scholarly journals Dependence of the Clogging Possibility of the Submerged Entry Nozzle during Steel Continuous Casting Process on the Liquid Fraction of Non-Metallic Inclusions in the Molten Al-Killed Ca-Treated Steel

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1205
Author(s):  
Weifu Li ◽  
Yi Wang ◽  
Weijian Wang ◽  
Ying Ren ◽  
Lifeng Zhang
Keyword(s):  
Liquid Fraction ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Liquid Inclusion ◽  
Inclusion Composition ◽  
Casting Condition ◽  
Nozzle Clogging ◽  
Liquid Phases ◽  
Metallic Inclusions ◽  
Inclusion Zone

In the current study, the nozzle clogging behavior and inclusion composition in Al-killed Ca-treated steels were observed to investigate the relationship between the liquid fraction of non-metallic inclusions and the clogging possibility of the submerged entry nozzle. Clogging materials were mainly MgO-Al2O3 with less than 20% liquid phases, while most of the inclusions were full liquid CaO-Al2O3-MgO in tundish at the casting temperature. Thus, it was proposed that the nozzle clogging can be effectively avoided by modification of solid inclusions to partial liquid ones rather than full liquid ones. There was a critical value of liquid fraction of inclusions causing the nozzle clogging. A critical condition of the inclusion attachment on the nozzle wall was a function of cosθN−S+cosθI−S<0. With the increase of T.Ca content in steel, the evolution route of inclusions was solid MgO-Al2O3→liquid CaO-Al2O3-MgO→solid CaS and CaO. To avoid the clogging of the submerged entry nozzle (SEN) under the current casting condition, the appropriate T.Ca concentration range in Al-killed Ca-treated steels can be enlarged from the 100% liquid inclusion zone of 10–14 ppm to the 20% liquid inclusion zone of 4–38 ppm.

scholarly journals Thermodynamic and Experimental Studies on Al Addition of 253MA Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 433 ◽  
Author(s):  
Yandong Li ◽  
Tongsheng Zhang ◽  
Chengjun Liu ◽  
Maofa Jiang
Keyword(s):  
Phase Diagram ◽  
Continuous Casting ◽  
Experimental Studies ◽  
Casting Process ◽  
Al Alloy ◽  
Liquid Region ◽  
Continuous Casting Process ◽  
Nozzle Clogging ◽  
Calphad Technique ◽  
Liquid Phases

To solve the nozzle clogging issue in the continuous casting process of 253MA steel, a method of modifying solid inclusions to liquid phases is proposed. The CALPHAD technique was employed to predict the liquid region of the Al2O3-SiO2-Ce2O3 system. Then a thermodynamic package based on the extracted data during the phase diagram optimization process was developed. This package was then used to compute the appropriate aluminum addition, which was 0.01% in 253MA steel. The Si-Al alloy was chosen as the deoxidant according to the thermodynamic analysis. The solid inclusions were ultimately modified to liquid phases at 1500 °C when cerium was added through the equilibrium experiments in a MoSi2 tube furnace.

Study of Calcium Treatment in Steel Ladles for the Modification of Alumina Inclusions to Avoid Nozzle Clogging during Casting

2020 ◽  
Vol 978 ◽  
pp. 12-20
Author(s):  
Sujata Devi ◽  
R.K. Singh ◽  
Niladri Sen ◽  
N. Pradhan
Keyword(s):  
Volume Fraction ◽  
Submerged Entry Nozzle ◽  
Steel Ladle ◽  
Liquid Inclusion ◽  
Ladle Furnace ◽  
Calcium Treatment ◽  
Total Oxygen ◽  
Nozzle Clogging ◽  
Calcium Addition ◽  
Casting Nozzle

Presence of non-metallic inclusion deteriorates quality of steel and causes nozzle clogging during casting. Nozzle clogging eventually leads to a disruption of normal casting operations. This happens when solid alumina inclusions get accumulate in the nozzle of submerged entry nozzle (SEN). Therefore, it is required to understand the inclusion characteristics (shape, size and chemistry), which forms during the steelmaking process. Calcium is added in the steel ladle furnace (LF) in the form of CaSi wire to modify inclusions and to desulphurize steel. The range in which all the oxides become liquid and no solid sulphides begin to form is regarded as the "optimum window" or “liquid inclusion window” for calcium treatment. It is a target to obtain this calcium addition window, during calcium addition in the ladle furnace. This window mainly depends on the sulfur and total oxygen contents of the liquid steel bath. In the present study, inclusions characteristics such as volume fraction of inclusions, inclusion rating and EDS analysis of inclusions has been carried out using SEM-EDS. Thermodynamic study is carried out using thermodynamic software FACTSAGE and databases to find out formation of various calcium aluminates and the precipitation of CaS. Results show that liquid inclusion window mainly depends mainly on the sulphur level, total oxygen and aluminum content in the steel. These windows will help in calculation of calcium addition range for optimizing the addition of calcium in the ladle. These nomograms have been validated with actual plant condition to reduce the nozzle clogging during continuous casting.

Inclusions, lining materials and nozzle clogging during middle carbon steel billet continuous casting process

2008 ◽  
Vol 105 (2) ◽  
pp. 72-79 ◽  
Author(s):  
Shihong Liu ◽  
Xinhua Wang ◽  
Xiangjun Zuo ◽  
Yufeng Wang ◽  
Lifeng Zhang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Nozzle Clogging ◽  
Steel Billet ◽  
Billet Continuous Casting

Semi-Solid Casting of Pure Magnesium

2019 ◽  
Vol 285 ◽  
pp. 464-469 ◽  
Author(s):  
Ulyate Andries Curle ◽  
Jeremias D. Wilkins
Keyword(s):  
Temperature Interval ◽  
Liquid Fraction ◽  
Thermodynamic Temperature ◽  
Casting Process ◽  
Pure Magnesium ◽  
Time Interval ◽  
Thermal Arrest ◽  
Solidification Temperature ◽  
Semi Solid ◽  
Solid Liquid

Semi-solid processing works on the principal of a solidification temperature interval of a substance. The substance is heated to a temperature within this interval so that there exists a related solid-liquid fraction ratio. The substance with this phase structure is then shaped by a forging or casting process. It has been stated before that it is impossible to semi-solid process and cast pure metals or eutectic alloys due to their thermodynamic temperature invariance, meaning that there is no temperature interval. It was demonstrated recently that it is possible to semi-solid casting high purity aluminium (Curle UA, Möller H, Wilkins JD. Scripta Materialia 64 (2011) 479-482) and the Al-Si binary eutectic (Curle UA, Möller H, Wilkins JD. Materials Letters 65 (2011) 1469-1472). The working principal is that there exists a time interval during thermal arrest during which solidification takes place with a solid-liquid fraction ratio until all the liquid is consumed upon cooling. The aim with this work is to demonstrate that pure magnesium can also be rheo-high pressure die cast (R-HPDC) with the system developed at the CSIR in South Africa. Magnesium is notoriously difficult to cast due to the thermal properties of magnesium. The metal was poured into a cup, processed for about 6 seconds after which it was HPDC into a plate. The microstructure of the casting consists of a structure that was solid and a structure that was liquid during thermal arrest at the time of casting.

scholarly journals Ladle Nozzle Clogging during casting of Silicon-Steel

2019 ◽  
Vol 38 (2019) ◽  
pp. 813-821
Author(s):  
Wei Kong ◽  
Ying-Feng Chen ◽  
Da-Giang Cang
Keyword(s):  
Melting Point ◽  
Continuous Casting ◽  
Slide Gate ◽  
Casting Process ◽  
Silicon Steel ◽  
High Melting ◽  
High Melting Point ◽  
Continuous Casting Process ◽  
Nozzle Clogging ◽  
Flow Rates

AbstractTo figure out the reason causing ladle nozzle clogging during a continuous casting process (or CC for short) for the silicon steel and get away to solve it, this paper studied the theoretical calculation of flow rates during casting, inclusions around the slide gate where ladle nozzle clogging happened, and Ca-treatment on refining units for producing the silicon steel. The results showed that: The bigger diameter of a nozzle or less nozzle clogging can guarantee an enough flow rate for reaching the target casting speed. Ladle nozzle clogging can be predicted by analyzing the percentage of a slide gate being opened. Al2O3 and its composite inclusions were the main ones which cause the nozzle clogging during the CC process of the silicon steel. Ca-treatment could transform those high melting point inclusions into C12A7 by adding Si-Ca wires and prevent the ladle nozzle clogging of the silicon steel.

Characterization of Non-Metallic Inclusions in API Steel Grades Using Automated Energy Dispersive X-Ray

2018 ◽  
Vol 916 ◽  
pp. 217-220
Author(s):  
Masoud Al-Gahtani ◽  
Sunilkumar Pillai ◽  
Ahmad Al-Raddadi
Keyword(s):  
Inclusion Composition ◽  
X Ray ◽  
Steel Making ◽  
Metallic Inclusions ◽  
Hydrogen Induced Cracking ◽  
Steel Processing ◽  
Steel Grades ◽  
Formation And Evolution ◽  
Scanning Electron

Non-metallic inclusions in API steel grades deteriorate steels’ mechanical properties and their resistance to hydrogen induced cracking. The formation and evolution of inclusion during liquid steel processing was investigated by analyzing samples taken from different stages of the steel making process in API X52 and X60 steel grades. Scanning electron microscope (SEM) with automated feature EDX analyzer (INCAF 250) was used to identify each inclusion in terms of its size, area and composition. It was found that non-metallic inclusions in API X52 and X60 grades from steelmaking and casting samples were mainly Al2O3, Ca–Al and Ca-Mg-Al. In this work changes in inclusion composition, size and area fraction from ladle processing to casting were mapped and this information was used to improve steel cleanness and product quality.

scholarly journals Numerical Modelling of Metal/Flux Interface in a Continuous Casting Mould / Modelowanie Numeryczne Powierzchni Międzyfazowej Metal/Ciekły Żużel W Krystalizatorze Do Ciągłego Odlewania Stali

2015 ◽  
Vol 60 (4) ◽  
pp. 2905-2912 ◽  
Author(s):  
J. Jowsa ◽  
M. Bielnicki ◽  
A. Cwudziński
Keyword(s):  
Liquid Steel ◽  
Steel Casting ◽  
Liquid Slag ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Research Areas ◽  
Slab Casting ◽  
Metal Flux ◽  
Continuous Casting Mould

The behaviour of liquid slag in the mould is one of the key research areas of the continuous steel casting process. Numerical simulations of steel casting in the mould equipped with submerged entry nozzle, intended for slab casting, have been carried out within the study. For modelling the behaviour of the interfaces of the liquid steel - liquid slag - air system, the VOF method was employed. In the conducted simulations, seven different procedures for the discretization of the interface of individual phases were tested. The computation results have revealed that the “entrapment” of fine slag portions into liquid steel occurs in the system under investigation; the cause of this phenomenon is explicated by the Kelvin-Helmholtz theory.

Effect of Bottom Structure of Submerged Entry Nozzle on Flow Field in Ultra-Thick Slab Continuous Casting Mold

2010 ◽  
Vol 154-155 ◽  
pp. 840-845 ◽  
Author(s):  
Xin Xie ◽  
Deng Fu Chen ◽  
Qiang Liu ◽  
Jia Long Shen ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Flow Pattern ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Surface Flow ◽  
Water Model ◽  
Continuous Casting Mold ◽  
Flat Bottom ◽  
Thick Slab ◽  
Flow Intensity

Submerged entry nozzle (SEN) bottom structure plays an important role in determining the flow pattern in continuous casting process. This work applies a water model to evaluate the pointed-bottom, flat-bottom and recessed-bottom nozzle performance in ultra-thick slab mold. The jet properties and surface flow are compared for the three kinds of nozzles quantitatively. The results show that flat-bottom and recessed-bottom nozzles are similar in flow pattern, but the pointed-bottom nozzle has smaller jet angle, thinner flow pattern, larger surface asymmetry rate, and higher surface flow intensity.

scholarly journals Influence of Submerged Entry Nozzle Port Blockage on the Meniscus Fluctuation Considering Various Operational Parameters

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 269 ◽  
Author(s):  
Manish Kumar ◽  
Praveen Mishra ◽  
Apurba Kumar Roy
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Wave Amplitude ◽  
Water Flow Rate ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Water Model ◽  
Maximum Height ◽  
Operational Parameters ◽  
The Right

The continuous casting process (CCP) is the most vital part of steelmaking. The flow pattern near the submerged entry nozzle (SEN) and mould greatly influence the quality of the slab produced. The present investigation was carried out to gain knowledge regarding the meniscus fluctuation under different nozzle port blockage conditions by water model experiments. The experiments were carried out to study the effect of no blockage, 25% blockage, 50% blockage, and 75% blockage of the nozzle port on mould-level fluctuations. The result shows that when the liquid flow rate increases, the wave amplitude increases. In these experiments, the average and maximum meniscus fluctuations were measured while changing different variables such as the water flow rate, gas flow rate, and one-side percentage blockage of the SEN port while the other side was fully open. The observation shows that when the port size decreases, the fluid steel mixed from the obstructing side to the open side results in asymmetry. The average and maximum wave amplitude increases with decreasing submergence depth. It was observed that the maximum height of the standing waves in the mould continued rising on the non-blocked side of the SEN. Blockage increases from 25% to 75%, and with 75% blockage of the right side of the SEN port, the mould-level fluctuation at the left side of the mould was extreme, while that of the right side was relatively quiet.

Sign in / Sign up

Export Citation Format

Share Document