METHOD OF MANUFACTURING A HARDENED STAMPED STEEL SHEETS AND THE DETAILS OBTAINED THIS WAY Russian patent published in 2018 - IPC C21D9/46 C22C38/38 C22C38/40 C21D8/02 C23C2/12 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy. To improve the mechanical strength and resistance to delayed cracking of rolled steel sheet after hardening in a die sheet are made of steel, the chemical composition of which is, in weight %: 0.24 < C < 0.38, 0.40 ≤ Mn ≤ 3, 0.10 ≤ Si ≤ 0.70, 0.015 ≤ Al ≤ 0.070, 0 ≤ Cr ≤ 2, 0.25 ≤ Ni ≤2, 0.015 ≤ Ti ≤ 0.10, 0 ≤ Nb ≤ 0.060, 0.0005 ≤ B ≤ 0.0040, 0.003 ≤ N ≤ 0.010, 0.0001 ≤ S ≤ 0.005, 0.0001 ≤ P ≤ 0.025, provided that the titanium and nitrogen content is Ti / N > 3.42, the carbon content, manganese, chromium and silicon corresponds to formula , wherein the chemical composition comprises optionally one or more of the following: 0.05 ≤ Mo ≤ 0.65, 0.001 ≤ W ≤ 0.30, 0.0005 ≤ Ca ≤ 0.005, rest are iron and inevitable in the smelting of impurities, and the nickel content of Ni_surf in the sheet at any point of the near-surface layer at a depth Δ is equal to Ni_surf > Ni_nom, with Ni_nom means the nominal content of nickel in steel, Ni_max means the maximum nickel content at depth ∆: x (∆) ≥ 0.6 and ≥ 0.01, depth Δ is expressed in microns, the Ni content_max and Ni_nom are expressed in wt. %.

EFFECT: invention is aimed at increasing the mechanical strength and resistance to delayed cracking of rolled steel sheet after hardening in a die.

34 cl, 9 dwg, 6 tbl