Reaction of Al-Killed Manganese Steel with Ladle Slag

Some laboratory experiments are carried out to investigate the reaction between manganese steel and ladle slag. It is found that as expected when the slag basicity [R=w(CaO)/w(SiO2)] is sufficiently low, for example, R<4, the dissolved Al in conventional Al-killed steel could reduce the SiO2 component of the slag. In the case of manganese steel grades [w(Mn): 6-20%, w(Al): 0.025%], the reduction of SiO2 by dissolved Mn becomes much more profound compared with that by dissolved Al, resulting in the increase of MnO in slag. When the Mn content is high enough, for example, w(Mn)=20%, the reaction between the MgO in slag and the dissolved Mn in steel is also very evident. High slag basicity can restrain the reduction of SiO2 by dissolved Mn, but the reaction between MgO and Mn can still take place to generate MnO in slag. High-basicity refining slag (R>4) is recommended for manganese steel grades.