Irradiation surveillance data for an A508 forging and associated weld metal

Results are presented from the testing of irradiated surveillance specimens of unstrained and pre-strained A508 forging and weld metal. Tensile, Charp y impact and fracture toughness tests were performed on material in the uni rradiated condition and following irradiation at 293 degreesC to fast neutr on fluences of less than or equal to 6.5 x 10(18) n cm(-2). Modest changes in tensile properties were measured. Shifts in the ductile to brittle trans ition temperature, taken from the Charpy impact results at the 41J level, w ere generally within expectation, though significant scatter was evident in the data. Fracture toughness data obtained from standard 12.7 mm thick com pact tension specimens exhibited significantly higher toughnesses in the du ctile to brittle transition region than predicted by the ASME XI K-IC refer ence curve. Irradiation reduced upper shelf toughness levels. Pre-strained weld metal showed the largest drop in upper shelf toughness. Supplementary experiments indicated that this response was not due to strain ageing effec ts. (C) 2000 Elsevier Science Ltd. All rights reserved.