Teacher

prof. Fabio MIANI

Credits

6 CFU

Objectives:

The course is divided in two parts: physical chemistry of steelmaking processes and industrial steelmaking plants. Focus is any case on the basic principles.

Acquired skills:

- Use of the formalism of physical chemistry of steelmaking
- Ability to understand different steelmaking processes
- Ability to relate steelmaking processes to the technogical properties of steel

Contents:

Physical Chemistry of Steelmaking: Steelmaking thermochemistry. Free energy of formation of compounds, alloys and solution relevant to steelmaking. Raoultian and henrian activities. Equilibrium constants. Phase diagrams relevant to steelmaking. Kinetics principles useful in steelmaking (10 hours)
Physicochemical properties of steel: Binary and multicomponent solutions activity coefficients. Free energy of solution of elements in liquid Fe. Sievert's law. Nitrogen and Hydrogen solubility in liquid Fe. Fe-X diagrams in steelmaking. Solubility of CaO, CaS, MgS in liquid iron. Nitrides and carbides solubility in Fe solutions. Liquid Fe-X alloys: density, surface tension and viscosity. (5 hours)
Slags: Physico-chemical models of slags. Basicity and basicity index. Me-O-Xdiagrams relevant to steelmaking. Fe-O-MnO, CaO-MgO, CaO-SiO2, FeO-SiO2, FeO-SiO2, MgO-SiO2, CaO-Al2O3, CaO-SiO2-FeO diagrams. Activity and activity coefficients in slags. (6 hours)Equilibrium data on liquid steel-slag reactions: Oxydation of Fe, Mn, C, Si, P; sulphur reactions. Deoxydation equilibrium reaction and practises. (5 hours)
Blast furnace and oxygen steelmaking: Blast furnace layout. Oxygen steelamking: furnace charge, dynamic control of oxygen blowing, decarburisation, control of slag forming. (2 hours)
Electric steelmaking: Electric Arc Furnaces ( EAF): technology and processes. Elementary description of the electric principles of EAFs. Electrodes. Charging. Melting. Oxygen reactions. Energetic balances. Productivity. Refractories fo EAFs (5 hours)
Secondary metallurgy: Ferroalloys. Ladles and ladle refractories. Preheating. Stirring. Chill factors. Reactions at tapping. Arc reheating. Deoxidation. Desuplhurisation. Vacuum degassing. Calcium Treatment. (4 hours)
Solidification and continuous casting: Solidification phenomena. Heat flow in solidification. Ingot casting. Continuous casting: billet, bllom and slab casters. (2 hours)
Rolling metallurgy: Hot and cold rolling. Structural evolution in rolling. (2  hours)

References:

- E. T. Turkdogan Fundamental of Steelmaking Institute of Materials London 1996
- Ginzburg, Ballas Flat Rolling Fundamentals Dekker 2000
- W. Bleck Material Science of Steel, Verlag Mainz, Aachen, 200

Additional material or information on line http://www.steeluniversity.org

Type of exam:

Oral and/or thesis