By -
Date 09-08-2005 12:42
In 2205 Duplex, any sigma is too much sigma. I have seen fabricators try the very thing (2 welders exactly opposite each other) and it caused a vortex in the area being welded. Just be careful that you don't have your shielding gas turned up too high. It is pretty unlikely that sigma will form on the coupon using this technique. Of course, if the coupon is small enough (width, length, and thickness) to allow a very slow cooling rate, it is possible for sigma to form.
Chuck