Modeling Geometry and Structure of GAS-Metal-Arc Welded HSLA-100 Steel

A three-dimensional, transient, turbulent heat transfer and fluid flow model was developed to predict the weld geometry, thermal cycles, and understand the macro- and microstructures of gas-metal-arc welded HSLA-100 steel. The heat transfer and fluid flow were calculated by numerical solution of the equations of conservation of mass, momentum, and energy in three-dimensional form. The high computed values of turbulent viscosity and thermal conductivity indicated that the transport of heat and momentum in the weld pool was significantly aided by turbulence. The observed microstructures were consistent with those expected from the computed continuous cooling transformation (CCT) diagram and the cooling rates.