HOT-STAMPED STEEL Russian patent published in 2018 - IPC C21D1/18 B21D22/20 C23C2/06 C23C2/28 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely, to hot-stamped steel, which is used in the automotive industry. Hot stamped steel includes the base metal, which is formed in the shape of sheet and has the tempered portion at least on its surface, and the Zn coating layer, which is formed on the mentioned tempered portion of the base metal. Tempered portion of the base metal has a hardness corresponding to 85 % or less of the highest quench hardness, which is defined as the Vickers hardness at the position at the depth, which is 1/4 of the sheet thickness away from the surface, when quenching in water after heating up to the temperature that is equal to or higher than point A_c3, and after maintaining for 30 minutes. Zn coating layer includes the solid solution layer and the sheet-like layer. Solid solution layer includes the solid solution phase, which contains Fe and Zn, which is dissolved in α-Fe. Sheet layer is formed on the side of the surface layer of the zinc coating and includes the solid solution phase and the G phase, which is an intermetallic compound of Fe₃Zn_10. Phases of the solid solution and Fe₃Zn₁₀ are located in a repeated manner and alternately adjoin each other in the sheet-like shape, and the proportion of the area of the sheet layer in the Zn coating layer is 20 % or less.

EFFECT: increased the shock-absorbing properties of steel in case of an accident while maintaining high corrosion resistance are ensured.

9 cl, 8 dwg, 3 tbl