Microstructure evolution and yield strength of CLAM steel in low irradiation condition

The microstructure and yield strength of China low activation martensitic (CLAM) steel were observed and tested. The evolution of defects, including He bubbles and dislocation loops, and MC carbides were analyzed. According to the microstructure observation results, a two-step simulation model was established to analyze the relationship between microstructure and strength. For the first step, a rate theory model was used to simulate the evolution of defects (He bubbles and dislocation loops). The incubation, nucleation and growth stage of defects were shown by simulation results. For the second step, the simulation results of defect evolution were added into a superposition strengthening model, which combined different strengthening methods, to simulate the yield strength of CLAM steel in high temperature and irradiation condition. Based on both experimental and simulation results, the effect of high temperature and irradiation on microstructure and strength was discussed in CLAM steels. The simulation results of yield strength were basically consistent with experimental results.