Technical Papers and Presentations

Marangoni flow affects the heat and mass transfer occurring in the molten metal regions in welding and additive manufacturing processes. It originates from the surface tension gradient (∂γ/∂T) induced at the melt pool surface due to the temperature difference. The flow pattern within melt pool affects the segregation and melt-pool shape and size. The flow pattern and therefore the melt pool shape vary with the ∂γ/∂T, which is dependent on temperature and surface active elements concentration in the molten metal. Elements of the oxygen family, (O, S, Se and Te) are found to be strongly surface active. In the present study, numerical modeling and simulation is used to show the dependence of flow field and resulting melt pool shape on the surface active elements. Stainless steel alloy has been used as base for the modeling and sulfur is studied as the surface active element. Numerical simulation is used to show the dependence of flow field and resulting melt pool shape on the surface active elements. Stainless steel alloy has been used as base for the modeling and sulfur is studied as the surface active element.