Patent ID: 7976650

Claim:
A process for manufacturing a corrosion-resistant cold-rolled sheet of iron-carbon-manganese austenitic steel, the process comprising: providing a sheet which chemical composition comprises: 0.35 wt. %≦C≦1.05 wt. %, 16 wt. %≦Mn≦24 wt. %, with the balance of the composition being iron and inevitable impurities resulting from smelting of the steel; cold-rolling said sheet; and carrying out a recrystallization annealing treatment on said sheet in a furnace having an atmosphere that is reducing with respect to iron and oxidizing with respect to manganese, wherein parameters of said annealing are chosen so that said sheet is covered on both faces with an essentially amorphous (Fe,Mn)O oxide sublayer and with an external crystalline manganese oxide MnO layer, and the total thickness of the amorphous oxide and manganese oxide layers is equal to or greater than 0.5 microns.