Abstract
It is so-called internal shrinkage cavities to cause very often hydraulic defects of a cylinder block casting for Nissan Motor after surrender. The author explained internal shrinkage cavities, investigated the chemical composition of materials, the casting temperature and the cupola operation, and obtained their most suitable values ; that is, the chemical composition is C 3.15∼3.25%, Si 2.00∼2.20%, P 0.10∼0.20, and a ordinary content of Mn and S. The casting temperature as high as possible is desireable (1450∼1470°C). The Operation of a 3t cupola is best at 50 m3⁄min of a blast volume and at 400∼500mm water of a blast pressure. (M. I.)
