You probably mean Hastelloy C276. Other candidates are the other C-series Hastelloys (C-22 and C-2000), as well as Inconel 686. All these alloys have similar composition (largely Ni, Cr, and Mo) and properties. A version of Inconel with even more Nickel (greater than 70 %) is Alloy 600. Monel...
Like Wil, I also think you may not have thought this problem through. I don't get the picture of what you want to do. Are you proposing drilling a hole in the pipe on the side opposite the leak and injecting the sealant from the hole side? Are you looking for a thick sealant material to...
3M Scotch-Weld Acrylic Structural Plastic Adhesive DP8005.
Remarkably, this actually bonds very well to polyolefins. I've been testing a glued drop on PE film, and it has survived months in 180 F water. It's a two part adhesive, 10:1 mix, and it contains micro-beads for gap registration...
