Abstract
In previous research, the phenomenon of blue brittleness occurred on the cold-rolled Alloy 600 tensile test in simulated BWR air-saturated coolant environments at 200℃. Blue brittleness is the manifestation of dynamic strain ageing (DSA). When blue brittleness of metal occurred, Alloy 600 would be necking early which indicated degradation of mechanical properties. The objectives of this study are to understand the characteristics of DSA observed on Alloy 600 under simulated BWR coolant environments with hydrogen water chemistry (HWC) and its influence on mechanical properties. Stress-strain curves were obtained from the slow strain rate tensile (SSRT) test to evaluate mechanical properties. Cold work by uniaxial tension can produce specimens with uniform plastic deformation, by which the interaction of solute atoms with dislocations can be studied when DSA occurred. Effects of HWC on DSA can be understood from tensile test of different amount of cold work and temperature at a strain rate of 10-6/s. The effect of mechanical properties in HWC were investigated, such as: Blue brittleness, the type D serrations, the intense strain-localization-induced fracture for cold-worked specimens by uniaxial tension and the minimum value of reduction of area at 300℃.