The invention relates to an expendable pattern
casting (EPC) molding shell paint for
casting steel, and the EPC molding shell paint comprises surface a layer fireproof paint and a back layer reinforcing paint, wherein the
surface layer fireproof paint comprises the following components in parts by weight: 80-90 parts of high-
chromium alundum
powder, 10-20 parts of calcined
kaolinite, 6-8 parts ofcalcium rectorite
powder, 1-3 parts of
sodium tripolyphosphate, 3-5 parts of polyvinyl formal solution, 0.3-0.5 part of ethoxylated
alkyl sodium sulfate, 0.6-1.0 part of polyether type modified
polydimethylsiloxane and 60-75 parts of water; and the back layer reinforcing paint comprises the following components in parts by weight: 75-85 parts of
coal gangue sand, 15-25 parts of
kaolinite, 3-6 parts of
feldspar powder, 8-13 parts of
calcium rectorite powder, 8-10 parts of
sodium tripolyphosphate, 1.5-2.0 parts of wood
fiber and 30-45 parts of water. A molding shell manufactured by the
surface layer fireproof paint and the back layer reinforcing paint has the characteristics of high strength and refractoriness, good air permeability and the like.