. W procesie wielostopniowego starzenia otrzymano komercyjny stop aluminium (2024T6I6) umocniony dzięki wydzieleniom o budowie rdzeniowej, które są energetycznie stabilne i nie ulegają ścięciu podczas obróbki plastycznej. Stop ten może być stosowany do wykonywania detali w procesach technologicznych opartych na obróbce plastycznej na zimno.

EN

The overview of the literature and the results of own research on the microstructure of 2024 aluminium alloy, its chemical composition and the morphology of the precipitates of the strengthening phases received by T6I6 thermo treatment and HPT plastic treatment are presented in the paper. The results of the research that confirm the possibility of obtaining, among other strengthening phases, the ones precipitates of the core/shell structure are depicted as well. The giving of T6I6 treatment, the act of interrupting the precipitate process during the primary aging by cooling down until the room temperature and optimizing the factors of the secondary high-temperature aging created the conditions for the emergence of core/shell precipitates that affect the obtaining of relatively high strength features while maintaining plastic features, thus reducing the risk of formation of brittle cracks during the manufacturing process. Based on the results of chemical microanalysis EDS of the composition of precipitate, the fixed stoichiometric ratio of Mn:Cu:Fe atoms in outer phase and in the core is presented, which made it possible to establish that these phases are derivatives of Al6X or Al4X compounds. These can be written down as Alx(CuyFev) and Alx(CuzMnw) with significantly different concentration of Cu, Mn and Fe atoms and stable concentration of Si and Mg atoms, respectively in outer phase and in the core. The dependence of the changes of the morphology of precipitate during the HPT plastic treatment is presented. In the process of multi-stage aging the commercial aluminium alloy (2024T6I6) was received. It was strengthened by the core-shell precipitates which are energetically stable and are not chopped during the plastic treatment. This alloy may be used in production of elements in technological processes based on cool plastic treatment.

8

Analysis of the microstructure and properties of T92 steel after long-term service

63%

Merda A. , Klimaszewska K. , Sroka M. , Wieczorek P. , Golański G.

Archives of Materials Science and Engineering

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2018

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tom Vol. 93, nr 1

5--11

EN

Purpose: The purpose of the investigation was to determine and analyse the changes in the microstructure and mechanical properties of the T92 steel after service in creep conditions of the following parameters: temperature – 575°C, pressure – 28.2 MPa, service time – 41914 hrs. Design/methodology/approach: The tests were performed on the test samples taken from a pipe section of a steam superheater after long-term service. The range of the investigations included: microstructural investigation – the optical and SEM microscopy, the analysis of precipitation – carbide isolates, the investigation of mechanical properties: the Vickers hardness measurement, the impact test and static tensile test. Findings: The performed tests showed a slight degree of exhaustion of the structure of the analysed T92 steel. The relatively small changes in the microstructure of the examined steel were reflected in the still retained high mechanical properties. Research limitations/implications: he analysis of the microstructure of the examined steel using SEM was performed to determine the influence of the service on the processes of changes in the precipitate morphology. Practical implications: The metal science investigation of the sections taken from the elements of the power installations after long-term service is one of the basic elements of building the data base of materials and their joints used in the power industry. The results obtained from the performed research constitute a building block for the degradation characteristics of the microstructure and mechanical properties of martensitic steels of the 9-12%Cr type. Originality/value: The results of investigation and analysis of the metallographic and mechanical properties of martensitic T92 steel after long-term service are presented.

9

Comparison of temperature dependence of internal damping of selected magnesium alloys

63%

Oršulová T. , Palček P. , Uhríčik M.

Production Engineering Archives

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2019

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tom Vol. 22

7--10

EN

The research is focused on the study of the temperature dependence of the internal damping of selected magnesium alloys with different contents of aluminium - AZ31 and AZ61. These alloys are currently widely used in various types of industry, mainly in the automotive industry. It belongs to a group of materials called HIDAMETS because they have excellent damping properties. The internal damping of the samples was measured on a unique ultrasonic device constructed at Žilina University in Žilina. Specimens were measured at baseline in the temperature range from 25 °C to 400 °C. Changes in internal damping caused by varying aluminium contents in investigated alloys were noted. As the aluminium content increases, maximum internal damping is achieved due to the formation, growth and subsequent dissolution of the continuous precipitate in the microstructure.

10

Structure and mechanical properties of dual-phase steel following heat treatment simulations reproducing a continuous annealing line

63%

Radwanski K. , Kuziak R. , Rozmus R.

Archives of Civil and Mechanical Engineering

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2019

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tom Vol. 19, no. 2

453--468

EN

In the presented investigation, cold-rolled sheets of a selected dual-phase (DP) steel were heat-treated according to varying thermal profiles, thus reproducing continuous annealing process. Initially the samples were soaked at 780 and 810 °C for 0–60 s followed by water cooling. Next, samples were preliminary treated by applying the same conditions, however after water cooling these compositions were subject to tempering at 230, 380 and 460 °C for both 60 and 240 s. The characterization of the effect of heat-treatment parameters on the mechanical properties and structure is the main objective of this investigation. Mechanical properties of the samples after applied thermal profiles were in line with those requirements imposed on the commercial sheets of DP steels. The obtained results of the investigation showed that tempering deteriorates the Yield Ratio, defined as Rp0.2/Rm. This was caused by the martensite decomposition combined with carbide precipitation processes. Transmission electron microscopy observations revealed precipitated carbides, Fe3C in martensitic and M7C3 in ferritic areas. The quantitative results of the structural investigation were then applied to predict the Rp0.2 and Rm using the Perlade model. The results indicate that discrepancies between the measured tensile tests and calculated Rp0.2 and Rm do not exceed 10%.

11

Wpływ wydzieleń fazy gamma' na zjawisko Portevina-LeChateliera podczas odkształcania superstopu niklu EI-867.

51%

Poznańska A. , Sieniawski J. , Kubiak K.

Archiwum Nauki o Materiałach

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2000

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tom T. 21, nr 3-4

189-198

PL

W pracy przedstawiono badania superstopu niklu EI-867 umacnianego wydzieleniowo cząsteczkami fazy gamma', który w celu otrzymania różnych rozmiarów cząsteczek obrobiono cieplnie według czterech wariantów. Wykonano próbę statyczną rozciągania w zakresie temperatury 20-1000 stopni Celsjusza, wyznaczając wytrzymałość na rozciąganie Rm, umowną granicę plastyczności R0,2 oraz podstawowe charakterystyki zjawiska Portevina-LeChateliera (PLC): Tz - zakres temperatury występowania, epsilon c - odkształcenie krytyczne początku ząbkowania, delta sigma a - amplitudę naprężenia ząbków. Stwierdzono wyraźną zależność cech charakteryzujących zjawisko PLC od rozmiarów cząsteczek fazy gamma' i od umocnienia stopu przez cząsteczki fazy gamma'.

EN

The paper presents results of studies on nickel-base superalloy EI-867 precipitation strengthened with gamma' phase particles. The alloy was heat treated according to four schemes giving various sizes of gamma' phase particles. Static tensile tests were performed in the temperature range of 20-1000 degrees centigrade. Determining tensile strength Rm, 0,2 proof stress R0,2 and basic characteristics of the Portevin-LeChatelier effect (PLC) i.e. Tz - temperature range of jerky flow, epsilon c - critical strain of jerky flow onset, delta sigma a - stress serrations amplitude. It was found that the size of gamma' phase particles and intensity of alloy strengthening by gamma' phase particles strongly influence the characteristic features of the PLC effect.

12

Właściwości produktów otrzymanych w wyniku przetwarzania odpadu pofermentacyjnego z biogazowi rolniczej

51%

Makara A. , Kowalski Z. , Marszałek M.

Przemysł Chemiczny

|

2016

|

tom T. 95, nr 10

1884--1887

PL

Zbadano fizykochemiczne właściwości produktów otrzymanych w wyniku przetwarzania odpadu pofermentacyjnego pochodzącego z bio- gazowni rolniczej. Odpad pofermentacyjny prze- twarzano wg opracowanej metody umożliwiającej skuteczne rozdzielenie zawiesiny na frakcję stałą i ciekłą. Frakcja ciekła wykazywała żółte zabarwienie, mętność w zakresie 123-162 NTU, wartość chemicznego zapotrzebowania tlenu wynosiła ok. 2000 mg/dm³, a zawartość azotu Kjeldahla ok. 900 mg/dm³. W składzie fazowym osadu stwierdzono głównie obecność hydroksyapatytu. Zawartość fosforu i potasu w osadzie wynosiła odpowiednio ok. 8 i 0,6%.

EN

Biomass digestate was treated with aq. solns. of H₃PO₄ and H₂SO₄ as well as aq. slurry of Ca(OH)₂. The superphosphate was also added. The resulting product was sepd. into a liq. fraction and a solid by pressure filtration. The liq. fraction showed yellow color, turbidity in range of 123-162 NTU, and COD 2000 mg/L. The N content was approx. 900 mg/L. The solid phase contained hydroxyapatite (8% of P and 0.6% of K).

13

Wysuszone osady ściekowe województwa śląskiego : stałe paliwo wtórne

51%

Niesler J. , Nadziakiewicz J.

Piece Przemysłowe & Kotły

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2015

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tom Nr 3

17--22

PL

W artykule opisano obowiązujący system klasyfikacji stałych paliw wtórnych. Poddano analizie osady ściekowe wytworzone w okresie dwóch lat przez 59 oczyszczalni województwa śląskiego i przedstawiono wpływ ich suszenia na ocenę wartości użytkowej osadów jako paliwa zgodnie z przedstawionym w normie PN-EN 15359:2012 systemem klasyfikacji. Zwrócono uwagę na fakt że, w niniejszej normie wskaźnikiem środowiskowym (emisyjnym) nie powinna być zawartość Hg wyrażona w [mg/MJ], a zawartość Hg wyrażona w [mg/Mg] lub w [ppm], ponieważ wartość opałowa podlega już jej ocenie, a zawartość Hg wyrażona w [mg/Mg] lub [ppm] uwzględnia poprawnie wpływ wilgotności paliwa na emisję, na co przedstawiono dowód.

EN

The article describes the current classification system of solid recovered fuels. The analysis includes sewage sludge generated by 59 Silesian treatment plants within two years and the presentation of the influence of the sludge drying process on the assessment of the use value of the sludge assumed as fuel according to the classification system presented in the standard PN-EN 15359:2002. It has been pointed out that the said standard’s environmental indicator (emission) should not constitute the Hg content expressed in [mg/ MJ], but expressed in [mg/Mg] or in [ppm], because the heat of combustion falls under its analysis and the HG content expressed in [mg/Mg] or in [ppm] properly includes the influence of the fuel’s humidity on emission, which has already been proved.

14

Effect of thermomechanical treatment on properties and structure precipitates in high strength aluminium alloys.

51%

Dutkiewicz J. , Morgiel J. , Lityńska L.

Inżynieria Materiałowa

|

1998

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tom R. XIX, nr 3

423-428

EN

The effect of thermomechanical treatment on the structure and mechanical properties of 7278A (1) and AlCuAgMg alloys (2,3) containing 6%Cu, 0.4-0.8%Ag and 0.4-0.8%Mg in wt% was investigated. The alloys were continuously cast, then extruded, cold rolled and aged at temperatures up to 165 degrees centigrade. Alloy 1 attained maximum hardness of 210 HV and UTS 700 MPa after ageing at 120 degrees centigrade for 24 h. The 75% rolling prior to ageing resulted in 230 HV. A day ageing at 120 degrees centigrade caused precipitation of the eta' phase. The rolled and aged alloys contained the equilibrium eta phase formed by nonhomogeneous nucleation what causes smaller strengthening effect. Alloy 2 attained maximum hardness of 150 HV after ageing at 165 degrees centigrade for 24 h, i.e. significantly lower than the 7278A alloy. The deformation by rolling in the as quenched state increased UTS up to about 400 MPa after 75% rolling i.e. 200 MPa less than in the case of the 7278 alloy. Alloy 3 of higher Ag and Mg content reached maximum hardness of 190 HV during ageing, and 230 HV after deformation and ageing i.e. close to the 7000 alloys. TEM studies allowed to identify the main hardening phases as Theta' and Omega, the latter resulting from presence of Ag and forming platelets lying on {111} matrix planes. The deformation promoted the Theta' phase formation.