Cast iron & steel connection - filler?

[Highpower]

Recommended filler to use for attaching heavy wall steel pipe to a grey cast iron plate?

[radkins]

Ni55 rod. The MUCH more expensive Ni99 rod does not make a stronger weld contrary to popular belief, it does however make a softer weld that can be machined if necessary and that's it's purpose.

[Highpower]

Actually I should have mentioned that the end of the pipe will sit down inside a shallow counter bore in the cast iron piece. In order to keep the heat down on the CI, I was thinking of maybe tig brazing it with silicon bronze?

The pipe will actually be bolted on from the rear of the CI, but I would like to reinforce the pipe at the front (counter bore) for good measure. I just don't want to run the risk of cracking the cast iron.

[Jim Shaper]

JB weld is what I'd do then.

[radkins]

Actually I should have mentioned that the end of the pipe will sit down inside a shallow counter bore in the cast iron piece. In order to keep the heat down on the CI, I was thinking of maybe tig brazing it with silicon bronze?

The pipe will actually be bolted on from the rear of the CI, but I would like to reinforce the pipe at the front (counter bore) for good measure. I just don't want to run the risk of cracking the cast iron.

Yes of course that's the best way to do it, don't know why I just assumed you meant arc welding. The worst part of my suggestion is that most of the time when someone asks about joining iron castings I tend to discourage arc welding and only do it myself when brazing is not practical for some reason.