Analysis of the Corrosion Behavior of Vapor-Deposited CrN-Coated Zirconium under Normal Operation and Accident Scenarios
SourceChromium nitride (CrN) coatings are considered as possible protective barrier materials for Zircaloys. CrN-coated zirconium alloys were exposed to primary water (300°C) and steam environments to evaluate their resistance to corrosion under normal reactor operating conditions and under accident conditions. A number of surface analytical techniques, including scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, secondary ion mass spectrometry, and transmission electron microscopy were used to evaluate the effectiveness of the coatings. To examine the effects of irradiation, coated samples were exposed in-flux and out-of-flux at the Halden reactor at temperatures of 280°C and 325°C. The CrN coatings have been shown to be a barrier to corrosion and deuterium ingress under aqueous corrosion conditions and to act as a temporary barrier to corrosion under steam conditions.