비드온 플레이트 용접 시 저온용강 및 고장력강의 각변형 특성에 관한 연구

Abstract

Welding deformation depends on heat transfer, material properties, constraint, joint geometry, and so on. Since these factors work in combination, it is hard to predict the accurate welding deformation. So far, no comprehensive theory, experiments, and results have been reported. In this study, the material properties-induced angular distortion is discussed. For this purpose, bead-on-plate welding experiments were conducted on low-temperature and high-strength steels, which are widely used in shipyards. Based on the experimental results, a reference model of temperature-dependent material properties was established to perform the vast analysis. From the reference model, the effect of material properties was investigated on the angular distortion. They consist of specific heat, density, thermal conductivity, coefficient of thermal expansion, elastic modulus and yield strength. As a result, it was found that specific heat, density, and coefficient of thermal expansion have the most significant effect on weld deformation. Also, the effect of yield strength on deformation is increased at high heat input. This finding quantitatively explains the difference in angular distortion with various steels used in ship building. It is expected that the welding deformation can be predicted and controlled in the design and production stages, reflecting the results of this study.