Surface flow visualization of Gas Tungsten Arc weld pools for HY-80 steel is presented using a pulsed laser light source and a conventional night-vision image-intensif ier tube equipped video camera. Visualization of the weld pool free surface is made possible by seeding the flow with alumina particles for both stationary and moving arc welds. These visualizations reveal several new features not incorporated in the existing models for stationary welds. A strong clockwise stirring is observed contrary to the axi-symmetric computational models. Also, the pool surface shows a bulge near the center. Complex flow patterns are observed for moving arc welding. Interpretations of the observed flows based on the driving forces are provided.

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http://archive.org/details/visualizationofg1094528643

Lieutenant, United States Navy