Thermo-Fluid-Coupled Analysis of Double Fillet Welds on Tube Membrane Panels During Submerged Arc Welding

The purpose of this research is to understand the formation of double fillet welds using finite element modeling. This computational study is intended to be an advanced way to predict heat transfer mechanisms in the melt pool prior to empirical testing. AISI 304 austenitic stainless steels are used in this study, and a simplified model of fin-tubes is introduced to simulate submerged arc welding (SAW) on a water wall panel structure. The welding process is numerically implemented by a moving heat source, and the heat distribution is determined by thermo-physical phenomena, e.g., recoil pressure and surface tension due to the welding. Double fillet welding refers to two separate welds which have to be made one by one. A new coordinate system is thus introduced at every starting point of the welding process to overcome geometrical complexities. The computational results are discussed to compare the weld bead estimation with the experimental findings. The melting and evaporation of the metal appear appropriate to explain the formation of weld beads in submerged arc welding since the modeling is in good agreement with the experiments.