Solidification Analysis Of Bismuth Based Alloy In Continuous Casting Process

Continuous Casting is a manufacturing process for producing billets, slabs and flat products. It is used for casting non-ferrous and steel production to produce high quality products of slab or billet cast at reduced cost. A thin solidified metal shell is formed initially during continuous casting due to the intense cooling from the water cooled mould. Once the cast leaves the mould it goes through various cooling processes and in solid state will proceed to the further forming processes. To exploit the benefit of continuous casting process it is essential to develop close control of the production process. This is achieved through a good understanding of the influence of the various compositional and operational variables. The objective of the mathematical analysis presented here is to model the heat transfer during continuous casting of low melting point Bismuth alloy cast billets material for predicting the surface temperature. Good quality of the cast in conjunction with the surface quality of the cast is relied on the solidification temperature during continuous casting. In fact by simulating the solidification temperature of the continuous casting process through applying different operational casting parameters, the result are crucial for identifying the best operational casting parameters

Physical modelling of tundish slag entrainment under various technological conditions

This paper deals with the issue of physical modelling of vortexes creation and tundish slag entrainment over the mouth of the nozzle into the individual casting strands. Proper physical model is equivalent to the operational continuous casting machine No. 2 in TRINECKE ZELEZARN, a.s. Physical modelling methodology and simulated operational conditions are shortly described. Physical modelling was used for the evaluation of current conditions of steel casting at the application of different impact pads in the tundish. Further, laboratory measurement on the physical model aiming the determination of exact critical periods of vortexes creation and study of the slag entrainment as a consequence of changes in surface level during the tundish refilling to standard level were realised. The obtained results were analysed and discussed.Web of Science6231471146

In-situ steel solidification imaging in continuous casting using magnetic induction tomography

: Solidification process in continuous casting is a critical part of steel production. The speed and quality of the solidification process determines the quality of final product. Computational fluid dynamics (CFD) simulations are often used to describe the process and design of its control system, but so far, there is no any tool that provides an on-line measurement of the solidification front of hot steel during the continuous casting process. This paper presents a new tool based on magnetic induction tomography (MIT) for real time monitoring of this process. The new MIT system was installed at the end of the secondary cooling chamber of a casting unit and tested during several days in a real production process. MIT is able to create an internal map of electrical conductivity of hot steel deep inside the billet. The image of electrical conductivity is then converted to temperature profile that allows the measurement of the solid, mushy and liquid layers. In this study, such a conversion is done by synchronizing in one time step the MIT measurement and the thermal map generated with the actual process parameters available at that time. The MIT results were then compared with the results obtained of the CFD and thermal modelling of the industrial process. This is the first in-situ monitoring of the interior structure during a real continuous casting.The SHELL-THICK project has received funding from EU Research Fund for Coal and Steel under grant number 709830. This study reflects only the author's views and the European Commission is not responsible for any use that may be made of the information contained therein

Solidification microstructure of M2 high speed steel by different casting technologies

The present work investigated the solidification microstructure of AISI M2 high speed steel manufactured by different casting technologies, namely iron mould casting and continuous casting. The results revealed that the as-cast structure of the steel was composed of the iron matrix and the M2C eutectic carbide networks, which were greatly refined in the ingot made by continuous casting process, compared with that by the iron mould casting process. M2C eutectic carbides presented variation in their morphologies and growth characteristics in the ingots by both casting methods. In the ingot by iron mould casting, they have a plate-like morphology and grow anisotropically. However, in the ingot made by continuous casting, the carbides evolved into the fiber-like shape that exhibited little characteristics of anisotropic growth. It was noticed that the fiber-like M2C was much easier to decompose and spheroidize after heated, as a result, the carbides refined remarkably, compared with the case of plate-like carbides in the iron mould casting ingot

Silicon carbide fiber reinforced strontium aluminosilicate glass-ceramic matrix composite

A SrO-Al2O3 - 2SrO2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite. Organic constituents are burned out of the 'green' composite, and the remaining interim material is hot pressed

Continuous Casting of Aluminum Alloys

In the aluminium and the copper industries, deep attentions are paid to the continuous casting， because of the good properties of the slab obtained and the cheapness of the casting costs. And so, the authors made a continuous casting apparatus: The special point of this apparatus is that the bottom mould has a cooling jacket so as to prevent the occurence of the inverse segregation. Using this apparatus, the authors made slabs of aluminium-copper (4%) alloys, and investigated the distribution of copper. This experiment has shown that when the castig condition-casing temperature, casting velocity, cooling velocity and height of molten metal in the mould-are properly chosen, very sound slabs may be obtained by our apparatus above mentioned.連続鋳造による鋳塊は押揚を必要とせず，人件費，諸経費の節約等種々の利点があるばかりでなく，組織が非常に緻密で良好な製品が得られるので近時斯界の注目する所となった。この連続詩造法は企業の合理化を叫ばれている今日Al, Cu合金関係業界の注目する所となっているが尚幾多改良さるべき点が残されている。著者は従来Al合金鋳塊の偏析及びその防止法について研究を続けて来たが層一層凝固する連続鋳造法を採用することが最も望ましいと云う結論に達したので従来の方法を参考にして本稿第2図の如き装置を製作，それによる鋳塊の性質を検討して見た

Continuous Learning in a Hierarchical Multiscale Neural Network

We reformulate the problem of encoding a multi-scale representation of a sequence in a language model by casting it in a continuous learning framework. We propose a hierarchical multi-scale language model in which short time-scale dependencies are encoded in the hidden state of a lower-level recurrent neural network while longer time-scale dependencies are encoded in the dynamic of the lower-level network by having a meta-learner update the weights of the lower-level neural network in an online meta-learning fashion. We use elastic weights consolidation as a higher-level to prevent catastrophic forgetting in our continuous learning framework.Comment: 5 pages, 2 figures, accepted as short paper at ACL 201

Linear Contraction Behavior of Low-Carbon, Low-Alloy Steels During and After Solidification Using Real-Time Measurements

A technique for measuring the linear contraction during and after solidification of low-alloy steel was developed and used for examination of two commercial low-carbon and low-alloy steel grades. The effects of several experimental parameters on the contraction were studied. The solidification contraction behavior was described using the concept of rigidity in a solidifying alloy, evolution of the solid fraction, and the microstructure development during solidification. A correlation between the linear contraction properties in the solidification range and the hot crack susceptibility was proposed and used for the estimation of hot cracking susceptibility for two studied alloys and verified with the real casting practice. The technique allows estimation of the contraction coefficient of commercial steels in a wide range of temperatures and could be helpful for computer simulation and process optimization during continuous casting. © 2013 The Minerals, Metals & Materials Society and ASM International

Japanese irogane alloys and patination – a study of production and application

Japanese metalworkers use a wide range of irogane alloys (shakudo, shibuichi), which are colored with a single patination solution (niiro). This approach allows different alloys to be combined in one piece and patinated, producing a multi-colored piece of metalwork. At present the production of irogane alloys and their patination is an unreliable process. This study aims to develop reliable alloy production and a safe, easy-to use and repeatable patination process using standard ingredients available from chemical suppliers. The study has examined the production of shakudo and shibuichi alloys, characterizing the alloys produced by casting into cloth molds in hot water, into steel molds, and produced using continuous casting. The influence of traditional polishing methods was assessed using surface texture (Sa) measurements. Traditional rokusho, an ingredient of the niiro solution, was analyzed by XRF and XRD. Niiro patinated surfaces on a range of alloys were examined using XRD and L*a*b* color measurements.</p