Film Boiling and Water Film Ejection in the Secondary Cooling Zone of the Direct-Chill Casting Process

Accurate knowledge of the boundary conditions is essential when modeling the Direct-Chill (DC) casting process. Determining the surface heat flux in the secondary cooling zone, where the greater part of the heat removal takes place, is therefore of critical importance. Boiling water heat transfer phenomena are quantified with boiling curves which express the heat flux density as a function of the surface temperature. Compilations of boiling curves for the DC casting of aluminum alloys present a good agreement at low surface temperatures but a very poor agreement at higher surface temperatures, in the transition boiling and film boiling modes. Secondary cooling was simulated by spraying instrumented samples with jets of cooling water. Quenching tests were conducted first with a stationary sample, and then with a sample moving at a constant “casting speed” in order to better simulate the DC casting process. The ejection of the water film in quenching tests with a stationary sample and the relative motion between the sample and the water jets both lead to an Advanced Cooling Front (ACF) effect, in which cooling occurs through axial conduction within the sample rather than through boiling water heat transfer at the surface. The heat flux density and surface temperature were evaluated using the measured thermal history data in conjunction with a two-dimensional inverse heat conduction (IHC) model. The IHC model developed at the University of British Columbia was able to take into account the advanced cooling front effect. The effect of various parameters (initial sample temperature, casting speed, water flow rate) on the rate of heat removal in the film boiling and transition boiling regimes was investigated.

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CFD simulation of direct chill casting process of magnesium alloy billets

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2019.07.033 ◽

2019 ◽

Vol 45 ◽

pp. 447-454 ◽

Cited By ~ 2

Author(s):

Lee Wei Loon ◽

S. Sreekar Reddy ◽

Prasada Rao A.K.

Keyword(s):

Magnesium Alloy ◽

Cfd Simulation ◽

Casting Process ◽

Direct Chill ◽

Direct Chill Casting ◽

Chill Casting ◽

Direct Chill Casting Process

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Development of an 8090/3003 bimetal slab using a modified direct-chill casting process

Journal of Materials Processing Technology ◽

10.1016/j.jmatprotec.2014.03.029 ◽

2014 ◽

Vol 214 (9) ◽

pp. 1806-1811 ◽

Cited By ~ 17

Author(s):

Tongmin Wang ◽

Chunhui Liang ◽

Zongning Chen ◽

Yuanping Zheng ◽

Huijun Kang ◽

...

Keyword(s):

Casting Process ◽

Direct Chill ◽

Direct Chill Casting ◽

Chill Casting ◽

Direct Chill Casting Process

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Effects of Low Frequency Electromagnetic Field on Segregation Layer during Hot-Top Casting of Aluminium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.3795 ◽

2011 ◽

Vol 189-193 ◽

pp. 3795-3798

Author(s):

Xiang Jie Wang ◽

Jian Zhong Cui ◽

Hai Tao Zhang ◽

Hui Xue Jiang ◽

Gao Song Wang

Keyword(s):

Electromagnetic Field ◽

Aluminium Alloy ◽

Surface Segregation ◽

Low Frequency ◽

Casting Process ◽

Direct Chill ◽

Direct Chill Casting ◽

Chill Casting ◽

Direct Chill Casting Process

Surface segregation layer are frequently encountered during aluminium alloy direct chill casting process, and the removal of the surface segregation layer before further processing of the ingot decreases the ingot yield. In this work, the low frequency electromagnetic field was applied to study the effects of low frequency electromagnetic field on segregation layer during the direct chill casting process. The results show that under the effect of the low frequency electromagnetic field, the surface quality of ingot is improved, the structure of the ingot is refined, and the thickness of segregation layer is decreased.

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Heat-Transfer Measurements in the Primary Cooling Phase of the Direct-Chill Casting Process

Metallurgical and Materials Transactions B ◽

10.1007/s11663-012-9688-5 ◽

2012 ◽

Vol 43 (5) ◽

pp. 1202-1213 ◽

Cited By ~ 11

Author(s):

Etienne J. F. R. Caron ◽

Amir R. Baserinia ◽

Harry Ng ◽

Mary A. Wells ◽

David C. Weckman

Keyword(s):

Heat Transfer ◽

Casting Process ◽

Direct Chill ◽

Direct Chill Casting ◽

Chill Casting ◽

Cooling Phase ◽

Direct Chill Casting Process

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Fabrication of Cladding Billet in Diameter of 160mm/148mm by Direct Chill Casting Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.877.3 ◽

2016 ◽

Vol 877 ◽

pp. 3-8

Author(s):

Jian Zhong Cui ◽

Xing Han

Keyword(s):

Casting Process ◽

Direct Chill ◽

Bonding Interface ◽

Direct Chill Casting ◽

Interfacial Region ◽

Chill Casting ◽

Metallurgical Bonding ◽

Shearing Strength ◽

Interface Bonding Strength ◽

Direct Chill Casting Process

The AA4045/AA3003 cladding billet, which has a low clad ratio of 7.5% in size of φ160mm/φ148mm, was prepared successfully by the modified direct chill casting process. Microstructures, elements distribution and mechanical properties of the bonding interface were examined. The results show that metallurgical bonding interface can be obtained with the optimal parameters. The metallurgical bonding interface is free of any discontinuities due to the elements diffusion across the interface. The hardness of the interfacial region is higher than that of the AA3003 but lower than that of AA4045, suggesting that the interface bonding strength is higher than the strength of AA3003. The shearing strength is 82.3 MPa, indicating excellent metallurgical bonding.

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