GAS DESORPTION PROPERTIES OF LOW-ACTIVATION FERRITIC STEEL AS A BLANKET OR A VACUUM VESSEL MATERIAL

The gas desorption properties of low-activation ferritic steel (F82H) were evaluated by thermal desorption spectroscopy (TDS), and compared with those of austenitic steels (316SS and 316LSS). The major desorbed gas species of F82H were CO, H2O, CO2 and H-2. The fraction of oxygen -containing species such as CO, CO2 and H2O to the total outgassing am ount was 98%. The gas desorption behavior was very similar to the case of 316SS. The gas desorption spectra for F82H show the required preba king temperature becomes higher than 700 K. For the F82H sample expose d to atmosphere, the gas desorption properties were examined. As the t ime of exposure increase, desorption amounts of H2O and CO largely inc reased. This increase may be due to the corrosion in atmosphere. (C) 1 998 Elsevier Science S.A. All rights reserved.