鍛造した球状黒鉛鋳鉄の静的強度及び衝撃特性

抄録

  The effect of the forging ratio on the static strength and impact properties was investigated in a ferritized spheroidal graphite cast iron. Graphite spheres are changed into disk shapes by forging. The tension and impact tests were performed on two kinds of specimens, graphite disks are parallel and vertical to the direction of applied tensile stress. These are termed here as parallel and vertical specimens, respectively. The tensile strength of the parallel specimens hardly changes up to 60% of the forging ratio, while that of the vertical specimens decreases monotonously with increasing the forging ratio. The elongation decreases with increasing the forging ratio in both parallel and vertical specimens. The upper shelf energy, though depending on the kind of specimens, decreases with increasing the forging ratio. The energy transition temperature of the vertical specimens is not changed by forging, while that of the parallel specimens shifts to the lower temperature with increasing the forging ratio.