Special Weld Requirements for
AL-6XN Weld Areas
If post-weld annealing is not possible then an additional alloy must be added to the weld. We call this an over-alloyed weld. Although AL-6XN alloy is classified as a single-phase alloy, when it is melted—as in welding—it will solidify as a three-phase alloy: austenite, chi phase and delta ferrite.
Chi phase, a chromium-iron-molybdenum compound, depletes the grain boundary in molybdenum and chromium, which reduces corrosion resistance. Delta ferrite also exhibits poor corrosion resistance. When over-alloyed by using weld insert rings or filler, the alloy balance, and therefore corrosion resistance, of the weld is equal to or better than the base alloy.
Call 800.654.5635 or visit welding
AL-6XN for more information.