1. |
Heating and melting of wustite pellets in liquid slag |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 459-465
Shuang Xu,
Lauri Holappa,
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摘要:
The melting behaviour of the metallized, porous wustite pellets immersed in liquid slag, as well as the influences of the metallization ratio, pre‐heating temperature of the pellet and slag temperature were examined in this work by means of an X‐ray imaging system. The internal structure of the pellets after having been immersed in slag was checked by optical microscope and EPMA. The adoption of digital image processing improved the image analysis dramatically and, as a result, some important phenomena, such as solid slag shell forming and melting, slag penetration, wustite component dissolution as well as the influence of experimental conditions, were quantified.
ISSN:0003-8962
DOI:10.1002/srin.199401194
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Adaptive neural net (ANN) models for desulphurization of hot metal and steel |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 466-471
Amlan Datta,
Mavoori Hareesh,
Prem Kumar Kalra,
Brahma Deo,
Rob Boom,
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摘要:
Neural nets can be adapted to complex patterns of interrelated input and output variables in a process even if the data sets contain a lot of noise. In this work two specific examples for the application of adaptive neural nets (ANN) in steel Industry are described. First, the sulphur content of hot‐metal, obtained at the end of calcium carbide powder injection into 4001 torpedo ladles is predicted as a function of hot‐metal weight, treatment time, initial sulphur content, gas flow rate and powder injection rate. The values predicted by the trained ANN model for a completely new set of input test data compare well with the actual values obtained on the shop floor. In the second example, the sulphur content of steel, obtained at the end of blow is predicted as a function of liquid‐metal weight, total amount of oxygen injected, amount of iron ore added, and the temperature, contents of carbon, manganese, phosphorus and sulphur determined by in‐blow sampling in a 300 t converter. The ANN predicted values of sulphur content of steel at tap (without reblow) also agree well with the values obtained on the shop floor.
ISSN:0003-8962
DOI:10.1002/srin.199401195
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
Genetic adaptive search model of hot metal desulphurization |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 472-478
Ravi Rastogi,
Kalyanmoy Deb,
Brahma Deo,
Rob Boom,
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摘要:
Genetic adaptive search (GAS) techniques, based on the mechanics of natural genetics, are used in this paper to find an optimal model of desulphurization process of iron‐melt by powder injection. Industrial data on 400 t torpedo are used to evaluate contributions of transitory and permanent contact reactions to the overall desulphurization process during calcium carbide powder injection. The results obtained with GAS agree more closely with the plant data than the theoretical model. GAS solutions are also found to be better than regression models. These results suggest immediate application of GAS in similar metallurgical problems.
ISSN:0003-8962
DOI:10.1002/srin.199401196
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Application of fuzzy sets and neural network theory to the numerical pattern recognition of bubble flow and jet flow |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 479-484
Andreas Franzen,
Wolfgang Pluschkell,
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摘要:
The injection of gas into a liquid is associated with two characteristic flow regimes: bubble flow and jet flow. In metallurgy, these flow regimes are of interest with respect to refractory lifetime and mass transfer. The flow regimes were investigated in the systems water‐air and ethanol‐air by monitoring the bottom vibrations of a cold model. The vibrations were analyzed by numerical pattern recognition. The nominal Mach number of 1.1 is the criterion for the transition from bubble flow to jet flow. A numerical pattern recognition system which is able to distinguish between the flow regime below and above the nominal Mach number of 1.1, just by analyzing the vibration signal, is presented. This task can be accomplished in spite of the use of different liquids, nozzle diameters and liquid heights. As a classificator, both a fuzzyknearest neighbour algorithm and a neural network were employed successfully. Fuzzy logic was found to be especially useful for describing the different flow regimes.
ISSN:0003-8962
DOI:10.1002/srin.199401197
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
Optimization of a BOF's lining resistance by application of artificial neural network |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 485-487
Yudong Cai,
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摘要:
The artificial neural network approach for optimization of lining resistance of basic oxygen furnace is presented in this paper. A group of samples has been collected to study. 33 samples are divided into two classes, i.e. good samples (class 1) providing a furnace life of more than 1000 heats, and bad samples (class 2) meaning a furnace life of less than 1000 heats. Analysis of 18 factors influencing furnace life shows that the major factors are supplementary filling amount, blowing time, melting time, and production rate. In this research, 25 samples are used as learning material, while eight samples are used as testing material for the natural network. The factors of major influence are taken as input variables. As a result, the testing rate reaches 100 %, which indicates that the model trained is reliable. In order to increase the furnace life according to the model, the partial derivative value of the output to each feature variable at the average point of class‐2 samples was calculated. The results show, that, whereas blowing and melting time had to be decreased, both the supplementary filling amount and production rate had to be increased. This result is quite consistent with the practical experience obtained in the plant. In addition, the neural network approach also has a fault‐tolerant ability, prediction and optimization speed. To sum up, the neural network approach might be referred to as an effective assistant technique for optimization of iron and steel industry.
ISSN:0003-8962
DOI:10.1002/srin.199401198
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
Influence of hydrodynamic lubricant entrainment on friction effects in cold rolling |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 488-493
Oskar Pawelski,
Wolfgang Rasp,
Stephan Draese,
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摘要:
The cold rolling process is decisively influenced by the mechanisms of lubricant supply to the deformation zone. Rolling tests with thin aluminium sheets were performed based on a theoretical model of the hydrodynamic entrainment of lubricant. Aluminium was used as a model material for steel in order to get a soft rolling stock to enlarge the hydrodynamic effect. The rolling conditions were chosen so that changes in friction conditions could definitely be traced back to a hydrodynamic effect in the inlet zone. The changes in friction conditions were demonstrated by significant rolling parameters, dimensionless similarity numbers, and alterations of the surface structures of the rolled test sheets. The conclusions indicate some tribological problems in cold rolling.
ISSN:0003-8962
DOI:10.1002/srin.199401199
出版商:Wiley
年代:2016
数据来源: WILEY
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7. |
Effects of solution treatment temperatures on microstructure, tensile and fracture properties of Co‐free 18 Ni maraging steel |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 494-499
Parameshwar Prasad Sinha,
Thomas Tharian,
Dhenuvakonda Sivakumar,
Dharba Subhramanya Sarma,
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摘要:
The study presents the influences of solution treatment temperatures (S.T.T.) on microstructure, tensile and fracture properties of 18 Ni cobalt free maraging steel. The results are thoroughly discussed in light of the prevailing microstructural conditions as revealed by optical and transmission electron microscopy, and detailed scanning electron fractography. It is found that tensile strength in both unaged and aged conditions is independent of solutioning temperature and, consequently, grain size. However, the tensile ductility, CVN andKICin aged condition get severely affected with the increase in S.T.T. because of a change occurring in the martensitic lath morphology from blocky to stringer type. This transition in the martensitic morphology starts at the prior austenitic grain size of 35‐40 μm and is completed at 120‐130μm. Solutioning at 1323 K followed by air cooling, however, results in thermal embrittlement of the steel due to grain boundary precipitation of TiCN. The prior austenitic grain size in this reaction plays only an indirect role. Based on these results, it has been suggested that the existing controversies on the effect of S.T.T. grain size on tensile ductility and fracture behaviour of maraging steels can be rationalized if the changes in martensitic lath morphology are considered as an important variable.
ISSN:0003-8962
DOI:10.1002/srin.199401200
出版商:Wiley
年代:2016
数据来源: WILEY
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8. |
Orientation dependent surface segregation of antimony on non‐oriented electrical steel sheet |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 500-504
Monika Jenko,
Franc Vodopivec,
Hans Jürgen Grabke,
Helmut Viefhaus,
Borut Praček,
Manfred Lucas,
Matjaž Godec,
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摘要:
The surface segregation of antimony was studied using AES on a 1.8% Si steel alloyed with different mass contents of Sb (0.052 and 0.1%). The dependency of surface segregation on grain orientation and on the presence of other solute atoms (S. P. C, Al. Si) were investigated under UHV conditions in the temperature range from 450 to 900 °C.The results lead to an explanation for the formation of a texture rich in (100)‐grains in Si steel caused by the presence of Sb. Also grain boundaries were analysed by AES after annealing at 850, 700 and 550 °C for different times. Since the grain boundary segregation was negligible one can conclude that the texture formation results from orientation dependent surface segregation of Sb causing differences in surface energies and stabilities of different grains.
ISSN:0003-8962
DOI:10.1002/srin.199401201
出版商:Wiley
年代:2016
数据来源: WILEY
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9. |
Fatigue properties of laser‐beam weldments on high‐strength steels |
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Archiv für das Eisenhüttenwesen,
Volume 65,
Issue 11,
2016,
Page 505-510
Markus Ring,
Winfried Dahl,
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摘要:
The intention of this investigation is to evaluate the behaviour of laser‐beam weldments under cyclic loading. The materials tested are several high‐strength steel plates with thicknesses of 7‐8 mm differing in chemical composition, delivery state and strength level. A number of S‐N curves was established not only for the as‐welded condition but also for the stress relieved and dressed state. It was found that the fatigue properties of laser‐beam welded joints are considerably better than those of weld seams produced by other methods. The increase in fatigue strength amounts to approximately 50%, neither depending on the material used nor on an additional stress‐relief annealing. By using the R1 MS notch stress model, the good behaviour of the weld seams can be entirely attributed to the favourable weld geometry.
ISSN:0003-8962
DOI:10.1002/srin.199401202
出版商:Wiley
年代:2016
数据来源: WILEY
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