1. |
Interpretation of probe temperatures in the blast furnace using polynomial approximations |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 73-78
Henrik Saxén,
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摘要:
This paper describes a method for interpretation of temperature distributions measured by an above‐burden probe in a blast furnace. The distributions are approximated by polynomials, based on which indices are computed and depicted graphically in order to track the evolution of the gas distribution in the shaft. Using the indices, both gradual and abrupt (spontaneous) changes in the gas flow patterns have been detected. The indices can also be used to verify whether burden distribution control actions have led to desired results, and to detect imbalance in the gas flow.
ISSN:0003-8962
DOI:10.1002/srin.199605461
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Validity of rate equation based on Langmuir‐Hinshelwood mechanism for gasification of carbon ‐ a reappraisal |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 79-86
Debajyoti Bandyopadhyay,
Ahindra Ghosh,
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摘要:
Literature review on gasification of carbon by carbon dioxide reveals that the most widely accepted mechanism of gasification is based on the adsorption of oxidizing agent, proposed by Langmuir and Hinshelwood. But few investigators have cast doubt on the validity of the mechanism. In this paper, an attempt has been made to recheck the same with the help of critical analysis of literature information as well as rate data generated by the authors on gasification of electrode graphite and coconut char in different gaseous environments, namely, CO2, CO2‐Ar and CO2‐CO. It has been found that the parameters in the rate equation depend on the type of carbon contrary to the literature postulation that they are universal in nature. Expected linear dependence of rate on gas composition could not be observed under certain experimental conditions. Further, the equilibrium constants of the first elementary step of gasification i.e reversible oxygen exchange step, was found to be widely varying for both, different investigators and for different forms of carbon. Activation energy for the reverse step of oxygen exchange reaction was calculated to be negative tor graphite. Thus, the findings of the present study are not in conformity with the behaviour expected if Langmuir‐Hinshelwood mechanism is valid for gasification of carbon by carbon dioxide.
ISSN:0003-8962
DOI:10.1002/srin.199605462
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
Solubilities of carbon in CaO‐Al2O3‐SiO2slags saturated with liquid iron |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 87-92
Kwang Ro Lee,
Hideaki Suito,
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摘要:
By equilibrating the CaO‐Al2O3‐SiO2slags with Fe ‐ 0.0003∼0.07% Al ‐ 0.002∼3.5% Si ‐ 0.9∼2.0% C alloys (mass contents in %) at 1873 K, the solubilities of carbon were measured as a function of Si contents in metal, using an alumina or lime crucible. The distribution ratios of carbon as a C2‐‐ion were found to be linearly related to Si contents with a slope of 1/2 at a given slag composition. The carbide capacity,, defined by (% C), increased with increasing SiO2contents at a given CaO/AlO1.5molar ratio in the CaO‐AlO1.5SiO2system.
ISSN:0003-8962
DOI:10.1002/srin.199605463
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Austenite stabilization from direct cementite conversion in low‐alloy steels |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 93-99
Gregory N. Haidemenopoulos,
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摘要:
Transformationinducedplasticity (TRIP) effects associated with austenite dispersions in low alloy Fe‐Mn‐Si steels can be enhanced by austenite stabilisation. Austenite which forms during conventional intercritical annealing does not possess the required stability in order to exhibit TRIP effects. In this work, thermodynamic calculations indicated that it is feasible to form austenite by a cementite to austenite conversion which occurs under paraequilibrium conditions, i.e with partition of carbon but with no partition of substitutional alloying elements. In this way the austenite inherits the manganese content of cementite and is chemically stabilised. A treatment consisting of a two‐step annealing has been examined. In the first step, soft annealing, an Mn‐enriched cementite dispersion in ferrite is formed. In the second step, intercritical annealing, austenite nucleates on the cementite particles, which are consumed to form austenite. It was experimentally determined that this austenite has been enriched in manganese and carbon and, therefore, is stabilised. The conversion reaction is followed by the conventional austenite nucleation at ferrite grain boundaries. This austenite is lean in manganese and is not stable. The net effect of the two‐step annealing treatment is a significant austenite stabilisation relative to simple intercritical annealing, indicating a potential for enhanced TRIP effects in this class of steels.
ISSN:0003-8962
DOI:10.1002/srin.199605464
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
Production of ultra‐high strength wire rod steels by vanadium microalloying |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 100-105
Mamdouh Eissa,
Kamal El‐Fawakhry,
Hoda El‐Faramawy,
Ayman Fathy,
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摘要:
Ultra‐high strength high‐carbon wire rod steels have been produced using vanadium‐microalloying technique instead of the conventional expensive and environment polluting lead patenting treatment. The strength increment attained in the hot rolled steels due to vanadium additions is maintained in the cold drawn wire. By using this technique, high tensile strength levels of 1550‐1600 N/mm2were attained either by cold drawing of 0.17% V microalloyed high‐carbon steel to 45‐47% reduction or by cold drawing of 0.20% V microalloyed high‐carbon steel to 25‐30% reduction. An equation has been developed to predict the tensile strength from the chemical composition, cooling rate and reduction of area due to cold drawing.A combination of vanadium microalloying and accelerated cooling resulted in additional strength increment due to refining of microstructure and increasing the precipitation strengthening component. Inspite of the decrease in the amount of vanadium precipitates due to the increase in cooling rate, it is suggested that an increase in precipitation strengthening due to refining of these precipitates by accelerated cooling more than offsets the loss of precipitation strengthening due to decreasing the precipitates fraction.
ISSN:0003-8962
DOI:10.1002/srin.199605465
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
Creep equations for high temperature alloys on the basis of a parametric assessment of multi‐heat data |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 106-110
Karl Heinz Kloos,
Joachim Granacher,
Andreas Pfenning,
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摘要:
For the design of high temperature components creep equations are necessary. These describe the deformation behaviour of the material type used over its whole application range. The method of developing such an equation is demonstrated for the example of alloy G‐NiCo 15 Cr 10 Al 6 TiMo (Alloy 100). As a basic requirement, a multi‐heat assessment of time to specific strain is performed with the aid of a time temperature parameter procedure. In this way optimum correlated master curves are generated for the whole range of permanent strain and rupture. From these curves mean creep curves for the material type can be determined by minimal further smoothing. On the basis of these creep curves a modified Garofalo equation with initial plastic strain as well as primary, secondary and tertiary strain can be established to describe the creep behaviour of Alloy 100. Additionally, an equation for the time temperature dependent contraction of this alloy can be developed. These equations form a useful tool for the calculation of high temperature components with the finite element method.
ISSN:0003-8962
DOI:10.1002/srin.199605466
出版商:Wiley
年代:2016
数据来源: WILEY
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7. |
News from the Max‐Planck‐Institute for Eisenforschung GmbH |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 3,
2016,
Page 111-120
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ISSN:0003-8962
DOI:10.1002/srin.199605467
出版商:Wiley
年代:2016
数据来源: WILEY
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