Inflow Behavior Observation of Molten Mold Powder between Mold and Solidified Shell by Continuous Casting Simulator Using Sn-Pb Alloy and Stearic Acid.

Tsutsumi, K.; Ohtake, J.-I.; Hino, Mitsutaka

doi:10.2355/isijinternational.40.601

Cited by 17 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tsutsumi et al 61) reported that the inflow ratio of mold powder during the positive strip time was 60 % of the total powder consumption, based on observations of the periodic change of the distance between the mold wall and the solidifying shell in experiments on a Sn-Pb alloy (metal) and stearic acid (flux) system. Their direct observation of the formation of oscillation marks and mold flux consumption near the meniscus concluded that most oscillation marks formed due to meniscus overflow during the negative strip time.…”

Section: Estimation Of Lubrication Consumption With Oscillation Mark mentioning

confidence: 99%

Measurement and Prediction of Lubrication, Powder Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs

et al. 2006

View full text Add to dashboard Cite

The flow of melted mold powder into the interfacial gap between the strand and the mold wall is important for productivity and quality in continuous cast slabs. Some of the mold slag (flux) consumption provides true lubrication, while much of the rest is trapped in the oscillation marks on the slab surface. This work presents measurements of powder consumption from extensive careful plant trials on ultra-low carbon steels, and a new, simple, semi-empirical model to predict slag consumption. The model predicts "lubrication consumption" by deducting the slag carried in the oscillation marks from the measured total. The oscillation mark shape is estimated from a theoretical analysis of equilibrium meniscus shape, which is based on metallographic analysis of many hook and oscillation mark shapes. The model demonstrates that the fraction consumed in the oscillation marks decreases with increasing casting speed, because the oscillation mark depth depends more on casting speed than on mold oscillation conditions. The model is validated by successful prediction of known trends of oscillation mark depth and mold powder consumption with changing various operation parameters. The model provides new insight into mold lubrication phenomena, which is important for extending casting operation to higher speeds and new lubrication regimes.KEY WORDS: continuous casting; mold powder; slag; flux; lubrication; oscillation marks; mold oscillation; stroke; frequency; modification ratio; negative strip time; positive strip time; casting speed; meniscus; models; plant experiments.ISIJ International, Vol. 46 (2006), No. 11, pp. 1635No. 11, pp. -1644 slag as shown in Fig. 1(a). The solid slag layers are glassy, crystalline, or mixtures of both 14) depending on the slag composition and local cooling rate history. [15][16][17] Several previous models of heat transfer and lubrication assume that the gap has a uniform thickness. [18][19][20] However, the real strand surface contains periodic transverse depressions called oscillation marks (OM) in Fig. 1(b). The volume of these depressions generally consumes a significant amount of slag, which greatly affects lubrication and leads to nonuniform heat transfer in the mold. 21) Thus, quantifying the oscillation mark shape is a necessary prerequisite for the prediction of lubrication and heat transfer in the mold.In this study, mold powder consumption was measured during casting trials conducted at POSCO Gwangyang Works for several different oscillation conditions and casting speeds. The measured consumptions were divided into two components: 1) the slag entrapped in the oscillation marks and 2) the remaining flux, which provides lubrication to prevent sticking, as shown in Fig. 1(b). This "lubrication consumption" is a more realistic concept to represent lubrication than total mold powder consumption.17) The oscillation mark shape is calculated by combining measured OM depths with a realistic profile based on fundamentals. 22) Correlations are found for OM depth, corresponding OM consumption, l...

show abstract

Section: Estimation Of Lubrication Consumption With Oscillation Mark mentioning

confidence: 99%

Measurement and Prediction of Lubrication, Powder Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs

et al. 2006

View full text Add to dashboard Cite

show abstract

“…[11] The friction force between the mold and solidified shell was useful in determining the lubrication behavior of mold powder. The force was observed by Tsutsumi [12] with an experimental apparatus that simulated a continuous casting machine. Also, many systems [13,14] monitoring the mechanical interaction, or friction, between the mold and strand have also been built through load cells mounted in the mold housing.…”

Section: Previous Workmentioning

confidence: 99%

“…Ѩr 2 ϩ r s g According to Newton's law of fluid flow, shear stress is related to viscosity, calculating from the velocity distribution [12] [13]…”

Section: Calculation Of Liquid Lubricationmentioning

confidence: 99%

Analysis of the nonuniform slag film, mold friction, and the new cracking criterion for round billet continuous casting

Yin

Yao

2005

Metall Mater Trans B

View full text Add to dashboard Cite

A method predicting the thickness of solid and liquid slag films is presented to understand the complicated heat transfer from the strand to mold for round billet continuous casting. A mathematical model is also developed to calculate the liquid slag lubrication and solid slag friction on the basis of mechanics of viscous fluids and the contact state between the solidifying shell and mold. And a new criterion, based on the nonuniformity of mold heat transfer around the perimeter is proposed to predict the longitudinal crack. The results show that in the upper mold the distribution of the thickness of liquid slag film is similar with that of the solid one, and both of them are nonuniform around the mold perimeter, so does the mold friction. Increasing the casting speed could advance the time of crack formation for one casting process. By comparison, the sensitive area of the longitudinal crack predicted by the new criterion corresponds to that by a stress-based crack criterion. It may lay the theoretical foundation for the on-line detection of billet quality and the visualization of the continuous casting mold process.

show abstract

“…The cold-state simulate experiments through the using of low melting point material, such as organic substances [5] or Sn-Pb [6][7][8] alloys, are convenient and efficient to study the effect of different operation parameters on the initial shell solidification behaviors. However, this method cannot reflect the actual molten steel solidification behavior, in which the mold flux infiltration in between the mold and shell was missing.…”

Section: Introductionmentioning

confidence: 99%

Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold. Part I: Experiment Process and Measurement

Zhang

Wang

et al. 2015

Metall Mater Trans B

View full text Add to dashboard Cite

A mold simulator has been successfully used to study the initial solidification behavior of the molten low carbon steel. Coupled with 2D-IHCD calculation and PSD analysis, the variations of the responding temperatures and heat fluxes, as well as the relationship between shell surface profile, heat flux, shell thickness, mold level fluctuation, and the infiltrated slag film, were investigated in this article. The results suggested that the mold high-frequency temperatures and heat fluxes above liquid steel level vary with the oscillation of the mold, and show an opposite variation pattern as those below the shell tip. The formed shell surface profile is directly correlated to the variation of high-frequency heat fluxes, where the formation of oscillation mark is associated with a sudden increase of the heat flux during negative strip time. Mold level fluctuation contributes to the formation of the extra oscillation marks. The growth of shell thickness follows the square root law, and the instantaneous solidification factor is large near the shell tip and becomes small in the area where the deep shell surface depression is formed. The thickness of the slag film in between mold and shell is in the range of 1.4 to 2.46 mm, and the crystallization of mold flux in mold/shell gap is dynamic.

show abstract

Inflow Behavior Observation of Molten Mold Powder between Mold and Solidified Shell by Continuous Casting Simulator Using Sn-Pb Alloy and Stearic Acid.

Cited by 17 publications

References 8 publications

Measurement and Prediction of Lubrication, Powder Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs

Measurement and Prediction of Lubrication, Powder Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs

Analysis of the nonuniform slag film, mold friction, and the new cracking criterion for round billet continuous casting

Mold Simulator Study of the Initial Solidification of Molten Steel in Continuous Casting Mold. Part I: Experiment Process and Measurement

Contact Info

Product

Resources

About