HOT-STAMPED STEEL Russian patent published in 2020 - IPC C22C38/00 C23C2/06 C23C2/12 B21D22/20 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to hot-stamped steel for making structural elements of automobile. Hot-stamped steel contains base material and clad layer. Clad layer includes an interphase layer, an intermediate layer and an oxide layer in the specified order from the base material side to the surface side. In interphase layer structure includes 99 % by area or more in total αFe, Fe₃Al and FeAl, average content of Al is in range of 8.0 wt% or more and 32.5 wt% or less, average content of Zn is limited to value more than content of Zn in base material and 5 wt% or less, the rest of the chemical composition contains Fe and impurities, and the average thickness of layer is 1.0 mcm or more. In the intermediate layer, structure includes 99 % by area or more of Fe(Al,Zn)₂ and Fe₂(Al,Zn)₅, average content of Al ranges from 30 to 50 wt%, average content of Zn ranges from 10 to 40 wt%; the rest of the chemical composition includes Fe and impurities, and the average thickness of layer is 5.0 mcm or more. Average thickness of oxide layer ranges from 0.1 to 3.0 mcm.

EFFECT: steel has excellent fatigue characteristics, suitability for phosphatizing, adhesion of coating and weldability.

5 cl, 8 dwg, 4 tbl, 2 ex