|About this Abstract
||MS&T23: Materials Science & Technology
||Steels for Sustainable Development II
||Investigation of Microstructure and Fracture Performance of 9 wt.% Nickel Steel for Application Laser Arc Hybrid Welding
||Jeong Yeol Park, Changwook Ji, Jooyong Cheon, Hyun Uk Jun
|On-Site Speaker (Planned)
||Jeong Yeol Park
The most important part in construction an LNG vessel is to secure the structural integrity of the LNG storage tank. In order to secure the structural integrity of the LNG storage tank, many studies, such as using low-temperature materials or improving the quality of weldments, are being reviewed. Laser-Arc Hybrid Welding (LAHW) improves microstructure and weld quality (through gap bridge) to insert filler wire in welding process.
In this study, the possibility of applying LAHW to 9 wt. % nickel steel, which is mainly used for LNG storage tanks, is examined in terms of microstructure and fracture performance. The welding process is optimized through microstructure and macro graph, and a master curve derive to predict the change in fracture toughness by temperature based on the impact toughness. In addition, to evaluate the effect of the HAZ size, the crack propagation path was confirmed during the impact test.