극저온 소재인 9% 니켈강의 파이버 레이저 용접 공정을 모사하는 유한요소 해석 모델의 연구Part I. 열전달 해석을 통한 용접 열원 탐색 A Study for FEM Model Describing Fiber Laser Welding of 9% Nickel Steel Part I. Finding Heat Source Model with Heat Transfer Analysis of Bead on Plate Welding
pp.822-827
Due to environmental pollution, regulations on existing petroleum-based fuels are increasing day by day. LNG is in the spotlight as an eco-friendly fuel that does not emit NOx or SOx, but its boiling point is -163°C, so it needs to be handled with care. Materials that can be used at the above temperature are defined by IMO through the IGC Code. Among them, 9% nickel steel has great advantages in yield strength and tensile strength under cryogenic conditions, but it is difficult to use in arc welding such as FCAW for various reasons. This study is a study to apply fiber laser welding to solve this problem. As a previous study, this study conducted a study to find a welding heat source. After performing bead on plate welding, the optimal heat source was derived by analyzing the shape of the bead and adjusting the parameters of the heat source model. In this case, by applying the multi-island genetic algorithm, which is a global optimization algorithm, not the intuition of the researcher, accurate results could be derived in a wide range.