Kim Younghyun, Kim Jaewoong, Park Hyeongsam, Hong Sungbin, Pyo Changmin, Park Gyuhae
Automotive Materials & Components R&D Group, Korea Institute of Industrial Technology, Gwangju 61012, Republic of Korea.
School of Mechanical Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
Materials (Basel). 2023 Oct 11;16(20):6647. doi: 10.3390/ma16206647.
The International Maritime Organization (IMO) is tightening regulations on air pollutants. Consequently, more LNG-powered ships are being used to adhere to the sulfur oxide regulations. Among the tank materials for storing LNG, 9% nickel steel is widely used for cryogenic tanks and containers due to its high cryogenic impact toughness and high yield strength. Hence, numerous studies have sought to predict 9% nickel steel welding distortion. Previously, a methodology to derive the optimal parameters constituting the Goldak welding heat source for arc welding was developed. This was achieved by integrating heat transfer finite element analysis and optimization algorithms. However, this process is time-consuming, and the resulting shape of the weld differs by ~15% from its actual size. Therefore, this study proposes a simplified model to reduce the analysis time required for the arc welding process. Moreover, a new objective function and temperature constraints are presented to derive a more sophisticated heat source model for arc welding. As a result, the analysis time was reduced by ~70% compared to that previously reported, and the error rates of the weld geometry and HAZ size were within 10% and 15% of the actual weld, respectively. The findings of this study provide a strategy to rapidly predict welding distortion in the field, which can inform the revision of welding guidelines and overall welded structure designs.
国际海事组织（IMO）正在收紧对空气污染物的监管规定。因此，越来越多的液化天然气动力船被用于遵守硫氧化物规定。在储存液化天然气的罐体材料中，9%镍钢因其高低温冲击韧性和高屈服强度而被广泛用于低温罐体和容器。因此，许多研究致力于预测9%镍钢的焊接变形。此前，开发了一种推导弧焊Goldak焊接热源最佳参数的方法。这是通过整合传热有限元分析和优化算法实现的。然而，这个过程很耗时，并且焊接后的形状与实际尺寸相差约15%。因此，本研究提出了一个简化模型以减少弧焊过程所需的分析时间。此外，还提出了一个新的目标函数和温度约束条件，以推导更精确的弧焊热源模型。结果，与之前报道相比，分析时间减少了约70%，焊缝几何形状和热影响区尺寸的误差率分别在实际焊缝的10%和15%以内。本研究结果提供了一种在现场快速预测焊接变形的策略，可为焊接规范的修订和整体焊接结构设计提供参考。
