|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals and Materials
||Effect of Microstructure on Cleavage Fracture of Thick Section Quenched and Tempered S690 High Strength Steel
||Virgínia M. Bertolo, Quanxin Jiang, Carey L. Walters, Vera A. Popovich
|On-Site Speaker (Planned)
||Virgínia M. Bertolo
One of the main challenges in applying thick-section high strength steels (HSS) at low temperatures is to maintain a sufficient level of toughness to prevent cleavage failures. Cleavage fracture exhibits strong sensitivity to microstructure, and hence, microstructural investigation is of paramount importance. An aspect that requires special attention is the through-thickness microstructural variation which may result in different mechanical responses. In this study, the through-thickness microstructure and mechanical properties of 80mm S690QT HSS plate were investigated. The mechanical characterization was performed via tensile and CTOD testing at -100°C and microhardness testing. Microstructural characterization and fracture surface investigation were conducted using SEM, LECO and XRF analysis. Results show that the middle of the plate presents inferior properties compared to the outside positions which is associated to the non-uniform microstructure with local centreline segregation bands and larger grain sizes as well as larger hard and brittle inclusions, acting as crack initiation sites.