Interface stability of ultrasonic additively manufactured Zircaloy-4 during hydrothermal corrosion

Simulated pressurized water reactor conditions (330 °C, 15.6 MPa, ∼20 ppb oxygen) without irradiation were used to investigate the hydrothermal corrosion behavior of ultrasonic additively manufactured Zircaloy-4 up to 1000 h. X-ray computed tomography allowed for visualization of defects from processing and their progression after corrosion experiments. The specimens were found to have clear variability in the mass change data, compared to typical wrought Zircaloy-4 specimens. The variation in the mass change after exposure was attributed to weld defects connected to the specimen surface which allowed ingress of oxidant into the samples. Defects visualized by computed tomography were found via metallography and characterized. Ultrasonic additively manufactured Zircaloy-4 was found to have comparable corrosion behavior as wrought Zircaloy-4 for specimens which did not have clear surface defects along weld interfaces.

在无辐照的情况下，采用模拟压水堆条件（330°C，15.6 MPa，约20 ppb氧气）来研究超声增材制造的锆 - 4合金长达1000小时的水热腐蚀行为。X射线计算机断层扫描可用于观察加工过程中产生的缺陷以及腐蚀实验后这些缺陷的发展情况。与典型的锻造锆 - 4合金试样相比，发现这些试样的质量变化数据存在明显差异。暴露后质量变化的差异归因于与试样表面相连的焊接缺陷，这些缺陷使得氧化剂能够进入样品。通过计算机断层扫描观察到的缺陷经金相学方法发现并进行了表征。对于在焊接界面处没有明显表面缺陷的试样，发现超声增材制造的锆 - 4合金具有与锻造锆 - 4合金相当的腐蚀行为。