Study on lamellar tearing generated by corner joint welding in box column of ultrathick plate

摘要

In an attempt to reduce the risk of lamellar tearing during welding of ultrathick plates, the present study has evaluated the susceptibility to lamellar tearing of steel structures in relation to welding stress rather than metallurgical properties, and eventually attempted to determine the optimum groove shape and welding procedure by computer simulation based on the finite element method. Based on the simulation, it has been identified that controlling the shape of the deposited weld metal in the anticipated position of the occurrence of lamellar tearing is the most favourable method of preventing lamellar tearing by minimising welding residual stress and strain. Owing to the difference in weld deposited area, the cooling rate for the partial penetration condition is more rapid than for full penetration. Furthermore, in terms of welding residual stress, the full penetration condition is preferable to the partial penetration condition.