The Effect of Hydrostatic Pressure on Plastic Deformation and Creep of Polycrystalline Metals at Elevated Temperatures

Abstract

It has been the object of the present study to elucidate the effect of hydrostatic stress on the mechanical behavior of polycrystalline metals at elevated temperatures. In the studies hitherto made by authors, the effect of hydrostatic stress on metallic tensile creep and torsional creep was investigated through the tests under combined hydrostatic pressure at room temperature. The question concerning the pressure effect under the influence of elevated temperatures has, however, been left still for further inquiry. From (The present) analytical and experimental studies on tensile plastic deformation and tensile creep under hydrostatic pressure at elevated temperatures, the following conclusions have been made.(1) The effect of combined hydrostatic pressure on the plastic flow stress of polycrystalline metals at elevated temperature is observable in the region of large plastic deformation. Therefore, it is necessary to consider the influence of hydrostatic stress in the yielding condition at this region.(2) The effect of concentrated pressure on metallic creep results in decrease in the strain rate of second creep stage at elevated temperature as the same behavior at room temperature. The effect of hydrostatic pressure on metallic creep at elevated temperature may be more intensive than that on the static tensile strength at the same temperature.