Through compound modification treatment for coating with help of adding sub-nano RE alloy and alkali metal salt during centrifugal casting thick-walled casting steel sleeve

the solidification sequence of the steel sleeve could be controlled to reduce the undercooled rate of outer solidification of steel sleeve and refine grain size as well as controlling the directional growth of carbide in the steel sleeve

resolving the problems of thermal transferring during solidification process and eliminating the presence of crack.Based on the Lewis acid-base theory from the chemical point of view

the modification mechanism of the cerium-based rare earth alloy on steel was analyzed.The sulfur content in the steel sleeve was controlled.Subnano particles can greatly increase the number of heterogeneous nucleation substrate

and further reduce the solidification undercooling of outer steel sleeve as well as improving the coating suspension.After the steel sleeve solidified

the collapsed coating can be reclaimed

realizing green casting.