Hastelloy weld metal hot cracking susceptibility

Hastelloy tends to hot cracking during welding. This is due to alloying elements that enrich at grain boundaries during cooling, forming weak spots. When the weld cools under stress, it tends to crack. To control this, keep heat input low and control cooling. Don't let the weld cool too fast, but not too slow either. Clean work is important, as impurities promote cracking. Keep the penetration shallow to reduce contraction issues.