MATERIAL FOR HOT STAMPING AND METHOD FOR ITS OBTAINING Russian patent published in 2024 - IPC C22C38/38 C22C38/32 C22C38/28 C22C38/26 C22C38/24 C21D8/02 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: steel sheet contains carbon (C) in an amount from 0.19 to 0.25 wt.%, silicon (Si) in an amount from 0.1 to 0.6 wt.%, manganese (Mn) in an amount from 0.8 to 1.6 wt.%, phosphorus (P) in an amount less than or exactly 0.03 wt.%, sulphur (S) in an amount less than or exactly 0.015 wt.%, chromium (Cr) in an amount from 0.1 to 0.6 wt.%, boron (B) in an amount of from 0.001 to 0.005 wt.%, an additive containing at least one of titanium (Ti), niobium (Nb) and vanadium (V), in an amount less than or exactly 0.1 wt.%, the rest is iron (Fe) and inevitable impurities. The sheet contains fine-grained precipitates distributed in the steel sheet, and the fine-grained precipitates contain a nitride or carbide of at least one of titanium (Ti), niobium (Nb) and vanadium (V), and entrained hydrogen. The fine-grained precipitates are formed in an amount of more than or exactly 7000 particles or less or exactly 16,500 particles per unit area (100 mcm²), and more than or exactly 60% of the formed fine-grained precipitates have a diameter of less than or exactly 0.01 mcm. The tensile strength of steel sheet after hot stamping is more than or exactly 1350 MPa, the bendability of steel sheet after hot stamping is more than or exactly 50°, and the amount of activated hydrogen in the steel sheet after hot stamping is less than or exactly 0.8 wt.millionths.

EFFECT: hot-stamped parts obtained from steel sheets have high mechanical characteristics and delayed hydrogen cracking characteristics.

8 cl, 5 dwg, 3 tbl