Welding Cast Iron vs Cast Steel


It is often difficult to determine if a casting is iron or steel, the later being easily welded by any method.

Cast iron castings are not usually used in places that take shock loads as they are usually brittle and more easily crack and break.
I was just having a look around and here are a couple of identification suggestions that I liked.

1. When you drill steel, it makes chips and shavings that are easy to recognize. When you drill cast iron it will make a fine, graphite like dust. You only need to use a 3/16 or 1/4 drill, and only go deep enough to identify the shavings.

1) Weld a 1/2" x 2" Low Carbon Bar over the piece to be tested. Apply a weld bead with E-7018, just by one side.
2) Hit the bar welded by the side against the weld bead until it breaks.
3) a- If the weld bead breaks by the side of the piece being tested it is cast iron.
b- If it breaks by the side of the bar welded or in the middle of the bead, it is cast steel.

By the way: It is necessary to apply 150°C preheating at the area to be welded.

3. Spark Test, I find this one harder, but I am sure if you watch enough it can be fast and convenient.
spark test.jpg
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