1. |
Investigation of the sedimentation of FeNi fine grains entrained in ERF slag |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 179-187
Adamantios S. Diamantopoulos,
George N. Angelopoulos,
Demetrios C. Papamantellos,
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摘要:
Nickel losses in the slag generated at Larco electric reduction furnaces (ERF) during smelting of Greek laterites account for about 20% of the total nickel of the feed. The recovery of the nickel contained in the slag as well as in its magnetic concentrate was studied under different methods. The experimental results have shown that a nickel recovery in the range of 75‐90% is possible by allowing the slag to settle. Washing by low carbon steel can be performed during the final stages of the settling process as it improves the finally attained nickel recovery up to 94.4%. The simultaneous carbon reduction and settling process do not favour the Ni‐ recovery as the produced carbon monoxide and dioxide cause boiling of the bath which promotes the flotation of the metallic grains. In all cases a reoxidation of nickel was observed after 20min approximately. Settling of the ferronickel grains was described by a mathematical model. The model's results are in good agreement to the experimental ones for the initial 20min of the process. A modified model was elaborated combining the settling of the metallic grains with the nickel reoxidation reaction. This model describes with adequate accuracy the whole Ni‐ recovery process. The developed model can be proven helpful in the design of a slag cleaning step for metal recovery utilizing a slag settling furnace operating on line to the ERF.
ISSN:0003-8962
DOI:10.1002/srin.199605475
出版商:Wiley
年代:2016
数据来源: WILEY
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2. |
Thermal expansion and crown evaluations of rolls in rolling processes |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 188-199
Ampere A. Tseng,
S. X. Tong,
M. Raudensky,
T. C. Chen,
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摘要:
An understanding of the thermal expansion of work rolls is essential to the proper control of the flatness of a rolled strip in operating a modern, high‐speed rolling mill. In this paper, an analytical solution has been developed to provide the thermal displacements and expansions of the roll. The thermal expansion data, in turn, can be utilized to estimate the thermal crown for shape control and contributes to alleviating many shape problems of the rolled product. The thermal displacement potential function has been used to solve the governing partial differential equations for the thermal displacements. The general stress function is then obtained to modify the displacement potential solution to satisfy the boundary conditions of the free roll surface. To demonstrate the accuracy and reliability of the solution developed, the results of the present solution have been compared with previously published numerical and experimental results at typical rolling conditions; good agreement has been found between them. A parametric study is then performed to provide the required information for proper control of the roll and strip shape in operating a high‐speed rolling mill.
ISSN:0003-8962
DOI:10.1002/srin.199605476
出版商:Wiley
年代:2016
数据来源: WILEY
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3. |
Influence of roll geometry and strip width on flattening in flat rolling |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 200-204
Shunxin Zhou,
Paul Funke,
Jue Zhong,
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摘要:
The size of local roll flattening and its distribution along the direction of the roll axis in flat rolling were calculated by means of 3‐dimensional finite element method. For analysis of elastic flattening deformation of the roll stack the well‐known classical and analytical solutions are usually employed which were derived from elastic half space theory or two dimensional contact theory. By comparison of results from both the different methods the validity of the classical formulae was examined. Some of the formulae are more appropriate for calculating local flattening along the work roll/strip interface, however, they may result in a great deviation in calculating the flattening along the work roll/ back‐up roll interface, especially for the back‐up roll. Using the Fe model the influence of roll geometry and strip width under a specific rolling force on the flattening was taken into account, which is difficult to be treated with classical models.
ISSN:0003-8962
DOI:10.1002/srin.199605477
出版商:Wiley
年代:2016
数据来源: WILEY
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4. |
Calculation of some parameters of polyhedron bulging process |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 205-208
Dong Jianling,
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摘要:
Single‐curvature polyhedron bulging technology for manufacturing spherical vessels is to build spherical vessels by assembling and welding sheet blanks of zero‐curvature and single‐curvature into a polyhedron, then gradually bulging the polyhedron into a spherical vessel. With the technology, heavy presses and large dies are not needed, so spherical vessels can be built at low cost. In order to make a polyhedron after being bulged satisfy given dimension requirements of the spherical vessel, it is necessary to calculate wall thickness and diameter of the polyhedron under bulging pressure.In this paper, wall thickness decrement and deflection of a point on a single‐curvature polyhedron during bulging are measured, it proves that the wall thickness decrement is much smaller than the deflection. Under the assumption that wall thickness of a polyhedron keeps constant during bulging, the constant‐area spheritaxis principle is put forward. With this principle, methods of calculating diameter, wall thickness of a polyhedron and pressure under which the polyhedron becomes a spherical vessel are got. Besides, other applications of the principle are also given.
ISSN:0003-8962
DOI:10.1002/srin.199605478
出版商:Wiley
年代:2016
数据来源: WILEY
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5. |
A model for description of structure forming processes during reheating steels for thermal treatment |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 209-214
Uwe Jurdeczka,
Dieter Peisker,
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摘要:
Modern production technologies, applied for parts or billets of steels for heat treatment, demand a possibility to predict the resulting and important structure parameters. The description of the austenite structure before transformation is also interesting for technologies with austenite transformation. A concept is presented to model austenitizing, including austenite nucleation, austenite nuclei growth and austenite grain growth. Monte‐Carlo‐Simulation is the mathematical method for modelling. The influence of secondary phases, especially the dissolution, is taken into account by using an additional part of the model. The mathematical method therefore is finite‐differences. Based on this concept, a model is developed for description of austenization during reheating. The variables for input are estimated at metallografical plane. Tests were carried out with case hardening steels and tempering steels. Austenite nuclide density and grain growth behaviour were estimated, both according to the initial state.
ISSN:0003-8962
DOI:10.1002/srin.199605479
出版商:Wiley
年代:2016
数据来源: WILEY
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6. |
Finite element modelling of the creep deformation of T91 steel weldments at 600°C |
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Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 5,
2016,
Page 215-220
Arun Kumar Bhaduri,
Wolfgang Gaudig,
Heinrich Theofel,
Karl Maile,
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摘要:
Finite element modelling of the creep deformation of T91 steel weldments, welded using the manual metal arc (MMA) and submerged arc (SA) welding processes, was carried out to predict creep curves for both of the weldments under different stresses and compared with the experimental data. The stress and strain redistribution across the length of the transverse‐weld specimens has also been predicted. Data of creep tests at 600°C at stresses between 90‐130 MPa for the base metal, the MMA and SA weld metals, and the simulated heat‐affected zone were used to determine Garofalo's equation for creep strain. Finite element meshes for both of the weldments were constructed after calculating the HAZ locations using Rosenthal's heat flow equation.
ISSN:0003-8962
DOI:10.1002/srin.199605480
出版商:Wiley
年代:2016
数据来源: WILEY
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