Hydrothermal corrosion and steam oxidation behavior comparison of UAM and conventional Zry-4

Hydrothermal corrosion and steam exposures on ultrasonic additively manufactured (UAM) Zircaloy-4 (Zry-4) specimens were conducted to compare to wrought Zry-4 performance in both simulated pressurized water reactor (PWR) operation (330 degrees C, 15 MPa, <50 ppb oxygen, 500h) and representative accident conditions (100% H2O(g) at 700, 900, and 1100 degrees C for up to 1h). UAM Zry-4 specimens showed 50% higher mass gain in PWR conditions and 50-80% more mass gain in steam oxidation due to internal oxidation between build layers in both cases. UAM Zry-4 in 900 degrees C steam showed breakaway oxidation leading to sample deformation. Titanium used as an interlayer in the UAM process was detected in the substrate after the 1100 degrees C exposure. Additional experiments to better link as-built defects to oxidation behavior are needed. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

Hydrothermal corrosion and steam exposures were performed on ultrasonic additively manufactured Zircaloy-4 (Zry-4) specimens to compare their performance with wrought Zry-4 under simulated pressurized water reactor (PWR) operation and accident conditions. The results showed that UAM Zry-4 specimens had a 50% higher mass gain in PWR conditions and a 50-80% higher mass gain in steam oxidation. Breakaway oxidation was observed in UAM Zry-4 specimens exposed to 900 degrees C steam.