METHOD OF PRODUCING AUSTENITIC IRON/CARBON/MANGANESE STEEL SHEETS AND SHEETS THUS PRODUCED

The invention relates to an austenitic iron-carbon-manganese metal sheet whose chemical composition comprises the following contents expressed in 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 metallic element selected from the group consisting of vanadium, titanium, niobium, chromium, molybdenum 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 selected among 0.0005 % = B = 0.003 %, Ni = 1 %, Cu = 5 %, the remainder of the composition consisting of iron and of unavoidable impurities resulting from the processing, the quantity of said at least one metallic 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 %. Tôle en acier austénitique fer-carbone-manganèse, dont Ia composition chimique comprend, les teneurs étant exprimées en poids : 0,45% < C < 0,75%, 15%