The effect of oblique crack on stability and fracture properties of Cr-coated Zircaloy cladding

• Published in: Annals of nuclear energy 2021-12, Vol.163, p.108560, Article 108560
• Main Authors: Xu, Ze, Wei, Junlong, Liu, Yulan, Wang, Biao
• Format: Article
• Language: English
• Subjects: Coating spallation; Cr-coated cladding; Crack channel; Fracture property; Oblique crack; Stress intensity factor
• ISSN: 0306-4549; 1873-2100
• DOI: 10.1016/j.anucene.2021.108560

•A theoretical model of Cr-coated Zircaloy cladding with initial crack in the coating is established.•The effect of initial oblique cracks on stability of Cr-coated Zircaloy cladding has been investigated.•Fracture properties of Cr coating under different crack lengths and inclination angles are concluded. In this paper, fracture properties of Cr-coated Zircaloy cladding, which has initial oblique crack in the coating, have been investigated. The von Mises stress distribution caused by different modes of crack has been calculated. By comparing the stress intensity factor with the fracture toughness of material, the fracture mechanical behavior of Cr coating has been obtained. When the reactor is in normal operation, conditions for crack propagation along the axial direction are very strict. However, if the crack propagates in the plane perpendicular to the axial direction, two types of cladding failure may occur: 1) coating spallation and 2) a crack channel connecting the cladding to the coolant. Conditions of occurrence of these two types have been analyzed. Meanwhile, a map of the relation between initial crack state and crack development trend is given. It can provide reference and guidance for the coating monitoring in real nuclear engineering.