scholarly journals Investigation on the Slag-Steel Reaction of Mold Fluxes Used for Casting Al-TRIP Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 398 ◽  
Author(s):  
Kaitian Zhang ◽  
Jianhua Liu ◽  
Heng Cui
Keyword(s):  
Quality Control ◽  
Continuous Casting ◽  
Melting Temperature ◽  
Equilibrium Model ◽  
Trip Steel ◽  
Liquid Slag ◽  
Casting Process ◽  
Slag Layer ◽  
Lubrication Performance ◽  
Solid Slag

The reaction between [Al] in molten steel and (SiO2) in the liquid slag layer was one of the restrictive factors in the quality control for high Al-TRIP steel continuous casting. In this work, the composition and property variations of two slags during a slag-steel reaction were analyzed. Accordingly, the crystalline morphologies of slag were discussed and the solid layer lubrication performance was evaluated by Jackson α factors. In addition, a simple kinetics equilibrium model was established to analyze the factors which affected SiO2 consumption. The results reflected that slag-steel reacted rapidly in the first 20 minutes, resulting in the variation of viscosity and the melting temperature of slags. The slag-steel reaction also affected the crystal morphology significantly. Slag was precipitated as crystals with a higher melting temperature, a higher Jackson α factor, and a rougher boundary with the consumption of SiO2 and the generation of Al2O3. In other words, although generated Al2O3 acted as a network modifier to decrease the viscosity of the liquid slag layer adjacent slab shell, the consumption of SiO2 led to the deterioration of the lubrication performance in the solid slag layer adjacent copper, which was detrimental to the quality control for high Al-TRIP steel. Finally, a kinetics equilibrium model indicated that it is possible to reduce a slag-steel reaction by adjusting factors, such as the diffusion coefficient k, cSiO2, ρf and Lf, during the actual continuous casting process.

scholarly journals A Study on Quality Control Using Data Mining in Steel Continuous Casting Process

2011 ◽  
Vol 10 (3) ◽  
pp. 113-126
Author(s):  
Jae-Kyeong Kim ◽  
Taeck-Sung Kwon ◽  
Il-Young Choi ◽  
Hyea-Kyeong Kim ◽  
Min-Yong Kim
Keyword(s):  
Data Mining ◽  
Quality Control ◽  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Steel Continuous Casting ◽  
Using Data

scholarly journals On Modelling Parasitic Solidification Due to Heat Loss at Submerged Entry Nozzle Region of Continuous Casting Mold

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1375
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
Yong Tang ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Steel Slag ◽  
Phase Interface ◽  
Steel Production ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Material Model ◽  
Slag Layer ◽  
Continuous Casting Mold ◽  
High Production Rate

Continuous casting (CC) is one of the most important processes of steel production; it features a high production rate and close to the net shape. The quality improvement of final CC products is an important goal of scientific research. One of the defining issues of this goal is the stability of the casting process. The clogging of submerged entry nozzles (SENs) typically results in asymmetric mold flow, uneven solidification, meniscus fluctuations, and possible slag entrapment. Analyses of retained SENs have evidenced the solidification of entrapped melt inside clog material. The experimental study of these phenomena has significant difficulties that make numerical simulation a perfect investigation tool. In the present study, verified 2D simulations were performed with an advanced multi-material model based on a newly presented single mesh approach for the liquid and solid regions. Implemented as an in-house code using the OpenFOAM finite volume method libraries, it aggregated the liquid melt flow, solidification of the steel, and heat transfer through the refractory SENs, copper mold plates, and the slag layer, including its convection. The introduced novel technique dynamically couples the momentum at the steel/slag interface without complex multi-phase interface tracking. The following scenarios were studied: (i) SEN with proper fiber insulation, (ii) partial damage of SEN insulation, and (iii) complete damage of SEN insulation. A uniform 12 mm clog layer with 45% entrapped liquid steel was additionally considered. The simulations showed that parasitic solidification occurred inside an SEN bore with partially or completely absent insulation. SEN clogging was found to promote the solidification of the entrapped melt; without SEN insulation, it could overgrow the clogged region. The jet flow was shown to be accelerated due to the combined effect of the clogging and parasitic solidification; simultaneously, the superheat transport was impaired inside the mold cavity.

scholarly journals Formation of Surface Depression during Continuous Casting of High-Al TRIP Steel

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 204 ◽  
Author(s):  
Heng Cui ◽  
Kaitian Zhang ◽  
Zheng Wang ◽  
Bin Chen ◽  
Baisong Liu ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Trip Steel ◽  
Mold Flux ◽  
Casting Process ◽  
Peritectic Steel ◽  
Al Content ◽  
Steel Slab ◽  
Oscillation Marks ◽  
High Al Content ◽  
Surface Depression

High aluminum transformation-induced plasticity (TRIP) steels offer a unique combination of high tensile strength and ductility, high impact energy absorption and good formability. The surface of the slab is prone to depressions and longitudinal cracks during continuous casting due to the high Al content in steels. Surface depressions of the 1.35 wt.% Al-TRIP steel slab in a steel works were investigated by scanning electronic microscopy (SEM) and mold fluxes with different Al2O3/SiO2 ratios were researched by thermodynamic calculations and high-temperature static balance experiments. The results show that some micro-cracks were distributed along the grain boundary in the surface depression of the slab. Inclusions containing K and Na, which were probably from mold flux, were found in the depression samples. Meanwhile, the components of reactive mold flux showed significant variation in their chemical composition during the continuous casting process of the Al-TRIP steel. A large number of depressions and irregular oscillation marks on the Al-TRIP steel slab surface were generated due to serious deterioration in the physical properties of the mold flux. Since the TRIP steel is a typical hypo-peritectic steel, the overly large thermal contraction and volume contraction during initial solidification is the intrinsic cause of surface depression. The change of mold flux properties during casting aggravates the formation of depressions.

Study on Quality Control Technology for Square/Round Billet in Panzhihua Steel

2011 ◽  
Vol 396-398 ◽  
pp. 1138-1144 ◽  
Author(s):  
Hong Pan ◽  
Guo Rong Wu ◽  
Zhi Qiang Li
Keyword(s):  
Quality Control ◽  
Continuous Casting ◽  
Continuous Caster ◽  
Casting Process ◽  
Secondary Cooling ◽  
Mold Powder ◽  
Segregation Index ◽  
Round Billet ◽  
Billet Quality

The continuous casting technologies of the new square/round billet continuous caster in Panzhihua Steel have been studied. And on this basis, the effect of process parameters of primary cooling, mold powder, secondary cooling and electromagnetic stirring (EMS) on billet quality is investigated. With these studies, the continuous casting process is optimized, and the quality of square/round billet is improved as well. Comprehensive technologies for quality control of square/round billet in Panzhihua Steel have been proposed. The results of industrial tests show that the accept rate of surface quality for square billet is 98.44%, and that is 97.42% for round billet; the comprehensive rate below level 1.0 of internal defects of center porosity, center segregation and center cracks is more than 97%, and carbon segregation index is in the range of 0.93~1.09. The quality of square/round billet can meet the requirement of consumers absolutely.

The Air Reoxidation and the Formation of Large Inclusions in Continuous Casting Process

1973 ◽  
Vol 59 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Kichinosuke MATSUNAGA ◽  
Chikakazu NAMIKI ◽  
Taiji ARAKI
Keyword(s):  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process

The Effect of Temperature Fluctuation on the Formation of Billet Surface Defect in the Initial Solidification Area

2010 ◽  
Vol 148-149 ◽  
pp. 163-167
Author(s):  
Xiao Li Jin ◽  
Zuo Sheng Lei ◽  
Kang Deng ◽  
Zhong Ming Ren
Keyword(s):  
Continuous Casting ◽  
Temperature Fluctuation ◽  
Surface Defects ◽  
Casting Process ◽  
Effect Of Temperature ◽  
Billet Surface ◽  
Maximum Value ◽  
Key Factor ◽  
Oscillation Marks ◽  
Initial Solidification

The heat transfer in steel continuous casting process under mold oscillation was calculated, and temperature fluctuation phenomena was found in the initial solidification area, the maximum value was approximate 16 °C. The effect of different continuous casting parameters on temperature fluctuation were analyzed, and the temperature fluctuation was considered to be a key factor to the formation of oscillation marks. The Index of Temperature Fluctuation(ITF) was proposed to predict the effect of temperature fluctuation on the formation of billet surface defects.

scholarly journals Reduction of CO2 Emissions in Steelmaking by Means of Utilization of Steel Plant Waste Heat to Stabilize Seasonal Cooling Water Temperature

2021 ◽  
Vol 13 (11) ◽  
pp. 5957
Author(s):  
Tomas Mauder ◽  
Michal Brezina
Keyword(s):  
Continuous Casting ◽  
Water Temperature ◽  
Co2 Emissions ◽  
Waste Heat ◽  
Cooling Water ◽  
Main Idea ◽  
Casting Process ◽  
Spray Cooling ◽  
Steel Plant ◽  
Cooling Water Temperature

Production of overall CO2 emissions has exhibited a significant reduction in almost every industry in the last decades. The steelmaking industry is still one of the most significant producers of CO2 emissions worldwide. The processes and facilities used at steel plants, such as the blast furnace and the electric arc furnace, generate a large amount of waste heat, which can be recovered and meaningfully used. Another way to reduce CO2 emissions is to reduce the number of low-quality steel products which, due to poor final quality, need to be scrapped. Steel product quality is strongly dependent on the continuous casting process where the molten steel is converted into solid semifinished products such as slabs, blooms, or billets. It was observed that the crack formation can be affected by the water cooling temperature used for spray cooling which varies during the year. Therefore, a proper determination of the cooling water temperature can prevent the occurrence of steel defects. The main idea is based on the utilization of the waste heat inside the steel plant for preheating the cooling water used for spray cooling in the Continuous Casting (CC) process in terms of water temperature stabilization. This approach can improve the quality of steel and contribute to the reduction of greenhouse gas emissions. The results show that, in the case of billet casting, a reduction in the cooling water consumption can be also reached. The presented tools for achieving these goals are based on laboratory experiments and on advanced numerical simulations of the casting process.

Sign in / Sign up

Export Citation Format

Share Document