Washing out oxides

If you don't mind mechanically altering your sample, you could sand, grind, or shot blast it to get a majority of the scale off and try to get back to base metal. My impression is that you don't want to do this and are looking for chemical means to reverse oxidation.
I'm not sure but a furnace treatment in a reducing atmosphere at high temperture would make the oxide unstable. You want to reduce the oxygen partial pressure around the treated sample and drive the metal oxide to become a metal again. I don't know the rate of this reaction or which atmosphere would be best but I hope that's a start.
There may also be strong etches you could use. For example 10% nitric acid (depending on yoru alloy) and after scratching the exisiting oxide you might be able to eat out the steel underneath to remove the oxide. There are probably better chemical polishes out there though.
These are my guesses.

hi buddy
it seem like blue brittleness. this usaully occure when steel fractures above 450 C. a blue color film forms on the fracture surface. if it is not that than it will be simply scale which u can remove by acid pickling. H2so4 and one other acid is used for this purpose search web for the exact composition and temperature of the solution. this process is common in cold rolling mills where hot rolled steel is to be cold rolled
ibtesam hasan abidi Asst: eng: manager OPL Metallurgy and materials engineer NACE certified cp technician

Yeah his answer sounds better and more practical than mine.