METHOD FOR ENHANCING SELF-FEEDING ABILITY OF HEAVY SECTION CASTING BLANK

摘要

The present invention relates to the field of casting blank manufacturing, in particular to a method for enhancing the self-feeding ability of a heavy section casting blank, which can solve the problems of poor centre quality, surface crack and high rejection rate of the heavy section casting blanks in the prior art. By controlling the outer cooling conditions of different solidification stages of the casting blank, the present invention quickly solidifies and crusts the outer surface of the casting blank to increase the strength and prevent surface crack at first, and then performs thermal insulation on the casting blank surface such that large area of the core forms the mushy region such that the solidified layer of the casting blank surface is maintained at a relatively high temperature to facilitate realization of the plastic deformation, thus realizing synchronous solidification and solid movement in the subsequent solidification and shrinkage processes of the casting blank, fulfilling the aim of radial self-feeding of the high-temperature deformable metal, eliminating the inner shrinkage voids and surface crack, and obviously eliminating the inner shrinkage of the casting blank. The present invention is applicable to the heavy section metal castings, in particular to the round and square heavy section casting blanks which have a large height-diameter ratio and cannot eliminate the axis shrinkage pipe through the feeder head.