한국주조공학회

General criteria for the risering design o f steel castings and commercial codes for the flow and solidification analysis were used to design the optimized risering in V-process. Three type o f specimens were chosen including thin plates and a thick disc. Sided riser installed in the front o f a plate casting was effective to prevent the shrinkage defects and to increase the casting yield ratio. Exothermic sleeve and chill were also effective. It was possible to apply the general criteria for the risering design o f steel castings to V-process. Temperature o f a mold surface was expected to rise over 1,000°C in the temperature calculation considering radiation effect o f molten metal in the mold. Since weakening temperature o f the vinyl used in V- process is about 70°C, it should be emphasized that a proper coating o f the vinyl film is necessary to prevent the possibility o f burning out o f the vinyl by the molten metal.

Vacuum molding process, Risering design, Radiative heat, Vinyl coating.