Steel-Slag Reactions in Ladle Metallurgy: Mass Transfer and Steel Cleanliness
This paper discusses modeling of the kinetics of slag-based secondary steelmaking reactions which directly influence steel cleanliness.Refining reactions involving slags are commonly used in ladle metallurgy; as an example,ladle desulfurization is widely applied.The rate and extent of ladle desulfurization are affected by stirring,slag composition,degree of deoxidation,and side reactions which can affect oxygen activity at the steel-slag interface.Such side reactions include oxidation of aluminum,with possible sources of oxygen being atmospheric oxygen and reducible oxides(such as silica,iron oxide or manganese oxide)in the slag.In parallel with desulfurization,inclusions in the steel also change through interaction with the slag,in two main ways.First,inclusions float out of the steel and are removed to the slag; the rate constant for removal of micro-inclusions to the slag is approximately the same as for desulfurization,indicating that both are mainly limited by mass transfer in the steel.Second,inclusions which remain in the steel change chemically.For full slag-steel equilibrium,the activities in oxide inclusions would be the same as in the ladle slag.Limited mass transfer,specifically as a result of low concentrations of dissolved elements such as magnesium and calcium,limits the rate at which inclusion compositions change.Such changes do occur; formation of spinel inclusions in aluminum-killed steel in contact with magnesia-saturated slag is a familiar example.Examples are shown of how the rates of such changes in inclusion composition can be predicted based on assumption of mass transfer limitations and local equilibration at the steel-slag interface,and overall equilibrium in the bulk steel.Such reactions are conveniently modeled using a macro within FactSage.
ladle metallurgy mass transfer inclusions spinels
P. Chris PISTORIUS
Center for Iron and Steelmaking Research,Carnegie Mellon University,5000 Forbes Avenue,Pittsburgh PA 15213,USA
国际会议
the 6th International Congress on the Science and Technology of Steelmaking,ICS2015(第六届国际炼钢科技大会)
北京
英文
711-714
2015-05-12（万方平台首次上网日期，不代表论文的发表时间）