help welding steel to cast iron.

by Jon A.
(Tennessee)

I need to weld the steel axle tubes to the cast iron housing of a rear differential. I have a Hobart Handler 210 using flux cored wire. What's the best wire to use and what technique should be used. Do I need to preheat the cast iron? If so, how much and can it be accomplished with a propane torch? How would I prep the axle before welding? Do I need to try and bevel the edge of the axle housing to get good penetration? I know I need to weld in stages/alternate sides to keep warpage down to a minimum. Sorry for all the questions. New to mig welding, and welding in general. Love your site, which I have found to be extremely useful.

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Preheat? yes. A small propane torch will most likely not be enough to provide the kind of heat needed to slow the cooling rate on the cast iron.

there is quite a bit of information on this task on forums such as weldingingweb.com and others from folks who have actually done it