Effect of electrode change on solidification of slag and metal pool profile in electroslag remelting process

The technological parameters determine the metal pool profile and the grain size and orientation in the electroslag remelting process, and thus affect the quality of the final ingot. The microstructure in the small electroslag casting process was simulated by CA method by means of the software MATLAB. Along with the remelting process, the columnar grain begins to grow to certain angle with axles, the shape of the metal pool gets closer to paraboloid shape. Improving the slag pool temperature or increasing the coefficient of heat transfer at the bottom or decreasing the coefficient of heat transfer at the side can lead the axial trend of grain growing to increase and the depth of the pool to shallow, otherwise can lead the trend of grain growing to radial direction to increase and the depth of the pool to deep.

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A Comprehensive Mathematical Model of Electroslag Remelting with Two Series-Connected Electrodes Based on Sequential Coupling Simulation Method

Metals ◽

10.3390/met10050658 ◽

2020 ◽

Vol 10 (5) ◽

pp. 658

Author(s):

Wenjie Tong ◽

Wanming Li ◽

Ximin Zang ◽

Huabing Li ◽

Zhouhua Jiang ◽

...

Keyword(s):

Mathematical Model ◽

Molten Metal ◽

Skin Effect ◽

Simulation Method ◽

Melting Rate ◽

Joule Heat ◽

Electroslag Remelting ◽

Metal Pool ◽

Sequential Coupling ◽

Molten Metal Pool

A comprehensive mathematical model of electroslag remelting with two series-connected electrodes (TSCE-ESR) was constructed based on sequential coupling method. The influence of droplet effect on electroslag remelting process (ESR) was considered in this model. Compared with one-electrode electroslag remelting (OE-ESR), the multi-physics field, droplet formation and dripping behavior, and molten metal pool structure of TSCE-ESR process were studied. The results show that during the process of TSCE-ESR, the proximity effect of the electrodes suppresses the skin effect, and Joule heat is concentrated in the area between the two electrodes of slag pool, making the temperature distribution of the slag pool more uniform. The heat used to melt the electrode in the process of TSCE-ESR accounts for about 34% of the total Joule heat, which is lower than the OE-ESR (17%). Therefore, it makes a higher melting rate and a smaller droplet size in the process of TSCE-ESR. Compared with OE-ESR, TSCE-ESR process can realize the unification of higher melting rate and shallow flat molten metal pool. Compared with the results without droplet effect, it is found that in the simulation results with droplet effect, the depth and the cylindrical section of molten metal pool increased, and the width of the mushy zone is significantly reduced, which is more consistent with the actual electroslag remelting process.

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Numerical Simulation of Electroslag Remelting Process for Producing GH4169 under Different Current Frequency

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.482-484.1556 ◽

2012 ◽

Vol 482-484 ◽

pp. 1556-1565 ◽

Cited By ~ 1

Author(s):

Qiang Liang ◽

Xi Chun Chen ◽

Hao Ren ◽

Cheng Bin Shi ◽

Han Jie Guo

Keyword(s):

Molten Metal ◽

Simulation Software ◽

Electroslag Remelting ◽

Metal Pool ◽

Current Frequency ◽

Volumetric Heating ◽

Physical Fields ◽

Physical Phenomena ◽

Insight Into ◽

Molten Metal Pool

A comprehensive analysis of the physical processes that occur in Electroslag Remelting (ESR) process under steady state conditions and axisymmetric was performed using the simulation software MeltFlow. The detailed plots of current distribution, volumetric heating, flow, temperature and turbulent mixing provide insight into the various physical phenomena that occur in ESR process. The effect of current frequency on various physical fields was analyzed. It is shown that, the current in the slag tends to become more uniform due to the low electrical conductivity of the slag; after the current enters the ingot, the skin effect increases with the increase of the current frequency; the Joule heating and the Lorentz force are highest near the tip of the electrode in the slag, and increase with the increase of the current frequency; the velocities in the slag are slightly higher than those in the molten metal pool; with the increase of the current frequency, the liquidus temperature moves down, and the molten metal pool is deepened. Simulation results agree well with experimental results. Therefore, the generation and extent of defects could be predicted in different process.

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Effects of Mould Rotation on Element Segregation and Compact Density of Electroslag Ingots during Electroslag Remelting Process

High Temperature Materials and Processes ◽

10.1515/htmp-2014-0049 ◽

2015 ◽

Vol 34 (5) ◽

Author(s):

Lizhong Chang ◽

Xiaofang Shi ◽

Runxi Wang ◽

Junqiang Cong

Keyword(s):

Rotation Rate ◽

Chemical Element ◽

Solidification Process ◽

Element Distribution ◽

Electroslag Remelting ◽

Solidification Structure ◽

Metal Pool ◽

Solute Content ◽

Compact Density ◽

Element Segregation

AbstractSteel solidification process control, especially in the solidification process of high-alloy steel, and improving the solidification structure have been increasingly gaining interest among metallurgists, particularly the electroslag workers. To further develop the electroslag remelting (ESR) process and to improve the ingot solidification structure, the effects of mould rotation on chemical element distribution and the compact density were investigated in this study. The experimental results showed that chemical element distribution would become more uniform when the mould keeps the reasonable rotation rate. However, the excessive rotation rate would deteriorate the solidification structure of steel. When mould rotation rate was between 0 and 28 r/min, maximum segregation of carbon could decrease from 3.19 to 1.084, and statistical segregation decreased from 0.2636 to 0.0554. Maximum segregation of chromium could decrease from 1.316 to 1.131, and statistical segregation decreased from 0.2753 to 0.0657. The compact density increased from 0.7693 to 0.94. But element segregation would become bigger and compact density would become smaller if rotation rate further increased. The improvement in the solidification structure could be attributed to reasonable mould rotation rate which could initiate movement in the slag pool and further increase the uniformity of the temperature in the slag pool. At the same time, the movement in the slag pool could also affect the metal molten droplet, scattering the liquid drop randomly in the metal pool. But the excessive rotation rate made the slag pool violent motion, so as to drive the molten metal pool to rotate which would carry off enriched steel surrounding the dendrites in the mushy zone and reduce the solute content in the region. As a result, the element segregation would occur.

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Mixing in Liquid Metal Pool during Electroslag Remelting

Transactions of the Iron and Steel Institute of Japan ◽

10.2355/isijinternational1966.14.170 ◽

1974 ◽

Vol 14 (3) ◽

pp. 170-175

Author(s):

Yasushi NAKAMURA ◽

Naoki TOKUMITSU ◽

Kazumi HARASHIMA

Keyword(s):

Liquid Metal ◽

Electroslag Remelting ◽

Metal Pool

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Modeling of Electromagnetic Field and Liquid Metal Pool Shape in an Electroslag Remelting Process with Two Series-Connected Electrodes

Metallurgical and Materials Transactions B ◽

10.1007/s11663-013-9996-4 ◽

2013 ◽

Vol 45 (3) ◽

pp. 1122-1132 ◽

Cited By ~ 26

Author(s):

Baokuan Li ◽

Bo Wang ◽

Fumitaka Tsukihashi

Keyword(s):

Electromagnetic Field ◽

Liquid Metal ◽

Electroslag Remelting ◽

Metal Pool ◽

Pool Shape

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Kinetics of Phosphorus Transfer during Industrial Electroslag Remelting of G20CrNi2Mo Bearing Steel

Metals ◽

10.3390/met9040467 ◽

2019 ◽

Vol 9 (4) ◽

pp. 467

Author(s):

Shijian Li ◽

Guoguang Cheng ◽

Yu Huang ◽

Weixing Dai ◽

Zhiqi Miao

Keyword(s):

Kinetic Model ◽

Metal Film ◽

Bearing Steel ◽

Electroslag Remelting ◽

Metal Pool ◽

Industrial Furnace ◽

Kinetic Behavior ◽

Rate Determining Step ◽

P Content ◽

Kinetics Of

Phosphorus is undesirable in steel for it greatly decreases ductility and causes embrittlement in most cases. The kinetic behavior of phosphorus transfer was investigated during electroslag remelting (ESR) of G20CrNi2Mo bearing steel. Four heat treatments were carried out using an industrial furnace with a capacity to refine 2400 kg ingot. It was found the P content in the four ingots were all higher than that in the electrodes, indicating rephosphorization occurs during ESR. A kinetic model based on film and penetration theory was developed to elucidate the variation of phosphorus from metal film to droplet and metal pool. The model indicates that the rate-determining step of phosphorus transfer is at the slag side. Rephosphorization mainly occurs in the metal film and falling droplet. In addition, the effect of P in the slag and electrode, as well as the temperature of the slag pool on the P content in the metal pool were discussed. In order to achieve a low-P ingot of no more than 0.015%, the corresponding maximum P content in slag under the condition of a certain P content in the electrode was proposed.

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