318 高ひずみ速度域における高純度鉄に対する速度急変実験(OS 材料・構造の動的特性(4))

抄録

In order to evaluate a strain rate sensitivity of a dynamic flow stress "dσ/dlogε" of iron at very high strain rates, constant strain rate tests and strain rate reduction tests are conducted for a high purity iron-14ppmC in a strain rate range from about 4×10^3/s to 2×10^4/s. The flow stress depends on strongly on the strain rate and a instantaneous strain rate plays a dominant role in the flow stress. The "dσ/dlogε" in Fe-14ppmC is compared with that obtained in Fe-lOOppmC. An effect of a difference in carbon content to the "dσ/dlogε" is not observed explicitly and an increase in impurity atoms contribute to increasing in an internal stress.