Welding Tips and Tricks

Hello all, just curious, can you weld mild steel to cast iron? If possible, what type of electrode would be used? Thanks

What's the application?

just doing some hobby stuff. nothing structural.

I've done some art stuff with cast iron and mild steel with 6011. And self shielded flux core. Then some dummy stood on it and it held so...that worked it my case at least.

For a quick hack pretty much anything that welds steel will also do for most generic cast irons.

The issue with welding cast iron is that the high carbon content turns the weld and the area around it rock-hard and quite brittle and crack-prone.

So for just experimenting and testing stuff it's fine. Not advisable in 'real' situations where any cast-iron work tends to usually go more for brazing (no melting of the base material), nickel-based rods when welding (to dilute the parent material and reduce the hardening and carbide formations) or even mechanical repairs (eg. engine blocks are often stitched when they crack)

The cast iron types that are on the lower end of the scale for carbon content will be the least troublesome as they are still the most ductile. Go up and it gets progressively worse until things like white cast iron which is just too hard and brittle to not crack after welding.

Cast steels (often used for car knuckles and such, anything that's exposed to impacts or bending forces) can be confused with cast iron, but it is no issue to weld as far as the material goes. Big steel castings do still usually need good preheating and controlled cooling to stop stress areas from building up.

Bye, Arno.