Research on elastic-plastic creep damage of notched P92 steel specimens

Creep tests were performed on P92 steel specimens with notches of three different sizes at 650 degrees C. The results showed that the specimens switched from exhibiting ductility to showing brittleness at their center and at the notch root under multiaxial stress, but to varying degrees. This transformation was accompanied by a decrease in the reduction in area as well as in the number of dimples in the sample cross-section. The multiaxiality had a marked impact on the precipitation of the secondary phase, with its value determining the extent of precipitation of the secondary phase at the center and the root of the notch during creep. Using finite element analysis, an elastic-plastic creep damage model is embedded into the interface program and the creep behavior of the notched specimens was simulated. The results showed that plastic deformation at the notch root can accelerate specimen damage.