Patent ID: 11279994

Abstract:
A method for manufacturing a weldable steel component having a chemical composition including, by weight: 0.40%≤C≤0.45%; 0.75%≤Si≤1.50%; 0.3%≤Mn≤3%; 0%≤Ni≤5%; 1.11%≤Cr≤4%; 0%≤Cu≤1%; 0.410%≤Mo≤1.5%; 0.410%≤Mo+W/2≤1.5%; 0.038%≤Nb≤0.3%; 0.0005%≤B≤0.010%; 0.006%≤N≤0.025%; Al≤0.9%; Si+Al≤2.0%, optionally at least one element selected among V, Nb, Ta, S and Ca, in contents less than 0.3%, and among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from the preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B≥⅓×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; 1), and J*=Max (0; J), I=Min(N; N−0.29(Ti−5)), J=Min(N; 0.5(N−0.52 Al+√{square root over ((N−0.52 Al)2+283)})), and whereof the structure is bainitic, martensitic or martensitic/bainitic and additionally comprises 3 to 20% of residual austenite.