The effects of adding Ce(0-0. 32% ) -Mg(0-0. 04% ) alloy on the as-cast inclusions and solidification organization of GCr15 bearing steel are investigated. The results show that the addition of Ce-Mg alloy can lead to the modification of inclusions and the generation of a large number of Ce-and Mg inclusions with regular shape

fine size and disperssed distribution ；and the inclusions are more fine and diffuse as 0.016% [ Ce] and 0.002% [ Mg]. With the increase of the mass fraction of Ce-Mg alloy

the distribution of carbides in the as-cast structure of steel becomes more uniform and the reticular carbide network structure becomes thinner

and as 0.016% [ Ce] and 0. 002% [ Mg]

the pearlite lamellae is the thinner and the lamellae spacing is the minimized. The addition of Ce-Mg alloy can significantly reduce the segregation of C and Cr elements between dendrites and dendrite stem

and reduce the dendrite spacing to hinder the coarsening of dendrites.