高Si球状黒鉛鋳鉄の切欠き強度とその構造部材としての考察

抄録

In this study, the notch strength σ_B^notch was investigated for high silicon solid solution strengthened ferritic ductile cast iron in comparison with the tensile strength σ_B^smooth. High speed tensile tests were conducted on notched and smooth specimens at various strain rate and temperatures. The strain rate-temperature parameter (R parameter) is found to be useful for evaluating the temperature and strain rate upon the notch strength. The required range of R parameter was investigated for welded structural members in several industrial fields. The notch strength σ_B^notch is always larger than the tensile strength at room temperature σ_B,^smooth_RT in the range of R parameter required for the welded structures. Therefore, tensile strength σ_B,^smooth_RT is confirmed to be more useful than Charpy absorbed energy for the structural design. It is expected that the high Si ductile cast iron has wide industrial application potentiality.