1996 Explorer 5.0 Gt40 Piston Rings - Are These Steel?

I am trying to find out what kind of material is my top piston ring which was on my 1996 Explorer 5.0.

When I removed the piston rings, in my rebuild, the top one came out intact but all of the bottom one broke which I can assume are cast iron. I even bent in pretzel and would would not break.

Are these steel? Moly?

Waid

Thanks

Oh, here is the broken bottom ring which I assume is cast iron.

Waid

Thanks