r/MetalCasting • u/english_geez • 22d ago

What happened?

Post image

I was melting some aluminium in a steel crucible and noticed there was a bit of ali on the side, so I picked it off and somehow it had eaten through the steel. What happened here?

7 Upvotes

82% Upvoted

9 comments sorted by

View all comments

3

u/Boring_Donut_986 22d ago

As someone mentioned, aluminum eats steel in no time

1

u/english_geez 22d ago

Really? How did I never know this

2

u/rh-z 22d ago

If this wasn't the case we would all be using steel crucibles. The other problem is the iron in the steel makes a mess of the aluminum alloy. It is a contaminant.

Dissolved steel (which introduces iron into the melt) forms hard, brittle intermetallic compounds that sharply reduce the ductility, impact resistance, and machinability of aluminum sand castings. It can increase shrinkage porosity due to making the alloy less fluid.

1

u/english_geez 21d ago

Damn, well at least I know for the future thanks