Elevated-temperature fatigue characterization of transition joint weld metal and composite material in support of LMFBR steam generator development

Piping systems in Liquid Metal Fast Breeder Reactor (LMFBR) plants will require transition joint weldments between austenitic and ferritic materials. Specifically, annealed 2 1/4 Cr-1 Mo steel will be welded with ERNiCr-3 by the hot wire automatic gas tungsten-arc process. These weldments will see elevated-temperature service for periods of up to 30 years and, accordingly, prototypic weldments will require extensive mechanical property characterization. The objective of this effort was to define the strain-controlled low-cycle fatigue behavior of as-deposited and stress-relieved ERNiCr-3 weld metal and to develop test methods for establishing the cyclic behavior of heat-affected zone (HAZ) material. Low cycle fatigue and the cyclic stress-strain response for ERNiCr-3 were established over the temperature range from 295 to 866 K. A number of low-cycle fatigue tests of hourglass-shaped specimens demonstrated that the low-cycle fatigue behavior of HAZ material adjacent to the fusion line could be characterized