Actually, powder coating can be stripped using paint stripper.
I have done that on several occasions.
Remove the crown race and soak in a small container of a good paint stripper and the coating should bubble off like paint.
It may take a while.
But, as headsets do not cost a bunch, it may be more economical to just replace the whole shebang.
You can touch up the rough edges at the ends of the head tube with an emery board or nail file after removing the headset parts.
Be careful and try to avoid removing all the powder coating down to bare metal. If yo do, touch up
with model paint. As for the faces of the head tube, those are routinely left bare after facing with cutting tools at the manufacturer.
Apply a thin coat of grease if you are concerned about corrosion.