On Jul 14, 11:00 pm, cynic wrote:

Cast is VERY difficult to weld properly. the usual way is to slowly
heat the piece up to red hot, weld it with appropriate rods and cool
it down slowly. Unless you know someone with the right skills its
going to be expensive.
I'd be inclined to try brazing then make a shaped clamp plate to go
over the flange and once complete hide it with paint. Is it an exhaust
pipe from some static engine or something else?

The pipe is bolted inside a firebox that's red hot and contains steam
at 110 psi.