Corrosion fatigue of phosphor bronze reinforcing tapes on underground power transmission cables - Failure analysis. (September 2018)

• Record Type: Journal Article
• Authors: Foresta, Maurizio; Gnanasambandam, Sivashangari; Weston, David; Li, Fan; Pan, Jingzhe; Le Blanc, Michelle
• Is Part Of: Engineering failure analysis. Volume 91(2018)
• Page Start: 507
• Page End: 515
• Publication Date: 2018-09
• Subjects: Corrosion fatigue -- Pitting -- Phosphor bronze -- Underground power transmission cables -- Failure analysis; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2018.02.006
• Languages: English
• ISSNs: 1350-6307

Abstract

Abstract: This paper is an investigation on the failure mechanism involved in underground power transmission cables with their life limited by corrosion of phosphor bronze reinforcing tapes. In the present work, a detailed analysis of failed bronze tapes in an ammonium free environment has been undertaken and corrosion fatigue failure mechanism has been identified. A detailed examination of the tape samples is carried out using 2D and 3D optical microscopy and SEM. It follows a mechanical approach that confirms corrosion fatigue as the failure mechanism. SEM images reveal that the pits present on the surface could be the starting point for the crack that eventually leads to failure. Stress calculation shows that the tape could fail only if corrosion pits are present on the tape surface. Presence of corrosion pits, multi cracks and striations on the fractured surface demonstrates corrosion fatigue cracking as the failure mechanism across the tape samples. Graphical abstract: Unlabelled Image Highlights: Failure mechanism of reinforced tapes used in underground power cables is identified as corrosion fatigue. Typical characteristics of corrosion fatigue such as corrosion pits, multi cracks and fatigue striations on the fractured face are observed on the failed tape. Stress calculations confirmed that the simultaneous presence of corrosion pits and a cyclic load is necessary for failure.