Patent ID: 7799148

Claim:
An iron-carbon-manganese austenitic steel sheet, the chemical composition of which comprises Fe and inevitable impurities and, 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 selected from the group consisting of 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%, and 0.14%≦Mo≦2%, and, optionally, one or more elements selected from the group consisting of 0.0005%≦B≦0.003% Ni≦1%, and Cu≦5%, wherein the steel sheet comprises vanadium, the amount of vanadium in the form of precipitated carbides, nitrides or carbonitrides being: 0.030%≦V p ≦0.150%.