Surface tension helps hold the metal in place, giving excellent bead contour in GTAW for which metal?

Surface tension helps hold the metal in place, giving excellent bead contour in GTAW for which metal?

• A. Low Carbon Steel
• B. Aluminum
• C. Stainless Steel
• D. Mild Steel

Answer: (B)

Surface tension in the molten weld pool strongly shapes the bead, so the metal’s flow characteristics determine how smooth and well-contoured the bead will be. Aluminum benefits most in GTAW because, when welded with alternating current, the oxide film on aluminum is continuously broken and the molten aluminum becomes very fluid. The surface tension then pulls the liquid metal into a tight, smooth, evenly contoured bead, giving excellent bead contour. Other metals don’t respond as favorably to this surface-tension shaping in GTAW. Their beads tend to be less uniform due to differences in oxide behavior and flow characteristics, so they don’t achieve the same level of contour as aluminum.

Surface tension in the molten weld pool strongly shapes the bead, so the metal’s flow characteristics determine how smooth and well-contoured the bead will be. Aluminum benefits most in GTAW because, when welded with alternating current, the oxide film on aluminum is continuously broken and the molten aluminum becomes very fluid. The surface tension then pulls the liquid metal into a tight, smooth, evenly contoured bead, giving excellent bead contour.

Other metals don’t respond as favorably to this surface-tension shaping in GTAW. Their beads tend to be less uniform due to differences in oxide behavior and flow characteristics, so they don’t achieve the same level of contour as aluminum.