Chemical segregation behavior under thermal aging of the low-activation F82H-modified steel

In this work, thermal aging of the low-activation F82H-modified steel has b een performed at temperatures in the range 300-600 degreesC during periods up to 5000 h. A detailed mechanical and microstructural characterization ha s been carried out in the aged materials, as well as in the as-received sta te material for reference. Auger electron spectroscopy (AES) analysis has b een performed for these materials to study the microchemistry at the grain boundaries. The results show a decrease of the impact properties after agin g at 600 degreesC that has been related to the precipitation of the Laves p hase. Auger analyses show chromium enrichment and iron depletion at grain b oundaries in all material conditions. In addition, sulphur and tungsten hav e been observed by this technique at grain boundaries, their presence and d istribution being dependent on the material state. (C) 2000 Elsevier Scienc e B.V. All rights reserved.