Corrosion fatigue behavior of austenitic stainless steel in a pure D 2 O environment

Abstract

Corrosion fatigue crack growth rate tests were performed at 288 °C in high purity, deuterated water (D 2 O), and crack tips were examined for the presence of deuterium (D). A sample from the interior of the specimen (1T-CT) was analyzed for D and total D+hydrogen (H) using time of flight-secondary ion mass spectrometry (ToF-SIMS) and hot vacuum extraction. With SIMS, two regions 500 × 500 µm in size were analyzed. The first region was located immediately in front of the crack tip. The second region was a control, and was 6 mm away from the plastic zone. The deuterium concentration was found to be enhanced by a factor of 8.7–9.3 over the natural abundance in the plastic zone/crack tip while the concentration was enhanced by 5.9 in the bulk material. With no other source of deuterium, the detection of deuterium represents a unique marker. These data also provide evidence that hydrogen species are concentrated at the crack tip in fatigue crack growth processes at elevated temperature.