[Interfacial Energy]
Interfacial phenomena and thermophysical properties of high-temperature liquids-Fundamental research of steel processing using electrostatic levitation

RESEARCH OVERVIEW

• Keeping high interfacial tension between molten steel and slag is necessary during continuous cast processing. This experiment seeks to study ways of preventing drop-off slag particles from falling into molten steel during processing. It is necessary to measure interfacial tension and phenomena accurately, but it is difficult to make core-shell structures of liquid metal covered by oxide melts under 1-g conditions on Earth. It is also difficult to levitate and melt oxides (included slag) on Earth.
• This research collects data on the thermophysical properties (including Interfacial tension) between molten Iron (Fe) and slag, which cannot be obtained on Earth. This research also provides observational results on interfacial vibration phenomena that occurs between molten steel and slag.
• Containerless approaches, which use the Electrostatic Levitation Furnace (ELF), can provide data to help better understand the interfacial phenomena between the molten steel and slag system by using core-shell structure droplets. By establishing the interfacial tension measurement technique in this research, this represents a powerful tool to study the interfacial phenomena of two phase fluids on Earth. The research provides insight to contribute to the precise process control for the production of high performance steels.

DESCRIPTION

The purpose of Interfacial phenomena and thermophysical properties of high-temperature liquids-Fundamental research of steel processing using electrostatic levitation (Interfacial Energy) is to clarify the interfacial phenomena between molten steel and the oxide melts, usually called slag, during the steel processing from the viewpoints of thermophysical properties of these liquids. Using an Electrostatic Levitation Furnace, the research team is able to obtain data on the density, surface tension, and viscosity of oxide melts, while also trying to obtain interfacial tension data between the molten steel and the oxide melts by using the oscillating drop technique. The research work contributes to precise process control for the production of high performance steels.

This experiment is carried out twice: The goal of the first trial is to acquire data on the thermophysical properties of oxides and two-phase droplets, by way of comparison of the information produced between samples produced in space and on Earth. The goal of the second trial is to obtain data on the thermophysical properties of the two-phase droplets that cannot be obtained on Earth.

The first experiment is performed during Increment 43/44.

SPACE APPLICATIONS

Density, surface tension and viscosity control the interaction between molten steel and slag, but on Earth, gravity also contributes to the formation of impurities. This investigation uses an Electrostatic Levitation Furnace (ELF) to study the interface between molten iron and slag without gravitational effects. Researchers can obtain new data on the interface between steel and slag that they could not obtain on Earth. Results also contribute to the development of containerless processing technology for use in microgravity.

EARTH APPLICATIONS

Experiments in this investigation yield a new understanding of the physical properties controlling slag formation, benefiting the steel industry on Earth. They also improve the reliability of computer models that simulate liquid mixing, which are useful in many materials science and industrial applications. Results also benefit research on two-phase liquids using levitation technology.

OPERATIONAL REQUIREMENTS AND PROTOCOLS

This experiment is carried out twice. Samples are required to be returned in the Sample Holders.

WATANABE Masahito [Gakushuin University]