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Search Results: 1 - 10 of 3427 matches for " continuous casting "
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Mold Thermo-Mechanical Rigidity Criterion for Surface Quality of Continuous Casting of Steel  [PDF]
Mostafa Omar El-Bealy
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.41006
Abstract:

A theoretical investigation of heat flow, solidification and solid shell resistance “Ic” has been undertaken by using a mathematical model and previous plant trials. The ultimate purpose is to develop operating conditions and therefore to improve the surface quality for continuously cast steel slabs. A new simple criterion called mold thermomechanical rigidity “MTMR” has been proposed to evaluate and to improve these purposes. The parameters of MTMR and its non-dimensional number which use to control the surface defects are present in this investigation. Previous plant trails of slab surface defects formation have been investigated thermo-mechanically with this criterion. The predications show that this criterion is very sensitive of operating parameters and is a significant qualitative tool to evaluate the surface quality. From examination of the behavior of MTMR, the susceptibility and mechanism of surface defects formations with MTMR have been primarily discussed.

非晶合金薄板的弧形连铸技术
Curved Continuous Casting of Glassy Alloy Sheets  [PDF]
陈招娣, 张涛, 张勇
Material Sciences (MS) , 2012, DOI: 10.12677/MS.2012.23021
Abstract: 本文简要介绍了非晶合金的发展现状及非晶连续制备技术，并提出了一种弧形连铸技术制备非晶合金薄板的新思路。非晶合金新型连续制备技术及其相关非晶样品不断涌现出来，对促进非晶合金快速发展和推广应用起了重要作用。经过近50年广泛而深入的科学研究，对块体非晶合金的研究已经进入开发性能卓越、质量稳定的非晶合金新产品和可大批量工业化生产的新技术阶段。非晶合金薄板弧形铸坯连铸技术可以充分发挥非晶合金的大过冷液体区间和塑性加工成形特性，有效减少样品再加工工序，提高生产效率，节约能源消耗，降低生产成本。
A new curved continuous casting method for massive production of glassy alloy sheets has been proposed in this paper. Recently, a lot of new methods for continuous producing of bulk metallic glasses have been adopted for massive preparation. The research and development of glassy alloys have been certainly improved by these methods. After nearly 50 years of extensive and in-depth research, attentions have been paid to develop new amorphous alloys with excellent performance, products with high quality and novel technique for industrial applications. Curved con- tinuous casting of glassy alloys could have high efficiencies, low energy consumptions and near net shape casting.
Effect of Cooling Intensity and Position on Solidification in Semi-Continuous Casting of Copper  [PDF]
Amar H. Hameed, Ahmed A. Mohammed, Obaid T. Fadhil
Open Journal of Fluid Dynamics (OJFD) , 2016, DOI: 10.4236/ojfd.2016.63015
Abstract: Cooling heat flux effect in both primary and secondary cooling zone has been studied in semi-continuous casting of copper billet. Sufficient cooling is essential to reduce casting defects and to get high productivity, however low rate of solidification is aimed in order to get coarser grain size and softer metal for less losses in extrusion. A three-dimensional numerical model has been developed including solidification behavior of copper through mushy zone. At steady state and constant casting speed, solid shell thickness is monitored during the reduction of cooling rate at mould region to avoid breaking out. Heat flux intensity at mould plays important role not only in the formation of solid shell thickness. But, pool length and mushy zone thickness can be significantly increased by decreasing primary cooling intensity. Increase intensity of secondary cooling zone for two particular cases of primary cooling is tested. First case is tested at mould inlet water temperature of 38°C, and second case at water temperature of 63°C. Results showed that the combination of increasing secondary cooling intensity and reduction of primary cooling intensity can increase pool length and mushy zone thickness. Also, it is shown that, secondary cooling intensity can be magnified by up to 1.5 times for cooling water temperature of 63°C to get pool length close to that of water temperature of 38°C.
Anchor-Shaped Design of a Submerged Entry Nozzle for the Continuous Casting of Steel  [PDF]
Carlos A. Hernandez, Miguel A. Barron, Raul Miranda
Open Journal of Applied Sciences (OJAppS) , 2016, DOI: 10.4236/ojapps.2016.69058
Abstract: An anchor-shaped geometrical design for a Submerged Entry Nozzle for the slab continuous casting of steel is presented in this work. To evaluate its performance, transient 3D multiphase numerical simulations were carried out using the Computational Fluid Dynamics technique. The performance of the proposed nozzle is numerically compared with that of a conventional cylindrical nozzle. Computer results show that the chance of formation of Karman’s vortexes and powder entrapment becomes small for the anchor-shaped SEN.
Simulación del vaciado continuo de perfiles de aceros al carbono de baja aleación
Díaz-Hernández,Yusdel; Fiol-Zulueta,Alberto; Arzola-Ruiz,José;
Ingenier？-a Mec？？nica , 2013,
Abstract: in this paper an algorithm to simulate the process of continuous casting based on a physical -mathematical model using finite element methods was presented. the most outstanding characteristic of the model was the inclusion of complex processes of heat interchange, metal phase changes, distribution of temperatures in the mould, chemical composition of the metal, flow of water in the primary and secondary cooling system and the casting speed. moreover, the algorithm permitted to predict the behaviour of the process variables in the continuous casting of steel according to its profile and type.
Cost of Quality as a Driver for Continuous Improvement - Case Study – Company X
Davison Zimwara,Lameck Mugwagwa,,Daniel Maringa,,Albert Mnkandla
International Journal of Innovative Technology and Exploring Engineering , 2013,
Abstract: In the manufacturing, metal casting industry is one of the oldest basic principal and most important industries. The casting process is hindered by the occurrence of various defects. High casting reject levels and customer returns have a considerable adverse effect on productivity, delivery performance, customer satisfaction and employee morale. In addition excessive rejection reduces yield, wastes valuable raw materials and involves management time in problem solving. All foundry processes generate a certain level of rejection that is closely related to the type of casting, the processes used and the equipment available. This paper seeks to establish the extent to which cost of quality can impact on continuous improvement of the products and the relationship with the customers of the organization. To determine the cost of quality (COQ) at casting company X, the researchers used existing company records, publications and historical evidence of the company. The researchers utilized techniques such as, bar charts and tables in presenting and interpreting data. The above techniques have the ability to provide methods for collecting, presenting, and analysis and meaningfully interpret data. The research findings estimated the COQ to be 6.6% of sales revenue.
Possibilities of S-EMS utilization for the improvement of central segregation in continuously cast billets in conditions of T
J. Cibulka,D. Bocek,T. Huczala,J. Cupek
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The aim of the paper is to investigate practical possibilities of the strand stirrer (S-EMS) for the improvement of inner quality and central segregation in high carbon billets. An optimal S-EMS setting was proposed for the billet caster producing billets 150x150 mm.Design/methodology/approach: Impact of different S-EMS settings on central segregation and inner quality of as-cast billets was investigated. A set of longitudinal and transverse samples were analysed including evaluation of baumann prints and central segregation by means of LECO method. Samples of wires for segregation survey in rolled products were picked up as well.Findings: It was observed that application of the strand stirrer (S-EMS) is capable to suppress central segregation. However, its impact is visible just to a certain stirring level. Subsequent increasing of stirring intensity does not cause further improvement of segregation in the analyzed central part. On the contrary, stronger white band can be seen in the solidification line. Moreover, concentration gradient between the central part and surrounding ring of negative central segregation is lowered. These two effects can play a significant role in the evaluation of segregation level in rolled wires.Research limitations/implications: Analysis of central segregation in a lower size than used 6 mm.Practical implications: Optimal S-EMS setting seems to be 300 A/14 Hz.Originality/value: Impact of S-EMS setting on changes in central segregation of as-cast billets, relationship between central segregation level in wires and cast structure.
Continuous roll casting of aluminium alloys – casting parameters analysis
E. Krsti？ Vukelja,I. Duplan？i？,B. Lela
Metalurgija , 2010,
Abstract: The main goal of the paper was to present the influence of casting parameters on casting conditions and interference of casting parameters on the final strip characteristics such as constant strip thickness, surface quality and roughness of aluminum alloys sheet 6,30 to 6,50 mm thick. The study shows that casting speed, roll force and roll gap should have the greatest influence on the final strip thickness, and that the examined parameters agree well with the theoretical standpoints.
Solidification microstructure of M2 high speed steel by different casting technologies
Zhou Xuefeng,Fang Feng,Jiang Jianjing
China Foundry , 2011,
Abstract: 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.
Numerical Analysis of Secondary Cooling in Continuous Slab Casting
Kee-Hyeon Cho,Byung-Moon Kim,
材料科学技术学报 , 2008,
Abstract: In the present study, a numerical optimization program has been developed for predicting the optimal secondary cooling patterns in a continuous slab caster. Optimization strategy using Broydon-Fletcher-Goldfarb-Shanno (BFGS) method is carried out by determining the constant heat transfer coefficients in each spray zone, which could satisfy the casting conditions and metallurgical criteria specified by the engineer. From the present results, it is found that even a slight variation in the pouring temperature, allowable surface temperature, and casting speed could give rise to the changes in the cooling pattern throughout the spray zones.
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