Effects of Rare Earth Lanthanum on Formation of Inclusions in Q450NQR1 Steel for Railway Carriage
In this paper,the effects of lanthanum content on inclusions in steel are studied by the induction furnace experiment and thermodynamic calculations. It was concluded that the rare earth oxysulfide was formed firstly,then alumi-nate,oxide,carbide and sulfide of rare earth lanthanum were formed as well as lanthanum-silicon and lanthanum-alumi-num intermetallic compounds and rare earth hydride with smaller reaction trend were formed finally under the thermodynamic condition of molten steel of Q450NQR1 steel for railway carriage. It is obtained that the inclusions of LaAs and LaP could be generated during solidification process through the calculations with Ohnaka segregation model.
steel for railway carriagerare earth lanthanumGibbs free energy of reactionformation of inclusions