Patent ID: 7361237

Claim:
A steel whose composition comprises, expressed in % by weight: 0.03 ≤ C ≤ 0.06 0.853 ⁢ % ≤ Mn ≤ 1.10 0.08 ≤ Si ≤ 0.20 0.015 ≤ Al ≤ 0.070 N ≤ 0.007 Ni ≤ 0.040 Cu ≤ 0.040 P ≤ 0.035 S ≤ 0.015 Mo ≤ 0.008 Ti ≤ 0.005 it being understood that it also includes boron in an amount such that: 0.65 ≤ B N ≤ 1.60 ; and the manganese content and the silicon content are such that: 4 ≤ % ⁢ ⁢ Mn % ⁢ ⁢ Si ≤ 15 ; ⁢ and the balance of the composition being formed from iron and impurities resulting from the smelting, and wherein the manganese content is at least 0.853% by weight.