Dependency of tensile strength of ductile cast iron on strain rate and temperature

The dependency of the tensile strength sigma(notch)(B) and the notch strength sigma(notch)(B) strain rate and temperature were investigated for conventional ferrite-pearlite type ductile cast iron (JIS-FCD500) to make clear the applicability of ductile cast iron to components for welded steel structures. High speed tensile tests were conducted on notched and smooth specimens with varying strain rate and temperature. Charpy absorbed energy was also evaluated on notched specimen with varying temperature. It is found that the tensile strength is in a good relationship with strain rate-temperature parameter R for the wide range of strain rate and temperature. With decreasing R parameter, both sigma(notch)(B) smooth and sigma(notch)(B) increase even when Charpy absorbed energy starts decreasing sigma(notch)(B) It should be noted that the notch strength . B notch is always larger than the tensile strength at room temperature sigma(B,) (smopoth)(RT) in the range of R parameter required for the welded structures. Therefore, the tensile strength sigma(B,) (smopoth)(RT) is confirmed to be useful for the structural design.