| 摘要 |
PROBLEM TO BE SOLVED: To prevent the recarburization by C residues accompanying expending of a foamed pattern material. SOLUTION: This method consists of steps of; forming a pattern by the foamed pattern material copolymerized with an EPMMA(expanded polymethyl methacrylate) and an EPS(expanded polystyrene), forming a mold coat attaining air permeability after drying of >=9.0 on the surface of the pattern, drying the mold coat applied to the surface of the pattern, packing the circumference of the pattern coated with the mold coat with molding sand and pouring molten steel. The gas produced by accompanying the pouring of the molten steel is sucked through the mold coat and the molding sand and is discharged outside the system. |
