HOT STAMPED BODY Russian patent published in 2020 - IPC C22C38/60 C22C38/06 B21D22/20 B21D22/26 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to high-strength hot-stamped steel sheet used as structural or reinforcing elements of cars or structures requiring strength. Hot-stamped sheet comprises middle part of sheet thickness, intermediate layer and surface layer, wherein intermediate layer adjoins middle part of sheet thickness and surface layer. Middle part of the leaf thickness contains the following, wt%: C: 0.20 or more and less than 0.70, Si: less than 3.00, Mn: 0.20 or more and less than 3.00, P: 0.10 or less, S: 0.10 or less, sol. Al: 0.0002 or more and 3.0000 or less, N: 0.01 or less, balance – Fe and unavoidable impurities. Middle part by sheet thickness has hardness of 500 Hv or more and 800 Hv or less, surface layer has change of hardness ΔH₁ in direction of sheet thickness of 10 Hv or more and less than 200 Hv, and intermediate layer has change in hardness ΔH₂ in direction of sheet thickness of 50 Hv or more and less than 200 Hv.

EFFECT: providing high impact strength and resistance to hydrogen embrittlement.

11 cl, 16 tbl, 2 dwg