1. |
Turbulence characteristics of a gas‐stirred steel bath outside the bubble plume |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 49-59
Soon‐Hyo Chung,
Klaus W. Lange†,
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摘要:
In order to understand the turbulence characteristic in melts stirred with injected gas, the relations for effective diffusion coefficient, turbulent kinetic energy and mean size of energy containing eddies were derived from the energy equation with an extended flow field for the steel bath, where strong bubble plume and surface currents are present. 67 or 23% of the energy is dissipated in the bubble plume or surface flow zone. An increasing entrainment coefficient leads to higher values of energy dissipation factor, effective diffusion coefficient and mean size of energy containing eddies, but to low degrees of turbulence. With increasing bath aspect ratio the energy dissipation factor increases, but the degree of turbulence decreases. With increasing gas flow rate and bath height the effective diffusion coefficient enlarges. Increasing bath size leads to large mean size of energy containing eddies, which reaches 17% of the bath diameter at high gas flow rates.
ISSN:0003-8962
DOI:10.1002/srin.198900962
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Modelling of submerged gas injecting lance design parameters |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 60-66
Satish C. Koria,
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摘要:
Submerged gas injecting bottom lance design parameters are modelled by applying the theory of compressible flow of gas under irreversible‐adiabatic conditions. Using the criterion of onsetting the jetting mode of injection of gas into liquid the lance design paramters such as upstream stagnation pressure and Mach number, length of the lance for a given diameter and material, gas injection rate etc. are determined. Nomograms are presented to determine the above mentioned lance design parameters. The derived parameters are discussed in relation to submerged gas injection practice.
ISSN:0003-8962
DOI:10.1002/srin.198900963
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
Kohlenstoffpräzisionsmessung mittels Sublanze – Ermittlung der Meßstrategie |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 67-73
Peter Wagenleithner,
Heinrich Aberl,
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摘要:
Die Konstruktion eines präzisen Meßgerätes zur Temperaturmessung von erstarrenden Fe–C‐Proben erforderte ein Überdenken der Auswertemethode bezüglich des Haltepunktes der Erstarrung. Die Bestimmungsgenauigkeit muß in der Größenordnung der elektrischen Temperaturmessung liegen. Eine numerische Analyse zeigt, daß im theoretischen Verlauf der gesuchte Punkt durch ein einfaches numerisches Kriterium angegeben werden kann. Für reale Messungen muß darüber hinaus eine Auswertemethode bezüglich Unterkühlung, Kurveneinbrüchen, etc. angewendet werden.Das Ergebnis weist eine statistische Genauigkeit von ca. 1,4°C bezogen auf die Sollhaltepunkttemperatur auf, was in Anbetracht der bei Thermoelementen garantierten Genauigkeit von ca. ± 1°C als sehr gut bezeichnet werden muß, enthält es doch auch alle elektrischen Fehler des Gerätes.
ISSN:0003-8962
DOI:10.1002/srin.198900964
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Incremental forging – flexible metal forming process improves utilisation of material and energy |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 74-80
Klaus Welschof,
Reiner Kopp,
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摘要:
Incremental forging is a flexible bulk‐forming process offering material and energy savings when compared to present‐day machining operations. Due to the forming load, which is low in comparison to the die forging method, and the use of simple tooling it is possible to enhance the application of conventional, integrated and computer‐controlled hand‐forging equipment by the incremental forging of components with flat basic shapes.
ISSN:0003-8962
DOI:10.1002/srin.198900965
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
Effect of molybdenum on tempered martensite embrittlement of medium carbon Si‐Mn steels |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 81-86
Ming Fu,
Yaojian Qiu,
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摘要:
This paper reports a study of the effects of molybdenum on tempered martensite embrittlement (TME) of medium carbon Si‐Mn steels. The study employed standard U‐notch impact tests, scanning electron fractography, transmission electron microscopy, Auger electron spectroscopy, and dilatometric measurements. It is shown that the addition of molybdenum to Si‐Mn steels does not eliminate TME, but molybdenum acts to decrease the ductile‐brittle transition temperature (DBTT), thus making the impact test temperature for revealing TME lowered. Furthermore, the deferring role of molybdenum on TME is observed. In the molybdenum doped steels the TME embrittlement trough is displaced to a higher tempering temperature. The embrittlement is found to be concurrent with the replacement of ∊‐carbide by cementite during tempering. In the molybdenum doped steels the displacement of TME to a higher tempering temperature is seen to be associated with the role of molybdenum retarding cementite precipitation.
ISSN:0003-8962
DOI:10.1002/srin.198900966
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
On the structure of Ni9 steel and its tensile fracture behaviour |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 87-90
Fu‐Tian Zhang,
Yun Yi Guo,
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摘要:
The tensile curves as well as original and selective dissoluted fracture surfaces have been studied. The function of the γ' phase on the mechanical properties of the steel has been investigated. The fracturing process consists of: formation of dimples – formation of splits in dimples – the splits in dimples join each other to form secondary cracks – formation of inner lips and tiny dimple regions. The morphology of fracture looks like ridges and peaks. It is considered that the column boundaries in ingots may split easily; this causes bedding fracture and the degradation ofZ–direction properties. The formation of bedding fracture is affected markedly by heat treatment and tensile temperature. Some ways of improving mechanical properties have been discussed.
ISSN:0003-8962
DOI:10.1002/srin.198900967
出版商:Wiley
年代:2016
数据来源: WILEY
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7. |
Microstructural hot corrosion behaviour of austenitic Fe‐29.7Mn‐8.7Al‐1.04C alloy in fused Na2SO4and Na2SO4‐NaCl mixture |
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Archiv für das Eisenhüttenwesen,
Volume 60,
Issue 2,
2016,
Page 91-94
Sie Chin Tjong,
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摘要:
A short‐time hot corrosion test was performed on the austenitic Fe‐29.7Mn‐8.7Al‐1.04C alloy in sodium sulphate at 900°C. The corrosion scales formed on the alloy investigated were studied by scanning electron microscopy and X‐ray mapping techniques. The hot‐corrosion scales morphology of the austenitic Fe‐29.7Mn‐8.7Al‐1.04C alloy were characterized by the formation of Al2S3and α‐MnS sulphides at and beneath the internal alumina scale. No fluxing of the scales was observed. The effect of the addition of sodium chloride to the fused sodium sulphate on the hot corrosion scales morphology was also investigated.
ISSN:0003-8962
DOI:10.1002/srin.198900968
出版商:Wiley
年代:2016
数据来源: WILEY
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