1. |
Monitoring two‐phase mixing in a 1:7 scale model reactor during combined blowing processes |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 291-300
Rinnert Siemssen,
Klaus W. Lange (†),
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摘要:
In the field of metallurgical processes there has been little knowledge on slag‐mixing and the phenomena accompanying mixing so far, when a model slag influences the mixing process in the model bath. However, these phenomena should be detected, investigated and taken into consideration for further process optimization and modelling. Thus, the present paper is a contribution to the investigation of slag‐mixing in a 1:7 scale model reactor during combined blowing processes. First of all the present paper deals with experimental results, gained in a 1:7 scale model reactor, and it is concerned with dispersion processes. Then global mixing times in the model bath are considered. Furthermore, as method to evaluate local slag‐mixing times these were calculated using the intensity of segregation, a method usually used in chemical engineering and turbulence theory. Special regard is given to the influence of different blowing modes on dispersion degrees, mixing ratios and to a possible explanation of the occurrence of turbulent zones in the model slag.
ISSN:0003-8962
DOI:10.1002/srin.198901656
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Measurements on the local properties of the vertical heterogeneous buoyant plume |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 301-307
Satish C. Koria,
Sarbjit Singh,
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摘要:
An electroresistivity sensor probe is developed and used to measure gas fraction and bubble frequency in turbulent air/water plume formed during upward injection of gas. The measured gas fraction and bubble frequency profiles at different axial positions in the plume are found to exhibit good similarity. It is found that the axial gas fraction decreases and plume radius increases with increase in axial distance. From the values of axial gas fraction and plume half radius, turbulent viscosity of liquid in bubble plume is determined and is found to be several times higher than the molecular viscosity.
ISSN:0003-8962
DOI:10.1002/srin.198901657
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
Optimierung der Durchmischung in diskontinuierlichen und kontinuierlichen Aufblasreaktoren für die Entkohlung von Fe–C‐Schmelzen mit Sauerstoff |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 308-313
Ekkehard Wulfmeier,
Klaus Koch,
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摘要:
Bei der schlackenfreien bzw. schlackenarmen Brennfleckentkohlung werden in der betrieblichen Praxis nicht die kinetisch möglichen hohen Entkohlungsgeschwindigkeiten erreicht. Modellversuche bei diskontinuierlicher und kontinuierlicher Betriebsweise sollen Möglichkeiten aufzeigen, wie durch richtige Wahl des Reaktortyps und der Prozeßparameter das Strömungsund Durchmischungsprofil im Reaktorbad zu optimieren ist. Wasser‐Luft‐Modellversuche wurden in den Reaktortypen Einzelrührkessel, Rührkesselkaskade und Rinne durchgeführt. Zur Unterstützung der schlackenfreien Entkohlungsreaktion muß der Strömungsverlauf innerhalb des Reaktorbades bei kontinuierlicher Arbeitsweise in verschiedenen Richtungen unterschiedlichen Anforderungen genügen. In Längsrichtung sind geringe Rückvermischungen mit einheitlichen Aufenthaltszeiten zur Erstellung eines homogenen Frischproduktes gefordert. In den Reaktorquerrichtungen soll die Durchmischung demgegenüber hoch sein, um einen hohen Stofftransport an den Reaktionsort Brennfleck zu sichern.Das Ziel gleichmäßiger Verweilzeiten in axialer Richtung wird am besten durch den Reaktortyp „Kaskade“ mit einer Stufenzahl von mindestensn= 8 erreicht, in dem der Strömungsverlauf aufgrund der baulichen Form bereits vorgeprägt ist. Ein Optimum der Blasbedingungen liegt bei Blasraten knapp unterhalb einer Tropfenversprühung. Die Vorgänge in Kaskadenquerrichtung und die weitere Verbesserung eines Rinnenreaktors, der technisch einfacher und kostengünstiger zu gestalten wäre, bleiben Gegenstand weiterer Untersuchungen.
ISSN:0003-8962
DOI:10.1002/srin.198901658
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Theoretical analysis of plastic deformation of non‐homogeneous materials |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 314-319
Zbigniew Malinowski,
Robert Szyndler,
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摘要:
This paper is concerned with the solution of the problem of non‐homogeneous material deformation. It has been assumed that the deformed material is composed of a finite number of rigid‐plastic bodies with strain hardening.For description of the shape and plastic properties of such a material isoparametric four‐node elements have been applied, whereas for velocity field approximation Hermitian shape functions of third degree have been used as well as bicubic rectangular elements generated before every computation step after transformation of material longitudinal section into square. The plastic deformation of bimetallic specimens was analysed consisting of a core tightly fastened in a ring made of material of lower yield stress and subjected to free upsetting. Minimum non‐uniformity of deformation was obtained for specimens of a core radius equal to about 0.6 of the specimen's initial radius.
ISSN:0003-8962
DOI:10.1002/srin.198901659
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
Scavenging additions of boron in low C – low Al steels |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 320-328
Pierre Messien,
Vincent Leroy,
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摘要:
Scavenging of boron on nitrogen is almost complete on the hot strip for B/N ≥ 0.7–0.8. Nitrogen ageing does not appear and low coiling can be used (650°C). BN precipitates as polycrystalline aggregates (spherulites) and in association with other precipitates or inclusions. Solute carbon is somewhat reduced in B steels coiled at 650°C but a more important reduction is achieved when coiling at 750°C due to an Fe23(C, B)6precipitation in the optimum range 1.0 ≤ B/N ≤ 1.5. Yield stresses (YS) lower than 190 MPa are obtained for optimized compositions of low Al‐B steels coiled at 650°C and continuously annealed (825°C – 60 s – cooling rate: 50°C/s). Further softening is achieved when coiling at 750°C (YS50 MPa). No ageing is observed in B steels coiled at 750°C of which the bake hardening is reduced (25 MPa). Deep drawability of B steels is improved at reduced C, Al, Mn contents and at higher coiling temperatures; a detrimental effect of a B excess is observed. Low nitrogen contents and reduced Al additions are needed to reach best B steel properties.
ISSN:0003-8962
DOI:10.1002/srin.198901660
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
ECSC announcements |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 328-328
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ISSN:0003-8962
DOI:10.1002/srin.198901661
出版商:Wiley
年代:2016
数据来源: WILEY
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7. |
Effect of weld heat input and creep strain on the elevated temperature and crack growth properties of austenitic steels |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 329-335
Helmut Kanbach,
Klaus Detert,
Armin Rukwied,
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摘要:
A potential material class for use at 600°C and more, e.g. for steam turbines with improved thermal efficiency, are austenitic steels. Using these steels with welded joints, it is to be considered that, by superposition of weld residual stresses and service stresses, extensive creep strains – and in the worst case crack formation – can occur locally. To assess the influence of these effects on service behaviour, different material states of CrNi‐steels and Incoloy 800 were investigated with respect to strength, ductility and, especially, to crack and creep crack growth in the temperature range around 600°C. It is shown that creep embrittlement, not microstructural changes as effected by weld heat input, causes heat affected zone (HAZ)‐reheat cracking. Creep embrittlement can be avoided by special design and fabrication rules.
ISSN:0003-8962
DOI:10.1002/srin.198901662
出版商:Wiley
年代:2016
数据来源: WILEY
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8. |
ECSC announcements |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 335-335
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ISSN:0003-8962
DOI:10.1002/srin.198901663
出版商:Wiley
年代:2016
数据来源: WILEY
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9. |
News from the Max‐Planck‐Institut für Eisenforschung GmbH |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 7,
2016,
Page 336-336
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ISSN:0003-8962
DOI:10.1002/srin.198901664
出版商:Wiley
年代:2016
数据来源: WILEY
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