Abstract
As the environmental regulations on ship emissions by the International Maritime Organization (IMO) become stricter, the demand for a ship powered by liquefied natural gas (LNG) is rapidly increasing worldwide. Compared to other materials, high-manganese steel has the advantages of superior impact toughness at cryogenic temperatures, a low thermal expansion coefficient, and a low-cost base material and welding rod. However, there is a limitation that the mechanical properties of a filler material are worse than those of a base material that has excellent mechanical properties. To solve these shortcomings, a basic study was performed to apply fiber laser welding with little welding deformation and no filler material to high-manganese steel. The relationship between laser welding parameters and penetration shapes was confirmed through cross-section observation and analysis by performing a bead on plate (BOP) test by changing laser power and welding speed, which are the main parameters of laser welding. In addition, the welding performance was evaluated through mechanical property tests (yield strength, tensile strength, hardness, cryogenic impact strength) of a welding part after performing the high-manganese steel laser butt welding experiment. As a result, it was confirmed that the yield strength of a high-manganese steel laser welding part was 97.5% of that of a base metal, and its tensile strength was 93.5% of that of a base metal.
Highlights
The International Maritime Organization (IMO) has decreased the allowable amount of sulfur in fuel oil from 3.5% m/m to 0.5% m/m in 2020 [1]
It was confirmed that the yield strength of a high-manganese steel laser welding part was
2, high-manganese steel is a non-metal without magnetism, so it does not have the magnetization phenomenonofthat occurs during welding of 9%
Summary
The International Maritime Organization (IMO) has decreased the allowable amount of sulfur in fuel oil from 3.5% m/m (mass by mass) to 0.5% m/m in 2020 [1]. The International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) limits the materials that can be used for a tank that transports cargo at cryogenic temperatures, and the materials are 9% nickel steel, STS 304L, Al 5083-O, Invar, and high-manganese steel. These materials have high cryogenic impact toughness to store cryogenic cargo.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
