TENSILE BEHAVIOR OF ALLOY 800H AS AFFECTED BY AGEING, STRAIN RATE AND NOTCHES

摘要

The objective of this work was characterizing the mechanical behavior in tension of Alloy 800H at the ambient temperature. Quasi-static tests were performed using an electro-mechanical universal testing machine, while a tensile split Hopkinson bar apparatus was used in the dynamic tests. The testing program was designed to elucidate the effects of: (a) material ageing, (b) strain rate, (c) strain-rate history, and (d) notches. The following conclusions were made: (a) Thermal aging at 900°C for 24 hrs leads to a slight increase in strength, and a decrease in ductility, (b) The flow stress is sensitive to strain rate. The apparent and true strain-rate sensitivity parameters decrease with increasing strain. (c) The alloy response to strain-rate history appears similar to that of other FCC metals. (d) The alloy response is notch sensitive. The notch-strength ratio increases with notch sharpness.