2022 年 94 巻 8 号 p. 465-471
Japanese Industrial Standards (JIS G 5502 : 2001) for ductile cast iron defines tensile properties using two types of cast samples (Y Block type and Knock off type). However, their tensile strength and elongation are expected to be different since their casting weight and sand mold material are not specified. We performed experiments using two types of cast samples with different mold materials, and investigated measurements of tensile strength and elongation, micro structure, cooling curve of cast sample and heating curve of sand mold. The Y Block type showed lower tensile strength and higher elongation than the Knock off type. Although the changes in tensile strength and elongation due to mold material could not be confirmed, the cooling curve and microstructure of green sand mold differed from the CO2 type and self-curing type.