The amount of steel in a refinery is tiny compared to what the world uses. Even if we could scrap them all in single day (as if it wouldn't take months to tear it down) it is a drop in the bucket of recycled iron.
Global fossil fuel infrastructure (which is much more than refineries) is estimated to be 1.34 billion tons of steel (and 10 million tons of copper). That's a bit less than 1 year of output of the world steel industry.