1. |
Development of a numerical model simulating the desulphurisation of liquid steel |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 309-314
Markus Reifferscheid,
Wolfgang Pluschkell,
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摘要:
A comprehensive numerical model is developed simulating the batch process of liquid steel desulphurisation. Special emphasis is placed on the exact figuring of real process engineering conditions. The model includes time dependent intensive parameters such as the aluminium content and the oxygen content of the liquid steel as well as the temporal course of the CaO‐, CaS, Al2O3‐component activities in the refining top slag. Mass transfer coefficients are derived from practical experience.The computations prove the outstanding influence of the stirring intensity on the rate of the refining reaction. Its progress is delayed by the dissolution of the lime charge at the beginning of the stirring treatment. The simulation model can also be applied to optimize the desulphurisation process with respect to stirring time, state of deoxidation and amount of refining slag.
ISSN:0003-8962
DOI:10.1002/srin.199401076
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Measurements of bubble plume behaviour and flow velocity in gas stirred liquid Wood's metal with an eccentric nozzle position |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 315-319
Yongkun Xie,
Franz Oeters,
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摘要:
The distribution of gas fraction and the flow field of gas‐stirred liquid metal in steel ladles at eccentric injection of the stirring gas through the bottom of the vessel were measured in melts of 437 kg liquid Wood's metal. The melts had a temperature of 100°C. The bath height was 37 cm and the vessel diameter 40 cm. The blowing nozzle was positioned at half of the vessel radius. Gas flow rates were between 100 and 800 cm3(STP)/s. The gas fractions were measured by electrical resistance probes. The flow velocity of the liquid metal was determined by magnet‐probes. The gas fraction and the velocity distribution in the plume were found to have a Gaussian shape. The cross‐section of the plume is ellipsoid, as the plume width in the direction of the radius was a little smaller than the width in the direction perpendicular to it. Moreover the plume was inclined to the wall. The results which were found for the plume are mathematically described. The flow field at eccentric gas‐stirring consists of one great loop, which fills almost the entire vessel. This is contrary to centric blowing, where for aspect ratios of the ladle in the order of 1, a toroid is formed in the upper and a dead zone exists in the lower part of the vessel. The consequences of this behaviour, especially for mixing in the melt, are discussed.
ISSN:0003-8962
DOI:10.1002/srin.199401077
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
CaO‐activities and structure of CaO‐Al2O3‐melts |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 320-321
Norbert Nowack,
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摘要:
By using structure chemical results taken from IR‐spectroscopic analyses, the CaO‐activity was calculated. In liquid state the aluminates dissociate into Ca2+and into the complexesand. By application of the Temkin‐theory the CaO‐acitivity can be calculated and compared with measured values.
ISSN:0003-8962
DOI:10.1002/srin.199401078
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Numerical results of temperature distribution and solidification behaviour during spray forming |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 322-325
Udo Fritsching,
Hong Zhang,
Klaus Bauckhage,
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摘要:
Based on a grid transformation method, the temperature and solidification behaviour in the substrate and deposit for the spray forming process of metals has been simulated. Numerical results will be compared with experimental data of temperature measurements in the deposit and substrate. Some limitations of this model will be outlined.
ISSN:0003-8962
DOI:10.1002/srin.199401079
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
Development of new methods for determining the formability and flow stress of materials based on intermetallic compounds |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 326-330
Oskar Pawelski,
Karl Edgar Hagedorn,
René Hop,
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摘要:
The following test methods were developed: the small‐cup tension test, the mantle compression test, and the ball compression test. They are applicable up to very high temperatures. The experiments with model materials and NiAl‐ and TiAl‐compounds were combined with plastomechanical calculations by the method of upper bound of deformation power and by the method of finite elements.
ISSN:0003-8962
DOI:10.1002/srin.199401080
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
Solubility of nitrogen in austenitic FeCrMn alloys |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 331-337
Joachim Kunze,
Ines Rothe,
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摘要:
The equilibrium solubility of nitrogen in austenitic iron‐chromium, iron‐manganese, and iron‐chromium‐manganese alloys with mass up to 20 % Cr and 18 % Mn was measured in the temperature range 1273 to 1473 K. The following interaction parameters were obtained:(1)Describing the effect of chromium and/or manganese on the nitrogen solubility by the excess term, the present measurements correspond satisfactorily to those of Hertzmann and Jarl and of Zheng in the system Fe‐Cr‐N, but they differ somewhat from values calculated by means of parameters published by Frisk. For the system Fe‐Mn‐N the present measurements correspond to measurements by Grabke et al. and to values calculated with parameters published by Qiu. Using parameters deduced from the present measurements in the austenitic Fe‐Cr‐Mn‐N system similar nitrogen solubilities were calculated as Zheng had measured, but small deviations were found between the analysis by Qiu and this investigation.
ISSN:0003-8962
DOI:10.1002/srin.199401081
出版商:Wiley
年代:2016
数据来源: WILEY
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7. |
Microstructure‐strength relationships for LC and HSLA steels |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 338-344
Werner Österle,
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摘要:
Unalloyed low carbon steel (LC) and high strength low alloy steel (HSLA) were investigated after systematically changing the microstructure by certain heat treatments. The microstructural parameters grain size and dislocation density as well as particle size and particle spacing were measured quantitatively and correlated with the yield strength obtained from tensile tests at ambient temperature. Three different relationships were used to describe the results. The Hall‐Petch and the Orowan relationship could only be applied to some of the investigated microstructures, whereas the work‐hardening formula which correlates flow stress with dislocation density was more generally valid, provided that dislocation density was measured in the deformed state. In several cases two alternative relationships could be used, showing that the microstructural parameters are mutually dependant. The widespread assumption that all strengthening mechanisms can be added up to give the yield strength as the sum of the single contributions was clearly disproved. The results of some previous work on thermo‐mechanically processed steels has been newly interpreted in the light of these findings.
ISSN:0003-8962
DOI:10.1002/srin.199401082
出版商:Wiley
年代:2016
数据来源: WILEY
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8. |
On the bainite structure in Cr‐Mo‐V rotor steel |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 345-349
Asok Joarder,
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摘要:
The morphology of continuously cooled and isothermally transformed bainite structures formed in a Cr‐Mo‐V rotor steel has been studied using transmission electron microscopy. The samples were austenitised at 955°C for an hour followed by air cooling to room temperature. The isothermal transformation reaction was carried out at 450°C for up to 100 000 s. The microconstituents observed are predominantly lower bainite with very small amount of upper bainite and martensite (formed from untransformed austenite due to water quenching). Analysis of the selected area diffraction patterns confirm that the carbide in bainite is orthorhombic cementite and the orientation relationship between ferrite and cementite is consistent with that of Bagaryatskii. The carbide particles in isothermally transformed bainite are coarser than those of continuously cooled bainite. Tempering one hour at 670°C of continuously cooled steel samples exhibited formation of fine spheroidal MC type carbides. In addition tempering leads to the enrichment of prior austenite grain boundaries by cementite particles. Tempering ten hours at 670°C exhibited microstructures almost identical to those observed in one hour tempering.
ISSN:0003-8962
DOI:10.1002/srin.199401083
出版商:Wiley
年代:2016
数据来源: WILEY
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9. |
Corrosion behaviour of low‐Cr high‐Al stainless steels in 65% boiling HNO3 |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 8,
2016,
Page 350-353
Ahmad Adel Abdul‐Azim,
Wafaa Abd‐el Rahem Ghanem,
Rabab Mohamed Abou‐Shahba,
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摘要:
The corrosion resistance of low‐Cr high‐Al steels has been tested in 65% boiling HNO3solution. Comparison of this resistance and that of stainless steels 304, 430 and 410 under the same conditions reveals that Al has a beneficial effect on the corrosion resistance of Fe‐Cr‐Ni steels. The reduction of about 7% Cr can be compensated by about 5% Al provided that Ni is maintained at about 15–18%.
ISSN:0003-8962
DOI:10.1002/srin.199401084
出版商:Wiley
年代:2016
数据来源: WILEY
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