What is the effect of hydrogen peroxide on iron residues?

Answer 1

The hydrogen peroxide will decompose rapidly to molecular oxygen (O2) because iron is a very efficient catalyst for that reaction.

Hydrogen peroxide (and the generated high concentration of O2) make a very oxidizing enviroment so the iron would go to mostly to Iron(III) oxide, also called ferric oxide (Fe2O3), a.k.a. "rust". Salts and water would greatly increase the rate of that reaction.

Answer 2

I would think it would tend to produce ferric oxide.