PROCESS FOR MANUFACTURING IRON-CARBON-MANGANESE AUSTENITIC STEEL SHEET WITH A HIGH RESISTANCE TO DELAYED CRACKING, AND SHEET THUS PRODUCED

Iron-carbon-manganese austenitic steel sheet, the chemical composition of which comprises, the contents being expressed by weight: 0.45% C 0.75%; 15% Mn 26%; Si 3%; Al 0.050%; S 0.030%; P 0.080%; N 0.1%; at least one metal element chosen from vanadium, titanium, niobium, chromium and molybdenum, where 0.050% V 0.50%; 0.040% Ti 0.50; 0.070% Nb 0.50%; 0.070% Cr 2%; 0.14% Mo 2%; and, optionally, one or more elements chosen from 0.0005% B 0.003%; Ni 1%; Cu 5%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the amounts of said at least one metal element in the form of precipitated carbides, nitrides or carbonitrides being: 0.030% Vp 0.150%; 0.030% Tip 0.130%; 0.040% Nbp 0.220%; 0.070% Crp 0.6%; 0.14% Mop 0.44%.