|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||High Performance Steels
||On the Microstructural Features Affecting Cleavage Fracture in Simulated Heat Affected Zones of S690QL High Strength Steel
||Virginia Bertolo, Quanxin Jiang, Carey L Walters, Jilt Sietsma, Vera Popovich
|On-Site Speaker (Planned)
Low-temperature fracture toughness of steel structures is affected by brittle microstructural features. Welding, widely used for connecting structural members, modifies the base material microstructure generating complex heat affected zones (HAZ). The coarse-grained and intercritically reheated coarse-grained HAZ (CGHAZ and ICCGHAZ) are the subzones with the most deteriorated toughness. This is associated to M-A constituents. However, Nb-rich inclusions, harder than M-A, are found to be the most detrimental feature in the studied base S690QL steel. These features exist in the HAZ and it is essential to understand their individual and joint effect on low-temperature toughness. The CGHAZ and ICCGHAZ at 750 and 800 °C intercritical peak temperatures were experimentally simulated via Gleeble, and their microstructures were characterised by various techniques (e.g., SEM and EBSD). Thermally simulated CTOD specimens were tested at low temperature, and their fractured surfaces were investigated. The relations of various microstructural features on cleavage fracture micromechanisms were established.
||Characterization, Mechanical Properties, Iron and Steel