THE DEVELOPMENT OF AUSTENITIC STAINLESS STEELS AS LOW ACTIVITY STRUCTURAL MATERIALS FOR FUSION REACTORS
Based on published information the feasibility has been examined of designing low activity austenitic stainless steels to replace conventional steels AISI 316, 320 and 321 and proprietary steel FV548 as first wall and blanket materials in fusion reactors. Determining criterion for alternative compositions: the contact gamma ray dose rate associated with the induced radioactivity is not to exceed 2.5 x 104U-4U5 Gyh**-1 after 100 years. The design approach adopted: replacement of high activity elements in conventional stainless steels with elements exhibiting low residual dose rates, while retaining the fully austenitic structure and equivalent transformation characteristics and mechanical properties. The major replacements suggested were Ni by Mn-N combinations, Mo by W, Ti and Nb by Ta; the low activity steels were to be assessed with regard to: the requisite low level of long term dose rate; constitution, with respect to the austenite/ferrite ratio phase stability, (transformation of austenite to martensite and precipitation of sigma phases); general cold working and formability; void swelling characteristics; and mechanical properties and creep resistance. In terms of these criteria the alternative alloys are expected to have similar characteristics to those of the established steels but with higher proof stress values and tensile strengths.
Bibliographic Reference: WRITE TO HER MAJESTY'S STATIONERY OFFICE, P.O. BOX 276, LONDON SE1 9NH (UK) MENTIONING REPORT CLM-R 255, 1985, PRICE: UKL 5.00
Record Number: 1989125020300 / Last updated on: 1987-02-01
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