Influence of impurities and grain size on the creep of polycrystalline copper in reactor irradiation

Abstract

Studying the radiational, creep of metallic materials is important for the goal-directed creation of steel and alloys for nuclear power plants. To obtain the required properties, alloying and various treatment methods (thermal, thermomechanical, etc.) must be used in most cases to produce a particular structure, with a particular grain size. Therefore, most investigations have been of complex alloy steel [1-3], which is characterized by a wide range of structural transformations. This leads to certain difficulties in the theoretical interpretation of the results obtained. Usually, the relative proportion of alloying elements in the alloys ranges from a few to a few tens of percent. The influence of small admixtures and the grain size on the creep rate has not been adequately studied, however, especially in conditions of reactor irradiation in a broad temperature range. Experimental data on the steady creep of polycrystalline copper of high purity (99.99 and 99.95%) at a pressure of 40 and 50 MPa and a temperature of (0.31-0.52)T m in the channel of a WR-K reactor with a neutron-flux density of 1.4"1016 sec-l.m -2 are outlined below. The experimental ap-