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Title: The properties and weldability of low activation ferritic steels

Technical Report ·
DOI:https://doi.org/10.2172/6823850· OSTI ID:6823850

A series of ferritic steels patterned on the chromium-molybdenum alloys, 2 1/4Cr--1Mo, 9Cr--1MoVNb and 12Cr--1MoVW, were tested for weldability. These steels are being developed as candidates for the first wall and blanket structures of fusion reactors. Use of these materials will minimize the long term radioactive hazards associated with disposal after service. In these low activation alloys, elements which become activated during irradiation with long half lives (Mo and Nb) are replaced. The major changes include the replacement of molybdenum with tungsten, the addition of vanadium in 2 1/4% Cr steels, and the replacement of niobium in the 9% Cr steel with tantalum. These replacement elements radically modify both the mechanical properties and weldability of the alloys. In this study, the effect of the alloy modifications on the microstructure and the mechanical properties of the welds are presented. Bainitic steels (2 1/4 Cr%) usually exhibit good weldability, while the martensitic steels (5, 9 and 12 Cr%) are suspectable to embrittlement in the heat affected zone (HAZ). The objective of this study was to characterize the welded microstructure and mechanical properties of these low activation alloys. Autogeneous bead-on-plate welds were produced using the gas tungsten arc welding (GTAW) process. Microstructure, microhardness, weld bend and tensile test results are reported for the base metal, heat affected zone and fusion zone of the weld. 46 refs., 36 figs., 14 tabs.

Research Organization:
Auburn Univ., AL (USA). Dept. of Materials Engineering
Sponsoring Organization:
DOE/ER
DOE Contract Number:
FG05-86ER52139
OSTI ID:
6823850
Report Number(s):
DOE/ER/52139-90-1; ON: DE90011872; TRN: 90-027009
Country of Publication:
United States
Language:
English