The invention belongs to the technical field of
casting, and particularly relates to a process for improving the appearance quality of a
casting by using a sand-isolating chilling block, which comprises the following steps: step 1, during molding or core making, firstly paving a layer of
molding sand between risers or in a hot spot area; step 2, fixing the chilling block by using
molding sand or supporting nails to ensure that the position of the chilling block is stable; 3, sand is discharged to wrap the chilling block, and it is ensured that a sand layer is firm through compaction operation; 4, after the
molten steel is poured, heat of the
molten steel is conducted to the chilling block through the sand layer, the local
cooling speed of the
casting is increased, and sequential solidification is achieved; and 5, after pouring, heat preservation is conducted till box opening is conducted, and an intact casting is formed. According to the invention, a layer of
molding sand with a specific thickness is placed between the external chilling block and the mold, so that the external chilling block is converted into the sand insulation chilling block, and in order to ensure that the chilling block achieves the effect of
process design requirements and can effectively play a chilling role on a casting, the thickness and size of the chilling block and the thickness of a sand
insulation layer can be properly adjusted according to the size of a hot spot of the casting.