|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||High Performance Steels
||Low-temperature impact properties of X70 line pipe steel depending on location and orientation
||Seoyoon Gong, Jeongho Han, Se-Eun Shin, Jihan Gwak
|On-Site Speaker (Planned)
Due to the continuous use of oil and gas resources, mining in extreme environments is increasing due to a decrease in resource reserves in areas with a good mining environment, and accordingly, the low-temperature properties of line pipe steels are important. In this study, the impact properties by Charpy impact testing at various low-temperatures and microstructure of X70 steels were analyzed depending on the location and orientation of hot-rolled specimens. The fracture toughness was measured by Charpy impact testing at –45 °C depending on the location and orientation (transverse & rolling direction). The microstructure shows the two-phase of degenerate pearlite and acicular/quasi-polygonal ferrite. As the result, the impact energy was 54.16 J from the outside and 115.21 J from the center, in the width direction, and it increased toward the center. It is considered that this is because the fraction of degenerate pearlite decreases toward the center.
||Iron and Steel, Mechanical Properties, Other