Effect of Heat Treatment on the Microstructure and Properties of 9Cr2WVTa Reduced Activation Steels

Abstract

The creep property of 9Cr2WVTa reduced activation steels (RAS) was studied after the optimized heat treatment, which was chosen based on the microstructure and tensile property under different heat treatment process. The microstructure and tensile fracture surfaces were observed by optical microscopy (OM) and SEM. The results show that there were significantly difference in the microstructure and tensile property of the 9Cr2WVTa RAS after different heat treatment process. According to the assessment method of static toughness, the optimized heat treatment process was chosen, which got the best static toughness on the promise of good ductility. The minimum creep rate and creep life of 9Cr2WVTa RAS under the optimized heat treatment was analyzed, the results show that the stress exponent was 27, indicating the dislocation creep mechanism. By using the extrapolation, the creep limit was estimated to be 209MPa when the minimum creep rate was 10−7%/h at 813K, which was comparable to EUROFER steels.